WorldWideScience

Sample records for defined contribution structure

  1. Contribution to Structural Elucidation: Behaviours of Substructures Partially Defined from 2D NMR

    Institute of Scientific and Technical Information of China (English)

    EPOUHE, Celine; FAN, Bo-Tao; YUAN, Shen-Gang; PANAYE, A.; DOUCET, J. P

    2003-01-01

    Structural elucidation (automatic determination of the structure of a molecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemble the identified substructures. We devised a new method which can avoid this pitfall by a systematic examination of allowed 13C chemical shifts ranges for all substructures chemically possible and combined with a progressive pruning thanks to neighbouring relationships appearing from 2D NMR. This method is explained by a detailed example.

  2. Optimization of the Actuarial Model of Defined Contribution Pension Plan

    Directory of Open Access Journals (Sweden)

    Yan Li

    2014-01-01

    Full Text Available The paper focuses on the actuarial models of defined contribution pension plan. Through assumptions and calculations, the expected replacement ratios of three different defined contribution pension plans are compared. Specially, more significant considerable factors are put forward in the further cost and risk analyses. In order to get an assessment of current status, the paper finds a relationship between the replacement ratio and the pension investment rate using econometrics method. Based on an appropriate investment rate of 6%, an expected replacement ratio of 20% is reached.

  3. 75 FR 27927 - Diversification Requirements for Certain Defined Contribution Plans

    Science.gov (United States)

    2010-05-19

    ... disclosure of the fund's portfolio holdings (for example, Form N-CSR, ``Certified Shareholder Report of... securities that violate the requirements of paragraph (e) of this section. (2) Definitions, effective dates, and transition rules. The definitions of applicable defined contribution plan, employer...

  4. Optimum Criteria for Developing Defined Structures

    Directory of Open Access Journals (Sweden)

    Ion IVAN

    2008-01-01

    Full Text Available Basic aspects concerning distributed applications are presented: definition, particularities and importance. For distributed applications linear, arborescent, graph structures are defined with different versions and aggregation methods. Distributed applications have associated structures which through their characteristics influence the costs of the stages in the development cycle and the exploitation costs transferred to each user. The complexity of the defined structures is analyzed. The minimum and maximum criteria are enumerated for optimizing distributed application structures.

  5. Which Teachers Choose a Defined Contribution Pension Plan? Evidence from the Florida Retirement System

    Science.gov (United States)

    Chingos, Matthew M.; West, Martin R.

    2015-01-01

    Since 2002, public school teachers in Florida have been permitted to choose between a defined benefit (DB) and a defined contribution (DC) retirement plan. We exploit this unique policy environment to study new teachers' revealed preferences over pension plan structures. Roughly 30 percent of teachers hired between 2003 and 2008 selected the DC…

  6. Optimal savings management for individuals with defined contribution pension plans

    DEFF Research Database (Denmark)

    Konicz, Agnieszka Karolina; Mulvey, John M.

    2015-01-01

    The paper provides some guidelines to individuals with defined contribution (DC) pension plans on how to manage pension savings both before and after retirement. We argue that decisions regarding investment, annuity payments, and the size of death sum should not only depend on the individual’s age...... characterizing the individual. The problem is solved via a model that combines two optimization approaches: stochastic optimal control and multi-stage stochastic programming. The first method is common in financial and actuarial literature, but produces theoretical results. However, the latter, which...

  7. Software Defined Radio Architecture Contributions to Next Generation Space Communications

    Science.gov (United States)

    Kacpura, Thomas J.; Eddy, Wesley M.; Smith, Carl R.; Liebetreu, John

    2015-01-01

    systems, as well as those communications and navigation systems operated by international space agencies and civilian and government agencies. In this paper, we review the philosophies, technologies, architectural attributes, mission services, and communications capabilities that form the structure of candidate next-generation integrated communication architectures for space communications and navigation. A key area that this paper explores is from the development and operation of the software defined radio for the NASA Space Communications and Navigation (SCaN) Testbed currently on the International Space Station (ISS). Evaluating the lessons learned from development and operation feed back into the communications architecture. Leveraging the reconfigurability provides a change in the way that operations are done and must be considered. Quantifying the impact on the NASA Space Telecommunications Radio System (STRS) software defined radio architecture provides feedback to keep the standard useful and up to date. NASA is not the only customer of these radios. Software defined radios are developed for other applications, and taking advantage of these developments promotes an architecture that is cost effective and sustainable. Developments in the following areas such as an updated operating environment, higher data rates, networking and security can be leveraged. The ability to sustain an architecture that uses radios for multiple markets can lower costs and keep new technology infused.

  8. Moving from payg pensions to defined-contribution plan in the Russian Federation

    Directory of Open Access Journals (Sweden)

    Arnautova Yulia Valerievna

    2016-03-01

    Full Text Available This article is devoted to the moving from PAYG Pensions to Defined-Contribution Plan. The special aspects of this reorganization are analyzed. Pen-sion models of OECD countries are compared. Inability of the Defined-Contribution Plan in Russia is being proved. The present paper provides modern ways to improve the Defined-Contribution pension schemes.

  9. Groups definable in o-minimal structures: structure theorem, G^000, definable amenability and bounded orbits

    CERN Document Server

    Pillay, Anand

    2010-01-01

    We settle some open problems in the special case of groups in o-minimal structures, such as the equality of G^00 and G^000 and the equivalence of definable amenability and existence of a type with bounded orbit. We prove almost exactness of the G to G^00 functor. We ask further questions about types with bounded orbits in NIP theories.

  10. Defining the contribution of CNTNAP2 to autism susceptibility.

    Directory of Open Access Journals (Sweden)

    Srirangan Sampath

    Full Text Available Multiple lines of genetic evidence suggest a role for CNTNAP2 in autism. To assess its population impact we studied 2148 common single nucleotide polymorphisms (SNPs using transmission disequilibrium test (TDT across the entire ~3.3 Mb CNTNAP2 locus in 186 (408 trios multiplex and 323 simplex families with autistic spectrum disorder (ASD. This analysis yielded two SNPs with nominal statistical significance (rs17170073, p = 2.0 x 10(-4; rs2215798, p = 1.6 x 10(-4 that did not survive multiple testing. In a combined analysis of all families, two highly correlated (r (2 = 0.99 SNPs in intron 14 showed significant association with autism (rs2710093, p = 9.0 x 10(-6; rs2253031, p = 2.5 x 10(-5. To validate these findings and associations at SNPs from previous autism studies (rs7794745, rs2710102 and rs17236239 we genotyped 2051 additional families (572 multiplex and 1479 simplex. None of these variants were significantly associated with ASD after corrections for multiple testing. The analysis of Mendelian errors within each family did not indicate any segregating deletions. Nevertheless, a study of CNTNAP2 gene expression in brains of autistic patients and of normal controls, demonstrated altered expression in a subset of patients (p = 1.9 x10(-5. Consequently, this study suggests that although CNTNAP2 dysregulation plays a role in some cases, its population contribution to autism susceptibility is limited.

  11. Lithographically defined microporous carbon-composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Burckel, David Bruce; Washburn, Cody M.; Lambert, Timothy N.; Finnegan, Patrick Sean; Wheeler, David R.

    2016-12-06

    A microporous carbon scaffold is produced by lithographically patterning a carbon-containing photoresist, followed by pyrolysis of the developed resist structure. Prior to exposure, the photoresist is loaded with a nanoparticulate material. After pyrolysis, the nanonparticulate material is dispersed in, and intimately mixed with, the carbonaceous material of the scaffold, thereby yielding a carbon composite structure.

  12. CSIR Contribution to Defining Adaptive Capacity in the Context of Environmental Change

    Science.gov (United States)

    2015-06-30

    CSIR Contribution to Defining Adaptive Capacity in the Context of Environmental Change 4th Interim Report Report Documentation Page Form...Interim report 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE CSIR Contribution to Defining Adaptive Capacity in the Context...NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) CSIR ,PO Box 395,Pretoria, 0001, South Africa, 8. PERFORMING

  13. Model of managing pension assets of the defined contribution mandatory state pension system

    Directory of Open Access Journals (Sweden)

    Rudensky Roman A.

    2014-01-01

    Full Text Available Introduction of the defined contribution mandatory state pension system in Ukraine actualises the issue of efficient management of its pension assets. The goals of the article are development of theoretical and methodical provisions and development of the economic and mathematical model of management of pension assets of the defined contribution pension system on the basis of the fuzzy set approach. The necessity to refer to the theory of fuzzy sets when modelling this process is caused by, firstly, absence of rather complete consistent “a priori” information, secondly, uncertainty of flows of insurance contributions and pension payments and, thirdly, significant influence of the instable market environment upon investment processes. The proposed fuzzy set economic and mathematical model of the task of optimal management of pension assets of the defined contribution system is a target function of minimisation of the investment risk as the risk of insufficiency of net pension assets and system of restrictions that reflect restriction of the investment activity with pension assets of the defined contribution pension system, determined by the current pension legislation.

  14. Mean-variance portfolio selection for defined-contribution pension funds with stochastic salary.

    Science.gov (United States)

    Zhang, Chubing

    2014-01-01

    This paper focuses on a continuous-time dynamic mean-variance portfolio selection problem of defined-contribution pension funds with stochastic salary, whose risk comes from both financial market and nonfinancial market. By constructing a special Riccati equation as a continuous (actually a viscosity) solution to the HJB equation, we obtain an explicit closed form solution for the optimal investment portfolio as well as the efficient frontier.

  15. Mean-Variance Portfolio Selection for Defined-Contribution Pension Funds with Stochastic Salary

    Directory of Open Access Journals (Sweden)

    Chubing Zhang

    2014-01-01

    Full Text Available This paper focuses on a continuous-time dynamic mean-variance portfolio selection problem of defined-contribution pension funds with stochastic salary, whose risk comes from both financial market and nonfinancial market. By constructing a special Riccati equation as a continuous (actually a viscosity solution to the HJB equation, we obtain an explicit closed form solution for the optimal investment portfolio as well as the efficient frontier.

  16. Mean-variance portfolio selection and efficient frontier for defined contribution pension schemes

    DEFF Research Database (Denmark)

    Højgaard, Bjarne; Vigna, Elena

    We solve a mean-variance portfolio selection problem in the accumulation phase of a defined contribution pension scheme. The efficient frontier, which is found for the 2 asset case as well as the n + 1 asset case, gives the member the possibility to decide his own risk/reward profile. The mean...... as a mean-variance optimization problem. It is shown that the corresponding mean and variance of the final fund belong to the efficient frontier and also the opposite, that each point on the efficient frontier corresponds to a target-based optimization problem. Furthermore, numerical results indicate...

  17. Directional properties of sets definable in o-minimal structures

    CERN Document Server

    Koike, Satoshi; Paunescu, Laurentiu; Shiota, Masahiro

    2010-01-01

    In a former paper the first and third authors introduced the notion of direction set for a subset of R^n, and showed that the dimension of the common direction set of two subanalytic subsets, called directional dimension, is preserved by a bi-Lipschitz homeomorphism, provided that their images are also subanalytic. In this paper we give a generalisation of the above result to sets definable in an o-minimal structure on an arbitrary real closed field. More precisely, we first prove our main theorem and discuss in detail directional properties in the case of an Archimedean real closed field, and then we give a proof in the case of a general real closed field. In addition, related to our main result, we show the existence of special polyhedra in some Euclidean space, illustrating that the bi-Lipschitz equivalence does not always imply the existence of a definable one.

  18. Networks of self-defining memories as a contributing factor to emotional openness.

    Science.gov (United States)

    Houle, Iliane; Philippe, Frederick L; Lecours, Serge; Roulez, Josiane

    2017-02-06

    Emotional openness is characterised by a capacity to tolerate threatening self-relevant material and an interest towards new emotional situations. We investigated how specific networks of memories could be an important contributing factor to emotional openness. At Phase 1, participants completed measures of personality traits and emotional intelligence, described a self-defining memory, provided other memories associated with it, and rated the valence of each of their memories. A score assessing the complexity of this memory network, comprising the number of memories reported and their valence diversity, was created. Two weeks later, in laboratory, participants watched an anxiety-inducing film and took part in an interview assessing their emotional openness to the film. They completed a cognitive task before and after the film to measure ego depletion. Controlling for traits and emotional intelligence, memory network complexity was positively associated with emotional openness and negatively with ego depletion. The mental organisation of self-defining memories thus appears to be a critical factor contributing to emotional openness.

  19. Defining a neural network controller structure for a rubbertuator robot.

    Science.gov (United States)

    Ozkan, M; Inoue, K; Negishi, K; Yamanaka, T

    2000-01-01

    Rubbertuator (Rubber-Actuator) robot arm is a pneumatic robot, unique with its lightweight, high power, compliant and spark free nature. Compressibility of air in the actuator tubes and the elastic nature of the rubber, however, are the two major sources of increased non-linearity and complexity in motion control. Soft computing, exploiting the tolerance of uncertainty and vagueness in cognitive reasoning has been offering easy to handle, robust, and low-priced solutions to several non-linear industrial applications. Nonetheless, the black-box approach in these systems results in application specific architectures with some important design parameters left for fine tuning (i.e. number of nodes in a neural network). In this study we propose a more systematic method in defining the structure of a soft computing technique, namely the backpropagation neural network, when used as a controller for rubbertuator robot systems. The structure of the neural network is based on the physical model of the robot, while the neural network itself is trained to learn the trajectory independent parameters of the model that are essential for defining the robot dynamics. The proposed system performance was compared with a well-tuned PID controller and shown to be more accurate in trajectory control for rubbertuator robots.

  20. User Defined Structural Searches in MediaWiki

    DEFF Research Database (Denmark)

    Bouvin, Niels Olof; Albertsen, Johannes

    2008-01-01

    Wikipedia has been the poster child of user contributed content using the space of MediaWiki as the canvas on which to write. While well suited for authoring simple hypermedia documents, MediaWiki does not lend itself easily to let the author create dynamically assembled documents, or create pages...... that monitor other pages. While it is possible to create such "special" pages, it requires PHP coding and thus administrative rights to the MediaWiki server. We present in this paper work on a structural query language (MediaWiki Query Language - MWQL) to allow users to add dynamically evaluated searches...

  1. Toward structurally defined carbon dots as ultracompact fluorescent probes.

    Science.gov (United States)

    LeCroy, Gregory Ethan; Sonkar, Sumit Kumar; Yang, Fan; Veca, L Monica; Wang, Ping; Tackett, Kenneth N; Yu, Jing-Jiang; Vasile, Eugeniu; Qian, Haijun; Liu, Yamin; Luo, Pengju George; Sun, Ya-Ping

    2014-05-27

    There has been much discussion on the need to develop fluorescent quantum dots (QDs) as ultracompact probes, with overall size profiles comparable to those of the genetically encoded fluorescent tags. In the use of conventional semiconductor QDs for such a purpose, the beautifully displayed dependence of fluorescence color on the particle diameter becomes a limitation. More recently, carbon dots have emerged as a new platform of QD-like fluorescent nanomaterials. The optical absorption and fluorescence emissions in carbon dots are not bandgap in origin, different from those in conventional semiconductor QDs. The absence of any theoretically defined fluorescence color-dot size relationships in carbon dots may actually be exploited as a unique advantage in the size reduction toward having carbon dots serve as ultracompact QD-like fluorescence probes. Here we report on carbon dots of less than 5 nm in the overall dot diameter with the use of 2,2'-(ethylenedioxy)bis(ethylamine) (EDA) molecules for the carbon particle surface passivation. The EDA-carbon dots were found to be brightly fluorescent, especially over the spectral range of green fluorescent protein. These aqueous soluble smaller carbon dots also enabled more quantitative characterizations, including the use of solution-phase NMR techniques, and the results suggested that the dot structures were relatively simple and better-defined. The potential for these smaller carbon dots to serve as fluorescence probes of overall sizes comparable to those of fluorescent proteins is discussed.

  2. Contribution of volatiles to the antifungal effect of Lactobacillus paracasei in defined medium and yogurt.

    Science.gov (United States)

    Aunsbjerg, S D; Honoré, A H; Marcussen, J; Ebrahimi, P; Vogensen, F K; Benfeldt, C; Skov, T; Knøchel, S

    2015-02-02

    Lactic acid bacteria with antifungal properties can be used to control spoilage of food and feed. Previously, most of the identified metabolites have been isolated from cell-free fermentate of lactic acid bacteria with methods suboptimal for detecting possible contribution from volatiles to the antifungal activity. The role of volatile compounds in the antifungal activity of Lactobacillus paracasei DGCC 2132 in a chemically defined interaction medium (CDIM) and yogurt was therefore investigated with a sampling technique minimizing volatile loss. Diacetyl was identified as the major volatile produced by L. paracasei DGCC 2132 in CDIM. When the strain was added to a yogurt medium diacetyl as well as other volatiles also increased but the metabolome was more complex. Removal of L. paracasei DGCC 2132 cells from CDIM fermentate resulted in loss of both volatiles, including diacetyl, and the antifungal activity towards two strains of Penicillium spp. When adding diacetyl to CDIM or yogurt without L. paracasei DGCC 2132, marked inhibition was observed. Besides diacetyl, the antifungal properties of acetoin were examined, but no antifungal activity was observed. Overall, the results demonstrate the contribution of diacetyl in the antifungal effect of L. paracasei DGCC 2132 and indicate that the importance of volatiles may have been previously underestimated.

  3. Contribution to defining a geodetic reference frame for Africa (AFREF): Geodynamics implications

    Science.gov (United States)

    Saria, Elifuraha E.

    African Reference Frame (AFREF) is the proposed regional three-dimensional standard frame, which will be used to reference positions and velocities for geodetic sites in Africa and surrounding. This frame will play a crucial role in scientific application for example plate motion and crustal deformation studies, and also in mapping when it involves for example national boundary surveying, remote sensing, GIS, engineering projects and other development programs in Africa. To contribute to the definition of geodetic reference frame for Africa and provide the first continent-wide position/velocity solution for Africa, we processed and analyzed 16 years of GPS and 17 years of DORIS data at 133 GPS sites and 9 DORIS sites continuously operating geodetic sites in Africa and surroundings to describe the present-day kinematics of the Nubian and Somalian plates and constrain relative motions across the East African Rift. We use the resulting horizontal velocities to determine the level of rigidity of Nubia and updated a plate motion model for the East African Rift and revise the counter clockwise rotation of the Victoria plate and clockwise rotation of the Rovuma plate with respect to Nubia. The vertical velocity ranges from -2 to +2 mm/yr, close to their uncertainties with no clear geographical pattern. This study provides the first continent-wide position/velocity solution for Africa, expressed in International Terrestrial Reference Frame (ITRF2008), a contribution to the upcoming African Reference Frame (AFREF). In the next step we used the substantial increase in the geologic, geophysical and geodetic data in Africa to improve our understanding of the rift geometry and the block kinematics of the EAR. We determined the best-fit fault structure of the rift in terms of the locking depth and dip angle and use a block modeling approach where observed velocities are described as the contribution of rigid block rotation and strain accumulation on locked faults. Our results

  4. The defining features of the modern entrepreneurship network structures

    Directory of Open Access Journals (Sweden)

    R.V. Kochubey

    2011-03-01

    Full Text Available In the article the various forms of network enterprises are analyzed, the key characteristics of network structures are identified. The relationship between network types and forms of business organization is shown. The studies of different types of network structures are systematized.

  5. A rationale and approach for defining and structuring testability requirements

    Science.gov (United States)

    Klion, J.

    1985-08-01

    Testability concepts and requirements are being applied to many Air Force electronic equipment/system development programs. Insufficient guidance exists as to the definition and structure of testability requirements and the interface between such requirements and maintainability, availability, and integrated diagnostics. The purpose of this report is to provide one logical approach and associated guidance to the definition and structure of testability needs and: (1) the relationship of testability to other system parameters; (2) the translation of testability needs to testability requirements; (3) the interpretation of testability terms, concepts and requirements; (4) the structure and scope of testability requirements; (5) and the identification of those factors, constraints and contingencies which must be considered when invoking testability requirements.

  6. Structured attachment of bacterial molecular motors for defined microflow induction

    Directory of Open Access Journals (Sweden)

    Woerdemann Mike

    2014-01-01

    Full Text Available Bacterial rotational motor complexes that propel flagellated bacteria possess unique properties like their size of a few nanometres and the ability of selfreproduction that have led to various exciting applications including biohybrid nano-machines. One mandatory prerequisite to utilize bacterial nano motors in fluid applications is the ability to transfer force and torque to the fluid, which usually can be achieved by attachment of the bacterial cell to adequate surfaces. Additionally, for optimal transfer of force or torque, precise control of the position down to the single cell level is of utmost importance. Based on a PIV (particle image velocimetry evaluation of the induced flow of single bacteria,we propose and demonstrate attachment of arbitrary patterns of motile bacterial cells in a fast light-based two-step process for the first time to our knowledge. First, these cells are pre-structured by holographic optical tweezers and then attached to a homogeneous, polystyrene-coated surface. In contrast to the few approaches that have been implemented up to now and which rely on pre-structured surfaces, our scheme allows for precise control on a single bacterium level, is versatile, interactive and has low requirements with respect to the surface preparation.

  7. CONTRIBUTION TO DEFINE THE BLIZZARD PHENOMENA TROUGHT CLIMATE STUDY IN SOUTHEASTERN ROMANIA

    Directory of Open Access Journals (Sweden)

    DORUŢA CIURLĂU

    2016-03-01

    Full Text Available The definition of the phenomenon of blizzard implies two distinct aspects: the transport of snow on ground and the transport of snow at heights or also known as the actual blizzard. In order for a phenomenon to be defined as blizzard, it has to meet two mandatory conditions: strong wind (>15 m/s and snow cover (previously deposited or associated with snowing phenomenon. The delineation between the two phenomena, respectively snow transport at heights as compared to the one on the ground is often subjective or difficult to assess (being determined visually by the observatories at the meteorological stations. The topography of the place, the moment of day when the phenomenon is produced, the luminosity, the visibility landmarks, etc. can often times lead to the incorrect assessment of the phenomenon. The only parameter measured exactly (among the meteorological parameters that define the phenomenon is the wind (parameter that is determined automatically by the sensors in the meteorological stations where they exist, aspect that might be a delineating factor when the occurrence of the phenomenon is estimated. The climatological analysis of the data derived from 19 meteorological stations located in the South-East of Romania, throughout a period of over 50 years (1961-2012 revealed the existence of the phenomenon of blizzard (transported on ground or at height, associated/not-associated to the phenomenon of snow, with a snow layer/without and at different intensities of the wind. Being a natural phenomenon with climatic hazard and negative impact on the environment and the human society, the correct delineation of the two phenomena might highlight the territories with increased vulnerability to its occurrence. Starting from those presented above, the hereby paper aims to make a detailed climatological analysis regarding the snow transport on ground and at height and their delineation based on the data given by the 19 meteorological stations placed

  8. Chemically defined structured lipids: current status and future directions in gastrointestinal diseases.

    Science.gov (United States)

    Stein, J

    1999-04-01

    Over the past two decades various concepts for the supply of lipids in parenteral and enteral nutrition have been developed. Traditionally, the nutritional dietary management typically includes physical mixtures of medium chain and long-chain triglycerides. Recently, chemically defined structured lipids have been developed that combine the advantages of conventional fats with those of special purposes. The first structured lipids were produced by mixing pure medium-chain triglycerides and long-chain triglycerides, allowing hydrolysis to free fatty acids, followed by random transesterification of the fatty acids into mixed triglyceride molecules. This results in a triglyceride containing combinations of short-, medium-, and long-chain fatty acids on a single glycerol backbone. These have unique chemical, physical, and/or physiological properties which differ from simply blending mixtures from the starting fats. By use of 1,3-specific or 2-specific lipases it is now possible to synthesize 1,3-specific or 2-specific triglycerides containing short- and/or medium-chain acids. For instance, incorporation of linoleic, arachidonic, or eicosapentaenoic acid at the sn-2 position is being evaluated for the specific objective of modulating membrane fatty acid composition and essential fatty acid absorption in models of cancer, burns, and immune dysfunction. This contribution reviews the current status of experimental and clinical studies of chemically defined structured lipid-based fat emulsions, with emphasis on their therapeutic potential for nutritional support in hospitalized patients.

  9. Stochastic Funding of a Defined Contribution Pension Plan with Proportional Administrative Costs and Taxation under Mean-Variance Optimization Approach

    Directory of Open Access Journals (Sweden)

    Charles I Nkeki

    2014-11-01

    Full Text Available This paper aim at studying a mean-variance portfolio selection problem with stochastic salary, proportional administrative costs and taxation in the accumulation phase of a defined contribution (DC pension scheme. The fund process is subjected to taxation while the contribution of the pension plan member (PPM is tax exempt. It is assumed that the flow of contributions of a PPM are invested into a market that is characterized by a cash account and a stock. The optimal portfolio processes and expected wealth for the PPM are established. The efficient and parabolic frontiers of a PPM portfolios in mean-variance are obtained. It was found that capital market line can be attained when initial fund and the contribution rate are zero. It was also found that the optimal portfolio process involved an inter-temporal hedging term that will offset any shocks to the stochastic salary of the PPM.

  10. Architectural frameworks: defining the structures for implementing learning health systems.

    Science.gov (United States)

    Lessard, Lysanne; Michalowski, Wojtek; Fung-Kee-Fung, Michael; Jones, Lori; Grudniewicz, Agnes

    2017-06-23

    The vision of transforming health systems into learning health systems (LHSs) that rapidly and continuously transform knowledge into improved health outcomes at lower cost is generating increased interest in government agencies, health organizations, and health research communities. While existing initiatives demonstrate that different approaches can succeed in making the LHS vision a reality, they are too varied in their goals, focus, and scale to be reproduced without undue effort. Indeed, the structures necessary to effectively design and implement LHSs on a larger scale are lacking. In this paper, we propose the use of architectural frameworks to develop LHSs that adhere to a recognized vision while being adapted to their specific organizational context. Architectural frameworks are high-level descriptions of an organization as a system; they capture the structure of its main components at varied levels, the interrelationships among these components, and the principles that guide their evolution. Because these frameworks support the analysis of LHSs and allow their outcomes to be simulated, they act as pre-implementation decision-support tools that identify potential barriers and enablers of system development. They thus increase the chances of successful LHS deployment. We present an architectural framework for LHSs that incorporates five dimensions-goals, scientific, social, technical, and ethical-commonly found in the LHS literature. The proposed architectural framework is comprised of six decision layers that model these dimensions. The performance layer models goals, the scientific layer models the scientific dimension, the organizational layer models the social dimension, the data layer and information technology layer model the technical dimension, and the ethics and security layer models the ethical dimension. We describe the types of decisions that must be made within each layer and identify methods to support decision-making. In this paper, we outline

  11. Mean-variance inefficiency of CRRA and CARA utility functions for portfolio selection in defined contribution pension schemes

    OpenAIRE

    Elena Vigna

    2009-01-01

    We consider the portfolio selection problem in the accumulation phase of a defined contribution pension scheme in continuous time, and compare the mean-variance and the expected utility maximization approaches. Using the embedding technique pioneered by Zhou and Li (2000) we first find the efficient frontier of portfolios in the Black-Scholes financial market. Then, using standard stochastic optimal control we find the optimal portfolios derived via expected utility for popular utility functi...

  12. Drought response strategies define the relative contributions of hydraulic dysfunction and carbohydrate depletion during tree mortality.

    Science.gov (United States)

    Mitchell, Patrick J; O'Grady, Anthony P; Tissue, David T; White, Donald A; Ottenschlaeger, Maria L; Pinkard, Elizabeth A

    2013-02-01

    Plant survival during drought requires adequate hydration in living tissues and carbohydrate reserves for maintenance and recovery. We hypothesized that tree growth and hydraulic strategy determines the intensity and duration of the 'physiological drought', thereby affecting the relative contributions of loss of hydraulic function and carbohydrate depletion during mortality. We compared patterns in growth rate, water relations, gas exchange and carbohydrate dynamics in three tree species subjected to prolonged drought. Two Eucalyptus species (E. globulus, E. smithii) exhibited high growth rates and water-use resulting in rapid declines in water status and hydraulic conductance. In contrast, conservative growth and water relations in Pinus radiata resulted in longer periods of negative carbon balance and significant depletion of stored carbohydrates in all organs. The ongoing demand for carbohydrates from sustained respiration highlighted the role that duration of drought plays in facilitating carbohydrate consumption. Two drought strategies were revealed, differentiated by plant regulation of water status: plants maximized gas exchange, but were exposed to low water potentials and rapid hydraulic dysfunction; and tight regulation of gas exchange at the cost of carbohydrate depletion. These findings provide evidence for a relationship between hydraulic regulation of water status and carbohydrate depletion during terminal drought. © 2012 CSIRO. New Phytologist © 2012 New Phytologist Trust.

  13. Using operational and defined fractions to assess soil organic matter stabilization and structure

    Science.gov (United States)

    Horwath, W. R.

    2015-12-01

    Studies on soil organic matter (SOM) began with alkaline solvents revealing a dark colored substance that could be isolated under low pH. Further studies revealed fulvic and humic acids and humin fractions leading to theories on functional groups and metal-clay bridging mechanisms. The fate of isotopes in these fractions revealed soil carbon pools with varying turnover rates with half the soil carbon (C) in humin and acid hydrolyzed fractions over 1000 years old. These results are the basis of the three pool conceptual framework used in many biogeochemical models. Theories on the role of functional groups and compound classes further elaborated concepts on physical (aggregates) and chemical mechanisms of C stabilization. With the advance of analytical instrumentation, the operational fractions were further defined to the compound and molecular levels. These studies confirmed the majority of soil C is microbially derived. Our observation that all microbial groups contributed nonselectively to soil C maintenance independent of mineralogy suggests that compound characteristics within integrated structures are more important than the source of individual compounds for stabilizing soil C. In dissolved organic C floccing studies using Near Edge X-ray Fine Structure analysis, we found that aromatic compounds interacted first with Fe, however, the majority of direct bonds to Fe were polysaccharides, reinforcing that an integrative chemical structure rather than direct bonds imparted stability in organo-metal interactions. Using a novel differential scanning calorimeter coupled to an isotope ratio mass spectrometer setup, we confirmed that the presence of clays (independent of clay type) increased the microbial utilization of calcium stabilized high versus low temperature compounds, asserting that higher temperature compounds (i.e., phenolics) are likely less tightly bound by clay minerals. The integration of operational and defined fractions of SOM remains a legitimate

  14. The Evolving Contribution of Mass Spectrometry to Integrative Structural Biology

    Science.gov (United States)

    Faini, Marco; Stengel, Florian; Aebersold, Ruedi

    2016-06-01

    Protein complexes are key catalysts and regulators for the majority of cellular processes. Unveiling their assembly and structure is essential to understanding their function and mechanism of action. Although conventional structural techniques such as X-ray crystallography and NMR have solved the structure of important protein complexes, they cannot consistently deal with dynamic and heterogeneous assemblies, limiting their applications to small scale experiments. A novel methodological paradigm, integrative structural biology, aims at overcoming such limitations by combining complementary data sources into a comprehensive structural model. Recent applications have shown that a range of mass spectrometry (MS) techniques are able to generate interaction and spatial restraints (cross-linking MS) information on native complexes or to study the stoichiometry and connectivity of entire assemblies (native MS) rapidly, reliably, and from small amounts of substrate. Although these techniques by themselves do not solve structures, they do provide invaluable structural information and are thus ideally suited to contribute to integrative modeling efforts. The group of Brian Chait has made seminal contributions in the use of mass spectrometric techniques to study protein complexes. In this perspective, we honor the contributions of the Chait group and discuss concepts and milestones of integrative structural biology. We also review recent examples of integration of structural MS techniques with an emphasis on cross-linking MS. We then speculate on future MS applications that would unravel the dynamic nature of protein complexes upon diverse cellular states.

  15. Proposal of a new indicator to define ductility applied to corroded steel reinforcement on concrete structures

    OpenAIRE

    Cobo Escamilla, Alfonso; Moreno Fernandez, Maria Esther; Fernández Cánovas, Manuel

    2010-01-01

    The carbonation of concrete or the chlorides ingress in such quantity to reach the level of bars is triggers of reinforcement corrosion. One of the most significant effects of reinforcing steel corrosion on reinforced concrete structures is the decline in the ductility-related properties of the steel. Reinforcement ductility has a decisive effect on the overall ductility of reinforced concrete structures. Different Codes classify the type of steel depending on their ductility defined by...

  16. Legislative Provisions Underlying Trade Unions' Right to Define Their Organizational Structure

    Science.gov (United States)

    Korobchenko, Victoria V.; Penov, Yury V.; Safonov, Valery A.

    2016-01-01

    The article contains a comparative analysis of constitutional and other legislative provisions that ensure a trade union's right to define its own administrative structure in European states. The aim of the study is to reveal the management's problems of European trade unions, declarative and empirical mass-character legislative provisions, which…

  17. Squark Contributions to Photon Structure Functions and Positivity Constraints

    CERN Document Server

    Kitadono, Yoshio; Uematsu, Tsuneo; Yoshida, Yutaka

    2011-01-01

    Photon structure functions in supersymmetric QCD are investigated in terms of the parton model where squark contributions are evaluated. We calculate the eight virtual photon structure functions by taking the discontinuity of the squark massive one-loop diagrams of the photon-photon forward amplitude. The model-independent positivity constraints derived from the Cauchy-Schwarz inequalities are satisfied by the squark parton model calculation and actually the two equality relations hold for the squark contribution. We also show that our polarized photon structure function $g_1^\\gamma$ for the real photon leads to the vanishing 1st moment sum rule, and the constraint $|g_1^\\gamma|\\leq F_1^\\gamma$ is satisfied by the real photon. We also discuss a squark signature in the structure function $W_{TT}^\\tau$.

  18. Hadronic deuteron polarizability contribution the hyperfine structure in muonic deuterium

    Directory of Open Access Journals (Sweden)

    Eskin A.V.

    2017-01-01

    Full Text Available The calculation of the contribution to the polarizability of the nucleus to hyperfine structure of muonic hydrogen is carried out within the unitary isobar model and on the basis of experimental data on the structure functions of deep inelastic lepton-proton and lepton-deuteron scattering. The calculation of virtual absorption cross sections of transversely and longitudinally polarized photons by nucleons in the resonance region is performed in the framework of the program MAID.

  19. What contributes to individual differences in brain structure?

    Directory of Open Access Journals (Sweden)

    Jenny eGu

    2014-04-01

    Full Text Available Individual differences in adult human brain structure have been found to reveal a great deal of information about variability in behaviours, cognitive abilities and mental and physical health. Driven by such evidence, what contributes to individual variation in brain structure has gained accelerated attention as a research question. Findings thus far appear to support the notion that an individual’s brain architecture is determined largely by genetic and environmental influences. This review aims to evaluate the empirical literature on whether and how genes and the environment contribute to individual differences in brain structure. It first considers how genetic and environmental effects may separately contribute to brain morphology, by examining evidence from twin, genome-wide association, cross-sectional and longitudinal studies. Next, evidence for the influence of the complex interplay between genetic and environmental factors, characterised as gene-environment interactions and correlations, is reviewed. In evaluating the extant literature, this review will conclude that both genetic and environmental factors play critical roles in contributing to individual variability in brain structure.

  20. Superpose3D: a local structural comparison program that allows for user-defined structure representations.

    Directory of Open Access Journals (Sweden)

    Pier Federico Gherardini

    Full Text Available Local structural comparison methods can be used to find structural similarities involving functional protein patches such as enzyme active sites and ligand binding sites. The outcome of such analyses is critically dependent on the representation used to describe the structure. Indeed different categories of functional sites may require the comparison program to focus on different characteristics of the protein residues. We have therefore developed superpose3D, a novel structural comparison software that lets users specify, with a powerful and flexible syntax, the structure description most suited to the requirements of their analysis. Input proteins are processed according to the user's directives and the program identifies sets of residues (or groups of atoms that have a similar 3D position in the two structures. The advantages of using such a general purpose program are demonstrated with several examples. These test cases show that no single representation is appropriate for every analysis, hence the usefulness of having a flexible program that can be tailored to different needs. Moreover we also discuss how to interpret the results of a database screening where a known structural motif is searched against a large ensemble of structures. The software is written in C++ and is released under the open source GPL license. Superpose3D does not require any external library, runs on Linux, Mac OSX, Windows and is available at http://cbm.bio.uniroma2.it/superpose3D.

  1. Argentine Population Genetic Structure: Large Variance in Amerindian Contribution

    Science.gov (United States)

    Seldin, Michael F.; Tian, Chao; Shigeta, Russell; Scherbarth, Hugo R.; Silva, Gabriel; Belmont, John W.; Kittles, Rick; Gamron, Susana; Allevi, Alberto; Palatnik, Simon A.; Alvarellos, Alejandro; Paira, Sergio; Caprarulo, Cesar; Guillerón, Carolina; Catoggio, Luis J.; Prigione, Cristina; Berbotto, Guillermo A.; García, Mercedes A.; Perandones, Carlos E.; Pons-Estel, Bernardo A.; Alarcon-Riquelme, Marta E.

    2011-01-01

    Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies. PMID:17177183

  2. On the local integrability of almost-product structures defined by space-time metrics

    CERN Document Server

    Delphenich, D H

    2016-01-01

    The splitting of the tangent bundle of space-time into temporal and spatial sub-bundles defines an almost-product structure. In particular, any space-time metric can be locally expressed in time-orthogonal form, in such a way that whether or not that almost-product structure is locally generated by a coordinate chart is a matter of the integrability of the Pfaff equation that the temporal 1-form of that expression for the metric defines. When one applies that analysis to the known exact solutions to the Einstein field equations, one finds that many of the common ones are completely-integrable, although some of the physically-interesting ones are not.

  3. Well-defined azazirconacyclopropane complexes supported on silica structurally determined by 2D NMR comparative elucidation

    KAUST Repository

    El Eter, Mohamad

    2013-01-01

    Grafting of Zr(NMe2)4 on mesoporous silica SBA-15 afforded selectively well-defined surface species SiOZr(NMe2) (η2NMeCH2). 2D solid-state NMR (1H- 13C HETCOR, Multiple Quantum) experiments have shown a unique structural rearrangement occurring on the immobilised zirconium bis methylamido ligand. © The Royal Society of Chemistry 2013.

  4. CONTRIBUTIONS ON THE DESIGN OF UNCONVENTIONAL CORRUGATED BOARD STRUCTURES

    Directory of Open Access Journals (Sweden)

    NEIDONI Nadina

    2015-06-01

    Full Text Available The paper depicts a few contributions on the design of several unconventional corrugated board structures. In general, cardboard and corrugated cardboard is strongly linked to packaging. However, limiting these materials to their primary use does nothing else but to restrict the possibilities of using them in other interesting areas. Consequently, new structures built from cardboard have been imagined and in the paper there are presented a few unconventional uses of the corrugated fiberboard, namely as furniture elements, along with the technology used in the design and the manufacturing process.

  5. Contribution of volatiles to the antifungal effect of Lactobacillus paracasei in defined medium and yogurt

    DEFF Research Database (Denmark)

    Aunsbjerg, Stina Dissing; Honoré, Anders Hans; Marcussen, J.

    2015-01-01

    Lactic acid bacteria with antifungal properties can be used to control spoilage of food and feed. Previously, most of the identified metabolites have been isolated from cell-free fermentate of lactic acid bacteria with methods suboptimal for detecting possible contribution from volatiles to the a...... the contribution of diacetyl in the antifungal effect of L. paracasei DGCC 2132 and indicate that the importance of volatiles may have been previously underestimated....

  6. Salt Contribution to RNA Tertiary Structure Folding Stability

    Science.gov (United States)

    Tan, Zhi-Jie; Chen, Shi-Jie

    2011-01-01

    Accurate quantification of the ionic contribution to RNA folding stability could greatly enhance our ability to understand and predict RNA functions. Recently, motivated by the potential importance of ion correlation and fluctuation in RNA folding, we developed the tightly bound ion (TBI) model. Extensive experimental tests showed that the TBI model can lead to better treatment of multivalent ions than the Poisson-Boltzmann equation. In this study, we use the model to quantify the contribution of salt (Na+ and Mg2+) to the RNA tertiary structure folding free energy. Folding of the RNA tertiary structure often involves intermediates. We focus on the folding transition from an intermediate state to the native state, and compute the electrostatic folding free energy of the RNA. Based on systematic calculations for a variety of RNA molecules, we derive a set of formulas for the electrostatic free energy for tertiary structural folding as a function of the sequence length and compactness of the RNA and the Na+ and Mg2+ concentrations. Extensive comparisons with experimental data suggest that our model and the extracted empirical formulas are quite reliable. PMID:21723828

  7. Electrical and structural properties of ZnO synthesized via infiltration of lithographically defined polymer templates

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Chang-Yong, E-mail: cynam@bnl.gov; Stein, Aaron; Kisslinger, Kim; Black, Charles T. [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2015-11-16

    We investigate the electrical and structural properties of infiltration-synthesized ZnO. In-plane ZnO nanowire arrays with prescribed positional registrations are generated by infiltrating diethlyzinc and water vapor into lithographically defined SU-8 polymer templates and removing organic matrix by oxygen plasma ashing. Transmission electron microscopy reveals that homogeneously amorphous as-infiltrated polymer templates transform into highly nanocrystalline ZnO upon removal of organic matrix. Field-effect transistor device measurements show that the synthesized ZnO after thermal annealing displays a typical n-type behavior, ∼10{sup 19 }cm{sup −3} carrier density, and ∼0.1 cm{sup 2} V{sup −1} s{sup −1} electron mobility, reflecting highly nanocrystalline internal structure. The results demonstrate the potential application of infiltration synthesis in fabricating metal oxide electronic devices.

  8. Defining trauma in complex care management: Safety-net providers' perspectives on structural vulnerability and time.

    Science.gov (United States)

    Thompson-Lastad, Ariana; Yen, Irene H; Fleming, Mark D; Van Natta, Meredith; Rubin, Sara; Shim, Janet K; Burke, Nancy J

    2017-08-01

    In this paper, we delineate how staff of two complex care management (CCM) programs in urban safety net hospitals in the United States understand trauma. We seek to (1) describe how staff in CCM programs talk about trauma in their patients' lives; (2) discuss how trauma concepts allow staff to understand patients' symptoms, health-related behaviors, and responses to care as results of structural conditions; and (3) delineate the mismatch between long-term needs of patients with histories of trauma and the short-term interventions that CCM programs provide. Observation and interview data gathered between February 2015 and August 2016 indicate that CCM providers define trauma expansively to include individual experiences of violence such as childhood abuse and neglect or recent assault, traumatization in the course of accessing health care and structural violence. Though CCM staff implement elements of trauma-informed care, the short-term design of CCM programs puts pressure on the staff to titrate their efforts, moving patients towards graduation or discharge. Trauma concepts enable clinicians to name structural violence in clinically legitimate language. As such, trauma-informed care and structural competency approaches can complement each other. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Recurrent Somatic Structural Variations Contribute to Tumorigenesis in Pediatric Osteosarcoma

    Directory of Open Access Journals (Sweden)

    Xiang Chen

    2014-04-01

    Full Text Available Pediatric osteosarcoma is characterized by multiple somatic chromosomal lesions, including structural variations (SVs and copy number alterations (CNAs. To define the landscape of somatic mutations in pediatric osteosarcoma, we performed whole-genome sequencing of DNA from 20 osteosarcoma tumor samples and matched normal tissue in a discovery cohort, as well as 14 samples in a validation cohort. Single-nucleotide variations (SNVs exhibited a pattern of localized hypermutation called kataegis in 50% of the tumors. We identified p53 pathway lesions in all tumors in the discovery cohort, nine of which were translocations in the first intron of the TP53 gene. Beyond TP53, the RB1, ATRX, and DLG2 genes showed recurrent somatic alterations in 29%–53% of the tumors. These data highlight the power of whole-genome sequencing for identifying recurrent somatic alterations in cancer genomes that may be missed using other methods.

  10. Supporting and structuring "contributing student pedagogy" in Computer Science curricula

    Science.gov (United States)

    Falkner, Katrina; Falkner, Nickolas J. G.

    2012-12-01

    Contributing student pedagogy (CSP) builds upon social constructivist and community-based learning principles to create engaging and productive learning experiences. What makes CSP different from other, related, learning approaches is that it involves students both learning from and also explicitly valuing the contributions of other students. The creation of such a learning community builds upon established educational psychology that encourages deep learning, reflection and engagement. Our school has recently completed a review and update of its curriculum, incorporating student content-creation and collaboration into the design of key courses across the curriculum. Our experiences, based on several years of experimentation and development, support CSP-based curriculum design to reinforce the value of the student perspective, the clear description of their own transformative pathway to knowledge and the importance of establishing student-to-student networks in which students are active and willing participants. In this paper, we discuss the tools and approaches that we have employed to guide, support and structure student collaboration across a range of courses and year levels. By providing an account of our intentions, our approaches and tools, we hope to provide useful and transferrable knowledge that can be readily used by other academics who are considering this approach.

  11. Structure-function relationship of anticoagulant and antithrombotic well-defined sulfated polysaccharides from marine invertebrates.

    Science.gov (United States)

    Pomin, Vitor H

    2012-01-01

    Marine sulfated polysaccharides (MSPs), such as sulfated fucans (SFs), sulfated galactans (SGs), and glycosaminoglycans (GAGs) isolated from invertebrate animals, are highly anionic polysaccharides capable of interacting with certain cationic proteins, such as (co)-factors of the coagulation cascade during clotting-inhibition process. Primarily, these molecular complexes between MSPs and coagulation-related proteins seem to be driven mostly by electrostatic interactions. However, through a systematic comparison using several novel well-defined sulfated polysaccharides composed of repetitive oligosaccharides with clear sulfation patterns, it was proved that those molecular interactions are essentially regulated by the stereochemistry of the glycans (which depends on a conjunction of anomeric configurations, sugar types, conformational preferences, glycosylation, and sulfation sites), rather than just a mere consequence of the electronegative density charges (mainly from number of sulfate groups). Here, we present an overview about the structure-function relationship of the invertebrate MSPs with regular structures as potential anticoagulant and antithrombotic agents, as pathologies related to the cardiovascular system are one of the major causes of mortality in the world.

  12. Porous hydrogels with well-defined pore structure for biomaterials applications

    Science.gov (United States)

    Marshall, Andrew J.

    When any medical device is implanted inside the body, the natural inflammatory response causes the device to be encapsulated with a thin layer of dense, relatively avascular fibrous tissue, effectively sealing off the device from the surrounding tissue and isolating it from the rest of the body. For medical devices such as electrodes and glucose sensors, where functionality depends on the ability of the device to interact with the surrounding biochemistry, the "foreign body response" poses a formidable obstacle. Previous studies have demonstrated that porous materials with pore dimensions on the order of cell dimensions can induce a modified foreign body response, resulting in more vascularized capsule tissue. However, the utility of these studies is limited because the materials used had broad pore size distributions and poorly defined pore geometries. This thesis is motivated by the unavailability of biomaterials with well-defined and controlled pore size, and by the lack of understanding of the relationships between pore dimensions and the foreign body response. Our sphere templating technology permits the fabrication of open-pore structures with precisely controlled pore dimensions. We can produce these sphere-templated pore structures out of a variety of polymeric materials, including poly(2-hydroxyethyl methacrylate) (polyHEMA), silicone rubber, and degradable copolymers of polyHEMA and poly(epsilon-caprolactone). We applied our precision-engineered pore structures in vivo to investigate the role of pore size in the foreign body response. We implanted porous polyHEMA with various pore geometries under the skin of mice and found that the level of intra-pore vascularization increases with decreasing pore size, with vascular density directly proportional to the specific surface area of the implant, and that the threshold pore throat diameter for rapid tissue in-growth is approximately 8 mum. Based on our empirical results coupled with first principles, we

  13. Composition, structure and mechanical properties define performance of pulmonary surfactant membranes and films.

    Science.gov (United States)

    Parra, Elisa; Pérez-Gil, Jesús

    2015-01-01

    The respiratory surface in the mammalian lung is stabilized by pulmonary surfactant, a membrane-based system composed of multiple lipids and specific proteins, the primary function of which is to minimize the surface tension at the alveolar air-liquid interface, optimizing the mechanics of breathing and avoiding alveolar collapse, especially at the end of expiration. The goal of the present review is to summarize current knowledge regarding the structure, lipid-protein interactions and mechanical features of surfactant membranes and films and how these properties correlate with surfactant biological function inside the lungs. Surfactant mechanical properties can be severely compromised by different agents, which lead to surfactant inhibition and ultimately contributes to the development of pulmonary disorders and pathologies in newborns, children and adults. A detailed comprehension of the unique mechanical and rheological properties of surfactant layers is crucial for the diagnostics and treatment of lung diseases, either by analyzing the contribution of surfactant impairment to the pathophysiology or by improving the formulations in surfactant replacement therapies. Finally, a short review is also included on the most relevant experimental techniques currently employed to evaluate lung surfactant mechanics, rheology, and inhibition and reactivation processes.

  14. Neoplastic and stromal cells contribute to an extracellular matrix gene expression profile defining a breast cancer subtype likely to progress.

    Directory of Open Access Journals (Sweden)

    Tiziana Triulzi

    Full Text Available We recently showed that differential expression of extracellular matrix (ECM genes delineates four subgroups of breast carcinomas (ECM1, -2, -3- and -4 with different clinical outcome. To further investigate the characteristics of ECM signature and its impact on tumor progression, we conducted unsupervised clustering analyses in 6 additional independent datasets of invasive breast tumors from different platforms for a total of 643 samples. Use of four different clustering algorithms identified ECM3 tumors as an independent group in all datasets tested. ECM3 showed a homogeneous gene pattern, consisting of 58 genes encoding 43 structural ECM proteins. From 26 to 41% of the cases were ECM3-enriched, and analysis of datasets relevant to gene expression in neoplastic or corresponding stromal cells showed that both stromal and breast carcinoma cells can coordinately express ECM3 genes. In in vitro experiments, β-estradiol induced ECM3 gene production in ER-positive breast carcinoma cell lines, whereas TGFβ induced upregulation of the genes leading to ECM3 gene classification, especially in ER-negative breast carcinoma cells and in fibroblasts. Multivariate analysis of distant metastasis-free survival in untreated breast tumor patients revealed a significant interaction between ECM3 and histological grade (p = 0.001. Cox models, estimated separately in grade I-II and grade III tumors, indicated a highly significant association between ECM3 and worse survival probability only in grade III tumors (HR = 3.0, 95% CI = 1.3-7.0, p = 0.0098. Gene Set Enrichment analysis of ECM3 compared to non-ECM3 tumors revealed significant enrichment of epithelial-mesenchymal transition (EMT genes in both grade I-II and grade III subsets of ECM3 tumors. Thus, ECM3 is a robust cluster that identifies breast carcinomas with EMT features but with accelerated metastatic potential only in the undifferentiated (grade III phenotype. These findings support the

  15. Communication: Origin of the contributions to DNA structure in phages.

    Science.gov (United States)

    Myers, Christopher G; Pettitt, B Montgomery

    2013-02-21

    Cryo electron microscopy (cryo-EM) data of the interior of phages show ordering of the interior DNA that has been interpreted as a nearly perfectly ordered polymer. We show surface-induced correlations, excluded volume, and electrostatic forces are sufficient to predict most of the major features of the current structural data for DNA packaged within viral capsids without additional ordering due to elastic bending forces for the polymer. Current models assume highly-ordered, even spooled, hexagonally packed conformations based on interpretation of cryo-EM density maps. We show herein that the surface induced packing of short (6mer), unconnected DNA polymer segments is the only necessary ingredient in creating ringed densities consistent with experimental density maps. This implies the ensemble of possible conformations of polymeric DNA within the capsid that are consistent with cryo-EM data may be much larger than implied by traditional interpretations where such rings can only result from highly-ordered spool-like conformations. This opens the possibility of a more disordered, entropically-driven view of phage packaging thermodynamics. We also show the electrostatics of the DNA contributes a large portion of the internal hydrostatic and osmotic pressures of a phage virion, suggesting that nonlinear elastic anomalies might reduce the overall elastic bending enthalpy of more disordered conformations to have allowable free energies.

  16. Mean-Variance Portfolio Selection Problem with Stochastic Salary for a Defined Contribution Pension Scheme: A Stochastic Linear-Quadratic-Exponential Framework

    Directory of Open Access Journals (Sweden)

    Charles Nkeki

    2013-11-01

    Full Text Available This paper examines a mean-variance portfolio selection problem with stochastic salary and inflation protection strategy in the accumulation phase of a defined contribution (DC pension plan. The utility function is assumed to be quadratic. It was assumed that the flow of contributions made by the PPM are invested into a market that is characterized by a cash account, an inflation-linked bond and a stock. In this paper, inflationlinked bond is traded and used to hedge inflation risks associated with the investment. The aim of this paper is to maximize the expected final wealth and minimize its variance. Efficient frontier for the three classes of assets (under quadratic utility function that will enable pension plan members (PPMs to decide their own wealth and risk in their investment profile at retirement was obtained.

  17. 待遇确定和缴费确定模式下的企业年金精算模型研究%Research on Enterprise Annuity Fund in Defined Benefit and Defined Contribution Payment Models

    Institute of Scientific and Technical Information of China (English)

    洪娟

    2012-01-01

    Since 1970s, there has been a great upsurge of reform around the world in endowment insurance system and retirement system. Each country around the world has put forward the idea of setting up enterprise pension system and has put it into effect. Our country is no exception. In the firm pension system employed in China, there are mainly two models defined benefit and defined contribution payment models. In this paper, we introduce two types of occupational pension systems from the point of view of risk management: defined benefit (DB) plan and defined contribution (DC) plan. The differences between the two plans are examined. We uses quantitative analysis to construct two econometrics models, derives a reasonable substitution rate of pension asset, contribution rate of pension security, and establishes pension financial management and life-long financial analysis mode. By empirical analysis, we try to work out the mutual influence among government, business, beneficiaries, pension managers. In playing game, we will maximize the overall and individual efficiency and balance efficiency.%自二十世纪七十年代以来,在世界范围之内兴起了一场养老保险制度、退休制度改革的热潮,各国纷纷推出了建立企业年金制度的政策主张并得以贯彻实施,我国的养老保险制度改革也同样显示出这样的趋势.中国实行的是企业自愿设立年金的制度,主要有收益确定型(DB)和缴费确定型(DC)两种企业年金制度,本文用模型对DB和DC两种制度下年金给付的不确定性做了比较,指出了不同具体情况下两种企业年金制度的优劣,通过探讨企业年金给付的不同确定方式,待遇确定型计划和缴费确定型计划,运用数量分析,建立两种确定方式的精算模型,得出养老资产合理替代率,养老保障分担率,建立养老理财及终生财务分析模型;通过实证分析方法,探讨政府、企业、受益人、年金管理者在相互影响,以

  18. Composition, structure and mechanical properties define performance of pulmonary surfactant membranes and films

    DEFF Research Database (Denmark)

    Ortiz, Elisa Parra; Perez-Gil, Jesús

    2015-01-01

    The respiratory surface in the mammalian lung is stabilized by pulmonary surfactant, a membrane-based system composed of multiple lipids and specific proteins, the primary function of which is to minimize the surface tension at the alveolar air-liquid interface, optimizing the mechanics of breath......The respiratory surface in the mammalian lung is stabilized by pulmonary surfactant, a membrane-based system composed of multiple lipids and specific proteins, the primary function of which is to minimize the surface tension at the alveolar air-liquid interface, optimizing the mechanics...... of breathing and avoiding alveolar collapse, especially at the end of expiration. The goal of the present review is to summarize current knowledge regarding the structure, lipid-protein interactions and mechanical features of surfactant membranes and films and how these properties correlate with surfactant...... biological function inside the lungs. Surfactant mechanical properties can be severely compromised by different agents, which lead to surfactant inhibition and ultimately contributes to the development of pulmonary disorders and pathologies in newborns, children and adults. A detailed comprehension...

  19. Secretion and activation of the Serratia marcescens hemolysin by structurally defined ShlB mutants.

    Science.gov (United States)

    Pramanik, Avijit; Könninger, Ulrich; Selvam, Arun; Braun, Volkmar

    2014-05-01

    The ShlA hemolysin of Serratia marcescens is secreted across the outer membrane by the ShlB protein; ShlB belongs to the two-partner secretion system (type Vb), a subfamily of the Omp85 outer membrane protein assembly and secretion superfamily. During secretion, ShlA is converted from an inactive non-hemolytic form into an active hemolytic form. The structure of ShlB is predicted to consist of the N-terminal α-helix H1, followed by the two polypeptide-transport-associated domains POTRA P1 and P2, and the β-barrel of 16 β-strands. H1 is inserted into the pore of the β-barrel in the outer membrane; P1 and P2 are located in the periplasm. To obtain insights into the secretion and activation of ShlA by ShlB, we isolated ShlB mutants impaired in secretion and/or activation. The triple H1 P1 P2 mutant did not secrete ShlA. The P1 and P2 deletion derivatives secreted reduced amounts of ShlA, of which P1 showed some hemolysis, whereas P2 was inactive. Deletion of loop 6 (L6), which is conserved among exporters of the Omp85 family, compromised activation but retained low secretion. Secretion-negative mutants generated by random mutagenesis were located in loop 6. The inactive secreted ShlA derivatives were complemented in vitro to active ShlA by an N-terminal ShlA fragment (ShlA242) secreted by ShlB. Deletion of H1 did not impair secretion of hemolytic ShlA. The study defines domains of ShlB which are important for ShlA secretion and activation.

  20. A defining aspect of human resilience in the workplace: a structural modeling approach.

    Science.gov (United States)

    Everly, George S; Davy, Jeanettte A; Smith, Kenneth J; Lating, Jeffrey M; Nucifora, Frederick C

    2011-06-01

    It has been estimated that up to 90% of the US population is exposed to at least 1 traumatic event during their lifetime. Although there is growing evidence that most people are resilient, meaning that they have the ability to adapt to or rebound from adversity, between 5% and 10% of individuals exposed to traumatic events meet criteria for posttraumatic stress disorder. Therefore, identifying the elements of resilience could lead to interventions or training programs designed to enhance resilience. In this article, we test the hypothesis that the effects of stressor conditions on outcomes such as job-related variables may be mediated through the cognitive and affective registrations of those events, conceptualized as subjective stress arousal. The subjects were 491 individuals employed in public accounting, who were sampled from a mailing list provided by the American Institute of Certified Public Accountants. The stressors used in this study were role ambiguity, role conflict, and role overload and the outcome measures were performance, turnover intentions, job satisfaction, and burnout. Stress arousal was measured using a previously developed stress arousal scale. We conducted a series of 2 EQS structural modeling analyses to assess the impact of stress arousal. The first model examined only the direct effects from the role stressors to the outcome constructs. The second model inserted stress arousal as a mediator in the relations between the role stressors and the outcomes. The results of our investigation supported the notion that subjective stress arousal provides greater explanatory clarity by mediating the effects of stressors upon job-related outcome. Including stress arousal in the model provided a much more comprehensive understanding of the relation between stressor and outcomes, and the contribution of role ambiguity and role conflict were better explained. By understanding these relations, anticipatory guidance and crisis intervention programs can be

  1. Crystal structures of two transcriptional regulators from Bacillus cereus define the conserved structural features of a PadR subfamily.

    Directory of Open Access Journals (Sweden)

    Guntur Fibriansah

    Full Text Available PadR-like transcriptional regulators form a structurally-related family of proteins that control the expression of genes associated with detoxification, virulence and multi-drug resistance in bacteria. Only a few members of this family have been studied by genetic, biochemical and biophysical methods, and their structure/function relationships are still largely undefined. Here, we report the crystal structures of two PadR-like proteins from Bacillus cereus, which we named bcPadR1 and bcPadR2 (products of gene loci BC4206 and BCE3449 in strains ATCC 14579 and ATCC 10987, respectively. BC4206, together with its neighboring gene BC4207, was previously shown to become significantly upregulated in presence of the bacteriocin AS-48. DNA mobility shift assays reveal that bcPadR1 binds to a 250 bp intergenic region containing the putative BC4206-BC4207 promoter sequence, while in-situ expression of bcPadR1 decreases bacteriocin tolerance, together suggesting a role for bcPadR1 as repressor of BC4206-BC4207 transcription. The function of bcPadR2 (48% identical in sequence to bcPadR1 is unknown, but the location of its gene just upstream from genes encoding a putative antibiotic ABC efflux pump, suggests a role in regulating antibiotic resistance. The bcPadR proteins are structurally similar to LmrR, a PadR-like transcription regulator in Lactococcus lactis that controls expression of a multidrug ABC transporter via a mechanism of multidrug binding and induction. Together these proteins define a subfamily of conserved, relatively small PadR proteins characterized by a single C-terminal helix for dimerization. Unlike LmrR, bcPadR1 and bcPadR2 lack a central pore for ligand binding, making it unclear whether the transcriptional regulatory roles of bcPadR1 and bcPadR2 involve direct ligand recognition and induction.

  2. Crystal structures of two transcriptional regulators from Bacillus cereus define the conserved structural features of a PadR subfamily.

    Science.gov (United States)

    Fibriansah, Guntur; Kovács, Ákos T; Pool, Trijntje J; Boonstra, Mirjam; Kuipers, Oscar P; Thunnissen, Andy-Mark W H

    2012-01-01

    PadR-like transcriptional regulators form a structurally-related family of proteins that control the expression of genes associated with detoxification, virulence and multi-drug resistance in bacteria. Only a few members of this family have been studied by genetic, biochemical and biophysical methods, and their structure/function relationships are still largely undefined. Here, we report the crystal structures of two PadR-like proteins from Bacillus cereus, which we named bcPadR1 and bcPadR2 (products of gene loci BC4206 and BCE3449 in strains ATCC 14579 and ATCC 10987, respectively). BC4206, together with its neighboring gene BC4207, was previously shown to become significantly upregulated in presence of the bacteriocin AS-48. DNA mobility shift assays reveal that bcPadR1 binds to a 250 bp intergenic region containing the putative BC4206-BC4207 promoter sequence, while in-situ expression of bcPadR1 decreases bacteriocin tolerance, together suggesting a role for bcPadR1 as repressor of BC4206-BC4207 transcription. The function of bcPadR2 (48% identical in sequence to bcPadR1) is unknown, but the location of its gene just upstream from genes encoding a putative antibiotic ABC efflux pump, suggests a role in regulating antibiotic resistance. The bcPadR proteins are structurally similar to LmrR, a PadR-like transcription regulator in Lactococcus lactis that controls expression of a multidrug ABC transporter via a mechanism of multidrug binding and induction. Together these proteins define a subfamily of conserved, relatively small PadR proteins characterized by a single C-terminal helix for dimerization. Unlike LmrR, bcPadR1 and bcPadR2 lack a central pore for ligand binding, making it unclear whether the transcriptional regulatory roles of bcPadR1 and bcPadR2 involve direct ligand recognition and induction.

  3. Framework to Define Structure and Boundaries of Complex Health Intervention Systems: The ALERT Project

    DEFF Research Database (Denmark)

    Boriani, Elena; Esposito, Roberto; Frazzoli, Chiara

    2017-01-01

    with carefully defined system boundaries. Exploring individual components of such systems from different viewpoints gives a wide overview and helps to understand the elements and the relationships that drive actions and consequences within the system. In this study, we present an application and assessment...

  4. Transient Receptor Potential Channels Contribute to Pathological Structural and Functional Remodeling After Myocardial Infarction

    Science.gov (United States)

    Davis, Jennifer; Correll, Robert N.; Trappanese, Danielle M.; Hoffman, Nicholas E.; Troupes, Constantine D.; Berretta, Remus M.; Kubo, Hajime; Madesh, Muniswamy; Chen, Xiongwen; Gao, Erhe; Molkentin, Jeffery D.; Houser, Steven R.

    2014-01-01

    Rationale The cellular and molecular basis for post myocardial infarction (MI) structural and functional remodeling is not well understood. Objective To determine if Ca2+ influx through transient receptor potential (canonical) (TRPC) channels contributes to post-MI structural and functional remodeling. Methods and Results TRPC1/3/4/6 channel mRNA increased after MI in mice and was associated with TRPC-mediated Ca2+ entry. Cardiac myocyte specific expression of a dominant negative (dn: loss of function) TRPC4 channel increased basal myocyte contractility and reduced hypertrophy and cardiac structural and functional remodeling after MI while increasing survival. We used adenovirus-mediated expression of TRPC3/4/6 channels in cultured adult feline myocytes (AFMs) to define mechanistic aspects of these TRPC-related effects. TRPC3/4/6 over expression in AFMs induced calcineurin (Cn)-Nuclear Factor of Activated T cells (NFAT) mediated hypertrophic signaling, which was reliant on caveolae targeting of TRPCs. TRPC3/4/6 expression in AFMs increased rested state contractions and increased spontaneous sarcoplasmic reticulum (SR) Ca2+ sparks mediated by enhanced phosphorylation of the ryanodine receptor. TRPC3/4/6 expression was associated with reduced contractility and response to catecholamines during steady state pacing, likely due to enhanced SR Ca2+ leak. Conclusions Ca2+ influx through TRPC channels expressed after MI activates pathological cardiac hypertrophy and reduces contractility reserve. Blocking post-MI TRPC activity improved post-MI cardiac structure and function. PMID:25047165

  5. Nuclear structure contribution to the Lamb shift in muonic deuterium

    CERN Document Server

    Carlson, Carl E; Vanderhaeghen, Marc

    2014-01-01

    We consider the two-photon exchange contribution to the $2P-2S$ Lamb shift in muonic deuterium in the framework of forward dispersion relations. The dispersion integrals are evaluated using experimental data on elastic deuteron form factors and inelastic electron-deuteron scattering, both in the quasielastic and hadronic range. The subtraction constant that is required to ensure convergence of the dispersion relation for the forward Compton amplitude $T_1(\

  6. Dissecting the contribution of Staphylococcus aureus α-phenol-soluble modulins to biofilm amyloid structure

    Science.gov (United States)

    Marinelli, Patrizia; Pallares, Irantzu; Navarro, Susanna; Ventura, Salvador

    2016-01-01

    The opportunistic pathogen Staphylococcus aureus is recognized as one of the most frequent causes of biofilm-associated infections. The recently discovered phenol soluble modulins (PSMs) are small α-helical amphipathic peptides that act as the main molecular effectors of staphylococcal biofilm maturation, promoting the formation of an extracellular fibril structure with amyloid-like properties. Here, we combine computational, biophysical and in cell analysis to address the specific contribution of individual PSMs to biofilm structure. We demonstrate that despite their highly similar sequence and structure, contrary to what it was previously thought, not all PSMs participate in amyloid fibril formation. A balance of hydrophobic/hydrophilic forces and helical propensity seems to define the aggregation propensity of PSMs and control their assembly and function. This knowledge would allow to target specifically the amyloid properties of these peptides. In this way, we show that Epigallocatechin-3-gallate (EGCG), the principal polyphenol in green tea, prevents the assembly of amyloidogenic PSMs and disentangles their preformed amyloid fibrils. PMID:27708403

  7. NMR contributions to structural dynamics studies of intrinsically disordered proteins☆

    Science.gov (United States)

    Konrat, Robert

    2014-01-01

    Intrinsically disordered proteins (IDPs) are characterized by substantial conformational plasticity. Given their inherent structural flexibility X-ray crystallography is not applicable to study these proteins. In contrast, NMR spectroscopy offers unique opportunities for structural and dynamic studies of IDPs. The past two decades have witnessed significant development of NMR spectroscopy that couples advances in spin physics and chemistry with a broad range of applications. This article will summarize key advances in basic physical-chemistry and NMR methodology, outline their limitations and envision future R&D directions. PMID:24656082

  8. Charge-Induced Unzipping of Isolated Proteins to a Defined Secondary Structure.

    Science.gov (United States)

    González Flórez, Ana Isabel; Mucha, Eike; Ahn, Doo-Sik; Gewinner, Sandy; Schöllkopf, Wieland; Pagel, Kevin; von Helden, Gert

    2016-03-01

    Here we present a combined experimental and theoretical study on the secondary structure of isolated proteins as a function of charge state. In infrared spectra of the proteins ubiquitin and cytochrome c, amide I (C=O stretch) and amide II (N-H bend) bands can be found at positions that are typical for condensed-phase proteins. For high charge states a new band appears, substantially red-shifted from the amide II band observed at lower charge states. The observations are interpreted in terms of Coulomb-driven transitions in secondary structures from mostly helical to extended C5 -type hydrogen-bonded structures. Support for this interpretation comes from simple energy considerations as well as from quantum chemical calculations on model peptides. This transition in secondary structure is most likely universal for isolated proteins that occur in mass spectrometric experiments.

  9. X-ray structures define human P2X3 receptor gating cycle and antagonist action

    Science.gov (United States)

    Mansoor, Steven E.; Lü, Wei; Oosterheert, Wout; Shekhar, Mrinal; Tajkhorshid, Emad; Gouaux, Eric

    2016-10-01

    P2X receptors are trimeric, non-selective cation channels activated by ATP that have important roles in the cardiovascular, neuronal and immune systems. Despite their central function in human physiology and although they are potential targets of therapeutic agents, there are no structures of human P2X receptors. The mechanisms of receptor desensitization and ion permeation, principles of antagonism, and complete structures of the pore-forming transmembrane domains of these receptors remain unclear. Here we report X-ray crystal structures of the human P2X3 receptor in apo/resting, agonist-bound/open-pore, agonist-bound/closed-pore/desensitized and antagonist-bound/closed states. The open state structure harbours an intracellular motif we term the ‘cytoplasmic cap’, which stabilizes the open state of the ion channel pore and creates lateral, phospholipid-lined cytoplasmic fenestrations for water and ion egress. The competitive antagonists TNP-ATP and A-317491 stabilize the apo/resting state and reveal the interactions responsible for competitive inhibition. These structures illuminate the conformational rearrangements that underlie P2X receptor gating and provide a foundation for the development of new pharmacological agents.

  10. Correlating Precisely Defined Primary Structure with Crystalline Properties in Halogen Containing Polyolefins

    Science.gov (United States)

    Boz, Emine; Alamo, Rufina G.; Wagener, Kenneth B.

    Polyethylene (PE) and poly(vinyl chloride) (PVC) are among the most important polymers produced in industry, although other halogen-containing derivatives of PE, such as poly(tetrafluorethylene) (PTFE) have also found wides pread use. A related class of polymers is the ethylene-co-vinyl-halide family. Such copolymers are expected to show distinct properties relative to their better known industrial analogues. For example, much interest has focused on ethylene vinyl chloride (EVC) polymers based on their potential for improved thermal stability relative to PVC. Various techniques have been used to synthesize these ethylene vinyl halide (EVH) copolymers and the simplest approach is halogenation of PE, which results in an irregular distribution of halogens along the polymer backbone and poorly defined materials.

  11. Targeted Elimination of G Proteins and Arrestins Defines Their Specific Contributions to Both Intensity and Duration of G Protein-coupled Receptor Signaling.

    Science.gov (United States)

    Alvarez-Curto, Elisa; Inoue, Asuka; Jenkins, Laura; Raihan, Sheikh Zahir; Prihandoko, Rudi; Tobin, Andrew B; Milligan, Graeme

    2016-12-30

    G protein-coupled receptors (GPCRs) can initiate intracellular signaling cascades by coupling to an array of heterotrimeric G proteins and arrestin adaptor proteins. Understanding the contribution of each of these coupling options to GPCR signaling has been hampered by a paucity of tools to selectively perturb receptor function. Here we employ CRISPR/Cas9 genome editing to eliminate selected G proteins (Gαq and Gα11) or arrestin2 and arrestin3 from HEK293 cells together with the elimination of receptor phosphorylation sites to define the relative contribution of G proteins, arrestins, and receptor phosphorylation to the signaling outcomes of the free fatty acid receptor 4 (FFA4). A lack of FFA4-mediated elevation of intracellular Ca(2+) in Gαq/Gα11-null cells and agonist-mediated receptor internalization in arrestin2/3-null cells confirmed previously reported canonical signaling features of this receptor, thereby validating the genome-edited HEK293 cells. FFA4-mediated ERK1/2 activation was totally dependent on Gq/11 but intriguingly was substantially enhanced for FFA4 receptors lacking sites of regulated phosphorylation. This was not due to a simple lack of desensitization of Gq/11 signaling because the Gq/11-dependent calcium response was desensitized by both receptor phosphorylation and arrestin-dependent mechanisms, whereas a substantially enhanced ERK1/2 response was only observed for receptors lacking phosphorylation sites and not in arrestin2/3-null cells. In conclusion, we validate CRISPR/Cas9 engineered HEK293 cells lacking Gq/11 or arrestin2/3 as systems for GPCR signaling research and employ these cells to reveal a previously unappreciated interplay of signaling pathways where receptor phosphorylation can impact on ERK1/2 signaling through a mechanism that is likely independent of arrestins.

  12. How structure sculpts function: Unveiling the contribution of anatomical connectivity to the brain's spontaneous correlation structure

    Science.gov (United States)

    Bettinardi, R. G.; Deco, G.; Karlaftis, V. M.; Van Hartevelt, T. J.; Fernandes, H. M.; Kourtzi, Z.; Kringelbach, M. L.; Zamora-López, G.

    2017-04-01

    Intrinsic brain activity is characterized by highly organized co-activations between different regions, forming clustered spatial patterns referred to as resting-state networks. The observed co-activation patterns are sustained by the intricate fabric of millions of interconnected neurons constituting the brain's wiring diagram. However, as for other real networks, the relationship between the connectional structure and the emergent collective dynamics still evades complete understanding. Here, we show that it is possible to estimate the expected pair-wise correlations that a network tends to generate thanks to the underlying path structure. We start from the assumption that in order for two nodes to exhibit correlated activity, they must be exposed to similar input patterns from the entire network. We then acknowledge that information rarely spreads only along a unique route but rather travels along all possible paths. In real networks, the strength of local perturbations tends to decay as they propagate away from the sources, leading to a progressive attenuation of the original information content and, thus, of their influence. Accordingly, we define a novel graph measure, topological similarity, which quantifies the propensity of two nodes to dynamically correlate as a function of the resemblance of the overall influences they are expected to receive due to the underlying structure of the network. Applied to the human brain, we find that the similarity of whole-network inputs, estimated from the topology of the anatomical connectome, plays an important role in sculpting the backbone pattern of time-average correlations observed at rest.

  13. Nanocatalyst structure as a template to define chirality of nascent single-walled carbon nanotubes.

    Science.gov (United States)

    Gómez-Gualdrón, Diego A; Zhao, Jin; Balbuena, Perla B

    2011-01-01

    Chirality is a crucial factor in a single-walled carbon nanotube (SWCNT) because it determines its optical and electronic properties. A chiral angle spanning from 0° to 30° results from twisting of the graphene sheet conforming the nanotube wall and is equivalently expressed by chiral indexes (n,m). However, lack of chirality control during SWCNT synthesis is an obstacle for a widespread use of these materials. Here we use first-principles density functional theory (DFT) and classical molecular dynamics (MD) simulations to propose and illustrate basic concepts supporting that the nanocatalyst structure may act as a template to control the chirality during nanotube synthesis. DFT optimizations of metal cluster (Co and Cu)∕cap systems for caps of various chiralities are used to show that an inverse template effect from the nascent carbon nanostructure over the catalyst may exist in floating catalysts; such effect determines a negligible chirality control. Classical MD simulations are used to investigate the influence of a strongly interacting substrate on the structure of a metal nanocatalyst and illustrate how such interaction may help preserve catalyst crystallinity. Finally, DFT optimizations of carbon structures on stepped (211) and (321) cobalt surfaces are used to demonstrate the template effect imparted by the nanocatalyst surface on the growing carbon structure at early stages of nucleation. It is found that depending on the step structure and type of building block (short chains, single atoms, or hexagonal rings), thermodynamics favor armchair or zigzag termination, which provides guidelines for a chirality controlled process based on tuning the catalyst structure and the type of precursor gas.

  14. Facilitating the openEHR approach - organizational structures for defining high-quality archetypes.

    Science.gov (United States)

    Kohl, Christian Dominik; Garde, Sebastian; Knaup, Petra

    2008-01-01

    Using openEHR archetypes to establish an electronic patient record promises rapid development and system interoperability by using or adopting existing archetypes. However, internationally accepted, high quality archetypes which enable a comprehensive semantic interoperability require adequate development and maintenance processes. Therefore, structures have to be created involving different health professions. In the following we present a model which facilitates and governs distributed but cooperative development and adoption of archetypes by different professionals including peer reviews. Our model consists of a hierarchical structure of professional committees and descriptions of the archetype development process considering these different committees.

  15. Toward defining deep brain stimulation targets in MNI space: A subcortical atlas based on multimodal MRI, histology and structural connectivity.

    Science.gov (United States)

    Ewert, Siobhan; Plettig, Philip; Li, Ningfei; Chakravarty, M Mallar; Collins, D Louis; Herrington, Todd M; Kühn, Andrea A; Horn, Andreas

    2017-05-20

    Three-dimensional atlases of subcortical brain structures are valuable tools to reference anatomy in neuroscience and neurology. For instance, they can be used to study the position and shape of the three most common deep brain stimulation (DBS) targets, the subthalamic nucleus (STN), internal part of the pallidum (GPi) and ventral intermediate nucleus of the thalamus (VIM) in spatial relationship to DBS electrodes. Here, we present a composite atlas based on manual segmentations of a multimodal high resolution brain template, histology and structural connectivity. In a first step, four key structures were defined on the template itself using a combination of multispectral image analysis and manual segmentation. Second, these structures were used as anchor points to coregister a detailed histological atlas into standard space. Results show that this approach significantly improved coregistration accuracy over previously published methods. Finally, a sub-segmentation of STN and GPi into functional zones was achieved based on structural connectivity. The result is a composite atlas that defines key nuclei on the template itself, fills the gaps between them using histology and further subdivides them using structural connectivity. We show that the atlas can be used to segment DBS targets in single subjects, yielding more accurate results compared to priorly published atlases. The atlas will be made publicly available and constitutes a resource to study DBS electrode localizations in combination with modern neuroimaging methods. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Enzyme-free translation of DNA into sequence-defined synthetic polymers structurally unrelated to nucleic acids.

    Science.gov (United States)

    Niu, Jia; Hili, Ryan; Liu, David R

    2013-04-01

    The translation of DNA sequences into corresponding biopolymers enables the production, function and evolution of the macromolecules of life. In contrast, methods to generate sequence-defined synthetic polymers with similar levels of control have remained elusive. Here, we report the development of a DNA-templated translation system that enables the enzyme-free translation of DNA templates into sequence-defined synthetic polymers that have no necessary structural relationship with nucleic acids. We demonstrate the efficiency, sequence-specificity and generality of this translation system by oligomerizing building blocks including polyethylene glycol, α-(D)-peptides, and β-peptides in a DNA-programmed manner. Sequence-defined synthetic polymers with molecular weights of 26 kDa containing 16 consecutively coupled building blocks and 90 densely functionalized β-amino acid residues were translated from DNA templates using this strategy. We integrated the DNA-templated translation system developed here into a complete cycle of translation, coding sequence replication, template regeneration and re-translation suitable for the iterated in vitro selection of functional sequence-defined synthetic polymers unrelated in structure to nucleic acids.

  17. X-ray structures define human P2X3 receptor gating cycle and antagonist action

    NARCIS (Netherlands)

    Mansoor, Steven E.; Lü, Wei; Oosterheert, W.; Shekhar, Mrinal; Tajkhorshid, Emad; Gouaux, Eric

    2016-01-01

    P2X receptors are trimeric, non-selective cation channels activated by ATP that have important roles in the cardiovascular, neuronal and immune systems. Despite their central function in human physiology and although they are potential targets of therapeutic agents, there are no structures of human

  18. Tissue engineering by self-assembly of cells printed into topologically defined structures.

    Science.gov (United States)

    Jakab, Karoly; Norotte, Cyrille; Damon, Brook; Marga, Francoise; Neagu, Adrian; Besch-Williford, Cynthia L; Kachurin, Anatoly; Church, Kenneth H; Park, Hyoungshin; Mironov, Vladimir; Markwald, Roger; Vunjak-Novakovic, Gordana; Forgacs, Gabor

    2008-03-01

    Understanding the principles of biological self-assembly is indispensable for developing efficient strategies to build living tissues and organs. We exploit the self-organizing capacity of cells and tissues to construct functional living structures of prescribed shape. In our technology, multicellular spheroids (bio-ink particles) are placed into biocompatible environment (bio-paper) by the use of a three-dimensional delivery device (bio-printer). Our approach mimics early morphogenesis and is based on the realization that the genetic control of developmental patterning through self-assembly involves physical mechanisms. Three-dimensional tissue structures are formed through the postprinting fusion of the bio-ink particles, in analogy with early structure-forming processes in the embryo that utilize the apparent liquid-like behavior of tissues composed of motile and adhesive cells. We modeled the process of self-assembly by fusion of bio-ink particles, and employed this novel technology to print extended cellular structures of various shapes. Functionality was tested on cardiac constructs built from embryonic cardiac and endothelial cells. The postprinting self-assembly of bio-ink particles resulted in synchronously beating solid tissue blocks, showing signs of early vascularization, with the endothelial cells organized into vessel-like conduits.

  19. Argument structure and the child's contribution to language learning.

    Science.gov (United States)

    Lidz, Jeffrey; Gleitman, Lila R

    2004-04-01

    One of the oldest questions in cognitive science asks whether children are able to learn language (or anything) because they are equipped with a very powerful general-purpose learning mechanism or because they are equipped with a domain-specific constrained language acquisition device. Recent advances in statistical approaches to language learning seem to boost the plausibility of general-purpose learning. However, in this article we propose that in the domain of verb learning, children rely more on their internally generated preconceptions about linguistic structure than on robust cues in the input, suggesting that at least in this aspect of language learning, domain-specific grammatical knowledge guides linguistic development.

  20. Community Structure in Large Networks: Natural Cluster Sizes and the Absence of Large Well-Defined Clusters

    CERN Document Server

    Leskovec, Jure; Dasgupta, Anirban; Mahoney, Michael W

    2008-01-01

    A large body of work has been devoted to defining and identifying clusters or communities in social and information networks. We explore from a novel perspective several questions related to identifying meaningful communities in large social and information networks, and we come to several striking conclusions. We employ approximation algorithms for the graph partitioning problem to characterize as a function of size the statistical and structural properties of partitions of graphs that could plausibly be interpreted as communities. In particular, we define the network community profile plot, which characterizes the "best" possible community--according to the conductance measure--over a wide range of size scales. We study over 100 large real-world social and information networks. Our results suggest a significantly more refined picture of community structure in large networks than has been appreciated previously. In particular, we observe tight communities that are barely connected to the rest of the network ...

  1. Phytoplankton community structure defined by key environmental variables in Tagus estuary, Portugal.

    Science.gov (United States)

    Brogueira, Maria José; Oliveira, Maria do Rosário; Cabeçadas, Graça

    2007-12-01

    In this work, we analyze environmental (physical and chemical) and biological (phytoplankton) data obtained along Tagus estuary during three surveys, carried out in productive period (May/June/July) at ebb tide. The main objective of this study was to identify the key environmental factors affecting phytoplankton structure in the estuary. BIOENV analysis revealed that, in study period, temperature, salinity, silicate and total phosphorus were the variables that best explained the phytoplankton spatial pattern in the estuary (Spearman correlation, rho=0.803). A generalized linear model (GLM) also identified salinity, silicate and phosphate as having a high explanatory power (63%) of phytoplankton abundance. These selected nutrients appear to be consistent with the requirements of the dominant phytoplankton group, Baccilariophyceae. Apparently, phytoplankton community is adapted to fluctuations in light intensity, as suspended particulate matter did not come out as a key factor in shaping phytoplankton structure along Tagus estuary.

  2. Bayesian population structure analysis reveals presence of phylogeographically specific sublineages within previously ill-defined T group of Mycobacterium tuberculosis

    Science.gov (United States)

    Reynaud, Yann; Zheng, Chao; Wu, Guihui; Sun, Qun; Rastogi, Nalin

    2017-01-01

    Mycobacterium tuberculosis genetic structure, and evolutionary history have been studied for years by several genotyping approaches, but delineation of a few sublineages remains controversial and needs better characterization. This is particularly the case of T group within lineage 4 (L4) which was first described using spoligotyping to pool together a number of strains with ill-defined signatures. Although T strains were not traditionally considered as a real phylogenetic group, they did contain a few phylogenetically meaningful sublineages as shown using SNPs. We therefore decided to investigate if this observation could be corroborated using other robust genetic markers. We consequently made a first assessment of genetic structure using 24-loci MIRU-VNTRs data extracted from the SITVIT2 database (n = 607 clinical isolates collected in Russia, Albania, Turkey, Iraq, Brazil and China). Combining Minimum Spanning Trees and Bayesian population structure analyses (using STRUCTURE and TESS softwares), we distinctly identified eight tentative phylogenetic groups (T1-T8) with a remarkable correlation with geographical origin. We further compared the present structure observed with other L4 sublineages (n = 416 clinical isolates belonging to LAM, Haarlem, X, S sublineages), and showed that 5 out of 8 T groups seemed phylogeographically well-defined as opposed to the remaining 3 groups that partially mixed with other L4 isolates. These results provide with novel evidence about phylogeographically specificity of a proportion of ill-defined T group of M. tuberculosis. The genetic structure observed will now be further validated on an enlarged worldwide dataset using Whole Genome Sequencing (WGS). PMID:28166309

  3. Bayesian population structure analysis reveals presence of phylogeographically specific sublineages within previously ill-defined T group of Mycobacterium tuberculosis.

    Science.gov (United States)

    Reynaud, Yann; Zheng, Chao; Wu, Guihui; Sun, Qun; Rastogi, Nalin

    2017-01-01

    Mycobacterium tuberculosis genetic structure, and evolutionary history have been studied for years by several genotyping approaches, but delineation of a few sublineages remains controversial and needs better characterization. This is particularly the case of T group within lineage 4 (L4) which was first described using spoligotyping to pool together a number of strains with ill-defined signatures. Although T strains were not traditionally considered as a real phylogenetic group, they did contain a few phylogenetically meaningful sublineages as shown using SNPs. We therefore decided to investigate if this observation could be corroborated using other robust genetic markers. We consequently made a first assessment of genetic structure using 24-loci MIRU-VNTRs data extracted from the SITVIT2 database (n = 607 clinical isolates collected in Russia, Albania, Turkey, Iraq, Brazil and China). Combining Minimum Spanning Trees and Bayesian population structure analyses (using STRUCTURE and TESS softwares), we distinctly identified eight tentative phylogenetic groups (T1-T8) with a remarkable correlation with geographical origin. We further compared the present structure observed with other L4 sublineages (n = 416 clinical isolates belonging to LAM, Haarlem, X, S sublineages), and showed that 5 out of 8 T groups seemed phylogeographically well-defined as opposed to the remaining 3 groups that partially mixed with other L4 isolates. These results provide with novel evidence about phylogeographically specificity of a proportion of ill-defined T group of M. tuberculosis. The genetic structure observed will now be further validated on an enlarged worldwide dataset using Whole Genome Sequencing (WGS).

  4. A microtremor survey to define the subsoil structure in a mud volcano areas

    Science.gov (United States)

    Panzera, Francesco; D'Amico, Sebastiano; Lupi, Matteo; Karyono, Karyono; Mazzini, Adriano

    2017-04-01

    Mud erupting systems have been observed and studied in different localities on the planet. They are characterized by emissions of fluids and fragmented sedimentary rocks creating large structures with different morphologies. This is mainly due to the presence of clay-bearing strata that can be buoyant in the surrounding regions and over-pressured fluids that facilitate the formation of diapirs through sedimentary rocks. In this study, we investigate the Lusi mud erupting system mainly by using ambient vibration methods. In particular, thickness of the sediments and the body wave velocities have been investigated. Results are integrated with gravimetry and electrical resistivity data in order to locate the main geological discontinuities in the area as well as to reconstruct a 3D model of the buried structure. The approach commonly used for this type of studies is based on the ratio of the horizontal to vertical components of ground motion (HVSR) and on passive array techniques. The HVSR generally enables to recognize peaks that point out to the fundamental frequency of the site, which usually fit quite well the theoretical resonance curves. The combination of HVSR and shear wave velocity, coming from passive array techniques, enables to collect valuable information about the subsurface structures. Here we present new data collected at the mud volcano and sedimentary hosted hydrothermal system sites in order to investigate the depths of the main discontinuities and of the hypothesized hydrocarbon reservoirs. We present the case study of Salse di Nirano (northen Italy), Salinelle (Mt. Etna, Sicily) and Lusi hydrothermal systems (Indonesia). Our results indicate that the ambient vibrations study approach represents a swift and simplified methods that provides quick information on the shallow subsoil structure of the investigated areas.

  5. Contributions to reinforced concrete structures numerical simulations; Contributions a la simulation numerique de structures en beton arme

    Energy Technology Data Exchange (ETDEWEB)

    Badel, P.B

    2001-07-15

    In order to be able to carry out simulations of reinforced concrete structures, it is necessary to know two aspects: the behaviour laws have to reflect the complex behaviour of concrete and a numerical environment has to be developed in order to avoid to the user difficulties due to the softening nature of the behaviour. This work deals with these two subjects. After an accurate estimation of two behaviour models (micro-plan and mesoscopic models), two damage models (the first one using a scalar variable, the other one a tensorial damage of the 2 order) are proposed. These two models belong to the framework of generalized standard materials, which renders their numerical integration easy and efficient. A method of load control is developed in order to make easier the convergence of the calculations. At last, simulations of industrial structures illustrate the efficiency of the method. (O.M.)

  6. Mechanical properties of amyloid-like fibrils defined by secondary structures

    Science.gov (United States)

    Bortolini, C.; Jones, N. C.; Hoffmann, S. V.; Wang, C.; Besenbacher, F.; Dong, M.

    2015-04-01

    Amyloid and amyloid-like fibrils represent a generic class of highly ordered nanostructures that are implicated in some of the most fatal neurodegenerative diseases. On the other hand, amyloids, by possessing outstanding mechanical robustness, have also been successfully employed as functional biomaterials. For these reasons, physical and chemical factors driving fibril self-assembly and morphology are extensively studied - among these parameters, the secondary structures and the pH have been revealed to be crucial, since a variation in pH changes the fibril morphology and net chirality during protein aggregation. It is important to quantify the mechanical properties of these fibrils in order to help the design of effective strategies for treating diseases related to the presence of amyloid fibrils. In this work, we show that by changing pH the mechanical properties of amyloid-like fibrils vary as well. In particular, we reveal that these mechanical properties are strongly related to the content of secondary structures. We analysed and estimated the Young's modulus (E) by comparing the persistence length (Lp) - measured from the observation of TEM images by using statistical mechanics arguments - with the mechanical information provided by peak force quantitative nanomechanical property mapping (PF-QNM). The secondary structure content and the chirality are investigated by means of synchrotron radiation circular dichroism (SR-CD). Results arising from this study could be fruitfully used as a protocol to investigate other medical or engineering relevant peptide fibrils.Amyloid and amyloid-like fibrils represent a generic class of highly ordered nanostructures that are implicated in some of the most fatal neurodegenerative diseases. On the other hand, amyloids, by possessing outstanding mechanical robustness, have also been successfully employed as functional biomaterials. For these reasons, physical and chemical factors driving fibril self-assembly and morphology

  7. Complex structure of engineered modular domains defining molecular interaction between ICAM-1 and integrin LFA-1.

    Directory of Open Access Journals (Sweden)

    Sungkwon Kang

    Full Text Available Intermolecular contacts between integrin LFA-1 (α(Lβ(2 and ICAM-1 derive solely from the integrin α(L I domain and the first domain (D1 of ICAM-1. This study presents a crystal structure of the engineered complex of the α(L I domain and ICAM-1 D1. Previously, we engineered the I domain for high affinity by point mutations that were identified by a directed evolution approach. In order to examine α(L I domain allostery between the C-terminal α7-helix (allosteric site and the metal-ion dependent adhesion site (active site, we have chosen a high affinity variant without mutations directly influencing either the position of the α7-helix or the active sites. In our crystal, the α(L I domain was found to have a high affinity conformation to D1 with its α7-helix displaced downward away from the binding interface, recapitulating a current understanding of the allostery in the I domain and its linkage to neighboring domains of integrins in signaling. To enable soluble D1 of ICAM-1 to fold on its own, we also engineered D1 to be functional by mutations, which were found to be those that would convert hydrogen bond networks in the solvent-excluded core into vdW contacts. The backbone structure of the β-sandwich fold and the epitope for I domain binding of the engineered D1 were essentially identical to those of wild-type D1. Most deviations in engineered D1 were found in the loops at the N-terminal region that interacts with human rhinovirus (HRV. Structural deviation found in engineered D1 was overall in agreement with the function of engineered D1 observed previously, i.e., full capacity binding to α(L I domain but reduced interaction with HRV.

  8. Enantioselective Catalysis by Using Short, Structurally Defined DNA Hairpins as Scaffold for Hybrid Catalysts.

    Science.gov (United States)

    Marek, Jasmin J; Singh, Raghvendra P; Heuer, Andreas; Hennecke, Ulrich

    2017-05-02

    A new type of DNA metal complex hybrid catalyst, which is based on single-stranded DNA oligonucleotides, is described. It was shown that oligonucleotides as short as 14 nucleotides that fold into hairpin structures are suitable as nucleic acid components for DNA hybrid catalysts. With these catalysts, excellent enantioinduction in asymmetric Diels-Alder reactions with selectivity values as high as 96 % enantiomeric excess (ee) can be achieved. Molecular dynamics simulations indicate that a rather flexible loop combined with a rigid stem region provides DNA scaffolds with these high selectivity values. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. (Re)defining component structures in morphological constructions: a cognitive grammar perspective

    CSIR Research Space (South Africa)

    Van Huyssteen, GB

    2010-01-01

    Full Text Available in some other (Germanic) languages, Afrikaans compounding often employs a so-called linking morpheme to form a new compound. In a compound like perdekar ?horse cart? the question is whether it should be analyzed as [[[perd]e] kar] (i.e. where the -e...-rep ?untouched?) or with suffixes (like hag- in haglik ?precarious?).9 In Figure 6 cran morphemes are therefore indicated as central component structures, in line with stems. Linking morphemes occur in the middle of two stems (e.g. perd-e-kar ?horse cart...

  10. Preparation of Magnetic Hybrid Microspheres with Well-Defined Yolk-Shell Structure

    Directory of Open Access Journals (Sweden)

    Yuan Zhao

    2016-01-01

    Full Text Available A facile and efficient route was reported to prepare a kind of yolk-shell magnetic hybrid microspheres by suspension polymerization and calcinations method. The morphology, structure, and composition of the magnetic microspheres were characterized by FTIR, XRD, TEM, SEM, and TGA analysis. The vibrating-sample magnetometry (VSM results clearly showed that the magnetic particles were superparamagnetic with saturation magnetization of 32.82 emu/g which makes the microcomposites easily controlled by an external magnetic field. The results revealed that the magnetic hybrid microspheres might have important applications in magnetic bioseparation and drug delivery.

  11. Contribution of Small Wind Turbine Structural Vibration to Noise Emission

    Directory of Open Access Journals (Sweden)

    David Wood

    2013-07-01

    Full Text Available A major barrier to the acceptance of small wind turbines is that they are perceived to be noisy. This paper investigates an aspect of noise emission that has not been considered; vibration and noise generation from the tower. First, vibration measurements were made using accelerometers placed on the 10.2 m monopole tower of a Skystream 2.4 kW wind turbine, and natural frequencies and corresponding deflection shapes were calculated. Second, the results from the survey were used to verify the predictions of a finite element model of the tower structure. Lastly, the tower’s acoustic emission was simulated computationally, as it was not possible to measure it accurately. Most vibration energy occurred in the very low frequency band (≤10 Hz. It was found that wind itself can only excite the first two bending modes. On the other hand, emitted noise from the tower at large distances can be neglected, as close to the tower, the noise can reach 30 dB.

  12. Band structure engineering of graphene by a local gate defined periodic potential

    Science.gov (United States)

    Forsythe, Carlos; Maher, Patrick; Scarabelli, Diego; Dean, Cory; Kim, Philip

    Recent improvements in 2-dimensional (2D) material layering have resulted in enhanced device quality and created pathways for new device architectures. We fabricate periodic arrays from a patterned local back gate and a uniform top gate on hBN encapsulated graphene channels. The symmetry and lattice size of the periodic potential can be determined by state-of-art electron beam lithography and etching, achieving a lattice constant of 35 nm. The strength of the electric potential modulation can be controlled through applied voltage on the patterned gate. We observe signatures of superlattice modulation near the main Dirac peak in the density dependent resistance measurement at zero magnetic field. Current studies focus on the exploration of Hofstadter fractal band structures under magnetic fields. Our nano-patterned engineered superlattices on graphene hold great promise for wider applications.

  13. Structure of a Eurkaryotic CLC Transporter Defines an Intermediate State in the Transport Cycle

    Energy Technology Data Exchange (ETDEWEB)

    L Feng; E Campbell; Y Hsiung; R MacKinnon

    2011-12-31

    CLC proteins transport chloride (Cl{sup -}) ions across cell membranes to control the electrical potential of muscle cells, transfer electrolytes across epithelia, and control the pH and electrolyte composition of intracellular organelles. Some members of this protein family are Cl{sup -} ion channels, whereas others are secondary active transporters that exchange Cl{sup -} ions and protons (H{sup +}) with a 2:1 stoichiometry. We have determined the structure of a eukaryotic CLC transporter at 3.5 angstrom resolution. Cytoplasmic cystathionine beta-synthase (CBS) domains are strategically positioned to regulate the ion-transport pathway, and many disease-causing mutations in human CLCs reside on the CBS-transmembrane interface. Comparison with prokaryotic CLC shows that a gating glutamate residue changes conformation and suggests a basis for 2:1 Cl{sup -}/H{sup +} exchange and a simple mechanistic connection between CLC channels and transporters.

  14. SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED POLYMER-INORGANIC HYBRID NANOPARTICLES VIA ATRP

    Institute of Scientific and Technical Information of China (English)

    Jie Bai; Jie-bin Pang; Kun-yuan Qiu; Yen Wei

    2002-01-01

    Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graft polymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles. 2-(4-Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles through condensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated by this surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silica nanoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence of ATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases with polymerization conversion. The results above show that this "grafting from" reaction could be used for the preparation of polymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.

  15. Difficulties in Defining Social-Emotional Intelligence, Competences and Skills - a Theoretical Analysis and Structural Suggestion

    Directory of Open Access Journals (Sweden)

    Moana Monnier

    2015-04-01

    Full Text Available Demands related to the frequency of and time required for interactional tasks in everyday occupational routines are continuously growing. When it comes to qualifying a person’s ability to interact with others, two prototypical concepts are often used: social competences and emotional intelligence. In connection to discussions about curriculum standards in Germany, these are viewed as important attributes that should be taught, supported and if possible assessed in educational pathways toward an occupation (KMK, 2007. However, in looking for a generally approved and widely used definition, many problems arise on the inter-conceptual and intra-conceptual level, triggering implementation difficulties in educational curricula. This article highlights these difficulties by selecting five well-established key theories and comparing their communalities and differences. Analyzing definitions of intelligence, competences and skills, taking an action regulation perspective and highlighting the interdependence of social and emotional aspects, a structural system to facilitate the transfer into the educational context is proposed.

  16. Defining the electronic and geometric structure of one-electron oxidized copper-bis-phenoxide complexes.

    Science.gov (United States)

    Storr, Tim; Verma, Pratik; Pratt, Russell C; Wasinger, Erik C; Shimazaki, Yuichi; Stack, T Daniel P

    2008-11-19

    The geometric and electronic structure of an oxidized Cu complex ([CuSal](+); Sal = N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexane-(1R,2R)-diamine) with a non-innocent salen ligand has been investigated both in the solid state and in solution. Integration of information from UV-vis-NIR spectroscopy, magnetic susceptibility, electrochemistry, resonance Raman spectroscopy, X-ray crystallography, X-ray absorption spectroscopy, and density functional theory calculations provides critical insights into the nature of the localization/delocalization of the oxidation locus. In contrast to the analogous Ni derivative [NiSal](+) (Storr, T.; et al. Angew. Chem., Int. Ed. 2007, 46, 5198), which exists solely in the Ni(II) ligand-radical form, the locus of oxidation is metal-based for [CuSal](+), affording exclusively a Cu(III) species in the solid state (4-300 K). Variable-temperature solution studies suggest that [CuSal](+) exists in a reversible spin-equilibrium between a ligand-radical species [Cu(II)Sal(*)](+) (S = 1) and the high-valent metal form [Cu(III)Sal](+) (S = 0), indicative of nearly isoenergetic species. It is surprising that a bis-imine-bis-phenolate ligation stabilizes the Cu(III) oxidation state, and even more surprising that in solution a spin equilibrium occurs without a change in coordination number. The oxidized tetrahydrosalen analogue [CuSal(red)](+) (Sal(red) = N,N'-bis(3,5-di- tert-butylhydroxybenzyl)-1,2-cyclohexane-(1R,2R)-diamine) exists as a temperature-invariant Cu(II)-ligand-radical complex in solution, demonstrating that ostensibly simple variations of the ligand structure affect the locus of oxidation in Cu-bis-phenoxide complexes.

  17. Excitations in superfluid systems: contributions of the nuclear structure; Excitations dans les systemes superfluides: contributions de la structure nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Khan, E

    2005-12-15

    The author presents successively the theoretical aspect, the experimental aspect and the applied aspect of excitations in nuclear structures. The quasi-particle random phase approximation (QRPA) tool is first described. Recent approaches on QRPA are based on the theory of the density function where the ground state and excited states are described from the same nucleon-nucleon interaction. 2 methods for measuring the collective excitations are then presented: the proton scattering that has the potentiality to investigate the evolution of magicity, the second method is in fact a new method for measuring the giant mono-polar resonance (GMP) in exotic nuclei. Nuclear reactions are considered as a compulsory step on the way from observables like cross-sections to nuclear structure. The author highlights the assets of the convolution model that can generate the optical potential from the effective nucleon-nucleon interaction and from proton and neutron densities of the nuclei involved. R-processes in nucleosynthesis and neutron stars are reviewed as applications of collective excitations in the field of nuclear astrophysics. (A.C.)

  18. Electronic Structure and Reactivity of a Well-Defined Mononuclear Complex of Ti(II).

    Science.gov (United States)

    Wijeratne, Gayan B; Zolnhofer, Eva M; Fortier, Skye; Grant, Lauren N; Carroll, Patrick J; Chen, Chun-Hsing; Meyer, Karsten; Krzystek, J; Ozarowski, Andrew; Jackson, Timothy A; Mindiola, Daniel J; Telser, Joshua

    2015-11-02

    A facile and high-yielding protocol to the known Ti(II) complex trans-[(py)4TiCl2] (py = pyridine) has been developed. Its electronic structure has been probed experimentally using magnetic susceptibility, magnetic circular dichroism, and high-frequency and high-field electron paramagnetic resonance spectroscopies in conjunction with ligand-field theory and computational methods (density functional theory and ab initio methods). These studies demonstrated that trans-[(py)4TiCl2] has a (3)Eg ground state (dxy(1)dxz,yz(1) orbital occupancy), which, as a result of spin–orbit coupling, yields a ground-state spinor doublet that is EPR active, a first excited-state doublet at ∼60 cm(–1), and two next excited states at ∼120 cm(–1). Reactivity studies with various unsaturated substrates are also presented in this study, which show that the Ti(II) center allows oxidative addition likely via formation of [Ti(η(2)-R2E2)Cl2(py)n] E = C, N intermediates. A new Ti(IV) compound, mer-[(py)3(η(2)-Ph2C2)TiCl2], was prepared by reaction with Ph2C2, along with the previously reported complex trans-(py)3Ti═NPh(Cl)2, from reaction with Ph2N2. Reaction with Ph2CN2 also yielded a new dinuclear Ti(IV) complex, [(py)2(Cl)2Ti(μ2:η(2)-N2CPh2)2Ti(Cl)2], in which the two Ti(IV) ions are inequivalently coordinated. Reaction with cyclooctatetraene (COT) yielded a new Ti(III) complex, [(py)2Ti(η(8)-COT)Cl], which is a rare example of a mononuclear “piano-stool” titanium complex. The complex trans-[(py)4TiCl2] has thus been shown to be synthetically accessible, have an interesting electronic structure, and be reactive toward oxidation chemistry.

  19. Analysis of early accountable care organizations defines patient, structural, cost, and quality-of-care characteristics.

    Science.gov (United States)

    Epstein, Arnold M; Jha, Ashish K; Orav, E John; Liebman, Daniel L; Audet, Anne-Marie J; Zezza, Mark A; Guterman, Stuart

    2014-01-01

    Accountable care organizations (ACOs) have attracted interest from many policy makers and clinical leaders because of their potential to improve the quality of care and reduce costs. Federal ACO programs for Medicare beneficiaries are now up and running, but little information is available about the baseline characteristics of early entrants. In this descriptive study we present data on the structural and market characteristics of these early ACOs and compare ACOs' patient populations, costs, and quality with those of their non-ACO counterparts at baseline. We found that ACO patients were more likely than non-ACO patients to be older than age eighty and had higher incomes. ACO patients were less likely than non-ACO patients to be black, covered by Medicaid, or disabled. The cost of care for ACO patients was slightly lower than that for non-ACO patients. Slightly fewer than half of the ACOs had a participating hospital. Hospitals that were in ACOs were more likely than non-ACO hospitals to be large, teaching, and not-for-profit, although there was little difference in their performance on quality metrics. Our findings can be useful in interpreting the early results from the federal ACO programs and in establishing a baseline to assess the programs' development.

  20. Current relevance of fungal and trypanosomatid glycolipids and sphingolipids: studies defining structures conspicuously absent in mammals

    Directory of Open Access Journals (Sweden)

    Helio K. Takahashi

    2009-09-01

    Full Text Available Recently, glycosphingolipids have been attracting attention due to their role on biological systems as second messengers or modulators of signal transduction, affecting several events, which range from apoptosis to regulation of the cell cycle. In pathogenic fungi, glycolipids are expressed in two classes: neutral monohexosylceramides (glucosyl-or galactosylceramide and acidic glycosylinositol phosphorylceramides (the latter class carries longer glycan chains. It is worth to mention that monohexosylceramides exhibit significant structural differences in their lipid moieties compared to their mammalian counterparts, whereas the glycosylinositol phosphorylceramides exhibit remarkable structural differences in their carbohydrate moieties in comparison to mammal glycosphingolipids counterpart. We observed that glycosylinositol phosphorylceramides are capable of promoting immune response in infected humans. In addition, inhibiting fungal glycosphingolipid biosynthetic pathways leads to an inhibition of colony formation, spore germination, cell cycle, dimorphism and hyphal growth. Other pathogens, such as trypanosomatids, also present unique glycolipids, which may have an important role for the parasite development and/or disease establishment. Regarding host-pathogen interaction, cell membrane rafts, which are enriched in sphingolipids and sterols, participate in parasite/fungal infection. In this review, it is discussed the different biological roles of (glyco (sphingolipids of pathogenic/opportunistic fungi and trypanosomatids.Recentemente, glicoesfingolipídeos têm atraído atenção devido ao seu papel na biologia celular como segundo-mensageiro ou moduladores da transdução de sinal, afetando vários eventos, desde apoptose até a regulação do ciclo celular. Em fungos patogênicos, existem duas classes de glicolipídeos: monohexosil ceramidas neutras (glucosil-ou galactosilceramida e glicosilinositol fosforilceramidas (os quais apresentam

  1. Crystal Structures of Two Transcriptional Regulators from Bacillus cereus Define the Conserved Structural Features of a PadR Subfamily

    NARCIS (Netherlands)

    Fibriansah, Guntur; Kovacs, Akos T.; Pool, Trijntje J.; Boonstra, Mirjam; Kuipers, Oscar P.; Thunnissen, Andy-Mark W. H.

    2012-01-01

    PadR-like transcriptional regulators form a structurally-related family of proteins that control the expression of genes associated with detoxification, virulence and multi-drug resistance in bacteria. Only a few members of this family have been studied by genetic, biochemical and biophysical method

  2. Frontonasal dysplasia, macroblepharon, eyelid colobomas, ear anomalies, macrostomia, mental retardation and CNS structural anomalies: defining the phenotype.

    Science.gov (United States)

    Guion-Almeida, M L; Richieri-Costa, A

    2001-04-01

    We report a Brazilian boy, born to normal and nonconsanguineous parents showing, among other signs, brachycephaly, a wide forehead, a widow's peak, hypertelorism, wide palpebral fissures with multiple eyelid colobomas, a broad nasal root, a long philtrum, macrostomia, prominent lips, a high arched palate, a midline alveolar cleft, a small and grooved chin, ear anomalies, structural anomaly of the corpus callosum, and mental retardation. To our knowledge this additional patient defines a particular clinical condition previously reported [Guion-Almeida M.L. Richieri-Costa A. (1999) Clinical Dysmorphol 8;1-4; Masuno M. et al. (2000) Clin Dysmorphol 9:59-60].

  3. Poly(2-acetoxyethyl methacrylate)/polystyrene latex interpenetrating polymer networks with well-defined phase-separated structure

    Institute of Scientific and Technical Information of China (English)

    Tao Wang; Shan Shi; Li Na Bian; Li Min Zhou; Li Qun Zhao; Shin Ichi Kuroda

    2011-01-01

    A series of poly (2-acetoxyethyl methacrylate)/polystyrene (PAEMA/PS) latex interpenetrating polymer networks (LIPNs) were prepared by seeded soap-free emulsion polymerization of styrene on the crosslinked PAEMA seed particles using an oil-soluble initiator. These PAEMA/PS LIPNs showed a well-defined phase-separated structure with PS phase dispersing in continuous PAEMA phase. The domain size of PS phase was found to depend on the crosslinking degree of PAEMA seed particles and the amount of second-stage styrene monomer.

  4. Defining a Two-pronged Structural Model for PB1 (Phox/Bem1p) Domain Interaction in Plant Auxin Responses

    Energy Technology Data Exchange (ETDEWEB)

    Korasick, David A.; Chatterjee, Srirupa; Tonelli, Marco; Dashti, Hesam; Lee, Soon Goo; Westfall, Corey S.; Fulton, D. Bruce; Andreotti, Amy H.; Amarasinghe, Gaya K.; Strader, Lucia C.; Jez, Joseph M.

    2015-04-03

    Phox/Bem1p (PB1) domains are universal structural modules that use surfaces of different charge for protein-protein association. In plants, PB1-mediated interactions of auxin response factors (ARF) and auxin/indole 3-acetic acid inducible proteins regulate transcriptional events modulated by the phytohormone auxin. Here we investigate the thermodynamic and structural basis for Arabidopsis thaliana ARF7 PB1 domain self-interaction. Isothermal titration calorimetry and NMR experiments indicate that key residues on both the basic and acidic faces of the PB1 domain contribute to and organize coordinately to stabilize protein-protein interactions. Calorimetric analysis of ARF7PB1 site-directed mutants defines a two-pronged electrostatic interaction. The canonical PB1 interaction between a lysine and a cluster of acidic residues provides one prong with an arginine and a second cluster of acidic residues defining the other prong. Evolutionary conservation of this core recognition feature and other co-varying interface sequences allows for versatile PB1-mediated interactions in auxin signaling.

  5. Structural analysis and anticoagulant activities of the novel sulfated fucan possessing a regular well-defined repeating unit from sea cucumber.

    Science.gov (United States)

    Wu, Mingyi; Xu, Li; Zhao, Longyan; Xiao, Chuang; Gao, Na; Luo, Lan; Yang, Lian; Li, Zi; Chen, Lingyun; Zhao, Jinhua

    2015-04-13

    Sulfated fucans, the complex polysaccharides, exhibit various biological activities. Herein, we purified two fucans from the sea cucumbers Holothuria edulis and Ludwigothurea grisea. Their structures were verified by means of HPGPC, FT-IR, GC-MS and NMR. As a result, a novel structural motif for this type of polymers is reported. The fucans have a unique structure composed of a central core of regular (1→2) and (1→3)-linked tetrasaccharide repeating units. Approximately 50% of the units from L. grisea (100% for H. edulis fucan) contain sides of oligosaccharides formed by nonsulfated fucose units linked to the O-4 position of the central core. Anticoagulant activity assays indicate that the sea cucumber fucans strongly inhibit human blood clotting through the intrinsic pathways of the coagulation cascade. Moreover, the mechanism of anticoagulant action of the fucans is selective inhibition of thrombin activity by heparin cofactor II. The distinctive tetrasaccharide repeating units contribute to the anticoagulant action. Additionally, unlike the fucans from marine alga, although the sea cucumber fucans have great molecular weights and affluent sulfates, they do not induce platelet aggregation. Overall, our results may be helpful in understanding the structure-function relationships of the well-defined polysaccharides from invertebrate as new types of safer anticoagulants.

  6. Structural Analysis and Anticoagulant Activities of the Novel Sulfated Fucan Possessing a Regular Well-Defined Repeating Unit from Sea Cucumber

    Directory of Open Access Journals (Sweden)

    Mingyi Wu

    2015-04-01

    Full Text Available Sulfated fucans, the complex polysaccharides, exhibit various biological activities. Herein, we purified two fucans from the sea cucumbers Holothuria edulis and Ludwigothurea grisea. Their structures were verified by means of HPGPC, FT-IR, GC–MS and NMR. As a result, a novel structural motif for this type of polymers is reported. The fucans have a unique structure composed of a central core of regular (1→2 and (1→3-linked tetrasaccharide repeating units. Approximately 50% of the units from L. grisea (100% for H. edulis fucan contain sides of oligosaccharides formed by nonsulfated fucose units linked to the O-4 position of the central core. Anticoagulant activity assays indicate that the sea cucumber fucans strongly inhibit human blood clotting through the intrinsic pathways of the coagulation cascade. Moreover, the mechanism of anticoagulant action of the fucans is selective inhibition of thrombin activity by heparin cofactor II. The distinctive tetrasaccharide repeating units contribute to the anticoagulant action. Additionally, unlike the fucans from marine alga, although the sea cucumber fucans have great molecular weights and affluent sulfates, they do not induce platelet aggregation. Overall, our results may be helpful in understanding the structure-function relationships of the well-defined polysaccharides from invertebrate as new types of safer anticoagulants.

  7. Quantitative Analysis of Contribution of Industrial Structure to Economic Growth in Jiangsu Province

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The industrial structure in Jiangsu Province realizes the transformation from "secondary industry-primary industry-tertiary industry" to "tertiary industry-secondary industry-primary industry". However, the effectiveness of this model of industry-dominate industrial structure and the role of industrial structure pattern in promoting regional economic growth are yet to be researched. By using shift-share analysis method, we judge the importance of factors of industrial structure in regional economic growth of Jiangsu Province, and point out that factors of industrial structure are not the dominant forces in economic growth of Jiangsu Province; among the contributions of three industries to economic growth of Jiangsu Province, the contribution of the primary industry is greatest, followed by the contribution of secondary industry and the contribution of tertiary industry successively; real estate industry makes the greatest contribution to economic growth of Jiangsu Province; financial industry and construction industry make relatively small contributions; the potential of industry needs to be further developed. In the process of economic development of Jiangsu Province, the industrial structure is yet to be further optimized so as to give play to the role of industry in promoting the development of Jiangsu Province.

  8. Character-Defining Features of Contributing Buildings and Structures in the Fort Gordon, Georgia, Signal School Campus Historic District

    Science.gov (United States)

    2016-07-01

    Richard Aeck (1912–1996).” New Georgia Encyclopedia . Available at http://www.georgiaencyclopedia.org/articles/arts- culture /richard-aeck-1912-1996...Center 2902 Newmark Drive Champaign, IL 61822 Final report Approved for public release; distribution is unlimited. Prepared for Cultural Resources...359 ERDC/CERL TR-16-8 Preface This study was conducted for the Cultural Resources office in the Direc- torate of

  9. Quantifying the contributions of structure to annulus fibrosus mechanical function using a nonlinear, anisotropic, hyperelastic model.

    Science.gov (United States)

    Guerin, Heather Lynch; Elliott, Dawn M

    2007-04-01

    The annulus fibrosus of the intervertebral disc is comprised of concentric lamella of oriented collagen fibers embedded in a hydrated proteoglycan matrix with smaller amounts of minor collagens, elastin, and small proteoglycans. Its structure and composition enable the disc to withstand complex loads and result in inhomogeneous, anisotropic, and nonlinear mechanical behaviors. The specific contributions of the annulus fibrosus constituent structures to mechanical function remain unclear. Therefore, the objective of this study was to use a structurally motivated, anisotropic, nonlinear strain energy model of annulus fibrosus to determine the relative contributions of its structural components to tissue mechanical behavior. A nonlinear, orthotropic hyperelastic model was developed for the annulus fibrosus. Terms to describe fibers, matrix, and interactions between annulus fibrosus structures (shear and normal to the fiber directions) were explicitly included. The contributions of these structures were analyzed by including or removing terms and determining the effect on the fit to multidimensional experimental data. Correlation between experimental and model-predicted stress, a Bland-Altman analysis of bias and standard deviation of residuals, and the contribution of structural terms to overall tissue stress were calculated. Both shear and normal interaction terms were necessary to accurately model multidimensional behavior. Inclusion of shear interactions more accurately described annulus fibrosus nonlinearity. Fiber stretch and shear interactions dominated contributions to circumferential direction stress, while normal and shear interactions dominated axial stress. The results suggest that interactions between fibers and matrix, perhaps facilitated by crosslinks, elastin, or minor collagens, augment traditional (i.e., fiber-uncrimping) models of nonlinearity.

  10. A multidisciplinary geological and geophysical approach to define structural and hydrogeological implications of the Molinaccio spring (Spello, Italy)

    Science.gov (United States)

    Ercoli, Maurizio; Pauselli, Cristina; Forte, Emanuele; Di Matteo, Lucio; Mazzocca, Massimiliano; Frigeri, Alessandro; Federico, Costanzo

    2012-02-01

    In this paper, a multidisciplinary geological and geophysical approach has been applied in the complex area of Molinaccio spring (Spello, Umbria, Central Italy) to: 1) understand the large-scale geologic and tectonic structure of the area; 2) define the hydrogeological behavior of the various formations in relationship with the identified structural elements; 3) highlight at small-scale the tectonic structures and their relationships with the water caption tunnel, which is the draining structure of a still working, ancient Roman aqueduct giving water to the village of Spello and to the surrounding plain. Our approach includes different techniques like Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT), direct geological investigations, archaeological studies, GIS data collection and integration. The GPR data revealed, in the area of the water-caption tunnel, two main tectonic structures, both also confirmed by ERT data: the presence of a zone (maximum 2 m wide), interpreted as a normal fault area and an overthrust that puts in contact the permeable Scaglia Rossa limestone (Early Turonian-Middle Eocene), and the Scaglia Variegata-Cinerea marly limestones (Middle Eocene-Upper Oligocene) on the footwall, characterized by lower hydraulic permeability. Using some rough information available on the sub-surface path of the tunnel, that shows a sharp bend after a long straight course, together with the geophysical images, was possible to describe how Romans built the tunnel: they probably followed the wet outcropping rock during the excavation, and changed abruptly the dig direction when they intercepted the normal fault area, aligning then the excavation along its strike. This latter result is important also because recently a multidisciplinary project has been developed to restore and exploit the entire water supply structure, which is not only a well-preserved example of Roman remains with high archaeological value, but also a vital

  11. Structure of branching enzyme- and amylomaltase modified starch produced from well-defined amylose to amylopectin substrates

    DEFF Research Database (Denmark)

    Sorndecha, Waraporn; Sagnelli, Domenico; Meier, Sebastian

    2016-01-01

    Thermostable branching enzyme (BE, EC 2.4.1.18) from Rhodothermus obamensis in combination with amylomaltase (AM, EC 2.4.1.25) from Thermus thermophilus was used to modify starch structure exploring potentials to extensively increase the number of branch points in starch. Amylose is an important...... constituent in starch and the effect of amylose on enzyme catalysis was investigated using amylose-only barley starch (AO) and waxy maize starch (WX) in well-defined ratios. All products were analysed for amylopectin chain length distribution, α-1,6 glucosidic linkages content, molar mass distribution...... by the molar mass rather that the branching density of the glucan per se . Our data demonstrate that a higher amylose content in the substrate starch efficiently produces α-1,6 glucosidic linkages and that the present of amylose generates a higher Μw and more resistant product than amylopectin. The combination...

  12. Contribution of Structure and Morphology of Design Constituents to Performance Improvement of Multilayer Polaritonic Photodetector

    Directory of Open Access Journals (Sweden)

    O. B. Yastrubchak

    2003-10-01

    Full Text Available This paper is devoted to estimate contribution of structure and morphology of the individual design constituents to performance improvement of multilayer polaritonic photodetector (optochemical sensor. Surface plasmon resonance (SPR in the surface barrier heterostructure (SBH with the corrugated interface is used as the basic principle underlying the device operation. The demonstration of correlation of the contribution with the enhanced SBH features was performed through the adequate characterization tool.

  13. Design and synthesis of structurally well-defined functional polypropylenes via transition metal-mediated olefin polymerization chemistry

    Institute of Scientific and Technical Information of China (English)

    Dong Jinyong

    2006-01-01

    Functionalization of polyolefins is an industrially important yet scientifically challenging research subject.This paper summarizes our recent effort to access structurally well-defined functional polypropylenes via transition metal-mediated olefin polymerization.In one approach,polypropylenes containing side chain functional groups of controlled concentrations were obtained by Ziegler-Natta-catalyzed copolymerization of propylene in combination with either living anionic or controlled radical polymerization of polar monomers.The copolymerization of propylene with 1,4-divinylbenzene using an isospecific MgC12-supported TIC14 catalyst yielded potypropylenes containing pendant styrene moieties.Both metalation reaction with n-butyllithium and hydrochlorination reaction with dry hydrogen chloride selectively and quantitatively occurred at the pendant reactive sites,generating polymeric benzyllithium and 1-chloroethylbenzene species.These species initiated living anionic polymerization of styrene(S)and atom transfer radical polymerization(in the presence of CuC1 and pentamethyldiethylenetriamine) of methyl methacrylate(MMA),respectively,resulting in functional polypropylene graft copolymers(PP-g-PS and PP-g-PMMA)with controllable graft lengths.In another approach,chain end-functionalized polypropylenes containing a terminal OH-group with controlled molecular weights were directly prepared by propylene polymerization with a metaUocene catalyst through a selective aluminum chain transfer reaction.Both approaches proved to be desirable polyolefin functionalization routes in terms of efficiency and polymer structure controllability.

  14. Structure of dimeric, recombinant Sulfolobus solfataricus phosphoribosyl diphosphate synthase: a bent dimer defining the adenine specificity of the substrate ATP.

    Science.gov (United States)

    Andersen, Rune W; Leggio, Leila Lo; Hove-Jensen, Bjarne; Kadziola, Anders

    2015-03-01

    The enzyme 5-phosphoribosyl-1-α-diphosphate (PRPP) synthase (EC 2.7.6.1) catalyses the Mg(2+)-dependent transfer of a diphosphoryl group from ATP to the C1 hydroxyl group of ribose 5-phosphate resulting in the production of PRPP and AMP. A nucleotide sequence specifying Sulfolobus solfataricus PRPP synthase was synthesised in vitro with optimised codon usage for expression in Escherichia coli. Following expression of the gene in E. coli PRPP synthase was purified by heat treatment and ammonium sulphate precipitation and the structure of S. solfataricus PRPP synthase was determined at 2.8 Å resolution. A bent dimer oligomerisation was revealed, which seems to be an abundant feature among PRPP synthases for defining the adenine specificity of the substrate ATP. Molecular replacement was used to determine the S. solfataricus PRPP synthase structure with a monomer subunit of Methanocaldococcus jannaschii PRPP synthase as a search model. The two amino acid sequences share 35 % identity. The resulting asymmetric unit consists of three separated dimers. The protein was co-crystallised in the presence of AMP and ribose 5-phosphate, but in the electron density map of the active site only AMP and a sulphate ion were observed. Sulphate ion, reminiscent of the ammonium sulphate precipitation step of the purification, seems to bind tightly and, therefore, presumably occupies and blocks the ribose 5-phosphate binding site. The activity of S. solfataricus PRPP synthase is independent of phosphate ion.

  15. Matrix metalloproteinase-10/TIMP-2 structure and analyses define conserved core interactions and diverse exosite interactions in MMP/TIMP complexes.

    Science.gov (United States)

    Batra, Jyotica; Soares, Alexei S; Mehner, Christine; Radisky, Evette S

    2013-01-01

    Matrix metalloproteinases (MMPs) play central roles in vertebrate tissue development, remodeling, and repair. The endogenous tissue inhibitors of metalloproteinases (TIMPs) regulate proteolytic activity by binding tightly to the MMP active site. While each of the four TIMPs can inhibit most MMPs, binding data reveal tremendous heterogeneity in affinities of different TIMP/MMP pairs, and the structural features that differentiate stronger from weaker complexes are poorly understood. Here we report the crystal structure of the comparatively weakly bound human MMP-10/TIMP-2 complex at 2.1 Å resolution. Comparison with previously reported structures of MMP-3/TIMP-1, MT1-MMP/TIMP-2, MMP-13/TIMP-2, and MMP-10/TIMP-1 complexes offers insights into the structural basis of binding selectivity. Our analyses identify a group of highly conserved contacts at the heart of MMP/TIMP complexes that define the conserved mechanism of inhibition, as well as a second category of diverse adventitious contacts at the periphery of the interfaces. The AB loop of the TIMP N-terminal domain and the contact loops of the TIMP C-terminal domain form highly variable peripheral contacts that can be considered as separate exosite interactions. In some complexes these exosite contacts are extensive, while in other complexes the AB loop or C-terminal domain contacts are greatly reduced and appear to contribute little to complex stability. Our data suggest that exosite interactions can enhance MMP/TIMP binding, although in the relatively weakly bound MMP-10/TIMP-2 complex they are not well optimized to do so. Formation of highly variable exosite interactions may provide a general mechanism by which TIMPs are fine-tuned for distinct regulatory roles in biology.

  16. Factorization and infrared properties of non-perturbative contributions to DIS structure functions

    CERN Document Server

    Ermolaev, B I; Troyan, S I

    2010-01-01

    Analytical expressions for the non-perturbative components of the hadronic scattering amplitudes and the DIS structure functions are not usually obtained from theoretical considerations, but are introduced phenomenologically by fitting the data. We derive some restrictions for such contributions from the general concepts of factorization and integrability. These restrictions are obtained in the context of both k_T and collinear factorizations. We also show that the use of the collinear factorization basically makes the DIS structure functions be dependent on the factorization scale. Our analysis shows that singular factors of the type x^{-a} in the initial parton densities can be used for the singlet component of the structure function F_1, provided a <1, but excludes the use of them for the other structure functions. The restrictions for the non-perturbative contributions we obtain can also be applied to other QCD reactions at high energies.

  17. Big Data in Healthcare - Defining the Digital Persona through User Contexts from the Micro to the Macro. Contribution of the IMIA Organizational and Social Issues WG.

    Science.gov (United States)

    Kuziemsky, C E; Monkman, H; Petersen, C; Weber, J; Borycki, E M; Adams, S; Collins, S

    2014-08-15

    While big data offers enormous potential for improving healthcare delivery, many of the existing claims concerning big data in healthcare are based on anecdotal reports and theoretical vision papers, rather than scientific evidence based on empirical research. Historically, the implementation of health information technology has resulted in unintended consequences at the individual, organizational and social levels, but these unintended consequences of collecting data have remained unaddressed in the literature on big data. The objective of this paper is to provide insights into big data from the perspective of people, social and organizational considerations. We draw upon the concept of persona to define the digital persona as the intersection of data, tasks and context for different user groups. We then describe how the digital persona can serve as a framework to understanding sociotechnical considerations of big data implementation. We then discuss the digital persona in the context of micro, meso and macro user groups across the 3 Vs of big data. We provide insights into the potential benefits and challenges of applying big data approaches to healthcare as well as how to position these approaches to achieve health system objectives such as patient safety or patient-engaged care delivery. We also provide a framework for defining the digital persona at a micro, meso and macro level to help understand the user contexts of big data solutions. While big data provides great potential for improving healthcare delivery, it is essential that we consider the individual, social and organizational contexts of data use when implementing big data solutions.

  18. Structures of LeuT in bicelles define conformation and substrate binding in a membrane-like context

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui; Elferich, Johannes; Gouaux, Eric (Oregon HSU)

    2012-02-13

    Neurotransmitter sodium symporters (NSSs) catalyze the uptake of neurotransmitters into cells, terminating neurotransmission at chemical synapses. Consistent with the role of NSSs in the central nervous system, they are implicated in multiple diseases and disorders. LeuT, from Aquifex aeolicus, is a prokaryotic ortholog of the NSS family and has contributed to our understanding of the structure, mechanism and pharmacology of NSSs. At present, however, the functional state of LeuT in crystals grown in the presence of n-octyl-{beta}-D-glucopyranoside ({beta}-OG) and the number of substrate binding sites are controversial issues. Here we present crystal structures of LeuT grown in DMPC-CHAPSO bicelles and demonstrate that the conformations of LeuT-substrate complexes in lipid bicelles and in {beta}-OG detergent micelles are nearly identical. Furthermore, using crystals grown in bicelles and the substrate leucine or the substrate analog selenomethionine, we find only a single substrate molecule in the primary binding site.

  19. Structures of LeuT in bicelles define conformation and substrate binding in a membrane-like context.

    Science.gov (United States)

    Wang, Hui; Elferich, Johannes; Gouaux, Eric

    2012-01-15

    Neurotransmitter sodium symporters (NSSs) catalyze the uptake of neurotransmitters into cells, terminating neurotransmission at chemical synapses. Consistent with the role of NSSs in the central nervous system, they are implicated in multiple diseases and disorders. LeuT, from Aquifex aeolicus, is a prokaryotic ortholog of the NSS family and has contributed to our understanding of the structure, mechanism and pharmacology of NSSs. At present, however, the functional state of LeuT in crystals grown in the presence of n-octyl-β-D-glucopyranoside (β-OG) and the number of substrate binding sites are controversial issues. Here we present crystal structures of LeuT grown in DMPC-CHAPSO bicelles and demonstrate that the conformations of LeuT-substrate complexes in lipid bicelles and in β-OG detergent micelles are nearly identical. Furthermore, using crystals grown in bicelles and the substrate leucine or the substrate analog selenomethionine, we find only a single substrate molecule in the primary binding site.

  20. The contribution of work representation to solving the governance structure problem

    NARCIS (Netherlands)

    Berg, A. van den

    2004-01-01

    The aim of this paper is to explain in what ways work representation may contribute to an efficient governance structure. The insights from institutional economic theories will be applied to two different kinds of employee participation, namely trade unions and works councils. From the discussion it

  1. Bloom-Gilman Duality of Nucleon Spin Structure Function and Elastic Peak Contribution

    Institute of Scientific and Technical Information of China (English)

    DONG Yu-Bing

    2005-01-01

    By employing the parametrization form of the nucleon spin structure function in the resonance region,which includes the contributions of the resonance peaks and of nonresonance background, we study Bloom-Gilman quark-hadron duality of g1 both in the inelastic resonance region and elastic one.

  2. Higher-Twist Contribution to Pion Structure Function 4-Fermi Operators

    CERN Document Server

    Capitani, S; Horsley, R; Klaus, B; Linke, V; Rakow, P E L; Schäfer, A; Schierholz, G

    2000-01-01

    We present quenched lattice QCD results for the contribution of higher-twist operators to the lowest non-trivial moment of the pion structure function. To be specific, we consider the combination $F_2^{\\pi^+} + F_2^{\\pi^-} - 2 F_2^{\\pi^0}$ which has $I = 2$ and receives contributions from 4-Fermi operators only. We introduce the basis of lattice operators. The renormalization of the operators is done perturbatively in the $\\bar{\\rm{MS}}$ scheme using the 't Hooft-Veltman prescription for $\\gamma_5$, taking particular care of mixing effects. The contribution is found to be of $O(f_\\pi^2/Q^2)$, relative to the leading contribution to the moment of $F_2^{\\pi^+}$.

  3. Defining RNA motif-aminoglycoside interactions via two-dimensional combinatorial screening and structure-activity relationships through sequencing.

    Science.gov (United States)

    Velagapudi, Sai Pradeep; Disney, Matthew D

    2013-10-15

    RNA is an extremely important target for the development of chemical probes of function or small molecule therapeutics. Aminoglycosides are the most well studied class of small molecules to target RNA. However, the RNA motifs outside of the bacterial rRNA A-site that are likely to be bound by these compounds in biological systems is largely unknown. If such information were known, it could allow for aminoglycosides to be exploited to target other RNAs and, in addition, could provide invaluable insights into potential bystander targets of these clinically used drugs. We utilized two-dimensional combinatorial screening (2DCS), a library-versus-library screening approach, to select the motifs displayed in a 3×3 nucleotide internal loop library and in a 6-nucleotide hairpin library that bind with high affinity and selectivity to six aminoglycoside derivatives. The selected RNA motifs were then analyzed using structure-activity relationships through sequencing (StARTS), a statistical approach that defines the privileged RNA motif space that binds a small molecule. StARTS allowed for the facile annotation of the selected RNA motif-aminoglycoside interactions in terms of affinity and selectivity. The interactions selected by 2DCS generally have nanomolar affinities, which is higher affinity than the binding of aminoglycosides to a mimic of their therapeutic target, the bacterial rRNA A-site.

  4. Acoustic contributions of a sound absorbing blanket placed in a double panel structure: Absorption Versus Transmission

    CERN Document Server

    Doutres, Olivier; 10.1121/1.3458845

    2010-01-01

    The objective of this paper is to propose a simple tool to estimate the absorption vs. transmission loss contributions of a multilayered blanket unbounded in a double panel structure and thus guide its optimization. The normal incidence airborne sound transmission loss of the double panel structure, without structure-borne connections, is written in terms of three main contributions; (i) sound transmission loss of the panels, (ii) sound transmission loss of the blanket and (iii) sound absorption due to multiple reflections inside the cavity. The method is applied to four different blankets frequently used in automotive and aeronautic applications: a non-symmetric multilayer made of a screen in sandwich between two porous layers and three symmetric porous layers having different pore geometries. It is shown that the absorption behavior of the blanket controls the acoustic behavior of the treatment at low and medium frequencies and its transmission loss at high frequencies. Acoustic treatment having poor sound ...

  5. Structurally Well-Defined Sigmoidal Gold Clusters: Probing the Correlation between Metal Atom Arrangement and Chiroptical Response.

    Science.gov (United States)

    He, Xin; Wang, Yuechao; Jiang, Hong; Zhao, Liang

    2016-05-04

    Asymmetric arrangement of metal atoms is crucial for understanding the chirality origin of chiral metal nanoclusters and facilitating the design and development of new chiral catalysts and chiroptical devices. Here, we describe the construction of four asymmetric gold and gold-silver clusters by chirality transfer from diimido ligands. The acquired metal clusters show strong circular dichroism (CD) response with large anisotropy factors of up to 6 × 10(-3), larger than the values of most reported chiral gold nanoclusters. Regardless of the same absolute configuration of the applied three diimido ligands, sigmoidal and reverse-sigmoidal arrangements of gold atoms both can be achieved, which resultantly produce an opposite Cotton effect within a specific absorption range. On the basis of the detailed structural characterization via X-ray crystallography and contrast experiments, the chirality contribution of the imido ligand, the asymmetrically arranged metal cluster, and the chiral arrangement of aromatic rings of phosphine ligands have been qualitatively evaluated. Time-dependent DFT calculations reveal that the chiroptical property of the acquired metal clusters is mainly influenced by the asymmetrically arranged metal atoms. Correlation of asymmetric arrangements of metal atoms in clusters with their chiroptical response provides a viable means of fabricating a designable chiral surface of metal nanoclusters and opens a broader prospect for chiral cluster application.

  6. Gluon contribution to the structure function $g_{2}(x,Q^{2})$

    CERN Document Server

    Braun, V M; Manashov, A N

    2001-01-01

    We calculate the one-loop twist-3 gluon contribution to the flavor-singlet structure function g_2(x,Q^2) in polarized deep-inelastic scattering and find that it is dominated by the contribution of the three-gluon operator with the lowest anomalous dimension (for each moment N). The similar property was observed earlier for the nonsinglet distributions, although the reason is in our case different. The result is encouraging and suggests a simple evolution pattern of g_2(x,Q^2) in analogy with the conventional description of twist-2 parton distributions.

  7. Define Project

    DEFF Research Database (Denmark)

    Munk-Madsen, Andreas

    2005-01-01

    "Project" is a key concept in IS management. The word is frequently used in textbooks and standards. Yet we seldom find a precise definition of the concept. This paper discusses how to define the concept of a project. The proposed definition covers both heavily formalized projects and informally...... organized, agile projects. Based on the proposed definition popular existing definitions are discussed....

  8. Contribution of posterolateral corner structures to knee joint translational and rotational stabilities: a computational study.

    Science.gov (United States)

    Kim, Yoon Hyuk; Purevsuren, Tserenchimed; Kim, Kyungsoo; Oh, Kwang-Jun

    2013-09-01

    It has been reported that posterolateral corner structures, including the lateral collateral ligament, the popliteus tendon, and the popliteofibular ligament, may play important roles in reducing external rotational and posterior translational instabilities. However, there are few studies focusing on the quantitative influence of posterolateral corner structures on knee joint stability, due to the difficulty of controlling experimental conditions. In this study, a knee model that included posterolateral corner structures was developed. It was validated by comparison to previous experimental studies using the posterior drawer test, dial test, and varus stress test. The posterior translation, external rotation, and varus rotation were then predicted in order to investigate the contribution of posterolateral corner structures to translational and rotational stabilities. Our results indicate that posterolateral corner structures, including the popliteofibular ligament and the popliteus tendon, could contribute to posterior translational and external rotational stabilities, as clinical observations had suggested. Therefore, the addition of posterolateral corner structures to knee joint models may improve the utility of such models.

  9. Brain structure and function related to depression in Alzheimer's disease: contributions from neuroimaging research.

    Science.gov (United States)

    Brommelhoff, Jessica A; Sultzer, David L

    2015-01-01

    The development of minimally invasive in vivo methods for imaging the brain has allowed for unprecedented advancement in our understanding of brain-behavior relationships. Structural, functional, and multimodal neuroimaging techniques have become more sophisticated in detecting structural and physiological abnormalities that may underlie various affective disorders and neurological illnesses such as depression in Alzheimer's disease (AD). In general, neuroimaging studies of depression in AD investigate whether depression is associated with damage to structures in specific neural networks involving frontal and subcortical structures or with functional disruption of cortical neural systems. This review provides an overview of how various imaging modalities have contributed to our understanding of the neurobiology of depression in AD. At present, the literature does not conclusively support any specific pathogenesis for depression, and it is not clear whether patients with AD and depression have histopathological and neurochemical characteristics that contribute to mood symptoms that are different from cognitively intact individuals with depression. Neuroimaging studies suggest that atrophy of temporal or frontal structures, white matter lesions in frontal lobe or subcortical systems, reduced activity in dorsolateral frontal cortex, or small vessel cerebrovascular disease may be associated with depression in AD. Conceptual, clinical, and methodological challenges in studying this relationship are discussed. Further work is needed to understand the specific brain structures, relevant white matter tracts, and interactions among them that are most important. This review concludes with potential directions for future research.

  10. Structure-guided unravelling: Phenolic hydroxyls contribute to reduction of acrylamide using multiplex quantitative structure-activity relationship modelling.

    Science.gov (United States)

    Zhang, Yu; Huang, Mengmeng; Wang, Qiao; Cheng, Jun

    2016-05-15

    We reported a structure-activity relationship study on unravelling phenolic hydroxyls instead of alcoholic hydroxyls contribute to the reduction of acrylamide formation by flavonoids. The dose-dependent study shows a close correlation between the number of phenolic hydroxyls of flavonoids and their reduction effects. In view of positions of hydroxyls, the 3',4'(ortho)-dihydroxyls in B cycle, 3-hydroxyl or hydroxyls of 3-gallate in C cycle, and 5,7(meta)-dihydroxyls in A cycle of flavonoid structures play an important role in the reduction of acrylamide. Flavone C-glycosides are more effective at reducing the formation of acrylamide than flavone O-glycosides when sharing the same aglycone. The current multiplex quantitative structure-activity relationship (QSAR) equations effectively predict the inhibitory rates of acrylamide using selected chemometric parameters (R(2): 0.835-0.938). This pioneer study opens a broad understanding on the chemoprevention of acrylamide contaminants on a structural basis.

  11. Factorization and infrared properties of non-perturbative contributions to DIS structure functions

    Energy Technology Data Exchange (ETDEWEB)

    Ermolaev, B.I. [Ioffe Physico-Technical Institute, St. Petersburg (Russian Federation); Greco, M. [University Roma Tre, Department of Physics (Italy); INFN, Rome (Italy); Troyan, S.I. [St. Petersburg Institute of Nuclear Physics, Gatchina (Russian Federation)

    2011-09-15

    In this paper we present a new derivation of QCD factorization. We deduce the k{sub T} and collinear factorizations for the DIS structure functions by consecutive reductions of a more general theoretical construction. We begin by studying the amplitude of forward Compton scattering off a hadron target, representing this amplitude as a set of convolutions of two blobs connected by the simplest, two-parton intermediate states. Each blob in the convolutions can contain both the perturbative and non-perturbative contributions. We formulate conditions for separating the perturbative and non-perturbative contributions and attributing them to the different blobs. After that the convolutions correspond to QCD factorization. Then we reduce this totally unintegrated (basic) factorization first to k{sub T} -factorization and finally to collinear factorization. In order to yield a finite expression for the Compton amplitude, the integration over the loop momentum in the basic factorization must be free of both ultraviolet and infrared singularities. This obvious mathematical requirement leads to theoretical restrictions on the non-perturbative contributions (parton distributions) to the Compton amplitude and the DIS structure functions related to the Compton amplitude through the Optical Theorem. In particular, our analysis excludes the use of the singular factors x{sup -a} (with a >0) in the fits for the quark and gluon distributions because such factors contradict the integrability of the basic convolutions for the Compton amplitude. This restriction is valid for all DIS structure functions in the framework of both k{sub T} -factorization and collinear factorization if we attribute the perturbative contributions only to the upper blob. The restrictions on the non-perturbative contributions obtained in the present paper can easily be extended to other QCD processes where the factorization is exploited. (orig.)

  12. Intensity inhomogeneity correction of structural MR images: a data-driven approach to define input algorithm parameters

    Directory of Open Access Journals (Sweden)

    Marco eGanzetti

    2016-03-01

    Full Text Available Intensity non-uniformity (INU in magnetic resonance (MR imaging is a major issue when conducting analyses of brain structural properties. An inaccurate INU correction may result in qualitative and quantitative misinterpretations. Several INU correction methods exist, whose performance largely depend on the specific parameter settings that need to be chosen by the user. Here we addressed the question of how to select the best input parameters for a specific INU correction algorithm. Our investigation was based on the INU correction algorithm implemented in SPM, but this can be in principle extended to any other algorithm requiring the selection of input parameters. We conducted a comprehensive comparison of indirect metrics for the assessment of INU correction performance, namely the coefficient of variation of white matter (CV_WM, the coefficient of variation of gray matter (CV_GM, and the coefficient of joint variation between white matter and gray matter (CJV. Using simulated MR data, we observed the CJV to be more accurate than CV_WM and CV_GM, provided that the noise level in the INU-corrected image was controlled by means of spatial smoothing. Based on the CJV, we developed a data-driven approach for selecting INU correction parameters, which could effectively work on actual MR images. To this end, we implemented an enhanced procedure for the definition of white and gray matter masks, based on which the CJV was calculated. Our approach was validated using actual T1-weighted images collected with 1.5 T, 3 T and 7 T MR scanners. We found that our procedure can reliably assist the selection of valid INU correction algorithm parameters, thereby contributing to an enhanced inhomogeneity correction in MR images.

  13. Intensity Inhomogeneity Correction of Structural MR Images: A Data-Driven Approach to Define Input Algorithm Parameters.

    Science.gov (United States)

    Ganzetti, Marco; Wenderoth, Nicole; Mantini, Dante

    2016-01-01

    Intensity non-uniformity (INU) in magnetic resonance (MR) imaging is a major issue when conducting analyses of brain structural properties. An inaccurate INU correction may result in qualitative and quantitative misinterpretations. Several INU correction methods exist, whose performance largely depend on the specific parameter settings that need to be chosen by the user. Here we addressed the question of how to select the best input parameters for a specific INU correction algorithm. Our investigation was based on the INU correction algorithm implemented in SPM, but this can be in principle extended to any other algorithm requiring the selection of input parameters. We conducted a comprehensive comparison of indirect metrics for the assessment of INU correction performance, namely the coefficient of variation of white matter (CVWM), the coefficient of variation of gray matter (CVGM), and the coefficient of joint variation between white matter and gray matter (CJV). Using simulated MR data, we observed the CJV to be more accurate than CVWM and CVGM, provided that the noise level in the INU-corrected image was controlled by means of spatial smoothing. Based on the CJV, we developed a data-driven approach for selecting INU correction parameters, which could effectively work on actual MR images. To this end, we implemented an enhanced procedure for the definition of white and gray matter masks, based on which the CJV was calculated. Our approach was validated using actual T1-weighted images collected with 1.5 T, 3 T, and 7 T MR scanners. We found that our procedure can reliably assist the selection of valid INU correction algorithm parameters, thereby contributing to an enhanced inhomogeneity correction in MR images.

  14. Contribution of Quark Structure Term in Nucleon Electric and Magnetic Form Factors

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-Min; ZHANG Ben-Ai

    2004-01-01

    The constituent quarks in the nucleon have always been considered as a point-like particle in the relativistic constituent quark model. However its calculation results of GnE agree poorly with the new experimental data. The electromagnetic structure of light front constituent quarks is considered in this paper. We find that the calculation results have good agreement with the new experimental data of GnE after considering the contribution of the quark structure term. This treatment seems to be able to improve the fit to experimental data of Gep/GMp, /Q2F2p/kpF1p,and Gen/GMn as well.

  15. Do structural inequalities contribute to marital violence? Ethnographic evidence from rural South India.

    Science.gov (United States)

    Krishnan, Suneeta

    2005-06-01

    Ethnographic research was conducted in rural communities in Karnataka State, South India, to explore the contexts in which marital violence occurs and the relationships between structural inequalities (gender, caste, and class inequalities) and marital violence. Research highlighted that (a) marital violence is intimately linked to experiences of gender, caste, and class inequalities; (b) women's ability to resist violence hinges on access to economic and social resources; and (c) health care providers need to be actively involved in responding to violence. This study demonstrates the urgent need for violence prevention initiatives, particularly those that address the contribution of structural inequalities.

  16. Differential contributions of histone H3 and H4 residues to heterochromatin structure.

    Science.gov (United States)

    Yu, Qun; Olsen, Lars; Zhang, Xinmin; Boeke, Jef D; Bi, Xin

    2011-06-01

    Transcriptional silencing in Saccharomyces cerevisiae is mediated by heterochromatin. There is a plethora of information regarding the roles of histone residues in transcriptional silencing, but exactly how histone residues contribute to heterochromatin structure is not resolved. We address this question by testing the effects of a series of histone H3 and H4 mutations involving residues in their aminoterminal tails, on the solvent-accessible and lateral surfaces of the nucleosome, and at the interface of the H3/H4 tetramer and H2A/H2B dimer on heterochromatin structure and transcriptional silencing. The general state, stability, and conformational heterogeneity of chromatin are examined with a DNA topology-based assay, and the primary chromatin structure is probed by micrococcal nuclease. We demonstrate that the histone mutations differentially affect heterochromatin. Mutations of lysine 16 of histone H4 (H4-K16) and residues in the LRS (loss of rDNA silencing) domain of nucleosome surface markedly alter heterochromatin structure, supporting the notion that H4-K16 and LRS play key roles in heterochromatin formation. Deletion of the aminoterminal tail of H3 moderately alters heterochromatin structure. Interestingly, a group of mutations in the globular domains of H3 and H4 that abrogate or greatly reduce transcriptional silencing increase the conformational heterogeneity and/or reduce the stability of heterochromatin without affecting its overall structure. Surprisingly, yet another series of mutations abolish or reduce silencing without significantly affecting the structure, stability, or conformational heterogeneity of heterochromatin. Therefore, histone residues may contribute to the structure, stability, conformational heterogeneity, or other yet-to-be-characterized features of heterochromatin important for transcriptional silencing.

  17. RNA is an integral component of chromatin that contributes to its structural organization.

    Directory of Open Access Journals (Sweden)

    Antonio Rodríguez-Campos

    Full Text Available Chromatin structure is influenced by multiples factors, such as pH, temperature, nature and concentration of counterions, post-translational modifications of histones and binding of structural non-histone proteins. RNA is also known to contribute to the regulation of chromatin structure as chromatin-induced gene silencing was shown to depend on the RNAi machinery in S. pombe, plants and Drosophila. Moreover, both in Drosophila and mammals, dosage compensation requires the contribution of specific non-coding RNAs. However, whether RNA itself plays a direct structural role in chromatin is not known. Here, we report results that indicate a general structural role for RNA in eukaryotic chromatin. RNA is found associated to purified chromatin prepared from chicken liver, or cultured Drosophila S2 cells, and treatment with RNase A alters the structural properties of chromatin. Our results indicate that chromatin-associated RNAs, which account for 2%-5% of total chromatin-associated nucleic acids, are polyA(- and show a size similar to that of the DNA contained in the corresponding chromatin fragments. Chromatin-associated RNA(s are not likely to correspond to nascent transcripts as they are also found bound to chromatin when cells are treated with alpha-amanitin. After treatment with RNase A, chromatin fragments of molecular weight >3.000 bp of DNA showed reduced sedimentation through sucrose gradients and increased sensitivity to micrococcal nuclease digestion. This structural transition, which is observed both at euchromatic and heterochromatic regions, proceeds without loss of histone H1 or any significant change in core-histone composition and integrity.

  18. [Contributions and results of lipo-structure in repair and rejuvenation of frontal anatomical unit].

    Science.gov (United States)

    Chichery, A; Mojallal, A; Voulliaume, D; Comparin, J-P; Foyatier, J-L

    2009-04-01

    Forehead is the most large anatomical unit of face. It includes forehead and anterior part of temple. Deteriorations of frontal anatomical units are numerous, ageing forehead has atrophy with eyebrow ptosis. In this work, we want to estimate contribution of lipo-structure in repair and rejuvenation of frontal anatomical unit (FAU). We present seven cases of repair of FAU and three cases of rejuvenation of the forehead. Results are satisfactory, particularly about frontal band. Results are questionable about Lipo-structure of temple. Applications of Lipo-structure in plastic and aesthetic surgery of the forehead are huge. Lipo-structure is the reference technique of volumetric filling. It is preferred to other techniques as flaps (pediculed or free) or materials, because it is a safe, easy and efficient technique, which permits large fillings. In aesthetic surgery, Lipo-structure gives volume to eyebrow region and fills root of the nose. It can be used with injections of botulinum toxin A. Lipo-structure of forehead takes part in rejuvenation of eye and nose. In conclusion, lipo-structure is actually the major technique of filling with a large implication in plastic and aesthetic surgery of FAU.

  19. Acoustic contributions of a sound absorbing blanket placed in a double panel structure: absorption versus transmission.

    Science.gov (United States)

    Doutres, Olivier; Atalla, Noureddine

    2010-08-01

    The objective of this paper is to propose a simple tool to estimate the absorption vs. transmission loss contributions of a multilayered blanket unbounded in a double panel structure and thus guide its optimization. The normal incidence airborne sound transmission loss of the double panel structure, without structure-borne connections, is written in terms of three main contributions; (i) sound transmission loss of the panels, (ii) sound transmission loss of the blanket and (iii) sound absorption due to multiple reflections inside the cavity. The method is applied to four different blankets frequently used in automotive and aeronautic applications: a non-symmetric multilayer made of a screen in sandwich between two porous layers and three symmetric porous layers having different pore geometries. It is shown that the absorption behavior of the blanket controls the acoustic behavior of the treatment at low and medium frequencies and its transmission loss at high frequencies. Acoustic treatment having poor sound absorption behavior can affect the performance of the double panel structure.

  20. Contribution of the Reflected Waves Method in Structural Modeling of Albanides

    Directory of Open Access Journals (Sweden)

    Petraq Naço,

    2014-02-01

    Full Text Available Geophysical methods are widely used in Albania, both in terms of underground assets exploration, as well as geological modeling of depth. Through these methods is achieved to outline and to discover several oil and gas deposits, as well as to clarify and to resolve many problems and phenomena related to tectonic style, the relationship between units and structural-facial areas, with structural performance of rock formations to great depths, etc. Method of seismic is considered as elite method, in the sense of bringing information to wide space and great depths of underground. It, through the panorama of seismic reflectors that offers, in coordination with data and the other methods in the field of geology, enables the interpretation and modeling of geologic construction to considerable depths. Also, enables the conception of the tectonic style, the outlining of the structural building and especially the forecast of structures with the possibility for detection of hydrocarbon deposits. Through this information, are made the important steps in conception, tectonic style and behavior of major structural-facial units, in terms of relations to each other. Below some examples will help to show concrete contribution in the discovery of oil deposits, in the forecast of new oil-bearing areas, at bringing of new regional concepts to tectonic style, at explanation of the geological phenomena at depth, etc. All examples are selected along the geological structure of Albanides as cases with abundant and diversified information, while the conception and interpretation is made under our scientific viewpoint.

  1. Genetic and Environmental Contributions to the Relationships between Brain Structure and Average Lifetime Cigarette Use

    Science.gov (United States)

    Prom-Wormley, Elizabeth; Maes, Hermine H.M.; Schmitt, J. Eric; Panizzon, Matthew S.; Xian, Hong; Eyler, Lisa T.; Franz, Carol E.; Lyons, Michael J.; Tsuang, Ming T.; Dale, Anders M.; Fennema-Notestine, Christine; Kremen, William S.; Neale, Michael C.

    2015-01-01

    Chronic cigarette use has been consistently associated with differences in the neuroanatomy of smokers relative to nonsmokers in case-control studies. However, the etiology underlying the relationships between brain structure and cigarette use is unclear. A community-based sample of male twin pairs ages 51-59 (110 monozygotic pairs, 92 dizygotic pairs) was used to determine the extent to which there are common genetic and environmental influences between brain structure and average lifetime cigarette use. Brain structure was measured by high-resolution structural magnetic resonance imaging, from which subcortical volume and cortical volume, thickness and surface area were derived. Bivariate genetic models were fitted between these measures and average lifetime cigarette use measured as cigarette pack-years. Widespread, negative phenotypic correlations were detected between cigarette pack-years and several cortical as well as subcortical structures. Shared genetic and unique environmental factors contributed to the phenotypic correlations shared between cigarette pack-years and subcortical volume as well as cortical volume and surface area. Brain structures involved in many of the correlations were previously reported to play a role in specific aspects of networks of smoking-related behaviors. These results provide evidence for conducting future research on the etiology of smoking-related behaviors using measures of brain morphology. PMID:25690561

  2. Arterial mechanics considering the structural and mechanical contributions of ECM constituents.

    Science.gov (United States)

    Wang, Yunjie; Zeinali-Davarani, Shahrokh; Zhang, Yanhang

    2016-08-16

    Considering the organization and engagement behavior of different extracellular matrix (ECM) constituents in the medial and adventitial layer of the arterial wall, in this study, we proposed a new constitutive model of ECM mechanics that considers the distinct structural and mechanical contributions of medial elastin, medial collagen, and adventitial collagen, to incorporate the constituent-specific fiber orientation and the sequential fiber engagement in arterial mechanics. Planar biaxial tensile testing method was used to characterize the orthotropic and hyperelastic behavior of porcine thoracic aorta. Fiber distribution functions of medial elastin, medial collagen, and adventitial collagen were incorporated into the constitutive model. Considering the sequential engagement of ECM constituents in arterial mechanics, a recruitment density function was incorporated into the model to capture the delayed engagement of adventitial collagen. A freely jointed chain model was used to capture the mechanical behavior of elastin and collagen at the fiber level. The tissue-level ECM mechanics was obtained by incorporating fiber distribution, engagement, and elastin and collagen content. The multi-scale constitutive model considering the structural and mechanical contributions of the three major ECM constituents allows us to directly incorporate information obtained from quantitative multi-photon imaging and analysis, and biochemical assay for the prediction of tissue-level mechanical response. Moreover, the model shows promises in fitting and predicting with a small set of material parameters, which has physical meanings and can be related to the structure of the ECM.

  3. Measurement of the strange quark contribution to the vector structure of the proton

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Sarah

    2007-11-30

    The goal of the G0 experiment is to determine the contribution of the strange quarks in the quark-antiquark sea to the structure of the nucleon. To this end, the experiment measured parityviolating asymmetries from elastic electron-proton scattering from 0.12 ≤ Q2 ≤ 1.0 (GeV/c)2 at Thomas Jefferson National Accelerator Facility. These asymmetries come from the interference of the electromagnetic and neutral weak interactions, and are sensitive to the strange quark contributions in the proton. The results from the forward-angle measurement, the linear combination of the strange electric and magnetic form factors GsE +ηGsM, suggest possible non-zero, Q2 dependent, strange quark contributions and provide new information to understand the magnitude of the contributions. This dissertation presents the analysis and results of the forward-angle measurement. In addition, the G0 experiment measured the beam-normal single-spin asymmetry in the elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2 = 0.15, 0.25 (GeV/c)2 as part of the forward-angle measurement. The transverse asymmetry provides a direct probe of the imaginary component of the two-photon exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments. The results of the measurement indicate that calculations using solely the elastic nucleon intermediate state are insufficient and generally agree with calculations that include significant inelastic hadronic intermediate state contributions. This dissertation presents the analysis and results of this measurement.

  4. Contribution of Quark Structure Term in Nucleon Electric and Magnetic Form Factors

    Institute of Scientific and Technical Information of China (English)

    WANGHong-Min; ZHANGBen-Ai

    2004-01-01

    The constituent quarks in the nucleon have always been considered as a point-like particle in the relativisticconstituent quark model. However its calculation results of GEn agree poorly with the new experimental data. Theelectromagnetic structure of light front constituent quarks is considered in this paper. We find that the calculationresults have good agreement with the new experimental data of GEn after considering the contribution of the quarkstructure term. This treatment seems to be able to improve the fit to experimental data of GEp/GMp,√Q2F2p/kpF1p,and GEn/GMn as well.

  5. Measurement of the open-charm contribution to the diffractive proton structure function

    CERN Document Server

    Chekanov, S; Krakauer, D A; Loizides, J H; Magill, S; Musgrave, B; Repond, J; Yoshida, R; Mattingly, M C K; Antonioli, P; Bari, G; Basile, M; Bellagamba, L; Boscherini, D; Bruni, A; Bruni, G; Cara Romeo, G; Cifarelli, Luisa; Cindolo, F; Contin, A; Corradi, M; De Pasquale, S; Giusti, P; Iacobucci, G; Margotti, A; Nania, R; Palmonari, F; Pesci, A; Sartorelli, G; Zichichi, A; Aghuzumtsyan, G; Bartsch, D; Brock, I; Goers, S; Hartmann, H; Hilger, E; Irrgang, P; Jakob, H P; Kappes, A; Katz, U F; Kind, O; Meyer, U; Paul, E; Rautenberg, J; Renner, R; Stifutkin, A; Tandler, J; Voss, K C; Wang, M; Weber, A; Bailey, D S; Brook, N H; Cole, J E; Foster, B; Heath, G P; Heath, H F; Robins, S; Rodrigues, E; Scott, J; Tapper, R J; Wing, M; Capua, M; Mastroberardino, A; Schioppa, M; Susinno, G; Kim, J Y; Kim, Y K; Lee, J H; Lim, I T; Pac, M Y; Caldwell, A; Helbich, M; Liu, X; Mellado, B; Ning, Y; Paganis, S; Ren, Z; Schmidke, W B; Sciulli, F; Chwastowski, J; Eskreys, Andrzej; Figiel, J; Olkiewicz, K; Stopa, P; Zawiejski, L; Adamczyk, L; Bold, T; Grabowska-Bold, I; Kisielewska, D; Kowal, A M; Kowal, M; Kowalski, T; Przybycien, M B; Suszycki, L; Szuba, D; Szuba, J; Kotanski, A; Slominski, W; Bauerdick, L A T; Behrens, U; Bloch, I; Borras, K; Chiochia, V; Dannheim, D; Drews, G; Fourletova, J; Fricke, U; Geiser, A; Göbel, F; Göttlicher, P; Gutsche, O; Haas, T; Hain, W; Hartner, G F; Hillert, S; Kahle, B; Kötz, U; Kowalski, H; Kram, G; Labes, H; Lelas, D; Löhr, B; Mankel, R; Melzer-Pellmann, I A; Moritz, M; Nguyen, C N; Notz, D; Petrucci, M C; Polini, A; Raval, A; Schneekloth, U; Selonke, F; Stoesslein, U; Wessoleck, H; Wolf, G; Youngman, C; Zeuner, W; Schlenstedt, S; Barbagli, G; Gallo, E; Genta, C; Pelfer, P G; Bamberger, A; Benen, A; Coppola, N; Germany, L M; Bell, M; Bussey, P J; Doyle, A T; Glasman, C; Hamilton, J; Hanlon, S; Lee, S W; Lupi, A; Saxon, D H; Skillicorn, I O; Gialas, I; Bodmann, B; Carli, T; Holm, U; Klimek, K; Krumnack, N; Lohrmann, E; Milite, M; Salehi, H; Stonjek, S; Wick, K; Ziegler, A; Collins-Tooth, C; Foudas, C; Goncalo, R; Long, K R; Tapper, A D; Cloth, P; Filges, D; Nagano, K; Tokushuku, K; Yamada, S; Yamazaki, Y; Barakbaev, A N; Boos, E G; Pokrovskiy, N S; Zhautykov, B O; Lim, H; Son, D; Barreiro, F; González, O; Labarga, L; Del Peso, J; Tassi, E; Terron, J; Vázquez, M; Barbi, M; Corriveau, F; Gliga, S; Lainesse, J; Padhi, S; Stairs, D G; Tsurugai, T; Antonov, A; Danilov, P; Dolgoshein, B A; Gladkov, D; Sosnovtsev, V V; Suchkov, S; Dementiev, R K; Ermolov, P F; Golubkov, Yu A; Katkov, I I; Khein, L A; Korzhav--, I A; Kuzmin, V A; Levchenko, B B; Lukina, O Yu; Proskuryakov, A S; Shcheglova, L M; Vlasov, N N; Zotkin, S A; Grijpink, S; Koffeman, E; Kooijman, P; Maddox, E; Pellegrino, A; Schagen, S; Tiecke, H G; Velthuis, J J; Wiggers, L; De Wolf, E; Brümmer, N; Bylsma, B; Durkin, L S; Ling, T Y; Cooper-Sarkar, A M; Cottrell, A; Devenish, R C E; Ferrando, J; Grzelak, G; Patel, S; Sutton, M R; Walczak, R; Bertolin, A; Brugnera, R; Carlin, R; Dal Corso, F; Dusini, S; Garfagnini, A; Limentani, S; Longhin, A; Parenti, A; Posocco, M; Stanco, L; Turcato, M; Heaphy, E A; Metlica, F; Oh, B Y; Whitmore, J J; Iga, Y; D'Agostini, Giulio; Marini, G; Nigro, A; Hart, J C; McCubbin, N A; Heusch, C A; Park, I H; Pavel, N; Abramowicz, H; Gabareen, A; Kananov, S; Kreisel, A; Levy, A; Kuze, M; Abe, T; Fusayasu, T; Kagawa, S; Kohno, T; Tawara, T; Yamashita, T; Hamatsu, R; Hirose, T; Inuzuka, M; Kitamura, S; Matsuzawa, K; Nishimura, T; Arneodo, M; Ferrero, M I; Monaco, V; Ruspa, M; Sacchi, R; Solano, A; Koop, T; Levman, G M; Martin, J F; Mirea, A; Butterworth, J M; Gwenlan, C; Hall-Wilton, R; Jones, T W; Lightwood, M S; West, B J; Ciborowski, J; Ciesielski, R; Nowak, R J; Pawlak, J M; Sztuk, J; Tymieniecka, T; Ukleja, A; Ukleja, J; Adamus, M; Plucinsky, P P; Eisenberg, Y; Gladilin, L K; Hochman, D; Karshon, U; Kcira, D; Lammers, S; Li, L; Reeder, D D; Savin, A A; Smith, W H; Dhawan, S; Straub, P B; Bhadra, S; Catterall, C D; Fourletov, S; Hartner, G; Menary, S R; Soares, M; Standage, J

    2003-01-01

    Production of D*+/-(2010) mesons in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb^{-1}. Diffractive events were identified by the presence of a large rapidity gap in the final state. Differential cross sections have been measured in the kinematic region 1.5 1.5 GeV and |\\eta(D*+/-)| < 1.5. The measured cross sections are compared to theoretical predictions. The results are presented in terms of the open-charm contribution to the diffractive proton structure function. The data demonstrate a strong sensitivity to the diffractive parton densities.

  6. Contribution of environmental and spatial processes to rocky intertidal metacommunity structure

    Science.gov (United States)

    Okuda, Takehiro; Noda, Takashi; Yamamoto, Tomoko; Hori, Masakazu; Nakaoka, Masahiro

    2010-07-01

    It has been debated whether the community structure of an open system is more dependent on environmental processes associated with niche explanations, or on spatial processes related to dispersal. Their relative importance may differ among taxonomic groups with properties of the community such as ecological characteristics (e.g., dispersal ability and life history) and habitat type. We examined the relative importance of environmental and spatial processes on community structure for three taxonomic groups with different ecological characteristics (macroalgae, sessile invertebrates, and mobile molluscs) in rocky intertidal shores of Sanriku Coast, Japan. To evaluate the relative contribution of the two processes in determining community structure, we conducted variation partitioning to reveal the degree of variation of community structure (i.e., β-diversity) explained by environmental heterogeneity and spatial arrangement of local communities. The results of our analyses indicated that β-diversity was significantly explained by both environmental factors (macroalgae, 29.3% of community variation: sessile animal, 40.7%: mobile molluscs, 16.7%) and spatial factors (macroalgae, 19.9%: sessile animal, 3.6%: mobile molluscs, 6.6%) in all taxonomic groups. These results imply that although some taxonomic groups live in the same ecosystem, share common resources, and interact with each other, the mechanisms determining their community structure change depending on ecological characteristics such as dispersal ability and life history.

  7. Jim Starnes' Contributions to Residual Strength Analysis Methods for Metallic Structures

    Science.gov (United States)

    Young, Richard D.; Rose, Cheryl A.; Harris, Charles E.

    2005-01-01

    A summary of advances in residual strength analyses methods for metallic structures that were realized under the leadership of Dr. James H. Starnes, Jr., is presented. The majority of research led by Dr. Starnes in this area was conducted in the 1990's under the NASA Airframe Structural Integrity Program (NASIP). Dr. Starnes, respectfully referred to herein as Jim, had a passion for studying complex response phenomena and dedicated a significant amount of research effort toward advancing damage tolerance and residual strength analysis methods for metallic structures. Jim's efforts were focused on understanding damage propagation in built-up fuselage structure with widespread fatigue damage, with the goal of ensuring safety in the aging international commercial transport fleet. Jim's major contributions in this research area were in identifying the effects of combined internal pressure and mechanical loads, and geometric nonlinearity, on the response of built-up structures with damage. Analytical and experimental technical results are presented to demonstrate the breadth and rigor of the research conducted in this technical area. Technical results presented herein are drawn exclusively from papers where Jim was a co-author.

  8. Defining excellence.

    Science.gov (United States)

    Mehl, B

    1993-05-01

    Excellence in the pharmacy profession, particularly pharmacy management, is defined. Several factors have a significant effect on the ability to reach a given level of excellence. The first is the economic and political climate in which pharmacists practice. Stricter controls, reduced resources, and the velocity of change all necessitate nurturing of values and a work ethic to maintain excellence. Excellence must be measured by the services provided with regard to the resources available; thus, the ability to achieve excellence is a true test of leadership and innovation. Excellence is also time dependent, and today's innovation becomes tomorrow's standard. Programs that raise the level of patient care, not those that aggrandize the profession, are the most important. In addition, basic services must be practiced at a level of excellence. Quality assessment is a way to improve care and bring medical treatment to a higher plane of excellence. For such assessment to be effective and not punitive, the philosophy of the program must be known, and the goal must be clear. Excellence in practice is dependent on factors such as political and social norms, standards of practice, available resources; perceptions, time, the motivation to progress to a higher level, and the continuous innovation required to reshape the profession to meet the needs of society.

  9. Tergal and pleural structures contribute to the formation of ectopic prothoracic wings in cockroaches

    Science.gov (United States)

    Elias-Neto, Moysés

    2016-01-01

    Wings were a fundamental morphological innovation for the adaptive radiation of insects, the most diversified group among all animals. Pterygote insects have two pairs of wings, the mesothoracic (T2) forewings and the metathoracic (T3) hindwings, whereas the prothorax (T1) is wingless. Using RNA interference approaches, we have found that the gene Sex combs reduced (Scr) determines the wingless identity of T1 in the cockroach Blattella germanica. Interference of Scr triggers the formation of ectopic wing structures in T1, which are formed from the expansion of the latero-posterior region of the pronotum, along with a contribution of the epimeron, a pleurite of T1. These data support the theory of a dual origin for insect wings, from pronotal (tergal origin theory) and pleural (pleural origin theory) structures and genes. PMID:27853616

  10. Contribution of double scattering to structural coloration in quasiordered nanostructures of bird feathers

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Heeso; Liew, Seng Fatt; Saranathan, Vinodkumar; Prum, Richard O.; Mochrie, Simon G.J.; Dufresne, Eric R.; Cao, Hui (Yale)

    2010-07-28

    We measured the polarization- and angle-resolved optical scattering and reflection spectra of the quasiordered nanostructures in the bird feather barbs. In addition to the primary peak that originates from single scattering, we observed a secondary peak which exhibits depolarization and distinct angular dispersion. We explained the secondary peak in terms of double scattering, i.e., light is scattered successively twice by the structure. The two sequential single-scattering events are considered uncorrelated. Using the Fourier power spectra of the nanostructures obtained from the small-angle x-ray scattering experiment, we calculated the double scattering of light in various directions. The double-scattering spectrum is broader than the single-scattering spectrum, and it splits into two subpeaks at larger scattering angle. The good agreement between the simulation results and the experimental data confirms that double scattering of light makes a significant contribution to the structural color.

  11. A Review of Ribonuclease 7’s Structure, Regulation, and Contributions to Host Defense

    Directory of Open Access Journals (Sweden)

    Brian Becknell

    2016-03-01

    Full Text Available The Ribonuclease A Superfamily is composed of a group of structurally similar peptides that are secreted by immune cells and epithelial tissues. Several members of the Ribonuclease A Superfamily demonstrate antimicrobial activity, and it has been suggested that some of these ribonucleases play an essential role in host defense. Ribonuclease 7 (RNase 7 is an epithelial-derived secreted peptide with potent broad-spectrum antimicrobial activity. This review summarizes the published literature on RNase 7’s antimicrobial properties, structure, regulation, and contributions to host defense. In doing so, we conclude by highlighting key knowledge gaps that must be investigated to completely understand the potential of developing RNase 7 as a novel therapeutic for human infectious diseases.

  12. Geometric and electronic structure contributions to function in non-heme iron enzymes.

    Science.gov (United States)

    Solomon, Edward I; Light, Kenneth M; Liu, Lei V; Srnec, Martin; Wong, Shaun D

    2013-11-19

    Mononuclear non-heme Fe (NHFe) enzymes play key roles in DNA repair, the biosynthesis of antibiotics, the response to hypoxia, cancer therapy, and many other biological processes. These enzymes catalyze a diverse range of oxidation reactions, including hydroxylation, halogenation, ring closure, desaturation, and electrophilic aromatic substitution (EAS). Most of these enzymes use an Fe(II) site to activate dioxygen, but traditional spectroscopic methods have not allowed researchers to insightfully probe these ferrous active sites. We have developed a methodology that provides detailed geometric and electronic structure insights into these NHFe(II) active sites. Using these data, we have defined a general mechanistic strategy that many of these enzymes use: they control O2 activation (and limit autoxidation and self-hydroxylation) by allowing Fe(II) coordination unsaturation only in the presence of cosubstrates. Depending on the type of enzyme, O2 activation either involves a 2e(-) reduced Fe(III)-OOH intermediate or a 4e(-) reduced Fe(IV)═O intermediate. Nuclear resonance vibrational spectroscopy (NRVS) has provided the geometric structure of these intermediates, and magnetic circular dichroism (MCD) has defined the frontier molecular orbitals (FMOs), the electronic structure that controls reactivity. This Account emphasizes that experimental spectroscopy is critical in evaluating the results of electronic structure calculations. Therefore these data are a key mechanistic bridge between structure and reactivity. For the Fe(III)-OOH intermediates, the anticancer drug activated bleomycin (BLM) acts as the non-heme Fe analog of compound 0 in heme (e.g., P450) chemistry. However BLM shows different reactivity: the low-spin (LS) Fe(III)-OOH can directly abstract a H atom from DNA. The LS and high-spin (HS) Fe(III)-OOHs have fundamentally different transition states. The LS transition state goes through a hydroxyl radical, but the HS transition state is activated for

  13. The contribution of reinforcement sensitivity to the personality-psychopathology hierarchical structure in childhood and adolescence.

    Science.gov (United States)

    Slobodskaya, Helena R

    2016-11-01

    This study examined the contribution of reinforcement sensitivity to the hierarchical structure of child personality and common psychopathology in community samples of parent reports of children aged 2-18 (N = 968) and self-reports of adolescents aged 10-18 (N = 1,543) using the Inventory of Child Individual Differences-Short version (ICID-S), the Strengths and Difficulties Questionnaire (SDQ), and the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ). A joint higher-order factor analysis of the ICID-S and SDQ scales suggested a 4-factor solution; congruence coefficients indicated replicability of the factors across the 2 samples at all levels of the personality-psychopathology hierarchy. The canonical correlation analyses indicated that reinforcement sensitivity and personality-psychopathology dimensions shared much of their variance. The main contribution of reinforcement sensitivity was through opposing effects of reward and punishment sensitivities. The superordinate factors Beta and Internalizing were best predicted by reinforcement sensitivity, followed by the Externalizing and Positive personality factors. These findings provide evidence for consistency of the hierarchical structure of personality and common psychopathology across informants and highlight the role of reinforcement systems in the development of normal and abnormal patterns of behavior and affect. (PsycINFO Database Record

  14. SiC-like structures in edge-defined film-fed growth poly-silicon ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Pivac, B.; Borghesi, A.; Moscardini, M. (Pavia Univ. (Italy). Ist. di Fisica); Bottazzi, P. (CNR, Pavia (IT). Centro di Studio per la Cristallografia Strutturale); Desnica, U.V. (Institut Rudjer Boskovic, Zagreb (Yugoslavia))

    1990-04-01

    A brief article describes a study which shows that during the growth of edge-defined film fed growth (EFG) poly-silicon ribbons under highly asymmetrical conditions and in an atmosphere with carbon dioxide gas added, oxygen is diffused into the growing ribbon. Oxygen atoms further stimulated creation of carbon and silicon self-interstitial aggregates which in turn acted as precursors for SiC phase formation. These clusters of carbon and silicon self-interstitials are not as stable as a SiC phase and therefore can be annealed during a low-temperature thermal treatment. (UK).

  15. Structural and thermodynamic study on aldose reductase: nitro-substituted inhibitors with strong enthalpic binding contribution.

    Science.gov (United States)

    Steuber, Holger; Heine, Andreas; Klebe, Gerhard

    2007-05-04

    strongly favourable contribution to binding enthalpy in case the inhibitor is equipped with a nitro group at the corresponding position. To further investigate this phenomenon, we determined crystal structures and thermodynamic data of two similarly constituted IDD-type inhibitors addressing the specificity pocket with either a nitro or halogen-substituted aromatic moiety. As these data suggest, the nitro group provokes the enthalpic contribution, in addition to the H-bond mentioned above, by accepting two "non-classical" H-bonds donated by the aromatic tyrosine side-chain. In summary, this study provides the platform for further structure-guided design hypotheses of novel drug candidates with higher affinity and selectivity.

  16. Impaired Neural Structure and Function Contributing to Autonomic Symptoms in Congenital Central Hypoventilation Syndrome

    Directory of Open Access Journals (Sweden)

    Ronald M Harper

    2015-10-01

    Full Text Available Congenital central hypoventilation syndrome (CCHS patients show major autonomic alterations in addition to their better-known breathing deficiencies. The processes underlying CCHS, mutations in the PHOX2B gene, target autonomic neuronal development, with frame shift extent contributing to symptom severity. Many autonomic characteristics, such as impaired pupillary constriction and poor temperature regulation, reflect parasympathetic alterations, and can include disturbed alimentary processes, with malabsorption and intestinal motility dyscontrol. The sympathetic nervous system changes can exert life-threatening outcomes, with dysregulation of sympathetic outflow leading to high blood pressure, time-altered and dampened heart rate and breathing responses to challenges, cardiac arrhythmia, profuse sweating, and poor fluid regulation. The central mechanisms contributing to failed autonomic processes are readily apparent from structural and functional magnetic resonance imaging studies, which reveal substantial cortical thinning, tissue injury, and disrupted functional responses in hypothalamic, hippocampal, posterior thalamic, and basal ganglia sites and their descending projections, as well as insular, cingulate, and medial frontal cortices, which influence subcortical autonomic structures. Midbrain structures are also compromised, including the raphe system and its projections to cerebellar and medullary sites, the locus coeruleus, and medullary reflex integrating sites, including the dorsal and ventrolateral medullary nuclei. The damage to rostral autonomic sites overlaps metabolic, affective and cognitive regulatory regions, leading to hormonal disruption, anxiety, depression, behavioral control, and sudden death concerns. The injuries suggest that interventions for mitigating hypoxic exposure and nutrient loss may provide cellular protection, in the same fashion as interventions in other conditions with similar malabsorption, fluid turnover

  17. Defining Geopoetics

    Directory of Open Access Journals (Sweden)

    Federico Italiano

    2008-07-01

    Full Text Available Comme la notion de "Paysage", portion du monde coïncidant avec l’« Anschauungsraum » du sujet (l’« espace de l’intuition » phénoménologique, ne peut plus être appliquée de manière adéquate aux textes littéraires dotés d’une structure topologique complexe et de références géographiques hétérogènes, nous proposons d’introduire le concept de « Géopoétique ». En tant que catégorie opérative, la « Géopoétique » nous permet de comprendre et d’analyser la dimension territoriale, géographique et géo-écologique d’un texte littéraire. Par « Géopoétique », nous désignons la conscience géographique particulière, la connaissance territoriale, qui est une individualisation du rapport Homme-Terre, telle qu’elle ressort des textes littéraires, et qui transcende tous les cadres limitatifs de la perception, surpassant les frontières phénoménologiques de l’« Anschauungsraum ».The notion of “Landscape” —a represented portion of the world that coincides with the subject’s “Anschauungsraum” (the phenomenological “space of intuition” — cannot always be adequately applied to literary texts with a complex topological structure and heterogeneous geographical references. We therefore propose to introduce the concept of Geopoetics. As an operative category, ‘Geopoetics’ enables us to comprehend and to analyse the territorial, geographical and geo-ecological dimension of a literary text. By ‘Geopoetics’, we mean a particularly geographical consciousness, a territorial knowledge, which is an individualization of the nexus Man-Earth, as it emerges from a literary text, and which transcends every limiting frame of perception, surpassing the phenomenological borders of the “Anschauungsraum.”

  18. Cytotoxicity and photocytotoxicity of structure-defined water-soluble C{sub 60}/micelle supramolecular nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Metanawin, Tanapak; Tang Tian; Chen Rongjun; Wang Xiaosong [School of Chemistry, University of Leeds, LS2 9TJ (United Kingdom); Vernon, David, E-mail: X.S.Wang@leeds.ac.uk [School of Biological Sciences, University of Leeds, LS2 9TJ (United Kingdom)

    2011-06-10

    Well-defined, water-soluble C{sub 60}/micelle hierarchical colloids with varied amounts of C{sub 60} sitting on the surface of micellar cores were prepared via the self-assembly of PS-b-PDMA block copolymer micelles and C{sub 60}. The composites can generate a significant amount of reactive oxygen upon irradiation with red light. Cell studies showed that the colloids were either strongly associated with, or internalized by, the cells after 2 h incubation, but did not show obvious toxicity in the dark. In contrast, efficient cell killing was observed when the colloid-incubated cells were exposed to red light. This indicates that the supramolecular colloids are promising as photosensitizers for photodynamic cancer therapy.

  19. Structure of Staphylococcal Enterotoxin E in Complex with TCR Defines the Role of TCR Loop Positioning in Superantigen Recognition.

    Directory of Open Access Journals (Sweden)

    Karin E J Rödström

    Full Text Available T cells are crucial players in cell-mediated immunity. The specificity of their receptor, the T cell receptor (TCR, is central for the immune system to distinguish foreign from host antigens. Superantigens are bacterial toxins capable of inducing a toxic immune response by cross-linking the TCR and the major histocompatibility complex (MHC class II and circumventing the antigen specificity. Here, we present the structure of staphylococcal enterotoxin E (SEE in complex with a human T cell receptor, as well as the unligated T cell receptor structure. There are clear structural changes in the TCR loops upon superantigen binding. In particular, the HV4 loop moves to circumvent steric clashes upon complex formation. In addition, a predicted ternary model of SEE in complex with both TCR and MHC class II displays intermolecular contacts between the TCR α-chain and the MHC, suggesting that the TCR α-chain is of importance for complex formation.

  20. The Crystal Structure of Bacteriophage HK97 gp6: Defining a Large Family of Head-Tail Connector Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Cardarelli, Lia; Lam, Robert; Tuite, Ashleigh; Baker, Lindsay A; Sadowski, Paul D; Radford, Devon R; Rubinstein, John L; Battaile, Kevin P; Chirgadze, Nickolay; Maxwell, Karen L; Davidson, Alan R [UHN; (Toronto); (HWMRI)

    2011-11-23

    The final step in the morphogenesis of long-tailed double-stranded DNA bacteriophages is the joining of the DNA-filled head to the tail. The connector is a specialized structure of the head that serves as the interface for tail attachment and the point of egress for DNA from the head during infection. Here, we report the determination of a 2.1 Å crystal structure of gp6 of bacteriophage HK97. Through structural comparisons, functional studies, and bioinformatic analysis, gp6 has been determined to be a component of the connector of phage HK97 that is evolutionarily related to gp15, a well-characterized connector component of bacteriophage SPP1. Whereas the structure of gp15 was solved in a monomeric form, gp6 crystallized as an oligomeric ring with the dimensions expected for a connector protein. Although this ring is composed of 13 subunits, which does not match the symmetry of the connector within the phage, sequence conservation and modeling of this structure into the cryo-electron microscopy density of the SPP1 connector indicate that this oligomeric structure represents the arrangement of gp6 subunits within the mature phage particle. Through sequence searches and genomic position analysis, we determined that gp6 is a member of a large family of connector proteins that are present in long-tailed phages. We have also identified gp7 of HK97 as a homologue of gp16 of phage SPP1, which is the second component of the connector of this phage. These proteins are members of another large protein family involved in connector assembly.

  1. Networks of High Mutual Information Define the Structural Proximity of Catalytic Sites: Implications for Catalytic Residue Identification

    DEFF Research Database (Denmark)

    Buslje, Cristina Marino; Teppa, Elin; Di Doménico, Tomas

    2010-01-01

    to significantly outperform both the Shannon entropy and maximal frequency measurements. Residues in the proximity of catalytic sites were shown to be rich in shared MI. A structural proximity MI average score (termed pMI) was demonstrated to be a strong predictor for CR, thus confirming the proposed hypothesis....... A structural proximity conservation average score (termed pC) was also calculated and demonstrated to carry distinct information from pMI. A catalytic likeliness score (Cls), combining the KL, pC and pMI measures, was shown to lead to significantly improved prediction accuracy. At a specificity of 0...

  2. Analysis of the structure factor of dense krypton gas: Bridge contributions and many-body effects

    Science.gov (United States)

    Aers, G. C.; Dharma-Wardana, M. W. C.

    1984-05-01

    The pair-correlation function g(r) of the Kr-type model fluid with only pair interactions was calculated using the Rosenfeld-Ashcroft modification of the hypernetted-chain (HNC) equation which includes bridge diagrams, and gave results in excellent agreement with Monte Carlo g(r) data. These bridge functions and the known pair potential were used to analyze the neutron-diffraction structure-factor data of Teitsma and Egelstaff, to determine the effective strength of the three-body potential as a function of the density assuming it to be of the Axilrod-Teller (AT) form. The strength of the effective three-body contribution s=ννtheor, where νtheor is the theoretical value, decreases for higher densities, suggesting that the many-body terms (beyond the Axilrod-Teller form) screen the AT interaction as the density increases. The results are very sensitive to the uncertainties in the structure factor S(k) for small k if parameter optimization is used to determine the effective pair potential. However, prediction of the compressibility using s=1 allows us to conclude that νtheor is consistent with the experimental data for low densities, to within the uncertainties in the presently available pair potentials and in the structure-factor data.

  3. Structure of branching enzyme- and amylomaltase modified starch produced from well-defined amylose to amylopectin substrates

    DEFF Research Database (Denmark)

    Sorndecha, Waraporn; Sagnelli, Domenico; Meier, Sebastian

    2016-01-01

    Thermostable branching enzyme (BE, EC 2.4.1.18) from Rhodothermus obamensis in combination with amylomaltase (AM, EC 2.4.1.25) from Thermus thermophilus was used to modify starch structure exploring potentials to extensively increase the number of branch points in starch. Amylose is an important...

  4. Pauling and Corey's alpha-pleated sheet structure may define the prefibrillar amyloidogenic intermediate in amyloid disease.

    Science.gov (United States)

    Armen, Roger S; DeMarco, Mari L; Alonso, Darwin O V; Daggett, Valerie

    2004-08-10

    Transthyretin, beta(2)-microglobulin, lysozyme, and the prion protein are four of the best-characterized proteins implicated in amyloid disease. Upon partial acid denaturation, these proteins undergo conformational change into an amyloidogenic intermediate that can self-assemble into amyloid fibrils. Many experiments have shown that pH-mediated changes in structure are required for the formation of the amyloidogeneic intermediate, but it has proved impossible to characterize these conformational changes at high resolution using experimental means. To probe these conformational changes at atomic resolution, we have performed molecular dynamics simulations of these proteins at neutral and low pH. In low-pH simulations of all four proteins, we observe the formation of alpha-pleated sheet secondary structure, which was first proposed by L. Pauling and R. B. Corey [(1951) Proc. Natl. Acad. Sci. USA 37, 251-256]. In all beta-sheet proteins, transthyretin and beta(2)-microglobulin, alpha-pleated sheet structure formed over the strands that are highly protected in hydrogen-exchange experiments probing amyloidogenic conditions. In lysozyme and the prion protein, alpha-sheets formed in the specific regions of the protein implicated in the amyloidogenic conversion. We propose that the formation of alpha-pleated sheet structure may be a common conformational transition in amyloidosis.

  5. Defining the structure of the general stress regulon of Bacillus subtilis using targeted microarray analysis and random forest classification.

    NARCIS (Netherlands)

    Nannapaneni, P.; Hertwig, F.; Depke, M.; Hecker, M.; Mader, U.; Volker, U.; Steil, L.; Hijum, S.A.F.T. van

    2012-01-01

    The structure of the SigB-dependent general stress regulon of Bacillus subtilis has previously been characterized by proteomics approaches as well as DNA array-based expression studies. However, comparing the SigB targets published in three previous major transcriptional profiling studies it is obvi

  6. Structural equation modeling of factors contributing to quality of life in Japanese patients with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Kikuchi Hiromi

    2013-01-01

    Full Text Available Abstract Background To improve quality of life (QOL in patients with multiple sclerosis (MS, it is important to decrease disability and prevent relapse. The aim of this study was to examine the causal and mutual relationships contributing to QOL in Japanese patients with MS, develop path diagrams, and explore interventions with the potential to improve patient QOL. Methods Data of 163 Japanese MS patients were obtained using the Functional Assessment of MS (FAMS and Nottingham Adjustment Scale-Japanese version (NAS-J tests, as well as four additional factors that affect QOL (employment status, change of income, availability of disease information, and communication with medical staff. Data were then used in structural equation modeling to develop path diagrams for factors contributing to QOL. Results The Expanded Disability Status Scale (EDSS score had a significant effect on the total FAMS score. Although EDSS negatively affected the FAMS symptom score, NAS-J subscale scores of anxiety/depression and acceptance were positively related to the FAMS symptom score. Changes in employment status after MS onset negatively affected all NAS-J scores. Knowledge of disease information improved the total NAS-J score, which in turn improved many FAMS subscale scores. Communication with doctors and nurses directly and positively affected some FAMS subscale scores. Conclusions Disability and change in employment status decrease patient QOL. However, the present findings suggest that other factors, such as acquiring information on MS and communicating with medical staff, can compensate for the worsening of QOL.

  7. Structural equation modeling of factors contributing to quality of life in Japanese patients with multiple sclerosis.

    Science.gov (United States)

    Kikuchi, Hiromi; Mifune, Nobuhiro; Niino, Masaaki; Kira, Jun-Ichi; Kohriyama, Tatsuo; Ota, Kohei; Tanaka, Masami; Ochi, Hirofumi; Nakane, Shunya; Kikuchi, Seiji

    2013-01-22

    To improve quality of life (QOL) in patients with multiple sclerosis (MS), it is important to decrease disability and prevent relapse. The aim of this study was to examine the causal and mutual relationships contributing to QOL in Japanese patients with MS, develop path diagrams, and explore interventions with the potential to improve patient QOL. Data of 163 Japanese MS patients were obtained using the Functional Assessment of MS (FAMS) and Nottingham Adjustment Scale-Japanese version (NAS-J) tests, as well as four additional factors that affect QOL (employment status, change of income, availability of disease information, and communication with medical staff). Data were then used in structural equation modeling to develop path diagrams for factors contributing to QOL. The Expanded Disability Status Scale (EDSS) score had a significant effect on the total FAMS score. Although EDSS negatively affected the FAMS symptom score, NAS-J subscale scores of anxiety/depression and acceptance were positively related to the FAMS symptom score. Changes in employment status after MS onset negatively affected all NAS-J scores. Knowledge of disease information improved the total NAS-J score, which in turn improved many FAMS subscale scores. Communication with doctors and nurses directly and positively affected some FAMS subscale scores. Disability and change in employment status decrease patient QOL. However, the present findings suggest that other factors, such as acquiring information on MS and communicating with medical staff, can compensate for the worsening of QOL.

  8. Structural equation modeling of factors contributing to quality of life in Japanese patients with multiple sclerosis

    Science.gov (United States)

    2013-01-01

    Background To improve quality of life (QOL) in patients with multiple sclerosis (MS), it is important to decrease disability and prevent relapse. The aim of this study was to examine the causal and mutual relationships contributing to QOL in Japanese patients with MS, develop path diagrams, and explore interventions with the potential to improve patient QOL. Methods Data of 163 Japanese MS patients were obtained using the Functional Assessment of MS (FAMS) and Nottingham Adjustment Scale-Japanese version (NAS-J) tests, as well as four additional factors that affect QOL (employment status, change of income, availability of disease information, and communication with medical staff). Data were then used in structural equation modeling to develop path diagrams for factors contributing to QOL. Results The Expanded Disability Status Scale (EDSS) score had a significant effect on the total FAMS score. Although EDSS negatively affected the FAMS symptom score, NAS-J subscale scores of anxiety/depression and acceptance were positively related to the FAMS symptom score. Changes in employment status after MS onset negatively affected all NAS-J scores. Knowledge of disease information improved the total NAS-J score, which in turn improved many FAMS subscale scores. Communication with doctors and nurses directly and positively affected some FAMS subscale scores. Conclusions Disability and change in employment status decrease patient QOL. However, the present findings suggest that other factors, such as acquiring information on MS and communicating with medical staff, can compensate for the worsening of QOL. PMID:23339479

  9. Structure-Function Analysis of 2-Keto-3-Deoxy-D-Glycero-D-Galacto-Nononate-9-Phosphate Phosphatase Defines Specificity Elements in Type C0 had Family Members

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Z.; Wang, L; Dunaway-Mariano, D; Allen, K

    2009-01-01

    The phosphotransferases of the haloalkanoate dehalogenase superfamily (HADSF) act upon a wide range of metabolites in all eukaryotes and prokaryotes and thus constitute a significant force in cell function. The challenge posed for biochemical function assignment of HADSF members is the identification of the structural determinants that target a specific metabolite. The '8KDOP' subfamily of the HADSF is defined by the known structure and catalytic activity of 2-keto-3-deoxy-8-phospho-d-manno-octulosonic acid (KDO-8-P) phosphatase. Homologues of this enzyme have been uniformly annotated as KDO-8-P phosphatase. One such gene, BT1713, from the Bacteroides thetaiotaomicron genome was recently found to encode the enzyme 2-keto-3-deoxy-d-glycero-d-galacto-9-phosphonononic acid (KDN-9-P) phosphatase in the biosynthetic pathway of the 9-carbon ?-keto acid, 2-keto-3-deoxy-d-glycero-d-galactonononic acid (KDN). To find the structural elements that provide substrate-specific interactions and to allow identification of genomic sequence markers, the x-ray crystal structures of BT1713 liganded to the cofactor Mg2+and complexed with tungstate or Formula/Neu5Ac were determined to 1.1, 1.85, and 1.63 A resolution, respectively. The structures define the active site to be at the subunit interface and, as confirmed by steady-state kinetics and site-directed mutagenesis, reveal Arg-64*, Lys-67*, and Glu-56 to be the key residues involved in sugar binding that are essential for BT1713 catalytic function. Bioinformatic analyses of the differentially conserved residues between BT1713 and KDO-8-P phosphatase homologues guided by the knowledge of the structure-based specificity determinants define Glu-56 and Lys-67* to be the key residues that can be used in future annotations.

  10. Intensity inhomogeneity correction of structural MR images: a data-driven approach to define input algorithm parameters

    OpenAIRE

    Marco eGanzetti; Nicole eWenderoth; Dante eMantini

    2016-01-01

    Intensity non-uniformity (INU) in magnetic resonance (MR) imaging is a major issue when conducting analyses of brain structural properties. An inaccurate INU correction may result in qualitative and quantitative misinterpretations. Several INU correction methods exist, whose performance largely depend on the specific parameter settings that need to be chosen by the user. Here we addressed the question of how to select the best input parameters for a specific INU correction algorithm. Our inve...

  11. Developing a Structural Model to Define Influential Risk Elements in Islamic Banking: An Empirical Study in Iran

    OpenAIRE

    Akbar Alem Tabriz; Fariba Riahi; Zahra Banasadegh

    2015-01-01

    The aim of this study is to identify the most influential risk elements and determine causal relationships network of risk factors in Islamic banking in Iran. Due to some unique principles used by Islamic banks, they encounter difficulties to manage various risks effectively than conventional banks. Consequently, a structural model was developed from a comprehensive set of risk elements with five reflective and one formative output construct namely; credit, liquidity, market, operational, uni...

  12. Surface Structure Dependence of SO 2 Interaction with Ceria Nanocrystals with Well-Defined Surface Facets

    Energy Technology Data Exchange (ETDEWEB)

    Tumuluri, Uma; Li, Meijun; Cook, Brandon G.; Sumpter, Bobby; Dai, Sheng; Wu, Zili

    2015-12-31

    The effects of the surface structure of ceria (CeO2) on the nature, strength, and amount of species resulting from SO2 adsorption were studied using in situ IR and Raman spectroscopies coupled with mass spectrometry, along with first-principles calculations based on density functional theory (DFT). CeO2 nanocrystals with different morphologies, namely, rods (representing a defective structure), cubes (100 facet), and octahedra (111 facet), were used to represent different CeO2 surface structures. IR and Raman spectroscopic studies showed that the structure and binding strength of adsorbed species from SO2 depend on the shape of the CeO2 nanocrystals. SO2 adsorbs mainly as surface sulfites and sulfates at room temperature on CeO2 rods, cubes, and octahedra that were either oxidatively or reductively pretreated. The formation of sulfites is more evident on CeO2 octahedra, whereas surface sulfates are more prominent on CeO2 rods and cubes. This is explained by the increasing reducibility of the surface oxygen in the order octahedra < cubes < rods. Bulk sulfites are also formed during SO2 adsorption on reduced CeO2 rods. The formation of surface sulfites and sulfates on CeO2 cubes is in good agreement with our DFT results of SO2 interactions with the CeO2(100) surface. CeO2 rods desorb SO2 at higher temperatures than cubes and octahedra nanocrystals, but bulk sulfates are formed on CeO2 rods and cubes after high-temperature desorption whereas only some surface sulfates/sulfites are left on octahedra. This difference is rationalized by the fact that CeO2 rods have the highest surface basicity and largest amount of defects among the three nanocrystals, so they bind and react with SO2 strongly and are the most degraded after SO2 adsorption cycles. The fundamental understanding obtained in this work on the effects of the surface structure and defects on the interaction of SO2 with CeO2 provides insights for the design of more sulfur-resistant CeO2-based catalysts.

  13. Radioactive labeling of defined HPMA-based polymeric structures using [18F]FETos for in vivo imaging by positron emission tomography

    DEFF Research Database (Denmark)

    Herth, Matthias Manfred; Barz, Matthias; Moderegger, Dorothea

    2009-01-01

    During the last decades polymer-based nanomedicine has turned out to be a promising tool in modern pharmaceutics. The following article describes the synthesis of well-defined random and block copolymers by RAFT polymerization with potential medical application. The polymers have been labeled...... with the positron-emitting nuclide fluorine-18. The polymeric structures are based on the biocompatible N-(2-hydroxypropyl)-methacrylamide (HPMA). To achieve these structures, functional reactive ester polymers with a molecular weight within the range of 25,000-110,000 g/mol were aminolyzed by 2-hydroxypropylamine...

  14. Una propuesta de reforma del sistema de pensiones español basada en un modelo de contribución definida nocional || A Proposal for Reforming the Spanish Pension System Based on a Notional Defined Contribution Model

    Directory of Open Access Journals (Sweden)

    García, Jaime

    2011-06-01

    pension fund reached by applying a notional defined contribution model (NDC; and thirdly, an occupational system based on an auto-enrollment system, which we have called the National Saving System (NSS. Projections have been done up to the year 2039 with conclusive results with regard to retirement pensions (indicating the suitability of the model as well as the GDP relative cost (indicating viability. We analyze how the Spanish Social Security system is an unbalanced one. Our work reveals its lack of sustainability in financial terms, both in the medium and long term. We demonstrate how the new model we are proposing is financially sustainable, and along with a transition period in which the current resources from the Reserve Fund would be used, it would be suitable for the needs of the population.

  15. Towards large-cohort comparative studies to define the factors influencing the gut microbial community structure of ASD patients

    Directory of Open Access Journals (Sweden)

    Daniel McDonald

    2015-03-01

    Full Text Available Differences in the gut microbiota have been reported between individuals with autism spectrum disorders (ASD and neurotypical controls, although direct evidence that changes in the microbiome contribute to causing ASD has been scarce to date. Here we summarize some considerations of experimental design that can help untangle causality in this complex system. In particular, large cross-sectional studies that can factor out important variables such as diet, prospective longitudinal studies that remove some of the influence of interpersonal variation in the microbiome (which is generally high, especially in children, and studies transferring microbial communities into germ-free mice may be especially useful. Controlling for the effects of technical variables, which have complicated efforts to combine existing studies, is critical when biological effect sizes are small. Large citizen-science studies with thousands of participants such as the American Gut Project have been effective at uncovering subtle microbiome effects in self-collected samples and with self-reported diet and behavior data, and may provide a useful complement to other types of traditionally funded and conducted studies in the case of ASD, especially in the hypothesis generation phase.

  16. The actin family protein ARP6 contributes to the structure and the function of the nucleolus

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Hiroshi [Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi 1-1, Aoka-ku, Sendai 981-8555 (Japan); Matsumori, Haruka [Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan); Kalendova, Alzbeta; Hozak, Pavel [Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic, v.v.i., Vídeňská 1083, 142 20 Prague (Czech Republic); Goldberg, Ilya G. [Image Informatics and Computational Biology Unit, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 21224 (United States); Nakao, Mitsuyoshi [Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan); Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Tokyo 102-0076 (Japan); Saitoh, Noriko [Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811 (Japan); Harata, Masahiko, E-mail: mharata@biochem.tohoku.ac.jp [Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi 1-1, Aoka-ku, Sendai 981-8555 (Japan)

    2015-08-21

    The actin family members, consisting of actin and actin-related proteins (ARPs), are essential components of chromatin remodeling complexes. ARP6, one of the nuclear ARPs, is part of the Snf-2-related CREB-binding protein activator protein (SRCAP) chromatin remodeling complex, which promotes the deposition of the histone variant H2A.Z into the chromatin. In this study, we showed that ARP6 influences the structure and the function of the nucleolus. ARP6 is localized in the central region of the nucleolus, and its knockdown induced a morphological change in the nucleolus. We also found that in the presence of high concentrations of glucose ARP6 contributed to the maintenance of active ribosomal DNA (rDNA) transcription by placing H2A.Z into the chromatin. In contrast, under starvation, ARP6 was required for cell survival through the repression of rDNA transcription independently of H2A.Z. These findings reveal novel pleiotropic roles for the actin family in nuclear organization and metabolic homeostasis. - Highlights: • ARP6, an actin related protein, is important for nucleolar function and structure. • A population of ARP6 is localized in the center of nucleolus. • Depletion of ARP6 resulted in aberrant shape of the nucleolus. • ARP6 maintains the active rDNA transcription under high glucose. • ARP6 is required for the repression of rDNA transcription under starvation.

  17. Tinnitus Neural Mechanisms and Structural Changes in the Brain: The Contribution of Neuroimaging Research

    Directory of Open Access Journals (Sweden)

    Simonetti, Patricia

    2015-03-01

    Full Text Available Introduction Tinnitus is an abnormal perception of sound in the absence of an external stimulus. Chronic tinnitus usually has a high impact in many aspects of patients' lives, such as emotional stress, sleep disturbance, concentration difficulties, and so on. These strong reactions are usually attributed to central nervous system involvement. Neuroimaging has revealed the implication of brain structures in the auditory system. Objective This systematic review points out neuroimaging studies that contribute to identifying the structures involved in the pathophysiological mechanism of generation and persistence of various forms of tinnitus. Data Synthesis Functional imaging research reveals that tinnitus perception is associated with the involvement of the nonauditory brain areas, including the front parietal area; the limbic system, which consists of the anterior cingulate cortex, anterior insula, and amygdala; and the hippocampal and parahippocampal area. Conclusion The neuroimaging research confirms the involvement of the mechanisms of memory and cognition in the persistence of perception, anxiety, distress, and suffering associated with tinnitus.

  18. Substituent effect on the thermodynamic solubility of structural analogs: relative contribution of crystal packing and hydration.

    Science.gov (United States)

    Ozaki, Shunsuke; Nakagawa, Yoshiaki; Shirai, Osamu; Kano, Kenji

    2014-11-01

    Thermodynamic analysis of the solubility of benzoylphenylurea (BPU) derivatives was conducted to investigate the relative importance of crystal packing and hydration for improving solubility with minor structural modification. The contribution of crystal packing to solubility was evaluated from the change in Gibbs energy on the transition from the crystalline to liquid state. Hydration Gibbs energy was estimated using a linear free-energy relationship between octanol-water partition coefficients and gas-water partition coefficients. The established solubility model satisfactorily explained the relative thermodynamic solubility of the model compounds and revealed that crystal packing and hydration equally controlled solubility of the structural analogs. All hydrophobic substituents were undesirable for solubility in terms of hydration, as expected. On the other hand, some of these hydrophobic substituents destabilized crystal packing and improved the solubility of the BPU derivatives when their impact on crystal packing exceeded their negative influence on hydration. The replacement of a single substituent could cause more than a 10-fold enhancement in thermodynamic solubility; this degree of improvement was comparable to that generally achieved by amorphous formulations. Detailed analysis of thermodynamic solubility will allow us to better understand the true substituent effect and design drug-like candidates efficiently.

  19. A summary of recent NASA/Army contributions to rotorcraft vibrations and structural dynamics technology

    Science.gov (United States)

    Kvaternik, Raymond G.; Bartlett, Felton D., Jr.; Cline, John H.

    1988-01-01

    The requirement for low vibrations has achieved the status of a critical design consideration in modern helicopters. There is now a recognized need to account for vibrations during both the analytical and experimental phases of design. Research activities in this area were both broad and varied and notable advances were made in recent years in the critical elements of the technology base needed to achieve the goal of a jet smooth ride. The purpose is to present an overview of accomplishments and current activities of govern and government-sponsored research in the area of rotorcraft vibrations and structural dynamics, focusing on NASA and Army contributions over the last decade or so. Specific topics addressed include: airframe finite-element modeling for static and dynamic analyses, analysis of coupled rotor-airframe vibrations, optimization of airframes subject to vibration constraints, active and passive control of vibrations in both the rotating and fixed systems, and integration of testing and analysis in such guises as modal analysis, system identification, structural modification, and vibratory loads measurement.

  20. Silicon-on-glass pore network micromodels with oxygen-sensing fluorophore films for chemical imaging and defined spatial structure

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Kelly, Ryan T.; Suter, Jonathan D.; Anheier, Norman C.

    2012-11-21

    Pore network microfluidic models were fabricated by a silicon-on-glass technique that provides the precision advantage of dry etched silicon while creating a structure that is transparent across all microfluidic channels and pores, and can be imaged from either side. A silicon layer is bonded to an underlying borosilicate glass substrate and thinned to the desired height of the microfluidic channels and pores. The silicon is then patterned and through-etched by deep reactive ion etching (DRIE), with the underlying glass serving as an etch stop. After bonding on a transparent glass cover plate, one obtains a micromodel in oxygen impermeable materials with water wet surfaces where the microfluidic channels are transparent and structural elements such as the pillars creating the pore network are opaque. The micromodel can be imaged from either side. The advantageous features of this approach in a chemical imaging application are demonstrated by incorporating a Pt porphyrin fluorophore in a PDMS film serving as the oxygen sensing layer and a bonding surface, or in a polystyrene film coated with a PDMS layer for bonding. The sensing of a dissolved oxygen gradient was demonstrated using fluorescence lifetime imaging, and it is shown that different matrix polymers lead to optimal use in different ranges dissolved oxygen concentration. Imaging with the opaque pillars in between the observation direction and the continuous fluorophore film yields images that retain spatial information in the sensor image.

  1. A specific two-pore domain potassium channel blocker defines the structure of the TASK-1 open pore.

    Science.gov (United States)

    Streit, Anne K; Netter, Michael F; Kempf, Franca; Walecki, Magdalena; Rinné, Susanne; Bollepalli, Murali K; Preisig-Müller, Regina; Renigunta, Vijay; Daut, Jürgen; Baukrowitz, Thomas; Sansom, Mark S P; Stansfeld, Phillip J; Decher, Niels

    2011-04-22

    Two-pore domain potassium (K(2P)) channels play a key role in setting the membrane potential of excitable cells. Despite their role as putative targets for drugs and general anesthetics, little is known about the structure and the drug binding site of K(2P) channels. We describe A1899 as a potent and highly selective blocker of the K(2P) channel TASK-1. As A1899 acts as an open-channel blocker and binds to residues forming the wall of the central cavity, the drug was used to further our understanding of the channel pore. Using alanine mutagenesis screens, we have identified residues in both pore loops, the M2 and M4 segments, and the halothane response element to form the drug binding site of TASK-1. Our experimental data were used to validate a K(2P) open-pore homology model of TASK-1, providing structural insights for future rational design of drugs targeting K(2P) channels.

  2. A Specific Two-pore Domain Potassium Channel Blocker Defines the Structure of the TASK-1 Open Pore*

    Science.gov (United States)

    Streit, Anne K.; Netter, Michael F.; Kempf, Franca; Walecki, Magdalena; Rinné, Susanne; Bollepalli, Murali K.; Preisig-Müller, Regina; Renigunta, Vijay; Daut, Jürgen; Baukrowitz, Thomas; Sansom, Mark S. P.; Stansfeld, Phillip J.; Decher, Niels

    2011-01-01

    Two-pore domain potassium (K2P) channels play a key role in setting the membrane potential of excitable cells. Despite their role as putative targets for drugs and general anesthetics, little is known about the structure and the drug binding site of K2P channels. We describe A1899 as a potent and highly selective blocker of the K2P channel TASK-1. As A1899 acts as an open-channel blocker and binds to residues forming the wall of the central cavity, the drug was used to further our understanding of the channel pore. Using alanine mutagenesis screens, we have identified residues in both pore loops, the M2 and M4 segments, and the halothane response element to form the drug binding site of TASK-1. Our experimental data were used to validate a K2P open-pore homology model of TASK-1, providing structural insights for future rational design of drugs targeting K2P channels. PMID:21362619

  3. Soft chemistry routes for synthesis of rare earth oxide nanoparticles with well defined morphological and structural characteristics

    Science.gov (United States)

    Mancic, L.; Marinkovic, B. A.; Marinkovic, K.; Dramicanin, M.; Milosevic, O.

    2011-11-01

    Phosphors of (Y0.75Gd0.25)2O3:Eu3+ (5 at.%) have been prepared through soft chemistry routes. Conversion of the starting nitrates mixture into oxide is performed through two approaches: (a) hydrothermal treatment (HT) at 200 °C/3 h of an ammonium hydrogen carbonate precipitated mixture and (b) by thermally decomposition of pure nitrate precursor solution at 900 °C in dispersed phase (aerosol) within a tubular flow reactor by spray pyrolysis process (SP). The powders are additionally thermally treated at different temperatures: 600, 1000, and 1100 °C for either 3 or 12 h. HT—derived particles present exclusively one-dimensional morphology (nanorods) up to the temperatures of 600 °C, while the leaf-like particles start to grow afterward. SP—derived particles maintain their spherical shape up to the temperatures of 1100 °C. These submicron sized spheres were actually composed of randomly aggregated nanoparticles. All powders exhibits cubic Ia- 3 structure (Y0.75Gd0.25)2O3:Eu and have improved optical characteristics due to their nanocrystalline nature. The detailed study of the influence of structural and morphological powder characteristics on their emission properties is performed based on the results of X-ray powder diffractometry, scanning electron microscopy, X-ray energy dispersive spectroscopy, transmission electron microscopy, and photoluminescence measurements.

  4. Atomic-Resolution Structures of Horse Liver Alcohol Dehydrogenase with NAD[superscript +] and Fluoroalcohols Define Strained Michaelis Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Plapp, Bryce V.; Ramaswamy, S. (inSTEM); (Iowa)

    2013-01-16

    Structures of horse liver alcohol dehydrogenase complexed with NAD{sup +} and unreactive substrate analogues, 2,2,2-trifluoroethanol or 2,3,4,5,6-pentafluorobenzyl alcohol, were determined at 100 K at 1.12 or 1.14 {angstrom} resolution, providing estimates of atomic positions with overall errors of 0.02 {angstrom}, the geometry of ligand binding, descriptions of alternative conformations of amino acid residues and waters, and evidence of a strained nicotinamide ring. The four independent subunits from the two homodimeric structures differ only slightly in the peptide backbone conformation. Alternative conformations for amino acid side chains were identified for 50 of the 748 residues in each complex, and Leu-57 and Leu-116 adopt different conformations to accommodate the different alcohols at the active site. Each fluoroalcohol occupies one position, and the fluorines of the alcohols are well-resolved. These structures closely resemble the expected Michaelis complexes with the pro-R hydrogens of the methylene carbons of the alcohols directed toward the re face of C4N of the nicotinamide rings with a C-C distance of 3.40 {angstrom}. The oxygens of the alcohols are ligated to the catalytic zinc at a distance expected for a zinc alkoxide (1.96 {angstrom}) and participate in a low-barrier hydrogen bond (2.52 {angstrom}) with the hydroxyl group of Ser-48 in a proton relay system. As determined by X-ray refinement with no restraints on bond distances and planarity, the nicotinamide rings in the two complexes are slightly puckered (quasi-boat conformation, with torsion angles of 5.9{sup o} for C4N and 4.8{sup o} for N1N relative to the plane of the other atoms) and have bond distances that are somewhat different compared to those found for NAD(P){sup +}. It appears that the nicotinamide ring is strained toward the transition state on the path to alcohol oxidation.

  5. The meta-epigenomic structure of purified human stem cell populations is defined at cis-regulatory sequences

    Science.gov (United States)

    Zhao, Yong Mei; Golden, Aaron; Mar, Jessica C.; Einstein, Francine H.; Greally, John M.

    2014-01-01

    The mechanism and significance of epigenetic variability in the same cell type between healthy individuals are not clear. Here, we purify human CD34+ hematopoietic stem and progenitor cells (HSPCs) from different individuals and find that there is increased variability of DNA methylation at loci with properties of promoters and enhancers. The variability is especially enriched at candidate enhancers near genes transitioning between silent and expressed states, and encoding proteins with leukocyte differentiation properties. Our findings of increased variability at loci with intermediate DNA methylation values, at candidate “poised” enhancers, and at genes involved in HSPC lineage commitment suggest that CD34+ cell subtype heterogeneity between individuals is a major mechanism for the variability observed. Epigenomic studies performed on cell populations, even when purified, are testing collections of epigenomes, or meta-epigenomes. Our findings show that meta-epigenomic approaches to data analysis can provide insights into cell subpopulation structure. PMID:25327398

  6. Developing a Structural Model to Define Influential Risk Elements in Islamic Banking: An Empirical Study in Iran

    Directory of Open Access Journals (Sweden)

    Akbar Alem Tabriz

    2015-04-01

    Full Text Available The aim of this study is to identify the most influential risk elements and determine causal relationships network of risk factors in Islamic banking in Iran. Due to some unique principles used by Islamic banks, they encounter difficulties to manage various risks effectively than conventional banks. Consequently, a structural model was developed from a comprehensive set of risk elements with five reflective and one formative output construct namely; credit, liquidity, market, operational, unique risks and total risk by using PLs path modeling which statistically supports all constructs. Fitness Indices imply homogeneity among risk elements and statistics indicate not severe multicollinearity and redundancy in the model. This study provides key insight into causal relationships of influential risk elements in Islamic banking essential for proper resource allocation to compete with conventional banks.

  7. Domain structures and inter-domain interactions defining the holoenzyme architecture of archaeal d-family DNA polymerase.

    Science.gov (United States)

    Matsui, Ikuo; Matsui, Eriko; Yamasaki, Kazuhiko; Yokoyama, Hideshi

    2013-07-05

    Archaea-specific D-family DNA polymerase (PolD) forms a dimeric heterodimer consisting of two large polymerase subunits and two small exonuclease subunits. According to the protein-protein interactions identified among the domains of large and small subunits of PolD, a symmetrical model for the domain topology of the PolD holoenzyme is proposed. The experimental evidence supports various aspects of the model. The conserved amphipathic nature of the N-terminal putative α-helix of the large subunit plays a key role in the homodimeric assembly and the self-cyclization of the large subunit and is deeply involved in the archaeal PolD stability and activity. We also discuss the evolutional transformation from archaeal D-family to eukaryotic B-family polymerase on the basis of the structural information.

  8. Domain Structures and Inter-Domain Interactions Defining the Holoenzyme Architecture of Archaeal D-Family DNA Polymerase

    Directory of Open Access Journals (Sweden)

    Hideshi Yokoyama

    2013-07-01

    Full Text Available Archaea-specific D-family DNA polymerase (PolD forms a dimeric heterodimer consisting of two large polymerase subunits and two small exonuclease subunits. According to the protein-protein interactions identified among the domains of large and small subunits of PolD, a symmetrical model for the domain topology of the PolD holoenzyme is proposed. The experimental evidence supports various aspects of the model. The conserved amphipathic nature of the N-terminal putative α-helix of the large subunit plays a key role in the homodimeric assembly and the self-cyclization of the large subunit and is deeply involved in the archaeal PolD stability and activity. We also discuss the evolutional transformation from archaeal D-family to eukaryotic B-family polymerase on the basis of the structural information.

  9. The UlaG protein family defines novel structural and functional motifs grafted on an ancient RNase fold

    Directory of Open Access Journals (Sweden)

    Coll Miquel

    2011-09-01

    Full Text Available Abstract Background Bacterial populations are highly successful at colonizing new habitats and adapting to changing environmental conditions, partly due to their capacity to evolve novel virulence and metabolic pathways in response to stress conditions and to shuffle them by horizontal gene transfer (HGT. A common theme in the evolution of new functions consists of gene duplication followed by functional divergence. UlaG, a unique manganese-dependent metallo-β-lactamase (MBL enzyme involved in L-ascorbate metabolism by commensal and symbiotic enterobacteria, provides a model for the study of the emergence of new catalytic activities from the modification of an ancient fold. Furthermore, UlaG is the founding member of the so-called UlaG-like (UlaGL protein family, a recently established and poorly characterized family comprising divalent (and perhaps trivalent metal-binding MBLs that catalyze transformations on phosphorylated sugars and nucleotides. Results Here we combined protein structure-guided and sequence-only molecular phylogenetic analyses to dissect the molecular evolution of UlaG and to study its phylogenomic distribution, its relatedness with present-day UlaGL protein sequences and functional conservation. Phylogenetic analyses indicate that UlaGL sequences are present in Bacteria and Archaea, with bona fide orthologs found mainly in mammalian and plant-associated Gram-negative and Gram-positive bacteria. The incongruence between the UlaGL tree and known species trees indicates exchange by HGT and suggests that the UlaGL-encoding genes provided a growth advantage under changing conditions. Our search for more distantly related protein sequences aided by structural homology has uncovered that UlaGL sequences have a common evolutionary origin with present-day RNA processing and metabolizing MBL enzymes widespread in Bacteria, Archaea, and Eukarya. This observation suggests an ancient origin for the UlaGL family within the broader trunk

  10. Contribution of solar radiation and geomagnetic activity to global structure of 27-day variation of ionosphere

    Science.gov (United States)

    Yao, Yibin; Zhai, Changzhi; Kong, Jian; Liu, Lei

    2017-04-01

    Twenty-seven-day variation caused by solar rotation is one of the main periodic effects of solar radiation influence on the ionosphere, and there have been many studies on this periodicity using peak electron density N_{mF2} and solar radio flux index F10.7. In this paper, the global electron content (GEC) and observation of Solar EUV Monitor (SEM) represent the whole ionosphere and solar EUV flux, respectively, to investigate the 27-day variation. The 27-day period components of indices (GEC_{27}, SEM_{27}, F10.7_{27}, Ap_{27}) are obtained using Chebyshev band-pass filter. The comparison of regression results indicates that the index SEM has higher coherence than F10.7 with 27-day variation of the ionosphere. The regression coefficients of SEM_{27 } varied from 0.6 to 1.4 and the coefficients of Ap_{27} varied from - 0.6 to 0.3, which suggests that EUV radiation seasonal variations are the primary driver for the 27-day variations of the ionosphere for most periods. TEC map grid points on three meridians where IGS stations are dense are selected for regression, and the results show that the contribution of solar EUV radiation is positive at all geomagnetic latitudes and larger than geomagnetic activity in most latitudes. The contribution of geomagnetic activity is negative at high geomagnetic latitude, increasing with decreasing geomagnetic latitudes, and positive at low geomagnetic latitudes. The global structure of 27-day variation of ionosphere is presented and demonstrates that there are two zonal anomaly regions along with the geomagnetic latitudes lines and two peaks in the north of Southeast Asia and the Middle Pacific where TEC_{27} magnitude values are notably larger than elsewhere along zonal anomaly regions.

  11. Contribution to the validation of thermal ratchetting prevision methods in metallic structures; Contribution a la validation des methodes de prevision du rochet thermique dans les structures metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Rakotovelo, A.M

    1998-03-01

    This work concerns the steady state assessment in the metallic structures subjected to thermomechanical cyclic loadings in biaxial stress state. The effect of the short time mechanical overloads is also investigated. The first chapter is devoted to a bibliographic research concerning the behaviour of the materials and the structures in the cyclic plasticity. Some works relate to the experimental aspect as well as the numerical one for the steady state assessment of such structures are presented. The experimental part of the study is presented in the second chapter. The experimental device was carried out in order to prescribe tension and torsion forces combined with cyclic thermal loading. Some tests was then carried out, among these tests certain include some overloads in tension or torsion. The last chapter describes the numerical calculations using different models (linear isotropic hardening, linear kinematic hardening and elasto-viscoplastic Chaboche's model) and the application of some simplified methods for the ratchetting assessment in the structures. We have considered two categories of methods. The first one is based on an elastic analysis (Bree's diagram, 3 Sm rule, efficiency rule) and the second one combines elastic analysis and elastoplastic analysis of the first cycle (Gatt's and Taleb's methods). The results of this study have enabled: to validate in the biaxial stress state an expression which takes into account the effect of mechanical short time overloads; to test the performances of considered models to describe the evolution of the structure during the first cycle and to take into account the effect of short time overloads. Among the considered models, the elastoplastic Chaboche's model seems to be the most accurate to describe the structure's behaviour during the first cycles; to validate some simplified methods. Certain methods based only on elastic analysis (Bee's diagram and efficiency rule) seem not

  12. Solution-phase parallel synthesis of a pharmacophore library of HUN-7293 analogues: a general chemical mutagenesis approach to defining structure-function properties of naturally occurring cyclic (depsi)peptides.

    Science.gov (United States)

    Chen, Yan; Bilban, Melitta; Foster, Carolyn A; Boger, Dale L

    2002-05-15

    HUN-7293 (1), a naturally occurring cyclic heptadepsipeptide, is a potent inhibitor of cell adhesion molecule expression (VCAM-1, ICAM-1, E-selectin), the overexpression of which is characteristic of chronic inflammatory diseases. Representative of a general approach to defining structure-function relationships of such cyclic (depsi)peptides, the parallel synthesis and evaluation of a complete library of key HUN-7293 analogues are detailed enlisting solution-phase techniques and simple acid-base liquid-liquid extractions for isolation and purification of intermediates and final products. Significant to the design of the studies and unique to solution-phase techniques, the library was assembled superimposing a divergent synthetic strategy onto a convergent total synthesis. An alanine scan and N-methyl deletion of each residue of the cyclic heptadepsipeptide identified key sites responsible for or contributing to the biological properties. The simultaneous preparation of a complete set of individual residue analogues further simplifying the structure allowed an assessment of each structural feature of 1, providing a detailed account of the structure-function relationships in a single study. Within this pharmacophore library prepared by systematic chemical mutagenesis of the natural product structure, simplified analogues possessing comparable potency and, in some instances, improved selectivity were identified. One potent member of this library proved to be an additional natural product in its own right, which we have come to refer to as HUN-7293B (8), being isolated from the microbial strain F/94-499709.

  13. The actin family protein ARP6 contributes to the structure and the function of the nucleolus.

    Science.gov (United States)

    Kitamura, Hiroshi; Matsumori, Haruka; Kalendova, Alzbeta; Hozak, Pavel; Goldberg, Ilya G; Nakao, Mitsuyoshi; Saitoh, Noriko; Harata, Masahiko

    2015-08-21

    The actin family members, consisting of actin and actin-related proteins (ARPs), are essential components of chromatin remodeling complexes. ARP6, one of the nuclear ARPs, is part of the Snf-2-related CREB-binding protein activator protein (SRCAP) chromatin remodeling complex, which promotes the deposition of the histone variant H2A.Z into the chromatin. In this study, we showed that ARP6 influences the structure and the function of the nucleolus. ARP6 is localized in the central region of the nucleolus, and its knockdown induced a morphological change in the nucleolus. We also found that in the presence of high concentrations of glucose ARP6 contributed to the maintenance of active ribosomal DNA (rDNA) transcription by placing H2A.Z into the chromatin. In contrast, under starvation, ARP6 was required for cell survival through the repression of rDNA transcription independently of H2A.Z. These findings reveal novel pleiotropic roles for the actin family in nuclear organization and metabolic homeostasis.

  14. Seismic structure beneath the Gulf of California: a contribution from group velocity measurements

    Science.gov (United States)

    Di Luccio, F.; Persaud, P.; Clayton, R. W.

    2014-12-01

    Rayleigh wave group velocity dispersion measurements from local and regional earthquakes are used to interpret the lithospheric structure in the Gulf of California region. We compute group velocity maps for Rayleigh waves from 10 to 150 s using earthquakes recorded by broad-band stations of the Network of Autonomously Recording Seismographs in Baja California and Mexico mainland, UNM in Mexico, BOR, DPP and GOR in southern California and TUC in Arizona. The study area is gridded in 120 longitude cells by 180 latitude cells, with an equal spacing of 10 × 10 km. Assuming that each gridpoint is laterally homogeneous, for each period the tomographic maps are inverted to produce a 3-D lithospheric shear wave velocity model for the region. Near the Gulf of California rift axis, we found three prominent low shear wave velocity regions, which are associated with mantle upwelling near the Cerro Prieto volcanic field, the Ballenas Transform Fault and the East Pacific Rise. Upwelling of the mantle at lithospheric and asthenospheric depths characterizes most of the Gulf. This more detailed finding is new when compared to previous surface wave studies in the region. A low-velocity zone in northcentral Baja at ˜28ºN which extends east-south-eastwards is interpreted as an asthenospheric window. In addition, we also identify a well-defined high-velocity zone in the upper mantle beneath central-western Baja California, which correlates with the previously interpreted location of the stalled Guadalupe and Magdalena microplates. We interpret locations of the fossil slab and slab window in light of the distribution of unique post-subduction volcanic rocks in the Gulf of California and Baja California. We also observe a high-velocity anomaly at 50-km depth extending down to ˜130 km near the southwestern Baja coastline and beneath Baja, which may represent another remnant of the Farallon slab.

  15. Decidability of definability

    CERN Document Server

    Tsankov, Manuel Bodirsky; Michael Pinsker; Todor

    2010-01-01

    For a fixed infinite structure $\\Gamma$ with finite signature $\\tau$, we study the following computational problem: Input are quantifier-free first-order $\\tau$-formulas $\\phi_0,\\phi_1,\\dots,\\phi_n$ that define relations $R_0,R_1,\\dots,R_n$ over $\\Gamma$. The question is whether the relation $R_0$ is primitive positive definable from $R_1,\\ldots,R_n$, i.e., definable by a first-order formula that uses only relation symbols for $R_1, \\dots, R_n$, equality, conjunctions, and existential quantification (disjunction, negation, and universal quantification are forbidden). We show decidability of this problem for all structures $\\Gamma$ that have a first-order definition in an ordered homogeneous structure $\\Delta$ with a finite language whose age is a Ramsey class and determined by finitely many forbidden substructures. Examples for structures $\\Gamma$ with this property are the order of the rationals, the random graph, the homogeneous universal poset, the random tournament, all homogeneous universal $C$-relations...

  16. PLATON SQUEEZE: a tool for the calculation of the disordered solvent contribution to the calculated structure factors.

    Science.gov (United States)

    Spek, Anthony L

    2015-01-01

    The completion of a crystal structure determination is often hampered by the presence of embedded solvent molecules or ions that are seriously disordered. Their contribution to the calculated structure factors in the least-squares refinement of a crystal structure has to be included in some way. Traditionally, an atomistic solvent disorder model is attempted. Such an approach is generally to be preferred, but it does not always lead to a satisfactory result and may even be impossible in cases where channels in the structure are filled with continuous electron density. This paper documents the SQUEEZE method as an alternative means of addressing the solvent disorder issue. It conveniently interfaces with the 2014 version of the least-squares refinement program SHELXL [Sheldrick (2015). Acta Cryst. C71. In the press] and other refinement programs that accept externally provided fixed contributions to the calculated structure factors. The PLATON SQUEEZE tool calculates the solvent contribution to the structure factors by back-Fourier transformation of the electron density found in the solvent-accessible region of a phase-optimized difference electron-density map. The actual least-squares structure refinement is delegated to, for example, SHELXL. The current versions of PLATON SQUEEZE and SHELXL now address several of the unnecessary complications with the earlier implementation of the SQUEEZE procedure that were a necessity because least-squares refinement with the now superseded SHELXL97 program did not allow for the input of fixed externally provided contributions to the structure-factor calculation. It is no longer necessary to subtract the solvent contribution temporarily from the observed intensities to be able to use SHELXL for the least-squares refinement, since that program now accepts the solvent contribution from an external file (.fab file) if the ABIN instruction is used. In addition, many twinned structures containing disordered solvents are now also

  17. 名义账户利率理论溯源及其应用局限性%Origin of Notional Defined Contribution Interest Rate Theory and Its Limitations in Application

    Institute of Scientific and Technical Information of China (English)

    齐传钧

    2016-01-01

    名义账户利率是名义账户制度的核心要素,也是选择名义账户利率指数化变量的主要依据。探讨名义账户利率实质上就等同于研究现收现付制养老金制度的内部收益率问题。在厘清现收现付制经济含义基础上,通过对相关理论的梳理、归纳和推演,名义账户制利率本质上就是“黄金律”条件下的经济增长率。但是,因为受制于经济、人口和养老金制度实际运行状况,这一利率理论应用局限性也非常明显,从而为进一步的应用讨论提供支持和借鉴。%The determination of the interest rate is the core element of the notional defined contribution ( NDC) system, and it is also the main basis for the choice of the interest rate index. The interest rate is essentially equivalent to internal rate of return of PAYG pension system. By combing the relevant theory, induction and deduction, the interest rate is essentially the economic growth rate at the Golden Rule level rule. However, due to subject to the actual operation of the economic, population and pension system, there are very obvious limitations for the application of the theory.

  18. Basal Ganglia Structures Differentially Contribute to Verbal Fluency: Evidence from Human Immunodeficiency Virus (HIV)-Infected Adults

    Science.gov (United States)

    Thames, April D.; Foley, Jessica M.; Wright, Matthew J.; Panos, Stella E.; Ettenhofer, Mark; Ramezani, Amir; Streiff, Vanessa; El-Saden, Suzie; Goodwin, Scott; Bookheimer, Susan Y.; Hinkin, Charles H.

    2012-01-01

    Background: The basal ganglia (BG) are involved in executive language functions (i.e., verbal fluency) through their connections with cortical structures. The caudate and putamen receive separate inputs from prefrontal and premotor cortices, and may differentially contribute to verbal fluency performance. We examined BG integrity in relation to…

  19. A Well-Defined Silicon Nanocone-Carbon Structure for Demonstrating Exclusive Influences of Carbon Coating on Silicon Anode of Lithium-Ion Batteries.

    Science.gov (United States)

    Wang, Chao; Luo, Fei; Lu, Hao; Rong, Xiaohui; Liu, Bonan; Chu, Geng; Sun, Yu; Quan, Baogang; Zheng, Jieyun; Li, Junjie; Gu, Changzhi; Qiu, Xinping; Li, Hong; Chen, Liquan

    2017-01-25

    Nanotechnology and carbon coating have been applied to silicon anodes to achieve excellent lithium-ion batteries, but the exclusive influence of carbon coating on solid-electrolyte interphase (SEI) formation is difficult to exhibit distinctly because of the impurity and morphological irregularity of most nanostructured anodes. Here, we design a silicon nanocone-carbon (SNC-C) composite structure as a model anode to demonstrate the significant influences of carbon coating on SEI formation and electrochemical performance, unaffectedly as a result of pure electrode component and distinctly due to regular nanocone morphology. As demonstrated by morphological and elemental analysis, compared to the SNC electrode, the SNC-C electrode maintains a thinner SEI layer (∼10 nm) and more stable structure during cycling as well as longer cycle life (>725 cycles), higher Coulombic efficiency (>99%), and lower electrode polarization. This well-defined structure clearly shows the interface stability attributed to carbon coating and is promising in fundamental research of the silicon anode.

  20. Synchrotron radiation circular dichroism spectroscopy-defined structure of the C-terminal domain of NaChBac and its role in channel assembly

    Science.gov (United States)

    Powl, Andrew M.; O’Reilly, Andrias O.; Miles, Andrew J.; Wallace, B. A.

    2010-01-01

    Extramembranous domains play important roles in the structure and function of membrane proteins, contributing to protein stability, forming association domains, and binding ancillary subunits and ligands. However, these domains are generally flexible, making them difficult or unsuitable targets for obtaining high-resolution X-ray and NMR structural information. In this study we show that the highly sensitive method of synchrotron radiation circular dichroism (SRCD) spectroscopy can be used as a powerful tool to investigate the structure of the extramembranous C-terminal domain (CTD) of the prokaryotic voltage-gated sodium channel (NaV) from Bacillus halodurans, NaChBac. Sequence analyses predict its CTD will consist of an unordered region followed by an α-helix, which has a propensity to form a multimeric coiled-coil motif, and which could form an association domain in the homotetrameric NaChBac channel. By creating a number of shortened constructs we have shown experimentally that the CTD does indeed contain a stretch of ∼20 α-helical residues preceded by a nonhelical region adjacent to the final transmembrane segment and that the efficiency of assembly of channels in the membrane progressively decreases as the CTD residues are removed. Analyses of the CTDs of 32 putative prokaryotic NaV sequences suggest that a CTD helical bundle is a structural feature conserved throughout the bacterial sodium channel family. PMID:20663949

  1. Structure of three-loop contributions to the β-function of N = 1 supersymmetric QED with N f flavors regularized by the dimensional reduction

    Science.gov (United States)

    Aleshin, S. S.; Kataev, A. L.; Stepanyantz, K. V.

    2016-01-01

    In the case of using the higher derivative regularization for N = 1 supersymmetric quantum electrodynamics (SQED) with N f flavors, the loop integrals giving the β-function are integrals of double total derivatives in themomentum space. This feature allows reducing one of the loop integrals to an integral of the δ-function and deriving the Novikov-Shifman-Vainshtein-Zakharov relation for the renormalization group functions defined in terms of the bare coupling constant. We consider N = 1 SQED with N f flavors regularized by the dimensional reduction in the overline {DR} -scheme. Evaluating the scheme-dependent three-loop contribution to the β-function proportional to ( N f)2 we find the structures analogous to integrals of the δ-singularities. After adding the schemeindependent terms proportional to ( N f)1, we obtain the known result for the three-loop β-function.

  2. Quantitative analysis on the contribution of industrial structure change to sustainable development: a case study of Fujian Province

    Institute of Scientific and Technical Information of China (English)

    Lin Qing; Wang Ying

    2009-01-01

    Development and sustainability are the core connotation of sustainable development.Sustainahility of economic development and the provision capability of resources and environment ore teo aspects of sustainable development.The former ones are the foundation of the latter ones.Industrial structure has a close relutionship with sustainable development.The optumization of industrial strneture is the important base for the sustainable development of modern economy and also the important ways of the sustainable utilization of resources and environment.The intensive growth effect of industrial structure change has the meaning of sustainable development.This paper reviews and explains the theory on the contribution of industrial structure change to sustainable development,builds the calculation model through introducing the coefficient of industrtal structure change,makes an empirical study on the contribution of indnstrial structure change to sustainable development in Fujian,and puts forward ways and polictes af optimizing industrial structure both among mdustries and inside the industry in the process of industrial structure change.

  3. The nuclear higher-order structure defined by the set of topological relationships between DNA and the nuclear matrix is species-specific in hepatocytes.

    Science.gov (United States)

    Silva-Santiago, Evangelina; Pardo, Juan Pablo; Hernández-Muñoz, Rolando; Aranda-Anzaldo, Armando

    2017-01-15

    During the interphase the nuclear DNA of metazoan cells is organized in supercoiled loops anchored to constituents of a nuclear substructure or compartment known as the nuclear matrix. The stable interactions between DNA and the nuclear matrix (NM) correspond to a set of topological relationships that define a nuclear higher-order structure (NHOS). Current evidence suggests that the NHOS is cell-type-specific. Biophysical evidence and theoretical models suggest that thermodynamic and structural constraints drive the actualization of DNA-NM interactions. However, if the topological relationships between DNA and the NM were the subject of any biological constraint with functional significance then they must be adaptive and thus be positively selected by natural selection and they should be reasonably conserved, at least within closely related species. We carried out a coarse-grained, comparative evaluation of the DNA-NM topological relationships in primary hepatocytes from two closely related mammals: rat and mouse, by determining the relative position to the NM of a limited set of target sequences corresponding to highly-conserved genomic regions that also represent a sample of distinct chromosome territories within the interphase nucleus. Our results indicate that the pattern of topological relationships between DNA and the NM is not conserved between the hepatocytes of the two closely related species, suggesting that the NHOS, like the karyotype, is species-specific.

  4. [Primordial structures of feminine maturation as reflected in fairy tales. Contribution to the anthropology of sexuality].

    Science.gov (United States)

    Schlee, T

    1976-01-01

    Two maturation fairy-tales with a high resonance effect are analysed. The method of interpretation was that of depth psychology, with observation of results of modern biological-anthropological research. The interpretation revealed 'hymenal' or retarding primary structures in the young female subject. These structures postpone the onset of sexual desires to the time after the defloration.

  5. Crystal-Structure Contribution to the Solid Solubility in Transition Metal Alloys

    DEFF Research Database (Denmark)

    Ruban, Andrei; Skriver, Hans Lomholt; Nørskov, Jens Kehlet

    1998-01-01

    The solution energies of 4d metals in other 4d metals as well as the bcc-hcp structural energy differences in random 4d alloys are calculated by density functional theory. It is shown that the crystal structure of the host plays a crucial role in the solid solubility. A local virtual bond...

  6. Research on the Replacement Ratio of Defined Contributed Occupational Pension Scheme under Stochastic Interest Rate%随机利率下缴费预定计划职业年金的替代率研究

    Institute of Scientific and Technical Information of China (English)

    吴忠; 王灵芝; 范君晖

    2011-01-01

    事业单位养老保险制度改革关系到我国基本养老保险制度的改革进程和可持续发展问题,而面对事业单位养老金替代率90%,企业单位替代率60%的差距,事业单位养老保险制度改革遇到了一定的阻力.本文考察了如果采用缴费预定计划(DC计划)建立职业年金,事业单位养老保险的替代率问题.养老金的投资收益率是影响替代率的关键因素,而这一因素受金融市场影响较大,这里假设它为随机变量.研究发现:(1)由于女性职工的法定退休年龄早,平均寿命又比较长,对于相同的缴费率,男性的养老金替代率明显高于女性的替代率;(2)缴费率是影响替代率的另一因素,为了保持较为合理的替代率,实现养老保险制度的平稳改革,我们建议合适的缴费率为11%.%The reformation of non-profit institution endowment insurance system relates to the basic endowment insurance 's reform process and its sustainable development. At present, the replacement ratio of non-profit institution is 90%, while the enterprise's is only 60%, the reformation encountered some resistance. This paper studied the replacement ratio of non-profit institution if there is a defined contribution plan to set up an occupational pension. The fund's return on investment is a key factor of the replacement ratio, and which is influenced a lot by the financial market, so we suppose it as a random variable. We found that: (1) Given the same payment, male's replacement is obviously higher than the female' s. For the female' s legal retirement age is lower and female's average lifetime is longer than the male' s. (2) The payment is another factor to influence the replacement ratio. Holding a reasonable replacement can help the reformation accomplished smoothly, we suggest the suitable payment of occupational pension is 11 %.

  7. Do extrafloral nectar resources, species abundances, and body sizes contribute to the structure of ant-plant mutualistic networks?

    Science.gov (United States)

    Chamberlain, Scott A; Kilpatrick, Jeffrey R; Holland, J Nathaniel

    2010-11-01

    Recent research has shown that many mutualistic communities display non-random structures. While our understanding of the structural properties of mutualistic communities continues to improve, we know little of the biological variables resulting in them. Mutualistic communities include those formed between ants and extrafloral (EF) nectar-bearing plants. In this study, we examined the contributions of plant and ant abundance, plant and ant size, and plant EF nectar resources to the network structures of nestedness and interaction frequency of ant-plant networks across five sites within one geographic locality in the Sonoran Desert. Interactions between ant and plant species were largely symmetric. That is, ant and plant species exerted nearly equivalent quantitative interaction effects on one another, as measured by their frequency of interaction. The mutualistic ant-plant networks also showed nested patterns of structure, in which there was a central core of generalist ant and plant species interacting with one another and few specialist-specialist interactions. Abundance and plant size and ant body size were the best predictors of symmetric interactions between plants and ants, as well as nestedness. Despite interactions in these communities being ultimately mediated by EF nectar resources, the number of EF nectaries had a relatively weak ability to explain variation in symmetric interactions and nestedness. These results suggest that different mechanisms may contribute to structure of bipartite networks. Moreover, our results for ant-plant mutualistic networks support the general importance of species abundances for the structure of species interactions within biological communities.

  8. Light induced structural changes of the photoprotein mnemiopsin: Characterization and contribution in photoinactivation.

    Science.gov (United States)

    Pashandi, Zaiddodine; Molakarimi, Maryam; Sajedi, Reza H; Taghdir, Majid; Naderi-Manesh, Hossein

    2016-12-01

    Mnemiopsin, an EF-hand Ca(2+) binding photoprotein isolated from luminous ctenophore Mnemiopsis leidyi, emits blue light from its chromophore, coelenterazine, which is non-covalently bond in its central hydrophobic core. Previous studies have revealed unique biochemical properties for ctenophore photoproteins such as inactivation by light, but only few have focused on photoinactivation process. To understand the nature of photoinactivation process we have investigated the impact of light alone and in the presence of Ca(2+) ion on the structure of this photoprotein. We used UV-Vis, circular dichroism (CD) and fluorescence spectroscopy following Ca(2+) binding assay to analyze the light effects on mnemiopsin conformation in comparison with aequorin at both apo and holo form. Our results showed light induced structural changes which resulted into photoinactivation. These changes include significant modification on secondary structure of mnemiopsin in comparison with aequorin. Our data also revealed that light could influence structure of apo protein regardless of presence of coelenterazine. The comparative studies of Ca(2+) ion binding affinity following light exposure, also showed that light induced structural changes could presumably affect coelenterazine binding or its conformation in binding site in such a way that causes photoinactivation. In conclusion, we have proposed that structural rearrangement of helix 5 and C-terminal motif could be responsible for light induced structural changes. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Structure changes, the contribution of sectors, income per capita Indonesia in 1990 – 2014

    Directory of Open Access Journals (Sweden)

    Paulina Harun

    2017-03-01

    Full Text Available Economic development is seen as a process of transition from one phase to another, from simple economic structure (agriculture to the modern economy structure. Economic development is characterized by changes in the structure of the agricultural sector into the modern sector. The changes affect all the matters related thereto. Therefore, a change or transformation of economic activity is referred to as a structural change. This study aims to analyze the structural changes in the national product, and the factors that cause changes in the structure and level of sectoral imbalances as a result of the structural changes. The study was conducted by using the economic sector, divided into four major groups, namely the primary, secondary, utilities and services from 1990 to 2014. Secondary data were collected by the method of sectoral trends, models Chanery Syrquin-Barua, Theil index. The results showed that the sectoral trend has a positive result such as utilities and services sectors, while the primary and secondary sectors tend to be negative. From the model Chenery, Syrquin-Barua shows the per capita income has a positive effect on the primary sector and the utilities, residents have positive effect on the secondary sector, utilities and services. Meanwhile dummy variable has a positive effect on the primary sector, secondary and services. Sectoral inequality occurs in the secondary sector.

  10. Contribution to the modelling and simulation of aircraft structures impacting on water

    OpenAIRE

    Toso, Nathalie Renée Solange

    2009-01-01

    The impact on water of aeronautical structures is of concern as soon as an aircraft is designed to operate over sea. For the need of the ditching certification, it can be summarised that the structure should be able to land on water and float long enough to enable the passengers and crew members to evacuate. Until the middle of the 90's, compliance to the regulations was mainly shown by tests performed in a basin using a mock-up structure completed by relative simple theoretical evaluations o...

  11. Contributions of Severe Burn and Disuse to Bone Structure and Strength in Rats

    Science.gov (United States)

    2013-01-01

    injuries of≥40% total body surface area (TBSA) has markedly reduced bone formation in both adults and children [1]. Burn induces a systemic catabolic...injury can also be a significant contributing factor to loss of bone density and strength [8]. Bed rest causes an uncoupling of resorption and...the reduction in bone formation [3,5,15] and thusmay be associated with a higher incidence of fractures and osteoporosis [3,16,17]. Using two and

  12. Tenth-Order QED Contribution to the Electron g-2 and an Improved Value of the Fine Structure Constant

    CERN Document Server

    Aoyama, Tatsumi; Kinoshita, Toichiro; Nio, Makiko

    2012-01-01

    This paper presents the complete QED contribution to the electron g-2 up to the tenth order. With the help of the automatic code generator, we have evaluated all 12672 diagrams of the tenth-order diagrams and obtained a_e^{(10)} = 9.16 (58) in units of (\\alpha/\\pi)^5. We have also improved the eighth-order contribution obtaining a_e^{(8)} = -1.9097 (20) in units of (\\alpha/\\pi)^4, which includes the mass-dependent contributions. These results together with the measurement of a_e lead to the improved value of the fine-structure constant \\alpha^{-1} = 137.035 999 166 (34) [0.25 ppb].

  13. Contribution of Shape Memory Alloys Elements in Designing Underwater Smart Structures

    Directory of Open Access Journals (Sweden)

    Daniel Amariei

    2007-10-01

    Full Text Available Shape memory alloys (SMA have generated a lot of new ideas in engineering. Application is however so far limited to clamps and springs. With respect to smart structures sensing as well as control has to be included. While sensing looks to be relatively feasible control is the big challenge. This paper describes some related a smart structure idea using SMAs and discusses the challenges which need to be solved before these ideas can be realised.

  14. Defining cyber warfare

    Directory of Open Access Journals (Sweden)

    Dragan D. Mladenović

    2012-04-01

    Full Text Available Cyber conflicts represent a new kind of warfare that is technologically developing very rapidly. Such development results in more frequent and more intensive cyber attacks undertaken by states against adversary targets, with a wide range of diverse operations, from information operations to physical destruction of targets. Nevertheless, cyber warfare is waged through the application of the same means, techniques and methods as those used in cyber criminal, terrorism and intelligence activities. Moreover, it has a very specific nature that enables states to covertly initiate attacks against their adversaries. The starting point in defining doctrines, procedures and standards in the area of cyber warfare is determining its true nature. In this paper, a contribution to this effort was made through the analysis of the existing state doctrines and international practice in the area of cyber warfare towards the determination of its nationally acceptable definition.

  15. Experimental Investigation on Contribution of CFRP Attachment to Durability of Reinforced Concrete Structure Subjected to Chloride Attack

    Institute of Scientific and Technical Information of China (English)

    Chen Fengshan; Zhao Guofan; Pan Deqiang

    2006-01-01

    The function of externally-bonded carbon fiber reinforced polymer (CFRP) in preventing chloride from entering into concrete is verified by experiment. The results show that externally-bonded CFRP can be considered as a part of corrosion prevention system of strengthened concrete structures subjected to chloride ingress, and the contribution of CFRP should be considered in evaluation of durability of reinforced concrete structures with externally-bonded CFRP. With the effective shielding function of CFRP considered, an equation for residual lifetime prediction of concrete structures with externally-bonded CFRP is derived from Ficks dispersion law. CFRP has two functions for coastal concrete structures, including strengthening and increasing durability as part of corrosion prevention system.

  16. Gravimetry contributions to the study of the complex western Haouz aquifer (Morocco): Structural and hydrogeological implications

    Science.gov (United States)

    Chouikri, Ibtissam; el Mandour, Abdennabi; Jaffal, Mohammed; Baudron, Paul; García-Aróstegui, José-Luis; Manar, Ahmed; Casas, Albert

    2016-03-01

    This study provides new elements that illustrate the benefits of combining gravity, structural, stratigraphic and piezometric data for hydrogeological purposes. A combined methodology was applied to the western Haouz aquifer (Morocco), one of the main sources of water for irrigation and human consumption in the Marrakech region. First, a residual anomaly map was calculated from the Bouguer anomaly data. The computed map provided information on the ground density variation, revealing a strong control by a regional gradient. We then used various filtering techniques to delineate the major geological structures such as faults and basins: vertical and horizontal derivatives and upward continuation. This technique highlighted news structures and provided information on their dip. The gravity anomalies perfectly delineated the basement uplifts and the sedimentary thickening in depressions and grabens. The interpretation of gravimetric filtering, geological and hydrogeological data then highlighted two types of groundwater reservoirs, an unconfined aquifer hosted in conglomeratic mio-pliocene and quaternary rocks, covering the entire western Haouz and a deep confined aquifer contained in cenomanian-turonian limestone and eocene dolomitic formations in the south. Combining piezometric and residual anomaly maps revealed that groundwater flow and storage was in perfect agreement with the structures showing a negative anomaly, while structures with positive anomalies corresponded to groundwater divides. The study of gravity gradient zones by contact analysis enhanced the existing structural pattern of the study area and highlighted new structures, mainly oriented N70 and N130. The results of this study present a common framework and provide a notable step forward in the knowledge of the geometry and the groundwater flow pattern of the western Haouz aquifer, and will serve as a solid basis for a better water resource management.

  17. Contributions of historical and contemporary geographic and environmental factors to phylogeographic structure in a Tertiary relict species, Emmenopterys henryi (Rubiaceae).

    Science.gov (United States)

    Zhang, Yong-Hua; Wang, Ian J; Comes, Hans Peter; Peng, Hua; Qiu, Ying-Xiong

    2016-05-03

    Examining how historical and contemporary geographic and environmental factors contribute to genetic divergence at different evolutionary scales is a central yet largely unexplored question in ecology and evolution. Here, we examine this key question by investigating how environmental and geographic factors across different epochs have driven genetic divergence at deeper (phylogeographic) and shallower (landscape genetic) evolutionary scales in the Chinese Tertiary relict tree Emmenopterys henryi. We found that geography played a predominant role at all levels - phylogeographic clades are broadly geographically structured, the deepest levels of divergence are associated with major geological or pre-Quaternary climatic events, and isolation by distance (IBD) primarily explained population genetic structure. However, environmental factors are clearly also important - climatic fluctuations since the Last Interglacial (LIG) have likely contributed to phylogeographic structure, and the population genetic structure (in our AFLP dataset) was partly explained by isolation by environment (IBE), which may have resulted from natural selection in environments with divergent climates. Thus, historical and contemporary geography and historical and contemporary environments have all shaped patterns of genetic structure in E. henryi, and, in fact, changes in the landscape through time have also been critical factors.

  18. Structural Analysis and Deletion Mutagenesis Define Regions of QUIVER/SLEEPLESS that Are Responsible for Interactions with Shaker-Type Potassium Channels and Nicotinic Acetylcholine Receptors.

    Directory of Open Access Journals (Sweden)

    Meilin Wu

    Full Text Available Ly6 proteins are endogenous prototoxins found in most animals. They show striking structural and functional parallels to snake α-neurotoxins, including regulation of ion channels and cholinergic signaling. However, the structural contributions of Ly6 proteins to regulation of effector molecules is poorly understood. This question is particularly relevant to the Ly6 protein QUIVER/SLEEPLESS (QVR/SSS, which has previously been shown to suppress excitability and synaptic transmission by upregulating potassium (K channels and downregulating nicotinic acetylcholine receptors (nAChRs in wake-promoting neurons to facilitate sleep in Drosophila. Using deletion mutagenesis, co-immunoprecipitations, ion flux assays, surface labeling and confocal microscopy, we demonstrate that only loop 2 is required for many of the previously described properties of SSS in transfected cells, including interactions with K channels and nAChRs. Collectively our data suggest that QVR/SSS, and by extension perhaps other Ly6 proteins, target effector molecules using limited protein motifs. Mapping these motifs may be useful in rational design of drugs that mimic or suppress Ly6-effector interactions to modulate nervous system function.

  19. Infilled masonry walls contribution in mitigating progressive collapse of multistory reinforced concrete structures according to UFC guidelines

    Science.gov (United States)

    Helmy, Huda; Hadhoud, Hamed; Mourad, Sherif

    2015-09-01

    A structure is subjected to progressive collapse when an element fails, resulting in failure of adjoining structural elements which, in their turn, cause further structural failure leading eventually to partial or total collapse. The failure of a primary vertical support might occur due to extreme loadings such as bomb explosion in a terrorist attack, gas explosion and huge impact of a car in the parking area. Different guidelines such as the General Services Administration (GSA 2003) and the Unified Facilities Criteria (UFC 2009) addressed the structural progressive collapse due to the sudden loss of a main vertical support. In the current study, a progressive collapse assessment according to the UFC guidelines is carried out for a typical ten-story reinforced concrete framed structure designed according to codes [(ACI 318-08) and (ASCE 7-10)] for minimum design loads for buildings and other structures. Fully nonlinear dynamic analysis for the structure was carried out using Applied Element Method (AEM). The investigated cases included the removal of a corner column, an edge column, an edge shear wall, internal columns and internal shear wall. The numerical analysis showed that simplification of the problem into 3D bare frames would lead to uneconomical design. It was found for the studied case that, the infilled masonry walls have a valuable contribution in mitigating progressive collapse of the reinforced concrete framed structures. Neglecting these walls would lead to uneconomical design.

  20. Structural contributions of antipsychotic drugs to their therapeutic profiles and metabolic side effects.

    Science.gov (United States)

    Jafari, Somayeh; Fernandez-Enright, Francesca; Huang, Xu-Feng

    2012-02-01

    Antipsychotic drugs have various neuropharmacological properties as a result of their structural diversity. Despite their therapeutic benefits, most of the prescribed atypical antipsychotics can induce severe side effects, including weight gain, type II diabetes mellitus, and cardiovascular diseases. Among the developed atypical antipsychotic agents, tetracyclic dibenzodiazepine and thienobenzodiazepine compounds, particularly clozapine and olanzapine, are associated with the greatest weight gain and metabolic disturbances. However, the unique chemical structure of these compounds causes the low risk of side effects reported for typical antipsychotics (e.g. extrapyramidal symptoms and tardive dyskinesia). This report reviews the recent discovery of the potential role of the chemical structure of antipsychotics in their therapeutic properties and metabolic disturbances. By developing structure-activity relationship studies for atypical antipsychotics, we will improve our understanding of the structural modifications of these chemical classes that lead to reduced weight gain, which will be an invaluable step toward the discovery of the next generation of atypical antipsychotics. In this review, we suggest that a novel dibenzodiazepine or thienobenzodiazepine antipsychotic drug with lower affinity for H(1) receptors may significantly advance schizophrenia therapy.

  1. Analysis of solvation and structural contributions in spectral characteristics of dipyrrin Zn(II) complexes.

    Science.gov (United States)

    Marfin, Yu S; Rumyantsev, E V

    2014-09-15

    Photophysical characteristics of several alkylated dipyrrin Zn(II) complexes in organic solvents were analyzed. Relations between spectral properties of complexes and physical-chemical parameters of solvents were determined with the use of linear regression analysis method. Each solvent parameter contribution in investigated spectral characteristics was estimated. Spectral properties of complexes under study depend on the specific interactions of zinc with the solvent molecules by specific axial coordination. Increasing of alkyl substitution lead to the bathochromic shifts in spectra due to the positive induction effect of alkyl groups.

  2. Analysis of solvation and structural contributions in spectral characteristics of dipyrrin Zn(II) complexes

    Science.gov (United States)

    Marfin, Yu. S.; Rumyantsev, E. V.

    2014-09-01

    Photophysical characteristics of several alkylated dipyrrin Zn(II) complexes in organic solvents were analyzed. Relations between spectral properties of complexes and physical-chemical parameters of solvents were determined with the use of linear regression analysis method. Each solvent parameter contribution in investigated spectral characteristics was estimated. Spectral properties of complexes under study depend on the specific interactions of zinc with the solvent molecules by specific axial coordination. Increasing of alkyl substitution lead to the bathochromic shifts in spectra due to the positive induction effect of alkyl groups.

  3. Contribution of 3D inversion of Electrical Resistivity Tomography data applied to volcanic structures

    Science.gov (United States)

    Portal, Angélie; Fargier, Yannick; Lénat, Jean-François; Labazuy, Philippe

    2016-04-01

    The electrical resistivity tomography (ERT) method, initially developed for environmental and engineering exploration, is now commonly used for geological structures imaging. Such structures can present complex characteristics that conventional 2D inversion processes cannot perfectly integrate. Here we present a new 3D inversion algorithm named EResI, firstly developed for levee investigation, and presently applied to the study of a complex lava dome (the Puy de Dôme volcano, France). EResI algorithm is based on a conventional regularized Gauss-Newton inversion scheme and a 3D non-structured discretization of the model (double grid method based on tetrahedrons). This discretization allows to accurately model the topography of investigated structure (without a mesh deformation procedure) and also permits a precise location of the electrodes. Moreover, we demonstrate that a complete 3D unstructured discretization limits the number of inversion cells and is better adapted to the resolution capacity of tomography than a structured discretization. This study shows that a 3D inversion with a non-structured parametrization has some advantages compared to classical 2D inversions. The first advantage comes from the fact that a 2D inversion leads to artefacts due to 3D effects (3D topography, 3D internal resistivity). The second advantage comes from the fact that the capacity to experimentally align electrodes along an axis (for 2D surveys) depends on the constrains on the field (topography...). In this case, a 2D assumption induced by 2.5D inversion software prevents its capacity to model electrodes outside this axis leading to artefacts in the inversion result. The last limitation comes from the use of mesh deformation techniques used to accurately model the topography in 2D softwares. This technique used for structured discretization (Res2dinv) is prohibed for strong topography (>60 %) and leads to a small computational errors. A wide geophysical survey was carried out

  4. Electronic structure contribution to hydrogen bonding interaction of a water dimer

    CERN Document Server

    Zhang, Zhiyuan; Wang, Bo; Wang, Zhigang

    2016-01-01

    Hydrogen bond (H-bond) covalency has recently been observed in ice and liquid water, while the penetrating molecular orbitals (MOs) in the H-bond region of most typical water dimer system, (H2O)2, have also been discovered. However, obtaining the quantitative contribution of these MOs to the H-bond interaction is still problematic. In this work, we introduced the orbital-resolved electron density projected integral (EDPI) along the H-bond to approach this problem. The calculations show that, surprisingly, the electronic occupied orbital (HOMO-4) of (H2O)2 accounts for about 40% of the electron density at the bond critical point. Moreover, the charge transfer analysis visualizes the electron accumulating effect of the orbital interaction within the H-bond between water molecules, supporting its covalent-like character. Our work expands the classical understanding of H-bond with specific contributions from certain MOs, and will also advance further research into such covalency and offer quantitative electronic ...

  5. Synthesis of well-defined structurally silica-nonlinear polymer core-shell nanoparticles via the surface-initiated atom transfer radical polymerization

    Science.gov (United States)

    Chen, Jiucun; Hu, Min; Zhu, Wendong; Li, Yaping

    2011-05-01

    We report on the synthesis of the well-defined structurally silica-nonlinear polymer core-shell nanoparticles via the surface-initiated atom transfer radical polymerization. At first, 3-(2-bromoisobutyramido)propyl(triethoxy)-silane (the ATRP initiator) was prepared by the reaction of 3-aminopropyltriethoxysilane with 2-bromoisobutyryl bromide. The ATRP initiator was covalently attached onto the nanosilica surface. The subsequent ATRP of HEMA from the initiator-attached SiO 2 surface was carried out in order to afforded functional nanoparticles bearing a hydroxyl moiety at the chain end, SiO 2-g-PHEMA-Br. The esterification reaction of pendent hydroxyl moieties of PHEMA segment with 2-bromoisobutyryl bromide afforded the SiO 2-based multifunctional initiator, SiO 2-g-PHEMA(-Br)-Br, bearing one bromine moiety on each monomer repeating unit within the PHEMA segment. Finally, the synthesis of SiO 2-g-PHEMA(-g-PSt)-b-PSt was accomplished by the ATRP of St monomer using SiO 2-g-PHEMA(-Br)-Br as multifunctional initiator. These organic/inorganic hybrid materials have been extensively characterized by FT-IR, XPS, TG, and TEM.

  6. Structure-interfacial properties relationship and quantification of the amphiphilicity of well-defined ionic and non-ionic surfactants using the PIT-slope method.

    Science.gov (United States)

    Ontiveros, Jesús F; Pierlot, Christel; Catté, Marianne; Molinier, Valérie; Salager, Jean-Louis; Aubry, Jean-Marie

    2015-06-15

    The Phase Inversion Temperature of a reference C10E4/n-Octane/Water system exhibits a quasi-linear variation versus the mole fraction of a second surfactant S2 added in the mixture. This variation was recently proposed as a classification tool to quantify the Hydrophilic-Lipophilic Balance (HLB) of commercial surfactants. The feasibility of the so-called PIT-slope method for a wide range of well-defined non-ionic and ionic surfactants is investigated. The comparison of various surfactants having the same dodecyl chain tail allows to rank the polar head hydrophilicity as: SO3Na⩾SO4Na⩾NMe3Br>E2SO3Na≈CO2Na⩾E1SO3Na⩾PhSO3Na>Isosorbide(exo)SO4Na≫IsosorbideendoSO4Na≫E8⩾NMe2O>E7>E6⩾Glucosyl>E5⩾Diglyceryl⩾E4>E3>E2≈Isosorbide(exo)>Glyceryl>Isosorbide(endo). The influence on the surfactant HLB of other structural parameters, i.e. hydrophobic chain length, unsaturation, replacement of Na(+) by K(+) counterion, and isomerism is also investigated. Finally, the method is successfully used to predict the optimal formulation of a new bio-based surfactant, 1-O-dodecyldiglycerol, when performing an oil scan at 25 °C.

  7. The Contribution of Family Structure and Differentiation to Identity Development in Females.

    Science.gov (United States)

    Perosa, Linda M.; And Others

    1996-01-01

    Relationships among S. Minuchin's structural family model, adolescent separation-individuation, and identity development were studied with 164 female undergraduates. Factor analysis of results from measures of ego identity support Minuchin's model and provide a framework for understanding individuation in the adolescent female. (SLD)

  8. A possible contribution of mRNA secondary structure to translation initiation efficiency in Lactococcus lactis

    NARCIS (Netherlands)

    Guchte, Maarten van de; Lende, Ted van der; Kok, Jan; Venema, Gerard

    1991-01-01

    Gene expression signals derived from Lactococcus lactis were linked to lacZ-fused genes with different 5'-nucleotide sequences. Computer predictions of mRNA secondary structure were combined with lacZ expression studies to direct base-substitutions that could possibly influence gene expression. Muta

  9. A review of structurally inspired approaches in housing studies: Concepts, contributions and future perspectives

    NARCIS (Netherlands)

    Lawson, J.M.

    2009-01-01

    Housing studies is a broad field, which has ploughed the disciplines of political economy, radical geography and sociology since the 1970s, making use of structural theories, concepts and methods. These studies have embroidered notions of human agency engaged in different aspects of housing provisio

  10. Cell surface attachment structures contribute to biofilm formation and xylem colonization by Erwinia amylovora.

    Science.gov (United States)

    Koczan, Jessica M; Lenneman, Bryan R; McGrath, Molly J; Sundin, George W

    2011-10-01

    Biofilm formation plays a critical role in the pathogenesis of Erwinia amylovora and the systemic invasion of plant hosts. The functional role of the exopolysaccharides amylovoran and levan in pathogenesis and biofilm formation has been evaluated. However, the role of biofilm formation, independent of exopolysaccharide production, in pathogenesis and movement within plants has not been studied previously. Evaluation of the role of attachment in E. amylovora biofilm formation and virulence was examined through the analysis of deletion mutants lacking genes encoding structures postulated to function in attachment to surfaces or in cellular aggregation. The genes and gene clusters studied were selected based on in silico analyses. Microscopic analyses and quantitative assays demonstrated that attachment structures such as fimbriae and pili are involved in the attachment of E. amylovora to surfaces and are necessary for the production of mature biofilms. A time course assay indicated that type I fimbriae function earlier in attachment, while type IV pilus structures appear to function later in attachment. Our results indicate that multiple attachment structures are needed for mature biofilm formation and full virulence and that biofilm formation facilitates entry and is necessary for the buildup of large populations of E. amylovora cells in xylem tissue.

  11. Nucleobase azide-ethynylribose click chemistry contributes to stabilizing oligonucleotide duplexes and stem-loop structures.

    Science.gov (United States)

    Kitamura, Yoshiaki; Asakura, Ryo; Terazawa, Koki; Shibata, Aya; Ikeda, Masato; Kitade, Yukio

    2017-06-15

    The formation of 1,4-disubstituted 1,2,3-triazoles through copper-catalyzed azide-alkyne cycloaddition (CuAAC) in oligonucleotides bearing 1-deoxy-1-ethynyl-β-d-ribofuranose (R(E)) can have a positive impact on the stability of oligonucleotide duplexes and stem-loop structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Biomass Structure and Its Contributions to Recalcitrance During Consolidated Bioprocessing with Clostridium Thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Akinosho, Hannah O. [Georgia Inst. of Technology, Atlanta, GA (United States)

    2017-07-01

    Each study provided compelling reasoning to strongly consider lignin’s part in limiting CBP efficiencies at the laboratory and eventually the industrial scale. To make cellulosic ethanol production feasible with CBP, lignin structure and content must be manipulated with genetic modifications or carefully selected in natural variants to combat these difficulties.

  13. Novel Structural Components Contribute to the High Thermal Stability of Acyl Carrier Protein from Enterococcus faecalis.

    Science.gov (United States)

    Park, Young-Guen; Jung, Min-Cheol; Song, Heesang; Jeong, Ki-Woong; Bang, Eunjung; Hwang, Geum-Sook; Kim, Yangmee

    2016-01-22

    Enterococcus faecalis is a Gram-positive, commensal bacterium that lives in the gastrointestinal tracts of humans and other mammals. It causes severe infections because of high antibiotic resistance. E. faecalis can endure extremes of temperature and pH. Acyl carrier protein (ACP) is a key element in the biosynthesis of fatty acids responsible for acyl group shuttling and delivery. In this study, to understand the origin of high thermal stabilities of E. faecalis ACP (Ef-ACP), its solution structure was investigated for the first time. CD experiments showed that the melting temperature of Ef-ACP is 78.8 °C, which is much higher than that of Escherichia coli ACP (67.2 °C). The overall structure of Ef-ACP shows the common ACP folding pattern consisting of four α-helices (helix I (residues 3-17), helix II (residues 39-53), helix III (residues 60-64), and helix IV (residues 68-78)) connected by three loops. Unique Ef-ACP structural features include a hydrophobic interaction between Phe(45) in helix II and Phe(18) in the α1α2 loop and a hydrogen bonding between Ser(15) in helix I and Ile(20) in the α1α2 loop, resulting in its high thermal stability. Phe(45)-mediated hydrophobic packing may block acyl chain binding subpocket II entry. Furthermore, Ser(58) in the α2α3 loop in Ef-ACP, which usually constitutes a proline in other ACPs, exhibited slow conformational exchanges, resulting in the movement of the helix III outside the structure to accommodate a longer acyl chain in the acyl binding cavity. These results might provide insights into the development of antibiotics against pathogenic drug-resistant E. faecalis strains.

  14. The contribution of off-shell gluons to the longitudinal structure function F{sub L}

    Energy Technology Data Exchange (ETDEWEB)

    Kotikov, A.V. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Lipatov, A.V. [Department of Physics, Lomonosov Moscow State University, 119899 Moscow (Russian Federation); Zotov, N.P. [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119992 Moscow (Russian Federation)

    2003-03-01

    We present the results for the structure function F{sub L} for a gluon target having a non-zero transverse momentum square at order {alpha}{sub s}. The results of a double convolution (with respect to the Bjorken variable x and the transverse momentum) of the perturbative part and the unintegrated gluon densities are compared with recent experimental data for F{sub L} at low x values and with the predictions of other approaches. (orig.)

  15. Contribution of subcortical structures to cognition assessed with invasive electrophysiology in humans

    Directory of Open Access Journals (Sweden)

    Thomas F Münte

    2008-07-01

    Full Text Available Implantation of deep brain stimulation (DBS electrodes via stereotactic neurosurgery has become a standard procedure for the treatment of Parkinson’s disease. More recently, the range of neuropsychiatric conditions and the possible target structures suitable for DBS have greatly increased. The former include obsessive compulsive disease, depression, obesity, tremor, dystonia, Tourette’s syndrome and cluster-headache. In this article we argue that several of the target structures for DBS (nucleus accumbens, posterior inferior hypothalamus, nucleus subthalamicus, nuclei in the thalamus, globus pallidus internus, nucleus pedunculopontinus are located at strategic positions with brain circuits related to motivational behaviors, learning, and motor regulation. Recording from DBS electrodes either during the operation or post-operatively from externalized leads while the patient is performing cognitive tasks tapping the functions of the respective circuits provides a new window on the brain mechanisms underlying these functions. This is exemplified by a study of a patient suffering from obsessive-compulsive disease from whom we recorded in a flanker task designed to tap action monitoring processes while he received a DBS electrode in the right nucleus accumbens. Clear error-related modulations were obtained from the target structure, demonstrating a role of the nucleus accumbens in action monitoring. Based on recent conceptualizations of several different functional loops and on neuroimaging results we suggest further lines of research using this new window on brain functions.

  16. Genetic variation in plant morphology contributes to the species-level structure of grassland communities.

    Science.gov (United States)

    Whitlock, Raj; Grime, J Phil; Burke, Terry

    2010-05-01

    It is becoming apparent that genetic diversity can influence the species diversity and structure of ecological communities. Here, we investigated the intraspecific trait variation responsible for this relationship. We grew 10 genotypes of the sedge Carex caryophyllea, as monocultures, under standardized conditions and measured traits related to morphology, growth, and life history. The same genotypes had been prominent in determining the structure of multispecies experimental communities, equivalent in species diversity, in which the genetic diversity of the constituent plant species had been varied in parallel. The trait measurements revealed substantial phenotypic variation among Carex genotypes, related predominantly to differences in physical size and to the spatial deployment of above- and belowground tissue. Genotypes successful in experimental communities were larger in size and tended to adopt a "guerrilla" clonal growth strategy. In general, multivariate trait summaries of genotype size (and to a lesser extent, variation along a linear discriminant axis) predicted genotype and species abundance in experimental communities. However, one genotype exhibited a large disparity in this respect. The performance of this genotype lay closer to prediction when it was growing with a highly competitive grass genotype. The strength of the relationship between genotype size and performance within communities decreased with decreasing community genetic diversity. These results indicate that intraspecific trait measurements are useful for predicting and understanding community structure. They also imply that competitive interactions between the genotypes of different species play an increased role in determining phenotype in genetically impoverished communities.

  17. Contributions of each isotope in structural material on radiation damage in a hybrid reactor

    Science.gov (United States)

    Günay, Mehtap

    2016-11-01

    In this study, the fluids were used in the liquid first-wall, blanket and shield zones of the designed hybrid reactor system. In this study, salt-heavy metal mixtures consisting of 93-85% Li20Sn80 + 5% SFG-PuO2 and 2-10% UO2, 93-85% Li20Sn80 + 5% SFG-PuO2 and 2-10% NpO2, and 93-85% Li20Sn80 + 5% SFG-PuO2 and 2-10% UCO were used as fluids. In this study, the effect on the radiation damage of spent fuel-grade (SFG)-PuO2, UO2, NpO2 and UCO contents was investigated in the structural material of a designed fusion-fission hybrid reactor system. In the designed hybrid reactor system were investigated the effect on the radiation damage of the selected fluid according to each isotopes of structural material in the structural material for 30 full power years (FPYs). Three-dimensional analyses were performed using the most recent MCNPX-2.7.0 Monte Carlo radiation transport code and the ENDF/B-VII.0 nuclear data library.

  18. Structural Biology Contributions to the Discovery of Drugs to Treat Chronic Myelogenous Leukemia

    Science.gov (United States)

    Cowan-Jacob, Sandra W.; Fendrich, Gabriele; Floersheimer, Andreas; Furet, Pascal; Liebetanz, Janis; Rummel, Gabriele; Rheinberger, Paul; Centeleghe, Mario; Fabbro, Doriano; Manley, Paul W.

    This case study illustrates how the determination of multiple co-crystal structures of the protein tyrosine kinase c-Abl was used to support drug discovery efforts leading to the design of nilotinib, a newly approved therapy for imatinib-intolerant and - resistant chronic myelogenous leukemia. Chronic myelogenous leukemia (CML) results from the BCR-Abl onco-protein, which possesses a constitutively activated Abl tyrosine kinase domain. Although many chronic-phase CML patients treated with imatinib as first-line therapy maintain excellent, durable responses, patients who have progressed to advanced-stage CML frequently fail, or lose their response to therapy, often due to the emergence of drug-resistant mutants of the protein. More than 60 such point mutations have been detected in imatinib-resistant patients. We determined the crystal structures of wild-type and mutant Abl kinase in complex with imatinib and other small molecule Abl inhibitors, with the aim of understanding the molecular basis for resistance and to aid in the design and optimization of inhibitors active against the resistance mutants. These results are presented in a way which illustrates the approaches used to generate multiple structures, the type of information that can be gained and the way this information is used to support drug discovery.

  19. Structural biology contributions to the discovery of drugs to treat chronic myelogenous leukaemia

    Energy Technology Data Exchange (ETDEWEB)

    Cowan-Jacob, Sandra W., E-mail: sandra.jacob@novartis.com; Fendrich, Gabriele; Floersheimer, Andreas; Furet, Pascal; Liebetanz, Janis; Rummel, Gabriele; Rheinberger, Paul; Centeleghe, Mario; Fabbro, Doriano; Manley, Paul W. [Novartis Institutes for Biomedical Research, Basel (Switzerland)

    2007-01-01

    A case study showing how the determination of multiple cocrystal structures of the protein tyrosine kinase c-Abl was used to support drug discovery, resulting in a compound effective in the treatment of chronic myelogenous leukaemia. Chronic myelogenous leukaemia (CML) results from the Bcr-Abl oncoprotein, which has a constitutively activated Abl tyrosine kinase domain. Although most chronic phase CML patients treated with imatinib as first-line therapy maintain excellent durable responses, patients who have progressed to advanced-stage CML frequently fail to respond or lose their response to therapy owing to the emergence of drug-resistant mutants of the protein. More than 40 such point mutations have been observed in imatinib-resistant patients. The crystal structures of wild-type and mutant Abl kinase in complex with imatinib and other small-molecule Abl inhibitors were determined, with the aim of understanding the molecular basis of resistance and to aid in the design and optimization of inhibitors active against the resistance mutants. These results are presented in a way which illustrates the approaches used to generate multiple structures, the type of information that can be gained and the way that this information is used to support drug discovery.

  20. Role of the Substrate Specificity-Defining Residues of Human SIRT5 in Modulating the Structural Stability and Inhibitory Features of the Enzyme.

    Directory of Open Access Journals (Sweden)

    Junru Yu

    Full Text Available Sirtuins are emerging as the key regulators of metabolism and aging, and their potential activators and inhibitors are being explored as therapeutics for improving health and treating associated diseases. Despite the global structural similarity among all seven isoforms of sirtuins (of which most of them catalyze the deacetylation reaction, SIRT5 is the only isoform that catalyzes the cleavage of negatively charged acylated substrates, and the latter feature appears to be encoded by the presence of Tyr102 and Arg105 residues at the active site pocket of the enzyme. To determine the contributions of the above residues in SIRT5 (vis a vis the corresponding residues of SIRT1 on substrate selectivity, inhibition by EX527 and nicotinamide, secondary structural features and thermal stability of the enzymes, we created single and double mutations (viz. Y102A, R105l, and Y102A/R105I in SIRT5. The kinetic data revealed that while Y102A mutant enzyme catalyzed both deacetylation and desuccinylation reactions with comparable efficiencies, R105I and Y102A/R105I mutant enzymes favored the deacetylase reaction. Like SIRT1, the nicotinamide inhibition of SIRT5 double mutant (Y102A/R105I exhibited the mixed non-competitive behavior. On the other hand, the desuccinylation reaction of both wild-type and Y102A mutant enzymes conformed to the competitive inhibition model. The inhibitory potency of EX527 progressively increased from Y102A, R105I, to Y102A/R105 mutant enzymes in SIRT5, but it did not reach to the level obtained with SIRT1. The CD spectroscopic data for the wild-type and mutant enzymes revealed changes in the secondary structural features of the enzymes, and such changes were more pronounced on examining their thermal denaturation patterns. A cumulative account of our experimental data reveal mutual cooperation between Y102 and R105 residues in promoting the desuccinylation versus deacetylation reaction in SIRT5, and the overall catalytic feature of

  1. Analysis of ABCB phosphoglycoproteins (PGPs) and their contribution to monocot biomass, structural stability, and productivity

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Angus Stuart [Purdue University

    2014-09-23

    Efforts to manipulate production of plant secondary cell walls to improve the quality of biofuel feedstocks are currently limited by an inability to regulate the transport of small molecule components out of the cell. Plant ABCB p-glycoproteins are a small family of plasma membrane organic molecule transporters that have become primary targets for this effort, as they can potentially be harnessed to control the export of aromatic compounds and organic acids. However, unlike promiscuous mammalian ABCBs that function in multidrug resistance, all plant ABCB proteins characterized to date exhibit relatively narrow substrate specificity. Although ABCBs exhibit a highly conserved architecture, efforts to modify ABCB activity have been hampered by a lack of structural information largely because an eukaryotic ABCB protein crystal structure has yet to be obtained. Structure/ function analyses have been further impeded by the lack of a common heterologous expression system that can be used to characterize recombinant ABCB proteins, as many cannot be functionally expressed in S. cereviseae or other systems where proteins with analogous function can be readily knocked out. Using experimentally-determined plant ABCB substrate affinities and the crystal structure of the bacterial Sav1866 “half” ABC transporter, we have developed sequence/structure models for ABCBs that provide a testable context for mutational analysis of plant ABCB transporters. We have also developed a flexible heterologous expression system in Schizosaccharomyces pombe in which all endogenous ABC transporters have been knocked out. The effectiveness of this system for transport studies has been demonstrated by the successful functional expression all of the known PIN, AUX/LAX and ABCB auxin transporters. Our central hypothesis is that the domains of the ABCB proteins that we have identified as substrate docking sites and regulators of transport directionality can be altered or swapped to alter the

  2. Thermochemical properties and contribution groups for ketene dimers and related structures from theoretical calculations.

    Science.gov (United States)

    Morales, Giovanni; Martínez, Ramiro

    2009-07-30

    This research's main goals were to analyze ketene dimers' relative stability and expand group additivity value (GAV) methodology for estimating the thermochemical properties of high-weight ketene polymers (up to tetramers). The CBS-Q multilevel procedure and statistical thermodynamics were used for calculating the thermochemical properties of 20 cyclic structures, such as diketenes, cyclobutane-1,3-diones, cyclobut-2-enones and pyran-4-ones, as well as 57 acyclic base compounds organized into five groups. According to theoretical heat of formation predictions, diketene was found to be thermodynamically favored over cyclobutane-1,3-dione and its enol-tautomeric form (3-hydroxycyclobut-2-enone). This result did not agree with old combustion experiments. 3-Hydroxycyclobut-2-enone was found to be the least stable dimer and its reported experimental detection in solution may have been due to solvent effects. Substituted diketenes had lower stability than substituted cyclobutane-1,3-diones with an increased number of methyl substituents, suggesting that cyclobutane-1,3-dione type dimers are the major products because of thermodynamic control of alkylketene dimerization. Missing GAVs for the ketene dimers and related structures were calculated through linear regression on the 57 acyclic base compounds. Corrections for non next neighbor interactions (such as gauche, eclipses, and internal hydrogen bond) were needed for obtaining a highly accurate and precise regression model. To the best of our knowledge, the hydrogen bond correction for GAV methodology is the first reported in the literature; this correction was correlated to MP2/6-31Gdagger and HF/6-31Gdagger derived geometries to facilitate its application. GAVs assessed by the linear regression model were able to reproduce acyclic compounds' theoretical thermochemical properties and experimental heat of formation for acetylacetone. Ring formation and substituent position corrections were calculated by consecutively

  3. Contribution of spoligotyping to the characterization of the population structure of Mycobacterium tuberculosis isolates in Portugal.

    Science.gov (United States)

    David, Suzana; Ribeiro, Diana Raposo; Antunes, Abílio; Portugal, Clara; Sancho, Luísa; de Sousa, José Germano

    2007-09-01

    Tuberculosis is a major health problem in Portugal. To begin characterizing the population structure of Mycobacterium tuberculosis, spoligotyping was used for the systematic typing, through consecutive sampling, of patient isolates from the Amadora-Sintra area of Greater Lisbon. Distribution amongst major spoligotype families, including the Latin American Mediterranean (LAM), T, Haarlem and Beijing, was compared to that of the international spoligotype database SpolDB4 and to the European countries of traditional Portuguese immigration represented in SpolDB4. Spoligotypes from 665 isolates were analyzed and 97 shared international types (SITs) identified. In SpolDB4 Portugal is represented by part of the spoligotypes from this study explaining the reduced number of unidentified patterns. The importance of the LAM family, and especially of LAM1 and LAM9 sub-families that alone represented 38% of all the isolates in this study as compared to 8% relative to the European sub group, led us to believe that at least in this respect the population structure was closer to that of Africa and South America than to Europe. Spoligotypes characteristic of Portugal or Portuguese related settings were identified. These included SIT244 a T1 sub-family predominant in Portugal and Bangladesh, SIT64 a LAM 6 sub-family common to Portugal and Brazil, and SIT1106 a LAM 9 sub-family. These studies were the first in Portugal stressing the importance of monitoring the population structure of M. tuberculosis isolates, an important step towards gaining an understanding of tuberculosis and the dynamics of this disease.

  4. CONTRIBUTION OF SATELLITE ALTIMETRY DATA IN GEOLOGICAL STRUCTURE RESEARCH IN THE SOUTH CHINA SEA

    Directory of Open Access Journals (Sweden)

    T. D. Tran

    2016-06-01

    Full Text Available The study area is bordered on the East China Sea, the Philippine Sea, and the Australian-Indo plate in the Northeast, in the East and in the South, respectively. It is a large area with the diversely complicated conditions of geological structure. In spite of over the past many years of investigation, marine geological structure in many places have remained poorly understood because of a thick seawater layer as well as of the sensitive conflicts among the countries in the region. In recent years, the satellite altimeter technology allows of enhancement the marine investigation in any area. The ocean surface height is measured by a very accurate radar altimeter mounted on a satellite. Then, that surface can be converted into marine gravity anomaly or bathymetry by using the mathematical model. It is the only way to achieve the data with a uniform resolution in acceptable time and cost. The satellite altimetry data and its variants are essential for understanding marine geological structure. They provide a reliable opportunity to geologists and geophysicists for studying the geological features beneath the ocean floor. Also satellite altimeter data is perfect for planning the more detailed shipboard surveys. Especially, it is more meaningful in the remote or sparsely surveyed regions. In this paper, the authors have effectively used the satellite altimetry and shipboard data in combination. Many geological features, such as seafloor spreading ridges, fault systems, volcanic chains as well as distribution of sedimentary basins are revealed through the 2D, 3D model methods of interpretation of satellite-shipboard-derived data and the others. These results are improved by existing boreholes and seismic data in the study area.

  5. Local and transient structural changes in stratum corneum at high electric fields: contribution of Joule heating.

    Science.gov (United States)

    Pliquett, U; Gallo, S; Hui, S W; Gusbeth, Ch; Neumann, E

    2005-09-01

    Electroporation of skin is accompanied by local heating, such that thermally induced structural changes of the stratum corneum (SC) accompany the field effect. Comparing on the time scale, the local changes in structure, temperature and conductance of the SC, during and after the pulse, it is seen that Joule heating also facilitates the subsequent molecular transport. It is found that the transport of medium-sized, ionic molecules occurs through localized transport regions (LTR). The size of a LTR increases with the pulse length, whereas the density of the LTRs increases with increasing voltage, for instance at U(SC=)80 V, the LTR cover approximately 0.02--1% of the surface area. The state of low resistance within the LTR is long-lived. During high voltage application, the center of the LTR is heated above the phase transition temperature of the SC lipids (70 degrees C) and the heat front propagates outwards. Inside the SC, the pulse causes aggregates of small-sized vesicles. At a higher temperature, the aggregate formation and their disappearance are delayed. Multiple pulses with the applied voltage of U(appl)=80 V induce the formation of long-lasting vesicle aggregates with a diameter of slashed circle=1--30 microm, covering 0.05--0.5% of the total sample area. The electric energy dissipated within the LTR during high voltage application is apparently sufficient to raise the temperature well above the phase transition temperature of the lipids of the SC, accounting for the conformational changes from the multi-lamella to the vesicular structures.

  6. Contribution of Satellite Altimetry Data in Geological Structure Research in the South China Sea

    Science.gov (United States)

    Dung Tran, Tuan; Ho, Thi Huong Mai

    2016-06-01

    The study area is bordered on the East China Sea, the Philippine Sea, and the Australian-Indo plate in the Northeast, in the East and in the South, respectively. It is a large area with the diversely complicated conditions of geological structure. In spite of over the past many years of investigation, marine geological structure in many places have remained poorly understood because of a thick seawater layer as well as of the sensitive conflicts among the countries in the region. In recent years, the satellite altimeter technology allows of enhancement the marine investigation in any area. The ocean surface height is measured by a very accurate radar altimeter mounted on a satellite. Then, that surface can be converted into marine gravity anomaly or bathymetry by using the mathematical model. It is the only way to achieve the data with a uniform resolution in acceptable time and cost. The satellite altimetry data and its variants are essential for understanding marine geological structure. They provide a reliable opportunity to geologists and geophysicists for studying the geological features beneath the ocean floor. Also satellite altimeter data is perfect for planning the more detailed shipboard surveys. Especially, it is more meaningful in the remote or sparsely surveyed regions. In this paper, the authors have effectively used the satellite altimetry and shipboard data in combination. Many geological features, such as seafloor spreading ridges, fault systems, volcanic chains as well as distribution of sedimentary basins are revealed through the 2D, 3D model methods of interpretation of satellite-shipboard-derived data and the others. These results are improved by existing boreholes and seismic data in the study area.

  7. Fibre cables in the lacunae of Typha leaves contribute to a tensegrity structure.

    Science.gov (United States)

    Witztum, Allan; Wayne, Randy

    2014-04-01

    Cables composed of long, non-lignified fibre cells enclosed in a cover of much shorter thin-walled, crystal-containing cells traverse the air chambers (lacunae) in leaves of the taller species of Typha. The non-lignified fibre cables are anchored in diaphragms composed of stellate cells of aerenchyma tissue that segment the long air chambers into smaller compartments. Although the fibre cables are easily observed and can be pulled free from the porous-to-air diaphragms, their structure and function have been ignored or misinterpreted. Leaves of various species of Typha were dissected and fibre cables were pulled free and observed with a microscope using bright-field and polarizing optics. Maximal tensile strength of freshly removed cables was measured by hanging weights from fibre cables, and Instron analysis was used to produce curves of load versus extension until cables broke. Polarized light microscopy revealed that the cellulose microfibrils that make up the walls of the cable fibres are oriented parallel to the long axis of the fibres. This orientation ensures that the fibre cables are mechanically stiff and strong under tension. Accordingly, the measured stiffness and tensile strength of the fibre cables were in the gigapascal range. In combination with the dorsal and ventral leaf surfaces and partitions that contain lignified fibre bundles and vascular strands that are strong in compression, the very fine fibre cables that are strong under tension form a tensegrity structure. The tensegrity structure creates multiple load paths through which stresses are redistributed throughout the 1-3 m tall upright leaves of Typha angustifolia, T. latifolia, T. × glauca, T. domingensis and T. shuttleworthii. The length of the fibre cables relative to the length of the leaf blades is reduced in the last-formed leaves of flowering individuals. Fibre cables are absent in the shorter leaves of Typha minima and, if present, only extend for a few centimetres from the sheath

  8. Contribution of lianas to plant area index and canopy structure in a Panamanian forest.

    Science.gov (United States)

    Rodríguez-Ronderos, M Elizabeth; Bohrer, Gil; Sanchez-Azofeifa, Arturo; Powers, Jennifer S; Schnitzer, Stefan A

    2016-12-01

    Lianas are an important component of tropical forests, where they reduce tree growth, fecundity, and survival. Competition for light from lianas may be intense; however, the amount of light that lianas intercept is poorly understood. We used a large-scale liana-removal experiment to quantify light interception by lianas in a Panamanian secondary forest. We measured the change in plant area index (PAI) and forest structure before and after cutting lianas (for 4 yr) in eight 80 m × 80 m plots and eight control plots (16 plots total). We used ground-based LiDAR to measure the 3-dimensional canopy structure before cutting lianas, and then annually for 2 yr afterwards. Six weeks after cutting lianas, mean plot PAI was 20% higher in control vs. liana removal plots. One yr after cutting lianas, mean plot PAI was ~17% higher in control plots. The differences between treatments diminished significantly 2 yr after liana cutting and, after 4 yr, trees had fully compensated for liana removal. Ground-based LiDAR revealed that lianas attenuated light in the upper- and middle-forest canopy layers, and not only in the upper canopy as was previously suspected. Thus, lianas compete with trees by intercepting light in the upper- and mid-canopy of this forest.

  9. The mycorrhizal contribution to plant productivity, plant nutrition and soil structure in experimental grassland.

    Science.gov (United States)

    van der Heijden, Marcel G A; Streitwolf-Engel, Ruth; Riedl, Ralph; Siegrist, Sabine; Neudecker, Angelica; Ineichen, Kurt; Boller, Thomas; Wiemken, Andres; Sanders, Ian R

    2006-01-01

    Previous studies have shown that arbuscular mycorrhizal fungi (AMF) can influence plant diversity and ecosystem productivity. However, little is known about the effects of AMF and different AMF taxa on other important community properties such as nutrient acquisition, plant survival and soil structure. We established experimental grassland microcosms and tested the impact of AMF and of different AMF taxa on a number of grassland characteristics. We also tested whether plant species benefited from the same or different AMF taxa in subsequent growing seasons. AMF enhanced phosphorus acquisition, soil aggregation and survival of several plant species, but AMF did not increase total plant productivity. Moreover, AMF increased nitrogen acquisition by some plant species, but AMF had no effect on total N uptake by the plant community. Plant growth responses to AMF were temporally variable and some plant species obtained the highest biomass with different AMF in different years. Hence the results indicate that it may be beneficial for a plant to be colonized by different AMF taxa in different seasons. This study shows that AMF play a key role in grassland by improving plant nutrition and soil structure, and by regulating the make-up of the plant community.

  10. Higher twist contributions to the structure functions F{sub 2}(x, Q{sup 2}) and g{sub 2}(x, Q{sup 2})

    Energy Technology Data Exchange (ETDEWEB)

    Bluemlein, Johannes; Boettcher, Helmut

    2012-07-15

    We report on recent results on higher twist contributions to the unpolarized structure functions F{sup p,d}{sub 2}(x,Q{sup 2}) at N{sup 3}LO in the large x region and constraints on the twist-3 contribution to polarized structure function g{sub 2}(x,Q{sup 2}).

  11. Does the structure of wood contribute to understanding the oaks decline phenomenon?

    Directory of Open Access Journals (Sweden)

    Mirela Tulik

    2014-04-01

    Full Text Available Vascular cambium is a meristematic tissue which produces wood centriphugaly and phloem centripetaly. In the structure of wood and phloem, data concerning developmental processes taking place in the cambium is recorded. The history of the cambium is encoded in the dimensions, numbers and arrangements of the wood and phloem cells. For investigations, the wood is usually preferred because it is durable and such data could remain unchanged for centuries, whereas in the phloem due to distorted processes, it deranges after a few years. In broadleaves, the wood is composed of vessels, tracheids, fibers and parenchyma cells. The process of the wood formation consists of the cambial cell derivatives expansion, lignification of its walls and programmed cell death. Since the seventies of the nineteenth century, the process of declining oaks taking place in Europe on a regular basis has been observed. Oak decline is a complex process that involves interactions of both biotic and abiotic factors leading to increased trees mortality. The main goal of the studies is the examination of the structure of wood in declining oaks (Quercus robur L. in respect to physiological (conductive role of this tissue. It is known that on the level of the wood structure, water transport efficiency depends on the diameter of vessels - the main elements of the hydraulic conductivity system. Any reduction of the vessels lumen causes the reduction of the water transport to the organs of the trees body and, therefore, influences organisms survival rate. Anatomical analyses were carried out on wood samples (comprising all annual rings formed during the 30-40 years life of the analyzed trees collected at breast height from the main stem of healthy, weakened and dead oaks. The anatomical traits of the wood like as the width of the annual increments, the diameter and density of early wood vessels were measured. The results which are described in the paper by Tulik (2014 revealed that

  12. Advancement of the 10-species subgingival Zurich Biofilm model by examining different nutritional conditions and defining the structure of the in vitro biofilms

    Directory of Open Access Journals (Sweden)

    Ammann Thomas W

    2012-10-01

    Full Text Available Abstract Background Periodontitis is caused by a highly complex consortium of bacteria that establishes as biofilms in subgingival pockets. It is a disease that occurs worldwide and its consequences are a major health concern. Investigations in situ are not possible and the bacterial community varies greatly between patients and even within different loci. Due to the high complexity of the consortium and the availability of samples, a clear definition of the pathogenic bacteria and their mechanisms of pathogenicity are still not available. In the current study we addressed the need of a defined model system by advancing our previously described subgingival biofilm model towards a bacterial composition that reflects the one observed in diseased sites of patients and analysed the structure of these biofilms. Results We further developed the growth media by systematic variation of key components resulting in improved stability and the firm establishment of spirochetes in the 10-species subgingival Zurich biofilm model. A high concentration of heat-inactivated human serum allowed the best proliferation of the used species. Therefore we further investigated these biofilms by analysing their structure by confocal laser scanning microscopy following fluorescence in situ hybridisation. The species showed mutual interactions as expected from other studies. The abundances of all organisms present in this model were determined by microscopic counting following species-specific identification by both fluorescence in situ hybridisation and immunofluorescence. The newly integrated treponemes were the most abundant organisms. Conclusions The use of 50% of heat-inactivated human serum used in the improved growth medium resulted in significantly thicker and more stable biofilms, and the quantitative representation of the used species represents the in vivo community of periodontitis patients much closer than in biofilms grown in the two media with less or no

  13. Advancement of the 10-species subgingival Zurich biofilm model by examining different nutritional conditions and defining the structure of the in vitro biofilms.

    Science.gov (United States)

    Ammann, Thomas W; Gmür, Rudolf; Thurnheer, Thomas

    2012-10-05

    Periodontitis is caused by a highly complex consortium of bacteria that establishes as biofilms in subgingival pockets. It is a disease that occurs worldwide and its consequences are a major health concern. Investigations in situ are not possible and the bacterial community varies greatly between patients and even within different loci. Due to the high complexity of the consortium and the availability of samples, a clear definition of the pathogenic bacteria and their mechanisms of pathogenicity are still not available. In the current study we addressed the need of a defined model system by advancing our previously described subgingival biofilm model towards a bacterial composition that reflects the one observed in diseased sites of patients and analysed the structure of these biofilms. We further developed the growth media by systematic variation of key components resulting in improved stability and the firm establishment of spirochetes in the 10-species subgingival Zurich biofilm model. A high concentration of heat-inactivated human serum allowed the best proliferation of the used species. Therefore we further investigated these biofilms by analysing their structure by confocal laser scanning microscopy following fluorescence in situ hybridisation. The species showed mutual interactions as expected from other studies. The abundances of all organisms present in this model were determined by microscopic counting following species-specific identification by both fluorescence in situ hybridisation and immunofluorescence. The newly integrated treponemes were the most abundant organisms. The use of 50% of heat-inactivated human serum used in the improved growth medium resulted in significantly thicker and more stable biofilms, and the quantitative representation of the used species represents the in vivo community of periodontitis patients much closer than in biofilms grown in the two media with less or no human serum. The appearance of T. denticola, P. gingivalis, and

  14. On the contribution of large scale structure to strong gravitational lensing

    CERN Document Server

    Faure, C; Hilbert, S; Massey, R; Covone, G; Finoguenov, A; Leauthaud, A; Taylor, J E; Pires, S; Scoville, N

    2008-01-01

    We study the correlation between the locations of galaxy-galaxy strong lensing candidates and tracers of large-scale structure from both weak lensing or X-ray emission. The COSMOS survey is a unique data set, combining deep, high resolution and contiguous imaging in which strong lenses have been discovered, plus unparalleled multiwavelength coverage. To help interpret the COSMOS data, we have also produced mock COSMOS strong and weak lensing observations, based on ray-tracing through the Millenium simulation. In agreement with the simulations, we find that strongly lensed images with the largest angular separations are found in the densest regions of the COSMOS field. This is explained by a prevalence among the lens population in dense environments of elliptical galaxies with high total-to-stellar mass ratios, which can deflect light through larger angles. However, we also find that the overall fraction of elliptical galaxies with strong gravitational lensing is independent of the local mass density; this obs...

  15. Estimation of Formation Enthalpies of Organic Pollutants from a New Structural Group Contribution Method

    Institute of Scientific and Technical Information of China (English)

    Mehdi Bagheri; Afshin Bakhtiari; Masoume Jaberi

    2013-01-01

    Chemical stability and reactivity of organic pollutants is dependent to their formation enthalpies.The main objective of this study is to provide simple straightforward strategy for prediction of the formation enthalpies of wide range organic pollutants only from their structural functional groups.Using such an extended dataset comprising 1694 organic chemicals from 77 diverse material classes benefits the generalizability and reliability of the study.The new suggested collection of 12 functional groups and a simple linear regression lead to promising statistics of R2=0.958,Q2Loo =0.956,and δAEE=57 kJ·mol-1 for the whole dataset.Moreover,unknown experimental formation enthalpies for 27 organic pollutants are estimated by the presented approach.The resultant model needs no technical software/calculations,and thus can be easily applied by a non-specialist user.

  16. The contribution of structural-, psittacofulvin- and melanin-based colouration to sexual dichromatism in Australasian parrots.

    Science.gov (United States)

    Taysom, A J; Stuart-Fox, D; Cardoso, G C

    2011-02-01

    Colour ornamentation in animals is exceptionally diverse, but some colours may provide better signals of individual quality or more efficient visual stimuli and, thus, be more often used as sexual signals. This may depend on physiological costs, which depend on the mechanism of colour production (e.g. exogenously acquired colouration in passerine birds appears to be most sexually dichromatic). We studied sexual dichromatism in a sample of 27 Australasian parrot species with pigment- (melanin and psittacofulvin) and structural-based colouration, to test whether some of these types of colouration are more prominent in sexual ornamentation. Unlike passerines, in which long wavelength colouration (yellow to red) usually involves exogenous and costly carotenoid pigments, yellow to red colouration in parrots is based on endogenously synthesized psittacofulvin pigments. This allows us to assess whether costly exogenous pigments are necessary for these plumage colours to have a prominent role in sexual signalling. Structural blue colouration showed the largest and most consistent sexual dichromatism, both in area and perceptually relevant chromatic differences, indicating that it is often ornamental in parrots. By contrast, we found little evidence for consistent sexual dichromatism in melanin-based colouration. Unlike passerines, yellow to red colouration was not strongly sexually dichromatic: although the area of colouration was generally larger in males, colour differences between the sexes were on average imperceptible to parrots. This is consistent with the idea that the prominent yellow to red sexual dichromatism in passerines is related to the use of carotenoid pigments, rather than resulting from sensory bias for these colours.

  17. Defining the minimal structural requirements for partial agonism at the type I myo-inositol 1,4,5-trisphosphate receptor.

    Science.gov (United States)

    Wilcox, R A; Fauq, A; Kozikowski, A P; Nahorski, S R

    1997-02-03

    The novel synthetic analogues D-3-fluoro-myo-inositol 1,5-bisphosphate-4-phosphorothioate, [3F-Ins(1,5)P2-4PS], D-3-fluoro-myo-inositol 1,4-bisphosphate-5-phosphorothioate [3F-Ins(1,4)P2-5PS], and D-3-fluoro-myo-inositol 1-phosphate-4,5-bisphosphorothioate [3F-Ins(1)P-(4,5)PS2] were utilised to define the structure-activity relationships which could produce partial agonism at the Ca2+ mobilising myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] receptor. Based on prior structure-activity data we hypothesised that the minimal structural requirements for lns(1,4,5)P3 receptor partial agonism, were phosphorothioate substitution of the crucial vicinal 4,5-bisphosphate pair accompanied by another structural perturbation, such fluorination of 3-position of the myo-inositol ring. All the analogues fully displaced [3H]Ins(1,4,5)P3 from a single Ins(1,4,5)P3 binding site in pig cerebellar membranes [3F-Ins(1,5)P2-4PS (1C50 = 26 nM), 3F-Ins(1,4)P2-5PS (IC50 = 80 nM) and 3F-Ins(1)P-(4,5)PS2 (IC50 = 109 nM) cf. Ins(1,4,5)P3 (IC50 = 11 nM)]. In contrast, 3F-Ins(1,5)P2-4PS (IC50 = 424 nM) and 3F-Ins(1,4)P2-5PS (IC50 = 3579 nM) were weak full agonists at the Ca2+ mobilising Ins(1,4,5)P3 receptor of permeabilised SH-SY5Y neuroblastoma cells, being respectively 4- and 36-fold less potent than Ins(1,4,5)P3 (EC50 = 99 nM). While 3F-Ins(1)P-(4,5)PS2 (EC50 = 11345 nM) was a partial agonist releasing only 64.3 +/- 1.9% of the Ins(1,4,5)P3-sensitive intracellular Ca2+ pools. 3F-Ins(1)P-(4,5)PS2 was unique among the Ins(1,4,5)P3 receptor partial agonists so far identified in having a relatively high affinity for the Ins(1,4,5)P3 binding site, accompanied by a significant loss of intrinsic activity for Ca2+ mobilisation. This improved affinity was probably due to the retention of the 1-position phosphate, which enhances interaction with the Ins-(1,4,5)P3 receptor. 3F-Ins(1)P-(4,5)PS2 may be an important lead compound for the development of efficient Ins(1,4,5)P3 receptor antagonists.

  18. [Clinical research. XIII. Research design contribution in the structured revision of an article].

    Science.gov (United States)

    Talavera, Juan O; Rivas-Ruiz, Rodolfo

    2013-01-01

    The quality of information obtained in accordance to research design is integrated to the revision structured in relation to the causality model, used in the article "Reduction in the Incidence of Nosocomial Pneumonia Poststroke by Using the 'Turn-mob' Program", which corresponds to a clinical trial design. Points to identify and analyze are ethical issues in order to safeguard the security and respect for patients, randomization that seek to create basal homogeneous groups, subjects with the same probability of receiving any of the maneuvers in comparison, with the same pre maneuver probability of adherence, and which facilitate the blinding of outcome measurement and the distribution between groups of subjects with the same probability of leaving the study for reasons beyond the maneuvers. Other aspects are the relativity of comparison, the blinding of the maneuver, the parallel application of comparative maneuver, early stopping, and analysis according to the degree of adherence. The analysis in accordance with the design is complementary, since it is done based on the architectural model of causality, and the statistical and clinical relevance consideration.

  19. Transposon Insertions, Structural Variations, and SNPs Contribute to the Evolution of the Melon Genome.

    Science.gov (United States)

    Sanseverino, Walter; Hénaff, Elizabeth; Vives, Cristina; Pinosio, Sara; Burgos-Paz, William; Morgante, Michele; Ramos-Onsins, Sebastián E; Garcia-Mas, Jordi; Casacuberta, Josep Maria

    2015-10-01

    The availability of extensive databases of crop genome sequences should allow analysis of crop variability at an unprecedented scale, which should have an important impact in plant breeding. However, up to now the analysis of genetic variability at the whole-genome scale has been mainly restricted to single nucleotide polymorphisms (SNPs). This is a strong limitation as structural variation (SV) and transposon insertion polymorphisms are frequent in plant species and have had an important mutational role in crop domestication and breeding. Here, we present the first comprehensive analysis of melon genetic diversity, which includes a detailed analysis of SNPs, SV, and transposon insertion polymorphisms. The variability found among seven melon varieties representing the species diversity and including wild accessions and highly breed lines, is relatively high due in part to the marked divergence of some lineages. The diversity is distributed nonuniformly across the genome, being lower at the extremes of the chromosomes and higher in the pericentromeric regions, which is compatible with the effect of purifying selection and recombination forces over functional regions. Additionally, this variability is greatly reduced among elite varieties, probably due to selection during breeding. We have found some chromosomal regions showing a high differentiation of the elite varieties versus the rest, which could be considered as strongly selected candidate regions. Our data also suggest that transposons and SV may be at the origin of an important fraction of the variability in melon, which highlights the importance of analyzing all types of genetic variability to understand crop genome evolution.

  20. Distinct structural alterations independently contributing to working memory deficits and symptomatology in paranoid schizophrenia.

    Science.gov (United States)

    Zierhut, Kathrin C; Schulte-Kemna, Anna; Kaufmann, Jörn; Steiner, Johann; Bogerts, Bernhard; Schiltz, Kolja

    2013-04-01

    Schizophrenia is considered a brain disease with a quite heterogeneous clinical presentation. Studies in schizophrenia have yielded a wide array of correlations between structural and functional brain changes and clinical and cognitive symptoms. Reductions of grey matter volume (GMV) in the prefrontal and temporal cortex have been described which are crucial for the development of positive and negative symptoms and impaired working memory (WM). Associations between GMV reduction and positive and negative symptoms as well as WM impairment were assessed in schizophrenia patients (symptomatology in 34, WM in 26) and compared to healthy controls (36 total, WM in 26). GMV was determined by voxel-based morphometry and its relation to positive and negative symptoms as well as WM performance was assessed. In schizophrenia patients, reductions of GMV were evident in anterior cingulate cortex, ventrolateral prefrontal cortex (VLPFC), superior temporal cortex, and insula. GMV reductions in the superior temporal gyrus (STG) were associated with positive symptom severity as well as WM impairment. Furthermore, the absolute GMV of VLPFC was strongly related to negative symptoms. These predicted WM performance as well as processing speed. The present results support the assumption of two distinct pathomechanisms responsible for impaired WM in schizophrenia: (1) GMV reductions in the VLPFC predict the severity of negative symptoms. Increased negative symptoms in turn are associated with a slowing down of processing speed and predict an impaired WM. (2) GMV reductions in the temporal and mediofrontal cortex are involved in the development of positive symptoms and impair WM performance, too.

  1. Rare species contribute disproportionately to the functional structure of species assemblages.

    Science.gov (United States)

    Leitão, Rafael P; Zuanon, Jansen; Villéger, Sébastien; Williams, Stephen E; Baraloto, Christopher; Fortunel, Claire; Mendonça, Fernando P; Mouillot, David

    2016-04-13

    There is broad consensus that the diversity of functional traits within species assemblages drives several ecological processes. It is also widely recognized that rare species are the first to become extinct following human-induced disturbances. Surprisingly, however, the functional importance of rare species is still poorly understood, particularly in tropical species-rich assemblages where the majority of species are rare, and the rate of species extinction can be high. Here, we investigated the consequences of local and regional extinctions on the functional structure of species assemblages. We used three extensive datasets (stream fish from the Brazilian Amazon, rainforest trees from French Guiana, and birds from the Australian Wet Tropics) and built an integrative measure of species rarity versus commonness, combining local abundance, geographical range, and habitat breadth. Using different scenarios of species loss, we found a disproportionate impact of rare species extinction for the three groups, with significant reductions in levels of functional richness, specialization, and originality of assemblages, which may severely undermine the integrity of ecological processes. The whole breadth of functional abilities within species assemblages, which is disproportionately supported by rare species, is certainly critical in maintaining ecosystems particularly under the ongoing rapid environmental transitions.

  2. Quality of Family Relationships: The Contributions of Family Structures and Gender – Role Orientations

    Directory of Open Access Journals (Sweden)

    Adebayo Sulaiman Olanrewaju

    2015-06-01

    Full Text Available Since the whole human population are products of the family, it may be deduced that a substantial proportion of the social-vices besieging the modern world emanate from maladaptive socialization process of the family domain. To achieve a capable and positive functioning socialization process, harmonious and healthy relationships must be ensured among and between each member of the family. Taking into consideration the overarching positive influence of valuable family relationship on healthy family lives, it is highly essential to investigate the predicting factors of good family relationships. Accordingly, this study tested whether family structures and gender role orientations would predict quality of family relationships. Ninety-eight participants who were selected using cluster sampling method from Ekiti State University, Ado-Ekiti, Nigeria, completed self-report instruments comprising of Index of Family Relations (IFR, Bem Sex-Role Inventory (BSRI and the Personal Data Sheet (PDS. Hypotheses were tested using one-way ANOVA and multiple regressions. Findings suggest that participants from traditional marriage families reported better family relationships than those from single-parent, divorced and court/legal marriage families. Additionally, the expression of feminine traits by family members (regardless of sex seems to account for a well knitted family relationship than the expression of the nearly feminine trait, androgynous trait and nearly masculine trait. Results were discussed in line with previous literature and it was recommended that traditional/customary marriage should not be jettisoned in the process of family formation but should be done in conjunction with court/legal marriage. Similarly, the expression of feminine traits by each family member regardless of their sex should be encouraged to forestall family conflicts and ensure good family relations.

  3. Factors contributing to academic achievement: a Bayesian structure equation modelling study

    Science.gov (United States)

    Payandeh Najafabadi, Amir T.; Omidi Najafabadi, Maryam; Farid-Rohani, Mohammad Reza

    2013-06-01

    In Iran, high school graduates enter university after taking a very difficult entrance exam called the Konkoor. Therefore, only the top-performing students are admitted by universities to continue their bachelor's education in statistics. Surprisingly, statistically, most of such students fall into the following categories: (1) do not succeed in their education despite their excellent performance on the Konkoor and in high school; (2) graduate with a grade point average (GPA) that is considerably lower than their high school GPA; (3) continue their master's education in majors other than statistics and (4) try to find jobs unrelated to statistics. This article employs the well-known and powerful statistical technique, the Bayesian structural equation modelling (SEM), to study the academic success of recent graduates who have studied statistics at Shahid Beheshti University in Iran. This research: (i) considered academic success as a latent variable, which was measured by GPA and other academic success (see below) of students in the target population; (ii) employed the Bayesian SEM, which works properly for small sample sizes and ordinal variables; (iii), which is taken from the literature, developed five main factors that affected academic success and (iv) considered several standard psychological tests and measured characteristics such as 'self-esteem' and 'anxiety'. We then study the impact of such factors on the academic success of the target population. Six factors that positively impact student academic success were identified in the following order of relative impact (from greatest to least): 'Teaching-Evaluation', 'Learner', 'Environment', 'Family', 'Curriculum' and 'Teaching Knowledge'. Particularly, influential variables within each factor have also been noted.

  4. A contribution to understanding the structure of amphivasal secondary bundles in monocotyledons

    Directory of Open Access Journals (Sweden)

    Joanna Jura-Morawiec

    2014-04-01

    Full Text Available Secondary growth of monocotyledonous plants is connected with the activity of the monocot cambium that accumulates most of the derivatives inner to the cambial cylinder. These derivatives differentiate into (a secondary bundles with the amphivasal arrangement, i.e. xylem composed of tracheids surrounds the phloem cells and (b the parenchymatous secondary conjunctive tissue in which the bundles are embedded. The amphivasal secondary bundles differ in the arrangement of xylem cells as visible on single cross sections through the secondary body of the monocots. Apart from the bundles with typical ring of tracheids also the bundles where tracheids do not quite surround the phloem are present. We aimed to elucidate the cross sectional anatomy of the amphivasal secondary bundles with the use of the serial sectioning method which allowed us to follow very precisely the bundle structure along its length. The studies were carried out with the samples of secondary tissues collected from the stem of Dracaena draco L. growing in the greenhouses of the Polish Academy of Sciences Botanical Garden – CBDC in Powsin and the Adam Mickiewicz University Botanical Garden. The material was fixed in a mixture of glycerol and ethanol (1:1; v/v, dehydrated stepwise with graded ethanol series and finally embedded in epon resin. Afterwards, the material was sectioned with microtome into continuous series of thin (3 μm sections, stained with PAS/toluidine blue and examined under the light microscope. The results, described in details in Jura‑Morawiec & Wiland-Szymańska (2014, revealed novel facts about tracheids arrangement. Each amphivasal bundle is composed of sectors where tracheids form a ring as well as of such where tracheids are separated by vascular parenchyma cells. We hypothesize that strands of vascular parenchyma cells locally separating the tracheids enable radial transport of assimilates from sieve elements of the bundle towards the sink tissues, e

  5. Telomere dysfunction and chromosome structure modulate the contribution of individual chromosomes in abnormal nuclear morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Pampalona, J.; Soler, D.; Genesca, A. [Department of Cell Biology, Physiology and Immunology, Universitat Autonoma de Barcelona, Bellaterra E-08193 (Spain); Tusell, L., E-mail: laura.tusell@uab.es [Department of Cell Biology, Physiology and Immunology, Universitat Autonoma de Barcelona, Bellaterra E-08193 (Spain)

    2010-01-05

    The cytokinesis-block micronucleus assay has emerged as a biomarker of chromosome damage relevant to cancer. Although it was initially developed to measure micronuclei, it is also useful for measuring nucleoplasmic bridges and nuclear buds. Abnormal nuclear morphologies are frequently observed in malignant tissues and short-term tumour cell cultures. Changes in chromosome structure and number resulting from chromosome instability are important factors in oncogenesis. Telomeres have become key players in the initiation of chromosome instability related to carcinogenesis by means of breakage-fusion-bridge cycles. To better understand the connection between telomere dysfunction and the appearance of abnormal nuclear morphologies, we have characterised the presence of micronuclei, nucleoplasmic bridges and nuclear buds in human mammary primary epithelial cells. These cells can proliferate beyond the Hayflick limit by spontaneously losing expression of the p16{sup INK4a} protein. Progressive telomere shortening leads to the loss of the capping function, and the appearance of end-to-end chromosome fusions that can enter into breakage-fusion-bridge cycles generating massive chromosomal instability. In human mammary epithelial cells, different types of abnormal nuclear morphologies were observed, however only nucleoplasmatic bridges and buds increased significantly with population doublings. Fluorescent in situ hybridisation using centromeric and painting specific probes for chromosomes with eroded telomeres has revealed that these chromosomes are preferentially included in the different types of abnormal nuclear morphologies observed, thus reflecting their common origin. Accordingly, real-time imaging of cell divisions enabled us to determine that anaphase bridge resolution was mainly through chromatin breakage and the formation of symmetric buds in daughter nuclei. Few micronuclei emerged in this cell system thus validating the scoring of nucleoplasmic bridges and

  6. A quantitative assessment approach of feasible optical mechanisms contributing to structural color of golden-like Chrysina aurigans scarab beetles

    Science.gov (United States)

    Azofeifa, D. E.; Hernández-Jiménez, M.; Libby, E.; Solís, A.; Barboza-Aguilar, C.; Vargas, W. E.

    2015-07-01

    Under normal incidence of non-polarized light, reflection spectra from the cuticle of golden-like C. aurigans scarabs shows a broad band displayed from 525 to 950 nm, with a spectral ripple structure that consists of a uniform sequence of peaks superimposed on the main reflection band. Cross sectional Scanning Electron Microscope (SEM) images of the cuticle initially suggest the presence of a multilayered structure. A radiative transfer matrix formalism is first applied to describe as much as possible the main features of coherent reflection spectra, by assuming optically homogenous layers distributed through the exocuticle, with chitin as the major constituent material. Additional non-coherent multiple reflections due to layers in the endocuticle are also evaluated from this approach. The presence of a pigmented micron sized structure beneath the procuticle requires the evaluation of a diffuse light contribution to the reflection. This was carried out from a four-flux radiative transfer model. Optical anisotropy is introduced by interpreting the SEM images in terms of a twisted Bouligand-type structure, and reflection spectra are evaluated from an implementation of the so-called 4×4 Berreman's formalism. We have been able to approach the main features characterizing the reflection spectra of C. aurigans' elytra following this progressive way.

  7. Definable deduction relation

    Institute of Scientific and Technical Information of China (English)

    张玉平

    1999-01-01

    The nonmonotonic deduction relation in default reasoning is defined with fixed point style, which has the many-extension property that classical logic is not possessed of. These two kinds of deductions both have boolean definability property, that is, their extensions or deductive closures can be defined by boolean formulas. A generalized form of fixed point method is employed to define a class of deduction relations, which all have the above property. Theorems on definability and atomless boolean algebras in model theory are essential in dealing with this assertion.

  8. From Genre Poetics to Structure: Nada Milošević-Đorđević's Contribution to Serbian Structural Folklore Studies

    Directory of Open Access Journals (Sweden)

    Dragana Antonijević

    2016-02-01

    Full Text Available This paper looks at the structural analyses of the composition of several oral literary genres in Serbian literature performed by Prof. Nada Milošević- Đorđević. By analyzing romantic tales, religious tales, tales of fate and sagas, Milošević-Đorđević, a renowned Serbian folklore scholar, has made original contributions to narrative semiotics and syntagmatic analysis. Taking as her starting point the morphology of Vladimir Propp but also of some other semioticians, she revised his narrative scheme, adapting it to the specific characteristics of these literary genres and also proposing an entirely original scheme for religious tales and tales of fate, thus becoming one of the first literary folklorists in Serbia to apply structural analysis.

  9. Contralesional cortical structural reorganization contributes to motor recovery after sub-cortical stroke: A longitudinal voxel-based morphometry study

    Directory of Open Access Journals (Sweden)

    Jianxin Cai

    2016-08-01

    Full Text Available Although changes in brain gray matter after stroke have been identified in some neuroimaging studies, lesion heterogeneity and individual variability make the detection of potential neuronal reorganization difficult. This study attempted to investigate the potential structural cortical reorganization after sub-cortical stroke using a longitudinal voxel-based gray matter volume (GMV analysis. Eleven right-handed patients with first -onset, subcortical, ischemic infarctions involving the basal ganglia regions underwent structural magnetic resonance imaging in addition to National Institutes of Health Stroke Scale and Motricity Index assessments in the acute (< 5 days and chronic stages (1 year later. The GMVs were calculated and compared between the two stages using nonparametric permutation paired t tests. Moreover, the Spearman correlations between the GMV changes and clinical recoveries were analyzed. Compared with the acute stage, significant decreases in GMV were observed in the ipsilesional precentral gyrus (PreCG, paracentral gyrus, and contralesional cerebellar lobule VII in the chronic stage. Additionally, significant increases in GMV were found in the contralesional orbitofrontal cortex (OFC and middle (MFG and inferior (IFG frontal gyri. Furthermore, severe GMV atrophy in the ipsilesional PreCG predicted poorer clinical recovery, and greater GMV increases in the contralesional OFG and MFG predicted better clinical recovery. Our findings suggest that structural reorganization of the contralesional ‘cognitive’ cortices might contribute to motor recovery after sub-cortical stroke.

  10. Cholesterol-based cationic lipids for gene delivery: contribution of molecular structure factors to physico-chemical and biological properties.

    Science.gov (United States)

    Sheng, Ruilong; Luo, Ting; Li, Hui; Sun, Jingjing; Wang, Zhao; Cao, Amin

    2014-04-01

    In this work, we prepared a series of cholesterol-based cationic (Cho-cat) lipids bearing cholesterol hydrophobe, natural amino acid headgroups (lysine/histidine) and linkage (carbonate ester/ether) bonds. In which, the natural amino acid headgroups made dominant contribution to their physico-chemical and biological properties. Among the lipids, the l-lysine headgroup bearing lipids (Cho-es/et-Lys) showed higher pDNA binding affinity and were able to form larger sized and higher surface charged lipoplexes than that of l-histidine headgroup bearing lipids (Cho-es/et-His), they also demonstrated higher transfection efficacy and higher membrane disruption capacities than that of their l-histidine headgroup bearing counterparts. However, compared to the contributions of the headgroups, the (carbonate ester/ether) linkage bonds showed much less affects. Besides, it could be noted that, Cho-es/et-Lys lipids exhibited very high luciferase gene transfection efficiency that almost reached the transfection level of "gold standard" bPEI-25k, made them potential transfection reagents for practical application. Moreover, the results facilitated the understanding for the structure-activity relationship of the cholesterol-based cationic lipids, and also paved a simple and efficient way for achieving high transfection efficiency by modification of suitable headgroups on lipid gene carriers.

  11. Invited award contribution for ACS Award in Inorganic Chemistry. Geometric and electronic structure contributions to function in bioinorganic chemistry: active sites in non-heme iron enzymes.

    Science.gov (United States)

    Solomon, E I

    2001-07-16

    Spectroscopy has played a major role in the definition of structure/function correlations in bioinorganic chemistry. The importance of spectroscopy combined with electronic structure calculations is clearly demonstrated by the non-heme iron enzymes. Many members of this large class of enzymes activate dioxygen using a ferrous active site that has generally been difficult to study with most spectroscopic methods. A new spectroscopic methodology has been developed utilizing variable temperature, variable field magnetic circular dichroism, which enables one to obtain detailed insight into the geometric and electronic structure of the non-heme ferrous active site and probe its reaction mechanism on a molecular level. This spectroscopic methodology is presented and applied to a number of key mononuclear non-heme iron enzymes leading to a general mechanistic strategy for O2 activation. These studies are then extended to consider the new features present in the binuclear non-heme iron enzymes and applied to understand (1) the mechanism of the two electron/coupled proton transfer to dioxygen binding to a single iron center in hemerythrin and (2) structure/function correlations over the oxygen-activating enzymes stearoyl-ACP Delta9-desaturase, ribonucleotide reductase, and methane monooxygenase. Electronic structure/reactivity correlations for O2 activation by non-heme relative to heme iron enzymes will also be developed.

  12. Defining and Differentiating the Makerspace

    Science.gov (United States)

    Dousay, Tonia A.

    2017-01-01

    Many resources now punctuate the maker movement landscape. However, some schools and communities still struggle to understand this burgeoning movement. How do we define these spaces and differentiate them from previous labs and shops? Through a multidimensional framework, stakeholders should consider how the structure, access, staffing, and tools…

  13. Historically defined autobiographical periods

    DEFF Research Database (Denmark)

    Brown, Norman R.; Hansen, Tia G. B.; Lee, Peter J.;

    2012-01-01

    The chapter reviews a research programme that has demonstrated the existence of historically defined autobiographical periods and identified the conditions that bring them about. Data from four samples of World War II-generation adults show that historically defined autobiographical periods endure...... over time and theoretical implications are discussed, notably by introducing a new approach to autobiographical memory, Transition Theory, which assumes that autobiographical memory is organized by transitional events that can be selfinitiated or externally imposed - historically defined...

  14. Structural Analysis and Anticoagulant Activities of the Novel Sulfated Fucan Possessing a Regular Well-Defined Repeating Unit from Sea Cucumber

    OpenAIRE

    Mingyi Wu; Li Xu; Longyan Zhao; Chuang Xiao; Na Gao; Lan Luo; Lian Yang; Zi Li; Lingyun Chen; Jinhua Zhao

    2015-01-01

    Sulfated fucans, the complex polysaccharides, exhibit various biological activities. Herein, we purified two fucans from the sea cucumbers Holothuria edulis and Ludwigothurea grisea. Their structures were verified by means of HPGPC, FT-IR, GC–MS and NMR. As a result, a novel structural motif for this type of polymers is reported. The fucans have a unique structure composed of a central core of regular (1→2) and (1→3)-linked tetrasaccharide repeating units. Approximately 50% of the units from...

  15. The ER-mitochondria encounter structure contributes to hyphal growth, mitochondrial morphology and virulence of the pathogenic mold Aspergillus fumigatus.

    Science.gov (United States)

    Geißel, Bernadette; Penka, Mirjam; Neubauer, Michael; Wagener, Johannes

    2017-01-01

    Aspergillus fumigatus is an opportunistic fungal pathogen and the primary causative species of invasive aspergillosis, a systemic disease associated with high mortality rates. Treatment of invasive fungal infection relies on a very limited number of antifungal drug classes. In order to extend the spectrum of antifungal drugs novel target structures have to be identified. The ER-mitochondria encounter structure (ERMES), a recently discovered tether that links mitochondria and endoplasmic reticulum, is a potential drug target based on its absence in Metazoa. Very recently, it was shown that ERMES is important for the fitness and immune evasion of the pathogenic yeast Candida albicans. We studied the role of the four ERMES core components Mdm10, Mdm12, Mdm34 and Mmm1 in the pathogenic mold A. fumigatus. By construction and characterizing conditional mutants of all four core components and deletion mutants of mdm10 and mdm12, we show that each component is of significant importance for growth of the fungal pathogen. While markedness of the individual mutant phenotypes differed slightly, all components are important for maintenance of the mitochondrial morphology and the intra-organellar distribution of nucleoids. Characterization of the Mmm1 ERMES mutant in a Galleria mellonella infection model indicates that ERMES contributes to virulence of A. fumigatus. Our results demonstrate that pharmacologic inhibition of ERMES could exert antifungal activity against this important pathogen.

  16. Defining Legal Moralism

    DEFF Research Database (Denmark)

    Thaysen, Jens Damgaard

    2015-01-01

    This paper discusses how legal moralism should be defined. It is argued that legal moralism should be defined as the position that “For any X, it is always a pro tanto reason for justifiably imposing legal regulation on X that X is morally wrong (where “morally wrong” is not conceptually equivalent...

  17. Defining the Interactions of Cellobiohydrolase with Substrate through Structure Function Studies: Cooperative Research and Development Final Report, CRADA Number CRD-10-409

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, G. T.; Himmel, M. E.

    2013-07-01

    NREL researchers will use their expertise and skilled resources in numerical computational modeling to generate structure-function relationships for improved cellulase variant enzymes to support the development of cellulases with improved performance in biomass conversion.

  18. Contribution of Structured Exercise Class Participation and Informal Walking for Exercise to Daily Physical Activity in Community-Dwelling Older Adults.

    Science.gov (United States)

    Tudor-Locke, C.; Jones, G. R.; Myers, A. M.; Paterson, D. H.; Ecclestone, N. A.

    2002-01-01

    Examined the physical activity and exercise habits of independent-living older adults from a structured exercise program, noting the contribution of formal and informal exercise participation relative to total daily physical activity measured using pedometer and daily activity logs. Participation in structured exercise was an important contributor…

  19. Contribution of Structured Exercise Class Participation and Informal Walking for Exercise to Daily Physical Activity in Community-Dwelling Older Adults.

    Science.gov (United States)

    Tudor-Locke, C.; Jones, G. R.; Myers, A. M.; Paterson, D. H.; Ecclestone, N. A.

    2002-01-01

    Examined the physical activity and exercise habits of independent-living older adults from a structured exercise program, noting the contribution of formal and informal exercise participation relative to total daily physical activity measured using pedometer and daily activity logs. Participation in structured exercise was an important contributor…

  20. Long range chromosome organization in Escherichia coli: The position of the replication origin defines the non-structured regions and the Right and Left macrodomains

    Science.gov (United States)

    2017-01-01

    The Escherichia coli chromosome is organized into four macrodomains (Ori, Ter, Right and Left) and two non-structured regions. This organization influences the segregation of sister chromatids, the mobility of chromosomal DNA, and the cellular localization of the chromosome. The organization of the Ter and Ori macrodomains relies on two specific systems, MatP/matS for the Ter domain and MaoP/maoS for the Ori domain, respectively. Here by constructing strains with chromosome rearrangements to reshuffle the distribution of chromosomal segments, we reveal that the difference between the non-structured regions and the Right and Left lateral macrodomains relies on their position on the chromosome. A change in the genetic location of oriC generated either by an inversion within the Ori macrodomain or by the insertion of a second oriC modifies the position of Right and Left macrodomains, as the chromosome region the closest to oriC are always non-structured while the regions further away behave as macrodomain regardless of their DNA sequence. Using fluorescent microscopy we estimated that loci belonging to a non-structured region are significantly closer to the Ori MD than loci belonging to a lateral MD. Altogether, our results suggest that the origin of replication plays a prominent role in chromosome organization in E. coli, as it determines structuring and localization of macrodomains in growing cell. PMID:28486476

  1. Defining Documentary Film

    DEFF Research Database (Denmark)

    Juel, Henrik

    2006-01-01

    A discussion of various attemts at defining documentary film regarding form, content, truth, stile, genre or reception - and a propoposal of a positive list of essential, but non-exclusive characteristica of documentary film......A discussion of various attemts at defining documentary film regarding form, content, truth, stile, genre or reception - and a propoposal of a positive list of essential, but non-exclusive characteristica of documentary film...

  2. Definably amenable NIP groups

    OpenAIRE

    Chernikov, Artem; Simon, Pierre

    2015-01-01

    We study definably amenable NIP groups. We develop a theory of generics, showing that various definitions considered previously coincide, and study invariant measures. Applications include: characterization of regular ergodic measures, a proof of the conjecture of Petrykowski connecting existence of bounded orbits with definable amenability in the NIP case, and the Ellis group conjecture of Newelski and Pillay connecting the model-theoretic connected component of an NIP group with the ideal s...

  3. Bohr effect of human hemoglobin A: magnitude of negative contributions determined by the equilibrium between two tertiary structures.

    Science.gov (United States)

    Okonjo, Kehinde O; Olatunde, Abimbola M; Fodeke, Adedayo A; Babalola, J Oyebamiji

    2014-06-01

    We have measured the affinity of the CysF9[93]β sulfhydryl group of human deoxyhemoglobin and oxyhemoglobin for 5,5'-dithiobis(2-nitrobenzoate), DTNB, between pH ≈5.6 and 9 in order to understand the basis of the reported reduction of the Bohr effect induced by chemical modification of the sulfhydryl. We analyzed the results quantitatively on the basis of published data indicating that the sulfhydryl exists in two conformations that are coupled to the transition between two tertiary structures of hemoglobin in dynamic equilibrium. Our analyses show that the ionizable groups linked to the DTNB reaction have lower pKas of ionization in deoxyhemoglobin compared to oxyhemoglobin. So these ionizable groups should make negative contributions to the Bohr effect. We identify these groups as HisNA2[2]β, HisEF1[77]β and HisH21[143]β. We provide explanations for the finding that hemoglobin, chemically modified at CysF9[93]β, has a lower Bohr effect and a higher oxygen affinity than unmodified hemoglobin.

  4. Flaxseed flour, compared to flaxseed oil, contributes to femoral structure in male rats subjected to early weaning.

    Science.gov (United States)

    Pessanha, Carolina Ribeiro; da Camara Boueri, Bianca Ferolla; da Costa, Luanna Rodrigues; Ferreira, Maitê Rocha; de Abreu, Maíra Duque Coutinho; Pessoa, Letícia Rozeno; Pereira, Aline D'Avila; Ribeiro, Danielle Cavalcante; da Silva, Eduardo Moreira; da Costa, Carlos Alberto Soares; Boaventura, Gilson Teles

    2016-03-01

    The aim of this study was to analyze whether flaxseed flour or flaxseed oil treatment contributes to femoral structure in male rats subjected to early weaning. Pups were weaned for separation from mothers at 14 days (early weaning, EW) or 21 days (control, C). After 21 days, the control (C60) was fed with the control diet. The EW group was divided based on control (EWC60), flaxseed flour (EWFF60) and flaxseed oil (EWFO60) diets until 60 days. Femoral dimension, bone mineral density (BMD), bone mineral content (BMC), area and biomechanical properties were determined. EWFO60 showed lower (P < 0.05) femur mass. EWC60 and EWFO60 showed lower (P < 0.05) distance between epiphyses, diaphysis width and BMD. BMC was lower (P < 0.05) in EWC60 (vs. C60 and EWFF60). EWC60 and EWFO60 showed lower (P < 0.05) maximum force (vs. C60). Breaking strength was lower (P < 0.05) in EWFO60 (vs. C60). EWFF60 showed higher (P < 0.05) rigidity. Flaxseed flour abbreviated the femoral fragility secondary to early weaning.

  5. The Crystal Structure of the Extracellular 11-heme Cytochrome UndA Reveals a Conserved 10-heme Motif and Defined Binding Site for Soluble Iron Chelates.

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Marcus; Hall, Andrea; Shi, Liang; Fredrickson, Jim K.; Zachara, John M.; Butt, Julea N.; Richardson, David; Clarke, Thomas A.

    2012-07-03

    Members of the genus Shewanella translocate deca- or undeca-heme cytochromes to the external cell surface thus enabling respiration using extracellular minerals and polynuclear Fe(III) chelates. The high resolution structure of the first undeca-heme outer membrane cytochrome, UndA, reveals a crossed heme chain with four potential electron ingress/egress sites arranged within four domains. Sequence and structural alignment of UndA and the deca-heme MtrF reveals the extra heme of UndA is inserted between MtrF hemes 6 and 7. The remaining UndA hemes can be superposed over the heme chain of the decaheme MtrF, suggesting that a ten heme core is conserved between outer membrane cytochromes. The UndA structure is the first outer membrane cytochrome to be crystallographically resolved in complex with substrates, an Fe(III)-nitrilotriacetate dimer or an Fe(III)-citrate trimer. The structural resolution of these UndA-Fe(III)-chelate complexes provides a rationale for previous kinetic measurements on UndA and other outer membrane cytochromes.

  6. A synthetic peptide derived from the animo acid sequence of canine parvovirus structural proteins which defines a B cell epitope and elicits antiviral antibody in BALB c mice.

    NARCIS (Netherlands)

    G.F. Rimmelzwaan (Guus); J. Carlson; F.G.C.M. Uytdehaag (Fons); A.D.M.E. Osterhaus (Albert)

    1990-01-01

    textabstractSynthetic peptides, recombinant fusion proteins and mouse monoclonal antibodies were used to delineate a B cell epitope of the VP'2 structural protein of canine parvovirus (CPV). Although this epitope is not preferentially recognized in the normal antibody response to CPV, virus-specific

  7. 论对外汉语语序结构排序%Defining and Sequencing Syntactic Structures in L2 Chinese Instructional Materials

    Institute of Scientific and Technical Information of China (English)

    邓守信

    2001-01-01

    This article presents a set of criteria that helps determine the sequence of grammatical structures in a systematic fashion. It is a component of what we shall refer to as a pedagogical grammar of L2 Chinese. It includes such factors as L1 Chinese natural sequence, L2 Chinese acquisitional sequence, usage frequency, structural complexity, semantic complexity, and interlinguistic distance. Ample illustrations from Man in this article. A brief description of a corpus of L2 Chinese interlanguage will also be given, as it plays a significant role in a pedagogical grammar. This article concludes that it is imperative that a theoretical framework of a L2 Chinese pedagogical grammar will be established in the field, so that the teaching and/or acquisition of Chinese can proceed on firmer ground.

  8. High-Hall-Mobility Al-Doped ZnO Films Having Textured Polycrystalline Structure with a Well-Defined (0001) Orientation.

    Science.gov (United States)

    Nomoto, Junichi; Makino, Hisao; Yamamoto, Tetsuya

    2016-12-01

    Five hundred-nanometer-thick ZnO-based textured polycrystalline films consisting of 490-nm-thick Al-doped ZnO (AZO) films deposited on 10-nm-thick Ga-doped ZnO (GZO) films exhibited a high Hall mobility (μ H) of 50.1 cm(2)/Vs with a carrier concentration (N) of 2.55 × 10(20) cm(-3). Firstly, the GZO films were prepared on glass substrates by ion plating with dc arc discharge, and the AZO films were then deposited on the GZO films by direct current magnetron sputtering (DC-MS). The GZO interface layers with a preferential c-axis orientation play a critical role in producing AZO films with texture development of a well-defined (0001) orientation, whereas 500-nm-thick AZO films deposited by only DC-MS showed a mixture of the c-plane and the other plane orientation, to exhibit a μ H of 38.7 cm(2)/Vs with an N of 2.22 × 10(20) cm(-3).

  9. High-Hall-Mobility Al-Doped ZnO Films Having Textured Polycrystalline Structure with a Well-Defined (0001) Orientation

    Science.gov (United States)

    Nomoto, Junichi; Makino, Hisao; Yamamoto, Tetsuya

    2016-06-01

    Five hundred-nanometer-thick ZnO-based textured polycrystalline films consisting of 490-nm-thick Al-doped ZnO (AZO) films deposited on 10-nm-thick Ga-doped ZnO (GZO) films exhibited a high Hall mobility ( μ H) of 50.1 cm2/Vs with a carrier concentration ( N) of 2.55 × 1020 cm-3. Firstly, the GZO films were prepared on glass substrates by ion plating with dc arc discharge, and the AZO films were then deposited on the GZO films by direct current magnetron sputtering (DC-MS). The GZO interface layers with a preferential c-axis orientation play a critical role in producing AZO films with texture development of a well-defined (0001) orientation, whereas 500-nm-thick AZO films deposited by only DC-MS showed a mixture of the c-plane and the other plane orientation, to exhibit a μ H of 38.7 cm2/Vs with an N of 2.22 × 1020 cm-3.

  10. Can play be defined?

    DEFF Research Database (Denmark)

    Eichberg, Henning

    2015-01-01

    Can play be defined? There is reason to raise critical questions about the established academic demand that at phenomenon – also in humanist studies – should first of all be defined, i.e. de-lineated and by neat lines limited to a “little box” that can be handled. The following chapter develops t....... Human beings can very well understand play – or whatever phenomenon in human life – without defining it........ The academic imperative of definition seems to be linked to the positivistic attempts – and produces sometimes monstrous definitions. Have they any philosophical value for our knowledge of what play is? Definition is not a universal instrument of knowledge-building, but a culturally specific construction...

  11. Nouns to Define Homophobia

    Directory of Open Access Journals (Sweden)

    Adalberto Campo Arias

    2013-09-01

    Full Text Available Background. The term ‘homophobia’ was introduced in the academic context more than 40 years ago. However, its meaning has changed over time. Objective. To review the nouns used in the last twelve years to define homophobia. Methodology. The authors conducted a systematic search in Medline through Pubmed that included editorials, letters to editors, comments and narrative reviews, in English and Spanish. A qualitative analysis (Grounded theory was applied to analyze nouns used to define homophobia since 2001 through 2012. Results. Authors reviewed three papers including ten nouns to define homophobia, the most common noun was fear. The terms were grouped into two domains: negative attitude and discomfort with homosexuality. Conclusion. Fear is the most used word to describe homophobia. The terms were grouped into two domains: negative attitude and discomfort toward homosexuality.

  12. Defining "intermittent UVR exposure"

    DEFF Research Database (Denmark)

    Bodekær, Mette; Philipsen, Peter Alshede; Petersen, Bibi Øager;

    2016-01-01

    to define and quantify “intermittent UVR exposure” by an objective measure. Methods: A broad study population of adults and children had data collected during a summer period. Data were personal UVR dosimetry measurements, from which the number of “intermittent days” was derived, sun behaviour diaries.......001). The corresponding numbers for prediction of nevi and lentigo density by retrospective questionnaire data was lower (R2 = 0.11, R2 = 0.26, p defined objective measure of intermittent UVR exposure. This measure may provide a better prediction of solar skin damage and CMM...

  13. Mutational and structural analysis of KIR3DL1 reveals a lineage-defining allotypic dimorphism that impacts both HLA and peptide sensitivity.

    Science.gov (United States)

    O'Connor, Geraldine M; Vivian, Julian P; Widjaja, Jacqueline M; Bridgeman, John S; Gostick, Emma; Lafont, Bernard A P; Anderson, Stephen K; Price, David A; Brooks, Andrew G; Rossjohn, Jamie; McVicar, Daniel W

    2014-03-15

    Killer Ig-like receptors (KIRs) control the activation of human NK cells via interactions with peptide-laden HLAs. KIR3DL1 is a highly polymorphic inhibitory receptor that recognizes a diverse array of HLA molecules expressing the Bw4 epitope, a group with multiple polymorphisms incorporating variants within the Bw4 motif. Genetic studies suggest that KIR3DL1 variation has functional significance in several disease states, including HIV infection. However, owing to differences across KIR3DL1 allotypes, HLA-Bw4, and associated peptides, the mechanistic link with biological outcome remains unclear. In this study, we elucidated the impact of KIR3DL1 polymorphism on peptide-laden HLA recognition. Mutational analysis revealed that KIR residues involved in water-mediated contacts with the HLA-presented peptide influence peptide binding specificity. In particular, residue 282 (glutamate) in the D2 domain underpins the lack of tolerance of negatively charged C-terminal peptide residues. Allotypic KIR3DL1 variants, defined by neighboring residue 283, displayed differential sensitivities to HLA-bound peptide, including the variable HLA-B*57:01-restricted HIV-1 Gag-derived epitope TW10. Residue 283, which has undergone positive selection during the evolution of human KIRs, also played a central role in Bw4 subtype recognition by KIR3DL1. Collectively, our findings uncover a common molecular regulator that controls HLA and peptide discrimination without participating directly in peptide-laden HLA interactions. Furthermore, they provide insight into the mechanics of interaction and generate simple, easily assessed criteria for the definition of KIR3DL1 functional groupings that will be relevant in many clinical applications, including bone marrow transplantation.

  14. On-line optical and X-ray spectroscopies with crystallography: an integrated approach for determining metalloprotein structures in functionally well defined states.

    Science.gov (United States)

    Ellis, Mark J; Buffey, Steven G; Hough, Michael A; Hasnain, S Samar

    2008-09-01

    X-ray-induced redox changes can lead to incorrect assignments of the functional states of metals in metalloprotein crystals. The need for on-line monitoring of the status of metal ions (and other chromophores) during protein crystallography experiments is of growing importance with the use of intense synchrotron X-ray beams. Significant efforts are therefore being made worldwide to combine different spectroscopies in parallel with X-ray crystallographic data collection. Here the implementation and utilization of optical and X-ray absorption spectroscopies on the modern macromolecular crystallography (MX) beamline 10, at the SRS, Daresbury Laboratory, is described. This beamline is equipped with a dedicated monolithic energy-dispersive X-ray fluorescence detector, allowing X-ray absorption spectroscopy (XAS) measurements to be made in situ on the same crystal used to record the diffraction data. In addition, an optical microspectrophotometer has been incorporated on the beamline, thus facilitating combined MX, XAS and optical spectroscopic measurements. By uniting these techniques it is also possible to monitor the status of optically active and optically silent metal centres present in a crystal at the same time. This unique capability has been applied to observe the results of crystallographic data collection on crystals of nitrite reductase from Alcaligenes xylosoxidans, which contains both type-1 and type-2 Cu centres. It is found that the type-1 Cu centre photoreduces quickly, resulting in the loss of the 595 nm peak in the optical spectrum, while the type-2 Cu centre remains in the oxidized state over a much longer time period, for which independent confirmation is provided by XAS data as this centre has an optical spectrum which is barely detectable using microspectrophotometry. This example clearly demonstrates the importance of using two on-line methods, spectroscopy and XAS, for identifying well defined redox states of metalloproteins during

  15. Defining 5S rRNA structure space: point mutation data can be used to predict the phenotype of multichange variants.

    Science.gov (United States)

    Nayar, Madhavi; Fox, George E

    2011-09-01

    A portion of the 5S ribosomal RNA (rRNA) structure space in the vicinity of the Vibrio proteolyticus 5S rRNA sequence is explored in detail with the intention of establishing principles that will allow a priori prediction of which sequences would be valid members of a particular RNA structure space. Four hundred and one sequence variants differing from the V. proteolyticus 5S rRNA wild-type sequence in 1-7 positions were characterized using an in vivo assay system. Most significantly, it was found that in general, the phenotypic effects of single changes were independent of the phenotypic effect of a second change. As a result, it was possible to use the new data in conjunction with results from prior studies of the same RNA to develop "truth tables" to predict which multiple change variants would be functional and which would be nonfunctional. The actual phenotype of 93.8% of the multichange variants studied was consistent with the predictions made using truth tables thereby providing for perhaps the first time an upper limit estimate of how frequent unexpected interactions are. It was also observed that single changes at positions involved in secondary structure were no more likely to be invalid than changes in other regions. In particular, internal changes in long standard stems were in fact almost always tolerated. Changes at positions that were hypervariable in the context of an alignment of related sequences were, as expected, usually found to be valid. However, the potential validity of changes that were idiosyncratic to a single lineage of related sequences when placed in the V. proteolyticus 5S rRNA context was unpredictable.

  16. Structurally related TPR subunits contribute differently to the function of the anaphase-promoting complex in Drosophila melanogaster.

    Science.gov (United States)

    Pál, Margit; Nagy, Olga; Ménesi, Dalma; Udvardy, Andor; Deák, Péter

    2007-09-15

    interaction with Apc8/Cdc23 that, together with the phenotypic data, assumes a limited functional role for Apc7. Taken together, these data suggest that the structurally related TPR subunits contribute differently to the function of the anaphase-promoting complex.

  17. Defining proximity relationships in the tertiary structure of the dopamine transporter. Identification of a conserved glutamic acid as a third coordinate in the endogenous Zn(2+)-binding site

    DEFF Research Database (Denmark)

    Løland, Claus Juul; Norregaard, L; Gether, U

    1999-01-01

    that Glu(396) is involved in Zn(2+) binding to hDAT. Importantly, Zn(2+) sensitivity was preserved following substitution of Glu(396) with histidine, indicating that the effect of mutating Glu(396) is not an indirect effect because of the removal of a negatively charged residue. The common participation...... of Glu(396), His(193), and His(375) in binding the small Zn(2+) ion implies their proximity in the unknown tertiary structure of hDAT. The close association between TM 7 and 8 was further established by engineering of a Zn(2+)-binding site between His(375) and a cysteine inserted in position 400 in TM 8...

  18. Photochemical tyrosine oxidation in the structurally well-defined α3Y protein: proton-coupled electron transfer and a long-lived tyrosine radical.

    Science.gov (United States)

    Glover, Starla D; Jorge, Christine; Liang, Li; Valentine, Kathleen G; Hammarström, Leif; Tommos, Cecilia

    2014-10-08

    Tyrosine oxidation-reduction involves proton-coupled electron transfer (PCET) and a reactive radical state. These properties are effectively controlled in enzymes that use tyrosine as a high-potential, one-electron redox cofactor. The α3Y model protein contains Y32, which can be reversibly oxidized and reduced in voltammetry measurements. Structural and kinetic properties of α3Y are presented. A solution NMR structural analysis reveals that Y32 is the most deeply buried residue in α3Y. Time-resolved spectroscopy using a soluble flash-quench generated [Ru(2,2'-bipyridine)3](3+) oxidant provides high-quality Y32-O• absorption spectra. The rate constant of Y32 oxidation (kPCET) is pH dependent: 1.4 × 10(4) M(-1) s(-1) (pH 5.5), 1.8 × 10(5) M(-1) s(-1) (pH 8.5), 5.4 × 10(3) M(-1) s(-1) (pD 5.5), and 4.0 × 10(4) M(-1) s(-1) (pD 8.5). k(H)/k(D) of Y32 oxidation is 2.5 ± 0.5 and 4.5 ± 0.9 at pH(D) 5.5 and 8.5, respectively. These pH and isotope characteristics suggest a concerted or stepwise, proton-first Y32 oxidation mechanism. The photochemical yield of Y32-O• is 28-58% versus the concentration of [Ru(2,2'-bipyridine)3](3+). Y32-O• decays slowly, t1/2 in the range of 2-10 s, at both pH 5.5 and 8.5, via radical-radical dimerization as shown by second-order kinetics and fluorescence data. The high stability of Y32-O• is discussed relative to the structural properties of the Y32 site. Finally, the static α3Y NMR structure cannot explain (i) how the phenolic proton released upon oxidation is removed or (ii) how two Y32-O• come together to form dityrosine. These observations suggest that the dynamic properties of the protein ensemble may play an essential role in controlling the PCET and radical decay characteristics of α3Y.

  19. Seismic reflection-based evidence of a transfer zone between the Wagner and Consag basins: implications for defining the structural geometry of the northern Gulf of California

    Science.gov (United States)

    González-Escobar, Mario; Suárez-Vidal, Francisco; Hernández-Pérez, José Antonio; Martín-Barajas, Arturo

    2010-12-01

    This study examines the structural characteristics of the northern Gulf of California by processing and interpreting ca. 415 km of two-dimensional multi-channel seismic reflection lines (data property of Petróleos Mexicanos PEMEX) collected in the vicinity of the border between the Wagner and Consag basins. The two basins appear to be a link between the Delfín Superior Basin to the south, and the Cerro Prieto Basin to the north in the Mexicali-Imperial Valley along the Pacific-North America plate boundary. The seismic data are consistent with existing knowledge of four main structures (master faults) in the region, i.e., the Percebo, Santa María, Consag Sur, and Wagner Sur faults. The Wagner and Consag basins are delimited to the east by the Wagner Sur Fault, and to the west by the Consag Sur Fault. The Percebo Fault borders the western margin of the modern Wagner Basin depocenter, and is oriented N10°W, dipping (on average) ˜40° to the northeast. The trace of the Santa María Fault located in the Wagner Basin strikes N19°W, dipping ˜40° to the west. The Consag Sur Fault is oriented N14°W, and dips ˜42° to the east over a distance of 21 km. To the east of the study area, the Wagner Sur Fault almost parallels the Consag Sur Fault over a distance of ˜86 km, and is oriented N10°W with an average dip of 59° to the east. Moreover, the data provide new evidence that the Wagner Fault is discontinuous between the two basins, and that its structure is more complex than previously reported. A structural high separates the northern Consag Basin from the southern Wagner Basin, comprising several secondary faults oriented NE oblique to the main faults of N-S direction. These could represent a zone of accommodation, or transfer zone, where extension could be transferred from the Wagner to the Consag Basin, or vice versa. This area shows no acoustic basement and/or intrusive body, which is consistent with existing gravimetric and magnetic data for the region.

  20. Crystal Structure of a Fibroblast Growth Factor Homologous Factor (FHF) Defines a Conserved Surface on FHFs for Binding and Modulation of Voltage-gated Sodium Channels

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, R.; Dover, K; Laezza, F; Shtraizent, N; Huang, X; Tchetchik, D; Eliseenkova, A; Goldfarb, M; Mohammadi, M; et. al.

    2009-01-01

    Voltage-gated sodium channels (Nav) produce sodium currents that underlie the initiation and propagation of action potentials in nerve and muscle cells. Fibroblast growth factor homologous factors (FHFs) bind to the intracellular C-terminal region of the Nav alpha subunit to modulate fast inactivation of the channel. In this study we solved the crystal structure of a 149-residue-long fragment of human FHF2A which unveils the structural features of the homology core domain of all 10 human FHF isoforms. Through analysis of crystal packing contacts and site-directed mutagenesis experiments we identified a conserved surface on the FHF core domain that mediates channel binding in vitro and in vivo. Mutations at this channel binding surface impaired the ability of FHFs to co-localize with Navs at the axon initial segment of hippocampal neurons. The mutations also disabled FHF modulation of voltage-dependent fast inactivation of sodium channels in neuronal cells. Based on our data, we propose that FHFs constitute auxiliary subunits for Navs.

  1. Generation of eye field/optic vesicle-like structures from human embryonic stem cells under two-dimensional and chemically defined conditions.

    Science.gov (United States)

    Parvini, Maryam; Parivar, Kazem; Safari, Fatemeh; Tondar, Mahdi

    2015-03-01

    Despite the enormous progress in studying retinal cell differentiation from human embryonic stem cells (hESCs), none of the reported protocols have produced a cost-effective eye field cells with the capability to further differentiate into retinal derivatives. In this study, by drawing chemicals on our four-step differentiation strategy, we demonstrated the ability of hESCs in assembling such qualifications to follow human retinogenesis in a serum- and feeder-free adherent condition. Two-dimensional (2D) populations of eye field cells arose within early forebrain progeny upon hESCs differentiation. Gene expression analysis showed that the treatment of hESCs with a combination of selected small molecules (SMs) gave rise to the higher expressions of eye field-specific genes, PAX6, RX, and SIX3. Thereafter, a subset of cells gained the transient features of advancing retinal differentiation, including optic vesicle (OV)-like structures, which expressed MITF and CHX10 in a manner imitated in vivo human retinal development. The competency of derived cells in differentiation to retinal derivatives was further investigated. The gene analysis of the cells showed more propensity for generating retinal pigment epithelial (RPE) than neural retina (NR). The generation of OV-like structures in 2D cultures can shed light on molecular events governing retinal specification. It can also facilitate the study of human retinal development.

  2. On Defining Mass

    Science.gov (United States)

    Hecht, Eugene

    2011-01-01

    Though central to any pedagogical development of physics, the concept of mass is still not well understood. Properly defining mass has proven to be far more daunting than contemporary textbooks would have us believe. And yet today the origin of mass is one of the most aggressively pursued areas of research in all of physics. Much of the excitement…

  3. Defining Data Science

    OpenAIRE

    Zhu, Yangyong; Xiong, Yun

    2015-01-01

    Data science is gaining more and more and widespread attention, but no consensus viewpoint on what data science is has emerged. As a new science, its objects of study and scientific issues should not be covered by established sciences. Data in cyberspace have formed what we call datanature. In the present paper, data science is defined as the science of exploring datanature.

  4. Defining Mathematical Giftedness

    Science.gov (United States)

    Parish, Linda

    2014-01-01

    This theoretical paper outlines the process of defining "mathematical giftedness" for a present study on how primary school teaching shapes the mindsets of children who are mathematically gifted. Mathematical giftedness is not a badge of honour or some special value attributed to a child who has achieved something exceptional.…

  5. Software Defined Networking

    DEFF Research Database (Denmark)

    Caba, Cosmin Marius

    resources are limited. Hence, to counteract this trend, current QoS mechanisms must become simpler to deploy and operate, in order to motivate NSPs to employ QoS techniques instead of overprovisioning. Software Defined Networking (SDN) represents a paradigm shift in the way telecommunication and data...

  6. Defining Effective Teaching

    Science.gov (United States)

    Layne, L.

    2012-01-01

    The author looks at the meaning of specific terminology commonly used in student surveys: "effective teaching." The research seeks to determine if there is a difference in how "effective teaching" is defined by those taking student surveys and those interpreting the results. To investigate this difference, a sample group of professors and students…

  7. Defining Game Mechanics

    DEFF Research Database (Denmark)

    Sicart (Vila), Miguel Angel

    2008-01-01

    This article defins game mechanics in relation to rules and challenges. Game mechanics are methods invoked by agents for interacting with the game world. I apply this definition to a comparative analysis of the games Rez, Every Extend Extra and Shadow of the Colossus that will show the relevance...... of a formal definition of game mechanics. Udgivelsesdato: Dec 2008...

  8. Software Defined Cyberinfrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Foster, Ian; Blaiszik, Ben; Chard, Kyle; Chard, Ryan

    2017-07-17

    Within and across thousands of science labs, researchers and students struggle to manage data produced in experiments, simulations, and analyses. Largely manual research data lifecycle management processes mean that much time is wasted, research results are often irreproducible, and data sharing and reuse remain rare. In response, we propose a new approach to data lifecycle management in which researchers are empowered to define the actions to be performed at individual storage systems when data are created or modified: actions such as analysis, transformation, copying, and publication. We term this approach software-defined cyberinfrastructure because users can implement powerful data management policies by deploying rules to local storage systems, much as software-defined networking allows users to configure networks by deploying rules to switches.We argue that this approach can enable a new class of responsive distributed storage infrastructure that will accelerate research innovation by allowing any researcher to associate data workflows with data sources, whether local or remote, for such purposes as data ingest, characterization, indexing, and sharing. We report on early experiments with this approach in the context of experimental science, in which a simple if-trigger-then-action (IFTA) notation is used to define rules.

  9. Defining in Classroom Activities.

    Science.gov (United States)

    Mariotti, Maria Alessandra; Fischbein, Efraim

    1997-01-01

    Discusses some aspects of the defining process in geometrical context in the reference frame of the theory of "figural concepts." Presents analysis of some examples taken from a teaching experiment at the sixth-grade level. Contains 30 references. (Author/ASK)

  10. Defining Game Mechanics

    DEFF Research Database (Denmark)

    Sicart (Vila), Miguel Angel

    2008-01-01

    This article defins game mechanics in relation to rules and challenges. Game mechanics are methods invoked by agents for interacting with the game world. I apply this definition to a comparative analysis of the games Rez, Every Extend Extra and Shadow of the Colossus that will show the relevance...... of a formal definition of game mechanics. Udgivelsesdato: Dec 2008...

  11. Quantitative evaluation of evaporation rate during spin-coating of polymer blend films: Control of film structure through defined-atmosphere solvent-casting.

    Science.gov (United States)

    Mokarian-Tabari, P; Geoghegan, M; Howse, J R; Heriot, S Y; Thompson, R L; Jones, R A L

    2010-12-01

    Thin films of polymer mixtures made by spin-coating can phase separate in two ways: by forming lateral domains, or by separating into distinct layers. The latter situation (self-stratification or vertical phase separation) could be advantageous in a number of practical applications, such as polymer optoelectronics. We demonstrate that, by controlling the evaporation rate during the spin-coating process, we can obtain either self-stratification or lateral phase separation in the same system, and we relate this to a previously hypothesised mechanism for phase separation during spin-coating in thin films, according to which a transient wetting layer breaks up due to a Marangoni-type instability driven by a concentration gradient of solvent within the drying film. Our results show that rapid evaporation leads to a laterally phase-separated structure, while reducing the evaporation rate suppresses the interfacial instability and leads to a self-stratified final film.

  12. Distinguish between Defined-benefit and Defined-contribution Pension Schemes

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-nan

    2015-01-01

    According to the data from IFSL (International Financial Services, London), Pension funds increased rapidly in recent year. Pension funds always have different ways to build up. One form always from the institutional investment and the funds will build up during the working life by the worker’s company and then workers use the funds as the retirement income during workers retired. Alternatively some employees invest in a fund of their choosing and the money can be used to buy an annuity to obtain the pension funds. For this form, one of the important forms of stock market investments of pension funds is shares and bonds.

  13. Defining the fascial system.

    Science.gov (United States)

    Adstrum, Sue; Hedley, Gil; Schleip, Robert; Stecco, Carla; Yucesoy, Can A

    2017-01-01

    Fascia is a widely used yet indistinctly defined anatomical term that is concurrently applied to the description of soft collagenous connective tissue, distinct sections of membranous tissue, and a body pervading soft connective tissue system. Inconsistent use of this term is causing concern due to its potential to confuse technical communication about fascia in global, multiple discipline- and multiple profession-spanning discourse environments. The Fascia Research Society acted to address this issue by establishing a Fascia Nomenclature Committee (FNC) whose purpose was to clarify the terminology relating to fascia. This committee has since developed and defined the terms a fascia, and, more recently, the fascial system. This article reports on the FNC's proposed definition of the fascial system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Defining Legal Moralism

    DEFF Research Database (Denmark)

    Thaysen, Jens Damgaard

    2015-01-01

    This paper discusses how legal moralism should be defined. It is argued that legal moralism should be defined as the position that “For any X, it is always a pro tanto reason for justifiably imposing legal regulation on X that X is morally wrong (where “morally wrong” is not conceptually equivalent...... to “harmful”)”. Furthermore, a distinction between six types of legal moralism is made. The six types are grouped according to whether they are concerned with the enforcement of positive or critical morality, and whether they are concerned with criminalising, legally restricting, or refraining from legally...... protecting morally wrong behaviour. This is interesting because not all types of legal moralism are equally vulnerable to the different critiques of legal moralism that have been put forth. Indeed, I show that some interesting types of legal moralism have not been criticised at all....

  15. Define Digital Vernacular

    Institute of Scientific and Technical Information of China (English)

    刘佳; 李海英; James Stevens; Rough Nelson

    2014-01-01

    As science and technology developed, the tools of humans developed from humans’hands, to mechanical and digital technologies. The tools influ-ence almost everything in the humans’world, so does vernacular. The digital vernacular could be understood as using digital technology to vernacular; the digital means technologies. It also could be understood as doing vernacular in a digital way;the digital means data and information, in other words it can be seeking truth from facts. Define digital vernacular is not only what is digital vernacular, but also about how to do the digital vernacular and what kind of attitude we should hold to-ward the digital vernacular. Define digital vernacular as both thinking and doing.

  16. Non-perturbative evaluation of some QED contributions to the muonic hydrogen $\\bm{n=2}$ Lamb shift and hyperfine structure

    CERN Document Server

    Indelicato, Paul

    2012-01-01

    The largest contributions to the $n=2$ Lamb-shift, fine structure interval and $2s$ hyperfine structure of muonic hydrogen are calculated by exact numerical evaluations of the Dirac equation, rather than by a perturbation expansion in powers of $1/c$, in the framework of non-relativistic quantum electrodynamics. Previous calculations and the validity of the perturbation expansion for light elements are confirmed. The dependence of the various effects on the nuclear size and model are studied

  17. Defining local food

    DEFF Research Database (Denmark)

    Eriksen, Safania Normann

    2013-01-01

    Despite evolving local food research, there is no consistent definition of “local food.” Various understandings are utilized, which have resulted in a diverse landscape of meaning. The main purpose of this paper is to examine how researchers within the local food systems literature define local...... food, and how these definitions can be used as a starting point to identify a new taxonomy of local food based on three domains of proximity....

  18. [To define internet addiction].

    Science.gov (United States)

    Tonioni, Federico

    2013-01-01

    Internet addiction is a new behavioral disorder difficult to define, especially when referring to young teenagers who make great use of web-mediated relationships. It's necessary to separate the cases of overt dependency on those in which the abuse of internet seems to have a different value, offering the only way to achieve the possible relationship. Internet is mediating a new way of communicating and thinking, this may favor the onset of clinical phenomena intended to surprise.

  19. Inversion of Gravity Data to Define the Pre-Cenozoic Surface and Regional Structures Possibly Influencing Groundwater Flow in the Rainier Mesa Region, Nye County, Nevada

    Science.gov (United States)

    Hildenbrand, Thomas G.; Phelps, Geoffrey A.; Mankinen, Edward A.

    2006-01-01

    A three-dimensional inversion of gravity data from the Rainier Mesa area and surrounding regions reveals a topographically complex pre-Cenozoic basement surface. This model of the depth to pre-Cenozoic basement rocks is intended for use in a 3D hydrogeologic model being constructed for the Rainier Mesa area. Prior to this study, our knowledge of the depth to pre-Cenozoic basement rocks was based on a regional model, applicable to general studies of the greater Nevada Test Site area but inappropriate for higher resolution modeling of ground-water flow across the Rainier Mesa area. The new model incorporates several changes that lead to significant improvements over the previous regional view. First, the addition of constraining wells, encountering old volcanic rocks lying above but near pre-Cenozoic basement, prevents modeled basement from being too shallow. Second, an extensive literature and well data search has led to an increased understanding of the change of rock density with depth in the vicinity of Rainier Mesa. The third, and most important change, relates to the application of several depth-density relationships in the study area instead of a single generalized relationship, thereby improving the overall model fit. In general, the pre-Cenozoic basement surface deepens in the western part of the study area, delineating collapses within the Silent Canyon and Timber Mountain caldera complexes, and shallows in the east in the Eleana Range and Yucca Flat regions, where basement crops out. In the Rainier Mesa study area, basement is generally shallow (model identifies previously unrecognized structures within the pre-Cenozoic basement that may influence ground-water flow, such as a shallow basement ridge related to an inferred fault extending northward from Rainier Mesa into Kawich Valley.

  20. Inversion of Gravity Data to Define the Pre-Cenozoic Surface and Regional Structures Possibly Influencing Groundwater Flow in the Rainier Mesa Region, Nye County, Nevada.

    Energy Technology Data Exchange (ETDEWEB)

    Thomas G. Hildenbrand; Geoffrey A. Phelps; Edward A. Mankinen

    2006-09-21

    A three-dimensional inversion of gravity data from the Rainier Mesa area and surrounding regions reveals a topographically complex pre-Cenozoic basement surface. This model of the depth to pre-Cenozoic basement rocks is intended for use in a 3D hydrogeologic model being constructed for the Rainier Mesa area. Prior to this study, our knowledge of the depth to pre-Cenozoic basement rocks was based on a regional model, applicable to general studies of the greater Nevada Test Site area but inappropriate for higher resolution modeling of ground-water flow across the Rainier Mesa area. The new model incorporates several changes that lead to significant improvements over the previous regional view. First, the addition of constraining wells, encountering old volcanic rocks lying above but near pre-Cenozoic basement, prevents modeled basement from being too shallow. Second, an extensive literature and well data search has led to an increased understanding of the change of rock density with depth in the vicinity of Rainier Mesa. The third, and most important change, relates to the application of several depth-density relationships in the study area instead of a single generalized relationship, thereby improving the overall model fit. In general, the pre-Cenozoic basement surface deepens in the western part of the study area, delineating collapses within the Silent Canyon and Timber Mountain caldera complexes, and shallows in the east in the Eleana Range and Yucca Flat regions, where basement crops out. In the Rainier Mesa study area, basement is generally shallow (< 1 km). The new model identifies previously unrecognized structures within the pre-Cenozoic basement that may influence ground-water flow, such as a shallow basement ridge related to an inferred fault extending northward from Rainier Mesa into Kawich Valley.

  1. Inversion of Gravity Data to Define the Pre-Cenozoic Surface and Regional Structures Possibly Influencing Groundwater Flow in the Rainier Mesa Region, Nye County, Nevada.

    Energy Technology Data Exchange (ETDEWEB)

    Thomas G. Hildenbrand; Geoffrey A. Phelps; Edward A. Mankinen

    2006-09-21

    A three-dimensional inversion of gravity data from the Rainier Mesa area and surrounding regions reveals a topographically complex pre-Cenozoic basement surface. This model of the depth to pre-Cenozoic basement rocks is intended for use in a 3D hydrogeologic model being constructed for the Rainier Mesa area. Prior to this study, our knowledge of the depth to pre-Cenozoic basement rocks was based on a regional model, applicable to general studies of the greater Nevada Test Site area but inappropriate for higher resolution modeling of ground-water flow across the Rainier Mesa area. The new model incorporates several changes that lead to significant improvements over the previous regional view. First, the addition of constraining wells, encountering old volcanic rocks lying above but near pre-Cenozoic basement, prevents modeled basement from being too shallow. Second, an extensive literature and well data search has led to an increased understanding of the change of rock density with depth in the vicinity of Rainier Mesa. The third, and most important change, relates to the application of several depth-density relationships in the study area instead of a single generalized relationship, thereby improving the overall model fit. In general, the pre-Cenozoic basement surface deepens in the western part of the study area, delineating collapses within the Silent Canyon and Timber Mountain caldera complexes, and shallows in the east in the Eleana Range and Yucca Flat regions, where basement crops out. In the Rainier Mesa study area, basement is generally shallow (< 1 km). The new model identifies previously unrecognized structures within the pre-Cenozoic basement that may influence ground-water flow, such as a shallow basement ridge related to an inferred fault extending northward from Rainier Mesa into Kawich Valley.

  2. Novel manufacturing process for direct methanol fuel cells (DMFC) by defined layer structures; Neuartiges Herstellungsverfahren fuer Direkt-Methanol-Brennstoffzellen (DMFC) durch definierte Schichtstrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Frey, Thomas

    2007-07-17

    A novel method to prepare membrane electrode assemblies (MEA) for direct methanol fuel cells (DMFC) by a layer-upon-layer fabrication onto a porous substrate is presented. The novel preparation technique is based on a single method for the fabrication of the whole MEA, e.g. spraying one functional layer onto the other, and therefore simplifies its preparation considerably. It also permits new fuel cell designs with in-plane serial connection of single cells. The new concept offers high flexibility in the choice of cell geometry as well as superior control of the structural parameters. Layer thickness, composition, catalyst and ionomer loadings can easily be varied and adapted. Cells fabricated with the new concept are especially suited for low power micro fuel cells operated at ambient conditions. In this work, process parameters enabling such a layer-upon-layer MEA preparation have been developed. Advanced catalyst inks and electrolyte solutions were formulated as precursors for each functional layer. Nafion {sup registered} as well as polyaryl-based polymers were investigated for the fabrication of dense electrolyte layers. Catalyst layers were prepared from inks containing Pt and PtRu-black catalysts which were suspended in suitable solvents with diluted proton-conducting electrolytes. The critical parameters for the layer build-up were identified and optimized afterwards. Various candidate materials for the porous substrate were characterized and selected for further investigation. Experiments and calculation models led to a concept and an advanced design for a serially connected multi-cells unit on the substrate. The inplane conductivity of the electrodes turned out to be the critical parameter resulting in high ohmic losses especially when the electrodes were applied on non-conductive substrates. Various conductive coatings were tested to selectively increase the conductivity of non-conductive substrates, which are prerequisite for serial connection. Only

  3. Defining the Core Citrus Leaf- and Root-Associated Microbiota: Factors Associated with Community Structure and Implications for Managing Huanglongbing (Citrus Greening) Disease.

    Science.gov (United States)

    Blaustein, Ryan A; Lorca, Graciela L; Meyer, Julie L; Gonzalez, Claudio F; Teplitski, Max

    2017-06-01

    Stable associations between plants and microbes are critical to promoting host health and productivity. The objective of this work was to test the hypothesis that restructuring of the core microbiota may be associated with the progression of huanglongbing (HLB), the devastating citrus disease caused by Liberibacter asiaticus, Liberibacter americanus, and Liberibacter africanus The microbial communities of leaves (n = 94) and roots (n = 79) from citrus trees that varied by HLB symptom severity, cultivar, location, and season/time were characterized with Illumina sequencing of 16S rRNA genes. The taxonomically rich communities contained abundant core members (i.e., detected in at least 95% of the respective leaf or root samples), some overrepresented site-specific members, and a diverse community of low-abundance variable taxa. The composition and diversity of the leaf and root microbiota were strongly associated with HLB symptom severity and location; there was also an association with host cultivar. The relative abundance of Liberibacter spp. among leaf microbiota positively correlated with HLB symptom severity and negatively correlated with alpha diversity, suggesting that community diversity decreases as symptoms progress. Network analysis of the microbial community time series identified a mutually exclusive relationship between Liberibacter spp. and members of the Burkholderiaceae, Micromonosporaceae, and Xanthomonadaceae This work confirmed several previously described plant disease-associated bacteria, as well as identified new potential implications for biological control. Our findings advance the understanding of (i) plant microbiota selection across multiple variables and (ii) changes in (core) community structure that may be a precondition to disease establishment and/or may be associated with symptom progression.IMPORTANCE This study provides a comprehensive overview of the core microbial community within the microbiomes of plant hosts that vary in

  4. The method used to set the pass mark in an objective structured clinical examination defines the performance of candidates for certification as rheumatologists.

    Science.gov (United States)

    Pascual-Ramos, Virginia; Guilaisne Bernard-Medina, Ana; Flores-Alvarado, Diana Elsa; Portela-Hernández, Margarita; Maldonado-Velázquez, María Del Rocío; Jara-Quezada, Luis Javier; Amezcua-Guerra, Luis Manuel; Rubio-Judith López-Zepeda, Nadina E; Álvarez-Hernandez, Everardo; Saavedra, Miguel Ángel; Arce-Salinas, César Alejandro

    2017-02-01

    The Mexican Accreditation Council for Rheumatology certifies trainees (TR) on an annual basis using both a multiple-choice question (MCQ) test and an objective structured clinical examination (OSCE). For 2013 and 2014, the OSCE pass mark (PM) was set by criterion referencing as ≥6 (CPM), whereas overall rating of borderline performance method (BPM) was added for 2015 and 2016 accreditations. We compared OSCE TR performance according to CPM and BPM, and examined whether correlations between MCQ and OSCE were affected by PM. Forty-three (2015) and 37 (2016) candidates underwent both tests. Altogether, OSCE were integrated by 15 validated stations; one evaluator per station scored TR performance according to a station-tailored check-list and a Likert scale (fail, borderline, above range) of overall performance. A composite OSCE score was derived for each candidate. Appropriate statistics were used. Mean (±standard derivation [SD]) MCQ test scores were 6.6±0.6 (2015) and 6.4±0.6 (2016) with 5 candidates receiving a failing score each year. Mean (±SD) OSCE scores were 7.4±0.6 (2015) and 7.3±0.6 (2016); no candidate received a failing CPM score in either 2015 or 2016 OSCE, although 21 (49%) and 19 (51%) TR, respectively, received a failing BPM score (calculated as 7.3 and 7.4, respectively). Stations for BPM ranged from 4.5 to 9.5; overall, candidates showed better performance in CPM. In all, MCQ correlated with composite OSCE, r=0.67 (2015) and r=0.53 (2016); P≤.001. Trainees with a passing BPM score in OSCE had higher MCQ scores than those with a failing score. Overall, OSCE-PM selection impacted candidates' performance but had a limited affect on correlation between clinical and practical examinations. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  5. Defining Z in Q

    CERN Document Server

    Koenigsmann, Jochen

    2010-01-01

    We show that ${\\mathbb Z}$ is definable in ${\\mathbb Q}$ by a universal first-order formula in the language of rings. We also present an $\\forall\\exists$-formula for ${\\mathbb Z}$ in ${\\mathbb Q}$ with just one universal quantifier. We exhibit new diophantine subsets of ${\\mathbb Q}$ like the set of non-squares or the complement of the image of the norm map under a quadratic extension. Finally, we show that there is no existential formula for ${\\mathbb Z}$ in ${\\mathbb Q}$, provided one assumes a strong variant of the Bombieri-Lang Conjecture for varieties over ${\\mathbb Q}$ with many ${\\mathbb Q}$-rational points.

  6. Software Process Improvement Defined

    DEFF Research Database (Denmark)

    Aaen, Ivan

    2002-01-01

    This paper argues in favor of the development of explanatory theory on software process improvement. The last one or two decades commitment to prescriptive approaches in software process improvement theory may contribute to the emergence of a gulf dividing theorists and practitioners....... It is proposed that this divide be met by the development of theory evaluating prescriptive approaches and informing practice with a focus on the software process policymaking and process control aspects of improvement efforts...

  7. Software Process Improvement Defined

    DEFF Research Database (Denmark)

    Aaen, Ivan

    2002-01-01

    This paper argues in favor of the development of explanatory theory on software process improvement. The last one or two decades commitment to prescriptive approaches in software process improvement theory may contribute to the emergence of a gulf dividing theorists and practitioners....... It is proposed that this divide be met by the development of theory evaluating prescriptive approaches and informing practice with a focus on the software process policymaking and process control aspects of improvement efforts...

  8. Software-Defined Cluster

    Institute of Scientific and Technical Information of China (English)

    聂华; 杨晓君; 刘淘英

    2015-01-01

    The cluster architecture has played an important role in high-end computing for the past 20 years. With the advent of Internet services, big data, and cloud computing, traditional clusters face three challenges: 1) providing flexible system balance among computing, memory, and I/O capabilities;2) reducing resource pooling overheads;and 3) addressing low performance-power efficiency. This position paper proposes a software-defined cluster (SDC) architecture to deal with these challenges. The SDC architecture inherits two features of traditional cluster: its architecture is multicomputer and it has loosely-coupled interconnect. SDC provides two new mechanisms: global I/O space (GIO) and hardware-supported native access (HNA) to remote devices. Application software can define a virtual cluster best suited to its needs from resources pools provided by a physical cluster, and traditional cluster ecosystems need no modification. We also discuss a prototype design and implementation of a 32-processor cloud server utilizing the SDC architecture.

  9. Externally definable sets and dependent pairs II

    CERN Document Server

    Chernikov, Artem

    2012-01-01

    We continue investigating the structure of externally definable sets in NIP theories and preservation of NIP after expanding by new predicates. Most importantly: types over finite sets are uniformly definable; over a model, a family of non-forking instances of a formula (with parameters ranging over a type-definable set) can be covered with finitely many invariant types; we give some criteria for the boundedness of an expansion by a new predicate in a distal theory; naming an arbitrary small indiscernible sequence preserves NIP, while naming a large one doesn't; there are models of NIP theories over which all 1-types are definable, but not all n-types.

  10. Analytic structure of the $n=7$ scattering amplitude in $\\mathcal{N}=4$ SYM theory at multi-Regge kinematics: Conformal Regge Pole Contribution

    CERN Document Server

    Bartels, Jochen; Lipatov, Lev

    2013-01-01

    We investigate the analytic structure of the $2\\to5$ scattering amplitude in the planar limit of $\\mathcal{N}=4$ SYM in multi-Regge kinematics in all physical regions. We demonstrate the close connection between Regge pole and Regge cut contributions: in a selected class of kinematic regions (Mandelstam regions) the usual factorizing Regge pole formula develops unphysical singularities which have to be absorbed and compensated by Regge cut contributions. This leads, in the corrections to the BDS formula, to conformal invariant 'renormalized' Regge pole expressions in the remainder function. We compute these renormalized Regge poles for the $2\\to5$ scattering amplitude.

  11. Analytic structure of the n=7 scattering amplitude in N=4 SYM theory at multi-Regge kinematics. Conformal Regge pole contribution

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, Jochen; Kormilitzin, Andrey [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Lipatov, Lev [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; St. Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation)

    2013-11-15

    We investigate the analytic structure of the 2 {yields} 5 scattering amplitude in the planar limit of N=4 SYM in multi-Regge kinematics in all physical regions. We demonstrate the close connection between Regge pole and Regge cut contributions: in a selected class of kinematic regions (Mandelstam regions) the usual factorizing Regge pole formula develops unphysical singularities which have to be absorbed and compensated by Regge cut contributions. This leads, in the corrections to the BDS formula, to conformal invariant 'renormalized' Regge pole expressions in the remainder function. We compute these renormalized Regge poles for the 2 {yields} 5 scattering amplitude.

  12. Implementing Software Defined Radio

    CERN Document Server

    Grayver, Eugene

    2013-01-01

    Software Defined Radio makes wireless communications easier, more efficient, and more reliable. This book bridges the gap between academic research and practical implementation. When beginning a project, practicing engineers, technical managers, and graduate students can save countless hours by considering the concepts presented in these pages. The author covers the myriad options and trade-offs available when selecting an appropriate hardware architecture. As demonstrated here, the choice between hardware- and software-centric architecture can mean the difference between meeting an aggressive schedule and bogging down in endless design iterations. Because of the author’s experience overseeing dozens of failed and successful developments, he is able to present many real-life examples. Some of the key concepts covered are: Choosing the right architecture for the market – laboratory, military, or commercial Hardware platforms – FPGAs, GPPs, specialized and hybrid devices Standardization efforts to ens...

  13. Defining Political Extremism in the Balkans. The Case of Serbia

    Directory of Open Access Journals (Sweden)

    Babić Marko

    2015-12-01

    Full Text Available Political extremism (and particularly right wing political extremism remains relatively insufficiently explored due to the fact that the phenomenon is controversial and hard to define. Its ambiguity and variability depending on time and spatial point of view further complicates its definition. Its structure is amorphous and eclectic as it often includes elements from different ideologies and connects incompatible ideas. A multidimensional conceptualization and an interdisciplinary approach - sociological, social, psychological and historical, are the Author’s tools in explaining the phenomenon of political extremism in Serbia, hopefully contributing to its clarification and laying a foundation for its further explanatory theoretical studies.

  14. Decoupling Contributions from Canopy Structure and Leaf Optics is Critical for Remote Sensing Leaf Biochemistry (Reply to Townsend, et al.)

    Science.gov (United States)

    Knyazikhin, Yuri; Lewis, Philip; Disney, Mathias I.; Stenberg, Pauline; Mottus, Matti; Rautianinen, Miina; Kaufmann, Robert K.; Marshak, Alexander; Schull, Mitchell A.; Carmona, Pedro Latorre; hide

    2013-01-01

    Townsend et al. (1) agree that we explained that the apparent relationship (2) between foliar nitrogen (%N) and near-infrared (NIR) canopy reflectance was largely attributable to structure (which is in turn caused by variation in fraction of broadleaf canopy). Our conclusion that the observed correlation with %N was spurious (i.e., lacking a causal basis) is, thus, clearly justified: we demonstrated that structure explained the great majority of observed correlation, where the structural influence was derived precisely via reconciling the observed correlation with radiative-transfer theory. What this also suggests is that such correlations, although observed, do not uniquely provide information on canopy biochemical constituents.

  15. Micromechanical modelling of heterogeneous materials in transient conditions: contributions for the study of the ageing of structural components under service; Modelisation micromecanique des materiaux heterogenes en regimes transitoires: contributions en vue de l'etude du vieillissement des structures en service

    Energy Technology Data Exchange (ETDEWEB)

    Masson, R.

    2010-12-20

    considering the particular situation where regions of the representative volume element have ill-defined mechanical properties. In the linear elastic case, new bounds for the effective behaviour are derived by marrying the structural analysis and a variational approach. This last work opens on important prospects for further works: more tightened bounds, nonlinear behaviours,... Considering homogenisation methods, further works are precisely defined, in particular for polycrystalline materials. In that situation, the field of investigation widens clearly (Fatigue, Large strains,...) thanks to the internal variables formulation proposed. Lastly, the simulation of irradiation effects constitutes the third topic of interest for the years to come, the general objective being to better predict the effects of the swelling strains induced by irradiation on the behaviour of structural components under service. (author) [French] La modelisation du comportement mecanique des materiaux de structure se nourrit de plus en plus de parametres microstructuraux. Dans ce cadre, les methodes d'homogeneisation presentent l'avantage de fournir des methodes deductives qui, a partir des proprietes et de la repartition spatiale des heterogeneites, deduisent les proprietes effectives du materiau considere. Neanmoins de nombreuses applications soulevent encore des difficultes. C'est en particulier le cas des materiaux de structure presentant un comportement elasto-viscoplastique et soumis a un trajet de chargement non monotone et non isotherme. Progresser sur le traitement par homogeneisation de ces situations concretes constitue precisement le fil conducteur des differentes contributions presentees dans ce memoire d'HDR. Dans le cas elastique lineaire, de nouvelles expressions pour le calcul du tenseur d'Eshelby sont tout d'abord etablies afin d'ameliorer l'efficacite des methodes d'homogeneisation habituellement proposees. Toujours pour des comportements

  16. Defining the Anthropocene

    Science.gov (United States)

    Lewis, Simon; Maslin, Mark

    2016-04-01

    Time is divided by geologists according to marked shifts in Earth's state. Recent global environmental changes suggest that Earth may have entered a new human-dominated geological epoch, the Anthropocene. Should the Anthropocene - the idea that human activity is a force acting upon the Earth system in ways that mean that Earth will be altered for millions of years - be defined as a geological time-unit at the level of an Epoch? Here we appraise the data to assess such claims, first in terms of changes to the Earth system, with particular focus on very long-lived impacts, as Epochs typically last millions of years. Can Earth really be said to be in transition from one state to another? Secondly, we then consider the formal criteria used to define geological time-units and move forward through time examining whether currently available evidence passes typical geological time-unit evidence thresholds. We suggest two time periods likely fit the criteria (1) the aftermath of the interlinking of the Old and New Worlds, which moved species across continents and ocean basins worldwide, a geologically unprecedented and permanent change, which is also the globally synchronous coolest part of the Little Ice Age (in Earth system terms), and the beginning of global trade and a new socio-economic "world system" (in historical terms), marked as a golden spike by a temporary drop in atmospheric CO2, centred on 1610 CE; and (2) the aftermath of the Second World War, when many global environmental changes accelerated and novel long-lived materials were increasingly manufactured, known as the Great Acceleration (in Earth system terms) and the beginning of the Cold War (in historical terms), marked as a golden spike by the peak in radionuclide fallout in 1964. We finish by noting that the Anthropocene debate is politically loaded, thus transparency in the presentation of evidence is essential if a formal definition of the Anthropocene is to avoid becoming a debate about bias. The

  17. Tissue heterogeneity in structure and conductivity contribute to cell survival during irreversible electroporation ablation by ``electric field sinks''

    Science.gov (United States)

    Golberg, Alexander; Bruinsma, Bote G.; Uygun, Basak E.; Yarmush, Martin L.

    2015-02-01

    Irreversible electroporation (IRE) is an emerging, minimally invasive technique for solid tumors ablation, under clinical investigation for cancer therapy. IRE affects only the cell membrane, killing cells while preserving the extracellular matrix structure. Current reports indicate tumors recurrence rate after IRE averaging 31% of the cases, of which 10% are local recurrences. The mechanisms for these recurrences are not known and new explanations for incomplete cell death are needed. Using finite elements method for electric field distribution, we show that presence of vascular structures with blood leads to the redistribution of electric fields leading to the areas with more than 60% reduced electric field strength in proximity to large blood vessels and clustered vessel structures. In an in vivo rat model of liver IRE ablation, we show that cells located in the proximity of larger vessel structures and in proximity of clustered vessel structures appear less affected by IRE ablation than cells in the tissue parenchyma or in the proximity of small, more isolated vessels. These findings suggest a role for ``electric field sinks'' in local tumors recurrences after IRE and emphasize the importance of the precise mapping of the targeted organ structure and conductivity for planning of electroporation procedures.

  18. Tissue heterogeneity in structure and conductivity contribute to cell survival during irreversible electroporation ablation by "electric field sinks".

    Science.gov (United States)

    Golberg, Alexander; Bruinsma, Bote G; Uygun, Basak E; Yarmush, Martin L

    2015-02-16

    Irreversible electroporation (IRE) is an emerging, minimally invasive technique for solid tumors ablation, under clinical investigation for cancer therapy. IRE affects only the cell membrane, killing cells while preserving the extracellular matrix structure. Current reports indicate tumors recurrence rate after IRE averaging 31% of the cases, of which 10% are local recurrences. The mechanisms for these recurrences are not known and new explanations for incomplete cell death are needed. Using finite elements method for electric field distribution, we show that presence of vascular structures with blood leads to the redistribution of electric fields leading to the areas with more than 60% reduced electric field strength in proximity to large blood vessels and clustered vessel structures. In an in vivo rat model of liver IRE ablation, we show that cells located in the proximity of larger vessel structures and in proximity of clustered vessel structures appear less affected by IRE ablation than cells in the tissue parenchyma or in the proximity of small, more isolated vessels. These findings suggest a role for "electric field sinks" in local tumors recurrences after IRE and emphasize the importance of the precise mapping of the targeted organ structure and conductivity for planning of electroporation procedures.

  19. Tissue heterogeneity in structure and conductivity contribute to cell survival during irreversible electroporation ablation by “electric field sinks”

    Science.gov (United States)

    Golberg, Alexander; Bruinsma, Bote G.; Uygun, Basak E.; Yarmush, Martin L.

    2015-01-01

    Irreversible electroporation (IRE) is an emerging, minimally invasive technique for solid tumors ablation, under clinical investigation for cancer therapy. IRE affects only the cell membrane, killing cells while preserving the extracellular matrix structure. Current reports indicate tumors recurrence rate after IRE averaging 31% of the cases, of which 10% are local recurrences. The mechanisms for these recurrences are not known and new explanations for incomplete cell death are needed. Using finite elements method for electric field distribution, we show that presence of vascular structures with blood leads to the redistribution of electric fields leading to the areas with more than 60% reduced electric field strength in proximity to large blood vessels and clustered vessel structures. In an in vivo rat model of liver IRE ablation, we show that cells located in the proximity of larger vessel structures and in proximity of clustered vessel structures appear less affected by IRE ablation than cells in the tissue parenchyma or in the proximity of small, more isolated vessels. These findings suggest a role for “electric field sinks” in local tumors recurrences after IRE and emphasize the importance of the precise mapping of the targeted organ structure and conductivity for planning of electroporation procedures. PMID:25684630

  20. Contributions of structural connectivity and cerebrovascular parameters to functional magnetic resonance imaging signals in mice at rest and during sensory paw stimulation.

    Science.gov (United States)

    Schroeter, Aileen; Grandjean, Joanes; Schlegel, Felix; Saab, Bechara J; Rudin, Markus

    2017-07-01

    Previously, we reported widespread bilateral increases in stimulus-evoked functional magnetic resonance imaging signals in mouse brain to unilateral sensory paw stimulation. We attributed the pattern to arousal-related cardiovascular changes overruling cerebral autoregulation thereby masking specific signal changes elicited by local neuronal activity. To rule out the possibility that interhemispheric neuronal communication might contribute to bilateral functional magnetic resonance imaging responses, we compared stimulus-evoked functional magnetic resonance imaging responses to unilateral hindpaw stimulation in acallosal I/LnJ, C57BL/6, and BALB/c mice. We found bilateral blood-oxygenation-level dependent signal changes in all three strains, ruling out a dominant contribution of transcallosal communication as reason for bilaterality. Analysis of functional connectivity derived from resting-state functional magnetic resonance imaging, revealed that bilateral cortical functional connectivity is largely abolished in I/LnJ animals. Cortical functional connectivity in all strains correlated with structural connectivity in corpus callosum as revealed by diffusion tensor imaging. Given the profound influence of systemic hemodynamics on stimulus-evoked functional magnetic resonance imaging outcomes, we evaluated whether functional connectivity data might be affected by cerebrovascular parameters, i.e. baseline cerebral blood volume, vascular reactivity, and reserve. We found that effects of cerebral hemodynamics on functional connectivity are largely outweighed by dominating contributions of structural connectivity. In contrast, contributions of transcallosal interhemispheric communication to the occurrence of ipsilateral functional magnetic resonance imaging response of equal amplitude to unilateral stimuli seem negligible.

  1. The 3-Loop Pure Singlet Heavy Flavor Contributions to the Structure Function $F_2(x,Q^2)$ and the Anomalous Dimension

    CERN Document Server

    Ablinger, J; Blümlein, J; De Freitas, A; von Manteuffel, A; Schneider, C

    2014-01-01

    The pure singlet asymptotic heavy flavor corrections to 3-loop order for the deep-inelastic scattering structure function $F_2(x,Q^2)$ and the corresponding transition matrix element $A_{Qq}^{(3), \\sf PS}$ in the variable flavor number scheme are computed. In Mellin-$N$ space these inclusive quantities depend on generalized harmonic sums. We also recalculate the complete 3-loop pure singlet anomalous dimension for the first time. Numerical results for the Wilson coefficients, the operator matrix element and the contribution to the structure function $F_2(x,Q^2)$ are presented.

  2. The 3-loop pure singlet heavy flavor contributions to the structure function F2(x,Q2 and the anomalous dimension

    Directory of Open Access Journals (Sweden)

    J. Ablinger

    2015-01-01

    Full Text Available The pure singlet asymptotic heavy flavor corrections to 3-loop order for the deep-inelastic scattering structure function F2(x,Q2 and the corresponding transition matrix element AQq(3,PS in the variable flavor number scheme are computed. In Mellin-N space these inclusive quantities depend on generalized harmonic sums. We also recalculate the complete 3-loop pure singlet anomalous dimension for the first time. Numerical results for the Wilson coefficients, the operator matrix element and the contribution to the structure function F2(x,Q2 are presented.

  3. The contribution of soil structural degradation to catchment flooding: a preliminary investigation of the 2000 floods in England and Wales

    Directory of Open Access Journals (Sweden)

    I. P. Holman

    2003-01-01

    Full Text Available During the autumn of 2000, England and Wales experienced the wettest conditions for over 270 years, causing significant flooding. The exceptional combination of a wet spring and autumn provided the potential for soil structural degradation. Soils prone to structural degradation under five common lowland cropping systems (autumn-sown crops, late-harvested crops, field vegetables, orchards and sheep fattening and livestock rearing systems were examined within four catchments that experienced serious flooding. Soil structural degradation of the soil surface, within the topsoil or at the topsoil/subsoil junction, was widespread in all five cropping systems, under a wide range of soil types and in all four catchments. Extrapolation to the catchment scale suggests that soil structural degradation may have occurred on approximately 40% of the Severn, 30–35 % of the Yorkshire Ouse and Uck catchments and 20% of the Bourne catchment. Soil structural conditions were linked via hydrological soil group, soil condition and antecedent rainfall conditions to SCS Curve Numbers to evaluate the volume of enhanced runoff in each catchment. Such a response at the catchment-scale is only likely during years when prolonged wet weather and the timing of cultivation practices lead to widespread soil structural degradation. Nevertheless, an holistic catchment-wide approach to managing the interactions between agricultural land use and hydrology, allowing appropriate runoff (and consequent flooding to be controlled at source, rather than within the floodplain or the river channel, should be highlighted in catchment flood management plans. Keywords: flooding, soil structure, land management, Curve Number, runoff, agriculture

  4. Relative Contribution of Matrix Structure, Patch Resources and Management to the Local Densities of Two Large Blue Butterfly Species.

    Science.gov (United States)

    Kajzer-Bonk, Joanna; Skórka, Piotr; Nowicki, Piotr; Bonk, Maciej; Król, Wiesław; Szpiłyk, Damian; Woyciechowski, Michal

    2016-01-01

    The type of matrix, the landscape surrounding habitat patches, may determine the distribution and function of local populations. However, the matrix is often heterogeneous, and its various components may differentially contribute to metapopulation processes at different spatial scales, a phenomenon that has rarely been investigated. The aim of this study was to estimate the relative importance of matrix composition and spatial scale, habitat quality, and management intensity on the occurrence and density of local populations of two endangered large blue butterflies: Phengaris teleius and P. nausithous. Presence and abundance data were assessed over two years, 2011-12, in 100 local patches within two heterogeneous regions (near Kraków and Tarnów, southern Poland). The matrix composition was analyzed at eight spatial scales. We observed high occupancy rates in both species, regions and years. With the exception of area and isolation, almost all of the matrix components contributed to Phengaris sp. densities. The different matrix components acted at different spatial scales (grassland cover within 4 and 3 km, field cover within 0.4 and 0.3 km and water cover within 4 km radii for P. teleius and P. nausithous, respectively) and provided the highest independent contribution to the butterfly densities. Additionally, the effects of a 0.4 km radius of forest cover and a food plant cover on P. teleius, and a 1 km radius of settlement cover and management intensity on P. nausithous densities were observed. Contrary to former studies we conclude that the matrix heterogeneity and spatial scale rather than general matrix type are of relevance for densities of butterflies. Conservation strategies for these umbrella species should concentrate on maintaining habitat quality and managing matrix composition at the most appropriate spatial scales.

  5. The contribution of Diamond Light Source to the study of strongly correlated electron systems and complex magnetic structures

    Energy Technology Data Exchange (ETDEWEB)

    Radaelli, P. G.; Dhesi, S. S.

    2015-01-26

    We review some of the significant contributions to the field of strongly correlated materials and complex magnets, arising from experiments performed at the Diamond Light Source (Harwell Science and Innovation Campus, Didcot, UK) during the first few years of operation (2007–2014). We provide a comprehensive overview of Diamond research on topological insulators, multiferroics, complex oxides and magnetic nanostructures. Several experiments on ultrafast dynamics, magnetic imaging, photoemission electron microscopy, soft X-ray holography and resonant magnetic hard and soft X-ray scattering are described.

  6. The contribution of Diamond Light Source to the study of strongly correlated electron systems and complex magnetic structures.

    Science.gov (United States)

    Radaelli, P G; Dhesi, S S

    2015-03-06

    We review some of the significant contributions to the field of strongly correlated materials and complex magnets, arising from experiments performed at the Diamond Light Source (Harwell Science and Innovation Campus, Didcot, UK) during the first few years of operation (2007-2014). We provide a comprehensive overview of Diamond research on topological insulators, multiferroics, complex oxides and magnetic nanostructures. Several experiments on ultrafast dynamics, magnetic imaging, photoemission electron microscopy, soft X-ray holography and resonant magnetic hard and soft X-ray scattering are described.

  7. On defining dietary fibre.

    Science.gov (United States)

    DeVries, Jonathan W

    2003-02-01

    Establishing a definition for dietary fibre has historically been a balance between nutrition knowledge and analytical method capabilities. While the most widely accepted physiologically-based definitions have generally been accurate in defining the dietary fibre in foods, scientists and regulators have tended, in practice, to rely on analytical procedures as the definitional basis in fact. As a result, incongruities between theory and practice have resulted in confusion regarding the components that make up dietary fibre. In November 1998 the president of the American Association of Cereal Chemists (AACC) appointed an expert scientific review committee and charged it with the task of reviewing and, if necessary, updating the definition of dietary fibre. The committee was further charged with assessing the state of analytical methodology and making recommendations relevant to the updated definition. After due deliberation, an updated definition of dietary fibre was delivered to the AACC Board of Directors for consideration and adoption (Anon, 2000; Jones 2000b). The updated definition includes the same food components as the historical working definition used for approximately 30 years (a very important point, considering that the majority of the research of the past 30 years delineating the positive health effects of dietary fibre is based on that working definition). However, the updated definition more clearly delineates the make-up of dietary fibre and its physiological functionality. As a result, relatively few changes will be necessary in analytical methodology. Current methodologies, in particular AACC-approved method of analysis 32-05 (Grami, 2000), Association of Official Analytical Chemists' official method of analysis 985.29 (Horwitz, 2000a) or AACC 32-07 (Grami, 2000) Association of Official Analytical Chemists 991.43 (Horwitz, 2000a) will continue to be sufficient and used for most foods. A small number of additional methods will be necessary to

  8. The structure-specific endonuclease Mus81 contributes to replication restart by generating double-strand DNA breaks.

    Science.gov (United States)

    Hanada, Katsuhiro; Budzowska, Magda; Davies, Sally L; van Drunen, Ellen; Onizawa, Hideo; Beverloo, H Berna; Maas, Alex; Essers, Jeroen; Hickson, Ian D; Kanaar, Roland

    2007-11-01

    Faithful duplication of the genome requires structure-specific endonucleases such as the RuvABC complex in Escherichia coli. These enzymes help to resolve problems at replication forks that have been disrupted by DNA damage in the template. Much less is known about the identities of these enzymes in mammalian cells. Mus81 is the catalytic component of a eukaryotic structure-specific endonuclease that preferentially cleaves branched DNA substrates reminiscent of replication and recombination intermediates. Here we explore the mechanisms by which Mus81 maintains chromosomal stability. We found that Mus81 is involved in the formation of double-strand DNA breaks in response to the inhibition of replication. Moreover, in the absence of chromosome processing by Mus81, recovery of stalled DNA replication forks is attenuated and chromosomal aberrations arise. We suggest that Mus81 suppresses chromosomal instability by converting potentially detrimental replication-associated DNA structures into intermediates that are more amenable to DNA repair.

  9. A POSSIBLE CONTRIBUTION OF MESSENGER-RNA SECONDARY STRUCTURE TO TRANSLATION INITIATION EFFICIENCY IN LACTOCOCCUS-LACTIS

    NARCIS (Netherlands)

    VANDEGUCHTE, M; VANDERLENDE, T; KOK, J; VENEMA, G

    1991-01-01

    Gene expression signals derived from Lactococcus lactis were linked to lacZ-fused genes with different 5'-nucleotide sequences. Computer predictions of mRNA secondary structure were combined with lacZ expression studies to direct base-substitutions that could possibly influence gene expression. Muta

  10. Macro and micro structures in the dorsal anterior cingulate cortex contribute to individual differences in self-monitoring.

    Science.gov (United States)

    Yang, Junyi; Tian, Xue; Wei, Dongtao; Liu, Huijuan; Zhang, Qinglin; Wang, Kangcheng; Chen, Qunlin; Qiu, Jiang

    2016-06-01

    Individual differences in self-monitoring, which are the capability to adjust behavior to adapt to social situations, influence a wide range of social behaviors. However, understanding of focal differences in brain structures related to individual self-monitoring is minimal, particularly when micro and macro structures are considered simultaneously. The present study investigates the relationship between self-monitoring and brain structure in a relatively large sample of young adults. Voxel-based morphometry (VBM) revealed a significant positive correlation between self-monitoring and gray matter volume in the dorsal cingulate anterior cortex (dACC), dorsal lateral prefrontal cortex (DLPFC), and bilateral ventral striatum (VS). Further analysis revealed a significant negative correlation between self-monitoring and white matter (WM) integrity, as indexed by fractional anisotropy (FA) in the anterior cingulum (ACG) bundle. Moreover, there was a significant positive correlation between self-monitoring and mean radius diffusion (RD). These results shed light on the structural neural basis of variation in self-monitoring.

  11. Does standardised structured reporting contribute to quality in diagnostic pathology? The importance of evidence-based datasets.

    Science.gov (United States)

    Ellis, D W; Srigley, J

    2016-01-01

    Key quality parameters in diagnostic pathology include timeliness, accuracy, completeness, conformance with current agreed standards, consistency and clarity in communication. In this review, we argue that with worldwide developments in eHealth and big data, generally, there are two further, often overlooked, parameters if our reports are to be fit for purpose. Firstly, population-level studies have clearly demonstrated the value of providing timely structured reporting data in standardised electronic format as part of system-wide quality improvement programmes. Moreover, when combined with multiple health data sources through eHealth and data linkage, structured pathology reports become central to population-level quality monitoring, benchmarking, interventions and benefit analyses in public health management. Secondly, population-level studies, particularly for benchmarking, require a single agreed international and evidence-based standard to ensure interoperability and comparability. This has been taken for granted in tumour classification and staging for many years, yet international standardisation of cancer datasets is only now underway through the International Collaboration on Cancer Reporting (ICCR). In this review, we present evidence supporting the role of structured pathology reporting in quality improvement for both clinical care and population-level health management. Although this review of available evidence largely relates to structured reporting of cancer, it is clear that the same principles can be applied throughout anatomical pathology generally, as they are elsewhere in the health system.

  12. Top-dressing nitrogen fertilizer rate contributes to decrease culm physical strength by reducing structural carbohydrate content in japonica rice

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wu-jun; WANG Shao-hua; WU Long-mei; DING Yan-feng; WENG Fei; WU Xiao-ran; LI Gang-hua; LIU Zheng-hui; TANG She; DING Cheng-qiang

    2016-01-01

    Lodging is an important factor limiting rice yield and quality by bending or breaking stem injaponica rice (Oryza sativaL.) production. The objectives of this study were to determine the mechanism of lodging resistance injaponica rice as affected by carbohydrate components, especialy its related arrangement in culm tissue and response to top-dressing nitrogen (N) fertilizer. Field experiments were conducted in Danyang County, Jiangsu Province, China, by using twojaponica rice vari-eties Wuyunjing 23 (lodging-resistance variety) and W3668 (lodging-susceptible variety) with three top-dressing N fertilizer rates (0, 135 and 270 kg N ha–1) in 2013 and 2014. Lodging related physical parameters, morphological characteristics and stem carbohydrate components were investigated at 30 d after ful heading stage. Results showed that with increasing N fertilizer rates, the lodging rate and lodging index increased rapidly primarily due to signiifcant reduction of breaking strength in twojaponica rice varieties. Correlation analysis revealed that breaking strength was signiifcantly and positively correlated with bending stress, but negatively correlated with section modulus, except for signiifcant correlation at W3668 in 2014. Higher stem plumpness status and structural carbohydrate contents signiifcantly enhanced stem stiffness, despite of lower non-structural carbohydrate. With higher N fertilizer rate, the culm wal thickness was almost identical, and culm diameter increased slightly. The structural carbohydrates, especialy for lignin content in culm, reduced signiifcantly under high N rate. Further histochemical staining analysis revealed that high N treatments decreased the lignin deposition rapidly in the sclerenchyma cels of mechanical tissue, large vascular bundle and smal vascular bundle region, which were consistent with reduction of bending stress, especialy for W3668 and thus, resulted in poor stem strength and higher lodging index. These results suggested that

  13. Limited Pollen Dispersal Contributes to Population Genetic Structure but Not Local Adaptation in Quercus oleoides Forests of Costa Rica.

    Directory of Open Access Journals (Sweden)

    Nicholas John Deacon

    Full Text Available Quercus oleoides Cham. and Schlect., tropical live oak, is a species of conservation importance in its southern range limit of northwestern Costa Rica. It occurs in high-density stands across a fragmented landscape spanning a contrasting elevation and precipitation gradient. We examined genetic diversity and spatial genetic structure in this geographically isolated and genetically distinct population. We characterized population genetic diversity at 11 nuclear microsatellite loci in 260 individuals from 13 sites. We monitored flowering time at 10 sites, and characterized the local environment in order to compare observed spatial genetic structure to hypotheses of isolation-by-distance and isolation-by-environment. Finally, we quantified pollen dispersal distances and tested for local adaptation through a reciprocal transplant experiment in order to experimentally address these hypotheses.High genetic diversity is maintained in the population and the genetic variation is significantly structured among sampled sites. We identified 5 distinct genetic clusters and average pollen dispersal predominately occurred over short distances. Differences among sites in flowering phenology and environmental factors, however, were not strictly associated with genetic differentiation. Growth and survival of upland and lowland progeny in their native and foreign environments was expected to exhibit evidence of local adaptation due to the more extreme dry season in the lowlands. Seedlings planted in the lowland garden experienced much higher mortality than seedlings in the upland garden, but we did not identify evidence for local adaptation.Overall, this study indicates that the Costa Rican Q. oleoides population has a rich population genetic history. Despite environmental heterogeneity and habitat fragmentation, isolation-by-distance and isolation-by-environment alone do not explain spatial genetic structure. These results add to studies of genetic structure by

  14. Contribution of geophysical methods in the study of the floodplain structure (the Litavka River, the Czech Republic)

    Science.gov (United States)

    Kotková, Kristýna; Matys Grygar, Tomáš; Tůmová, Štěpánka; Elznicová, Jitka

    2017-04-01

    Mining and processing of polymetallic ores near the city of Příbram (the Czech Republic) have strongly impacted the fluvial system of the Litavka River. Beside of polymetallic mining during several hundred years with a peak between 1850 and 1950, the Litavka River was also influenced by uranium ore mining between 1948 and 1989. Severe contamination of the Litavka River system is known, but the alluvial architecture and specific distribution of contamination has not yet been satisfactorily described. However, such pieces of information are necessary for the predictions of the future behaviour of contaminants in the river system. We used geophysical methods for visualisation of subsurface layers of sediments and we have proved them very useful for the survey of the floodplain structure. It is especially advantageous when the surface topography of the floodplain does not reveal its internal structure, e.g. due to floodplain levelling by aggradation. Specifically, dipole electromagnetic profiling, also denoted electromagnetic induction sensing (DEMP) was used for quick detection of major heterogeneities in the floodplain structure. In addition, electrical resistivity tomography (ERT) was used for the exploration of lines across the heterogeneities shown by DEMP. This approach allows to choose the appropriate plan for the subsequent sampling in the floodplain to include all its structural (lithogenetic) units. Such rational strategy allows for reducing total amount of sampled sites without the risk of losing important information and production of false images. Both used geophysical tools and manual drill coring and the elemental analysis by handheld X-ray fluorescence spectrometry produced clear images of floodplain architecture and pollutant distribution. The internal structure of the Litavka River floodplain shows that lateral deposition and reworking of sediments played the main roles in the floodplain building. In the next centuries the lateral channel movement

  15. Concomitant predation on parasites is highly variable but constrains the ways in which parasites contribute to food web structure.

    Science.gov (United States)

    Cirtwill, Alyssa R; Stouffer, Daniel B

    2015-05-01

    Previous analyses of empirical food webs (the networks of who eats whom in a community) have revealed that parasites exert a strong influence over observed food web structure and alter many network properties such as connectance and degree distributions. It remains unclear, however, whether these community-level effects are fully explained by differences in the ways that parasites and free-living species interact within a food web. To rigorously quantify the interrelationship between food web structure, the types of species in a web and the distinct types of feeding links between them, we introduce a shared methodology to quantify the structural roles of both species and feeding links. Roles are quantified based on the frequencies with which a species (or link) appears in different food web motifs - the building blocks of networks. We hypothesized that different types of species (e.g. top predators, basal resources, parasites) and different types of links between species (e.g. classic predation, parasitism, concomitant predation on parasites along with their hosts) will show characteristic differences in their food web roles. We found that parasites do indeed have unique structural roles in food webs. Moreover, we demonstrate that different types of feeding links (e.g. parasitism, predation or concomitant predation) are distributed differently in a food web context. More than any other interaction type, concomitant predation appears to constrain the roles of parasites. In contrast, concomitant predation links themselves have more variable roles than any other type of interaction. Together, our results provide a novel perspective on how both species and feeding link composition shape the structure of an ecological community and vice versa.

  16. How much does the core structure of a three-phase contact line contribute to the line tension near a wetting transition?

    Energy Technology Data Exchange (ETDEWEB)

    Indekeu, J O [Institute for Theoretical Physics, Katholieke Universiteit Leuven, BE-3001 Leuven (Belgium); Koga, K [Department of Chemistry, Faculty of Science, Okayama University, Okayama 700-8530 (Japan); Widom, B [Department of Chemistry, Baker Laboratory, Cornell University, Ithaca, NY 14853-1301 (United States)

    2011-05-18

    We initially simplify a three-phase contact line to a 'primitive' star-shaped structure formed by three planar interfaces meeting at a common line of intersection, and calculate the line tension associated with this primitive picture. Next, we consider the well-known more refined picture of the contact line that includes a 'core structure' consisting of interface deviations away from the planar interface picture. The corresponding contact line properties were calculated earlier, within mean-field theory, using an interface displacement model or a more microscopic density-functional theory. The question we ask is to what extent the thermodynamic line tension of the contact line near a wetting phase transition can be attributed to the core structure. To answer it we compare our result for the line tension contribution associated with the primitive structure to the known line tension of the full structure (within mean-field theory). While our primitive structure calculation provides a surprisingly useful upper bound to the known line tension near a critical wetting transition, the nontrivial core structure of the contact line near first-order wetting is found to be responsible for an important difference between the known line tension and the upper bound provided by the primitive picture calculation. This accounts also for the discrepancy between the line tensions calculated by two different methods in an earlier mean-field density-functional model of a first-order wetting transition.

  17. AN ESTIMATE OF THE CONTRIBUTION OF BUSINESS STRUCTURES OF MOTORSPORT IN THE FORMATION OF AN ATTRACTIVE IMAGE OF TERRITORY

    Directory of Open Access Journals (Sweden)

    A. B. Ilin

    2016-01-01

    Full Text Available The relevance of the topic chosen due to the modern event-state Olympic Park in Sochi, his post-Olympic legacy for the eff ective return of public investment. Currently, one of the operating entities of their own business in the city, the resort is a global company, "Formula 1", which has the contract to conduct the Grand Prix of Russia on the territory of "Sochi racetrack" from 2014 to 2020. with the right of prolongation. In this regard, the presented article deals with the general principles of assessing the contribution of business organizations in motorsport formation of an attractive image of the territory. The infl uence megasportivnyh activities on investment and social development of the foreign states. The main stages of preparation and holding of "Formula 1" as a basis for enhancing the use of the entrepreneurial potential of diff erent kinds of activities. We consider the entrepreneurial and institutional environment, "Formula 1" during the preparation, conduct and postpodgotovki Grand Prix of Russia. Graphically presented model the contribution of "Formula 1" at the macro, meso and micro levels of economic development.The purpose / goal. The aim of the article is to analyze the assessment of the impact of international business organizations in the field of sport, in particular the global company "Formula-1", to the national markets and refreshment area.Methodology. The methodological basis of this article are: content analysis of open analyzes of the development of sports business organizations, empirical and sociological (surveillance methods.Conclusions / relevance. The practical significance of the work lies in the justification of propositions and conclusions in order to understand the importance of the stage of "Formula 1" in Russia, the need for its promotion and revitalization of economic entities of interest to the development of the territories.

  18. Synchrotron-based and globar-sourced molecular (micro)spectroscopy contributions to advances in new hulless barley (with structure alteration) research on molecular structure, molecular nutrition, and nutrient delivery.

    Science.gov (United States)

    Yang, Ling; Yu, Peiqiang

    2017-01-02

    This paper aimed to review synchrotron-based and globar-sourced molecular infrared (micro)spectroscopy contributions to advances in new hulless barley (with structure alteration) research on molecular structure, molecular nutrition, and nutrient delivery in ruminants. It reviewed recent progress in barley varieties, its utilization for animal and human, inherent structure features and chemical make-up, evaluation and research methodology, breeding progress, rumen degradation, and intestinal digestion. The emphasis of this review was focused on the effect of alteration of carbohydrate traits of newly developed hulless barley on molecular structure changes and nutrient delivery and quantification of the relationship between molecular structure features and changes and truly absorbed nutrient supply to ruminants. This review provides an insight into how inherent structure changes on a molecular basis affect nutrient utilization and availability in ruminants.

  19. Contribution of interlayer hybridization to the electronic structure in iron pnictides: a study of EELS and first-principles calculations.

    Science.gov (United States)

    Ma, Chao; Yang, Huaixin; Tian, Huanfang; Shi, Honglong; Wang, Zhiwei; Li, Jianqi

    2013-03-20

    Using electron energy loss spectroscopy (EELS) measurements and first-principles electronic structure calculations, the significant interlayer hybridization between the insulating layers (ReO or Ba) and the conducting FeAs layers was investigated in the layered iron pnictides, which is quite different from the case in the cuprate superconductors. This interlayer hybridization would result in an increase in the bandwidth near the Fermi level and interorbital charge transfer in the Fe 3d orbitals, which subsequently leads to a decrease in the Fe local moment and the modification of the Fermi surface topology. Therefore, a three-dimensional character of the electronic structure due to the interlayer hybridization is expected, as observed in previous experiments. These findings indicate that reduced dimensionality is no longer a necessary condition in the search for high-T(c) superconductors in iron pnictides.

  20. Volumetric contributions of loop regions of G-quadruplex DNA to the formation of the tertiary structure.

    Science.gov (United States)

    Takahashi, Shuntaro; Sugimoto, Naoki

    2017-02-06

    DNA guanine-quadruplexes (G-quadruplexes) are unique DNA structures formed by guanine-rich sequences. The loop regions of G-quadruplexes play key roles in stability and topology of G-quadruplexes. Here, we investigated volumetric changes induced by pressure in the folding of the G-quadruplex formed by the thrombin binding aptamer (TBA) with mutations within the loop regions. The change of partial molar volume in the transition from coil to G-quadruplex, ∆Vtr, of TBA with a mutation from T to A in the 5' most loop (TBA T3A) was 75.5cm(3)mol(-1), which was larger than that of TBA (54.6cm(3)mol(-1)). TBA with a G to T mutation in the central loop (TBA G8T) had thermal stability similar to TBA T3A but a smaller ∆Vtr of 41.1cm(3)mol(-1). In the presence of poly(ethylene)glycol 200 (PEG200), ∆Vtr values were 14.7cm(3)mol(-1) for TBA T3A and 13.2cm(3)mol(-1) for TBA G8T. These results suggest that the two mutations destabilize the G-quadruplex structure differently. Thus, volumetric data obtained using pressure-based thermodynamic analyses provides information about the dynamics of the loop regions and the roles of loops in the stabilities and folding of G-quadruplex structures.

  1. Bilayer graphene quantum dot defined by topgates

    Energy Technology Data Exchange (ETDEWEB)

    Müller, André; Kaestner, Bernd; Hohls, Frank; Weimann, Thomas; Pierz, Klaus; Schumacher, Hans W., E-mail: hans.w.schumacher@ptb.de [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany)

    2014-06-21

    We investigate the application of nanoscale topgates on exfoliated bilayer graphene to define quantum dot devices. At temperatures below 500 mK, the conductance underneath the grounded gates is suppressed, which we attribute to nearest neighbour hopping and strain-induced piezoelectric fields. The gate-layout can thus be used to define resistive regions by tuning into the corresponding temperature range. We use this method to define a quantum dot structure in bilayer graphene showing Coulomb blockade oscillations consistent with the gate layout.

  2. A contribution to better understanding of structural characteristics and tectonic phases of the Boč region, Periadriatic Fault Zone

    Directory of Open Access Journals (Sweden)

    Lea Žibret

    2016-12-01

    Full Text Available The aim of this study was to determine properties of the tectonic contact between Permian/Mesozoic limestones and less competent Miocene clastites on the northeastern foothill of the Boč Mt. Because fault planes signifiantly mark the relief, this contact was studied by a detailed structural mapping, which showed that the Boč Mt. is limited by subvertical faults in its northeastern part. To ensure that mapped subvertical contact is compatible with regional geodynamics of the area, additionally paleostress analysis of fault-slip data was performed. Four individual paleostress tensor groups were documented in a wider Boč area and compared by published structural data from the border zone between Alps, Dinarides and Pannonian Basin. The oldest paleostress tensor group (Phase 1 is likely of Lower and Middle Miocene age and indicates SW-NE extension accommodated by W-E to WNW-ESE striking normal faults. Phase 2 can be correlated with Middle to Late Miocene NW-SE to WNWESE directed extension accommodated by NNE-SSW striking normal faults. Phase 3 is correlated with Late Miocene W-E directed contraction accommodated by N-S striking sinistral faults and NNE-SSW to NE-SW striking dextral faults. The youngest paleostress tensor group (Phase 4 fis well with Pliocene to Quaternary NNW-SSE to N-S directed contraction accommodated by NW-SE to W-E striking dextral faults and NE-SW striking reverse faults. Since the documented paleostress phases fis well with the geodynamic processes of the Alps-Dinarides-Carpathians territory the subvertical border in the northeastern part of Boč Mt. seems to be an acceptable structural solution. The study is important because the study area is located at interaction zone between two major Alpine fault systems: the Periadriatic and the Lavanttal faults.

  3. CAN DECENTRALISATION CONTRIBUTE TO PROMOTING RULE-OF-LAW STRUCTURES? THE DEMOCRATIC REPUBLIC OF CONGO, RWANDA AND BURUNDI AS EXAMPLES*

    Directory of Open Access Journals (Sweden)

    Hartmut Hamann

    2012-08-01

    Full Text Available Decentralisation can enable a country's population to exercise political influence at regional and local level. This presupposes a willingness to assume responsibility. It also presupposes that those in power are willing to hand over some of the power. Together these two factors can foster rule-of-law structures. This paper describes the constitutional and administrative framework for decentralisation in DR Congo, Rwanda and Burundi. It also explores the actual situation in those countries with reference to legal literature from those countries.In addition, it raises questions regarding the effect of instruments of international law on the decentralisation processes (international organisations, regional integration and international cooperation.

  4. Mammographic density and structural features can individually and jointly contribute to breast cancer risk assessment in mammography screening

    DEFF Research Database (Denmark)

    Winkel, Rikke Rass; von Euler-Chelpin, My; Nielsen, Mads;

    2016-01-01

    BACKGROUND: Mammographic density is a well-established risk factor for breast cancer. We investigated the association between three different methods of measuring density or parenchymal pattern/texture on digitized film-based mammograms, and examined to what extent textural features independently......-RADS alone). CONCLUSION: Our findings suggest that the (relative) amount of fibroglandular tissue (density) and mammographic structural features (texture/parenchymal pattern) jointly can improve risk segregation of screening women, using information already available from normal screening routine, in respect...... to future personalized screening strategies....

  5. Right person, right skills, right job: the contribution of objective structured clinical examinations in advancing staff nurse experts.

    Science.gov (United States)

    Mitchell, Marion; Strube, Petra; Vaux, Amanda; West, Nicky; Auditore, Anthony

    2013-10-01

    Recruitment processes need to discriminate among candidates to ensure that the right person with the right skills is selected for advancement opportunities. An innovative recruitment process using an objective structured clinical examination grounded in best practice guidelines resulted in improved recruitment practices for senior nursing clinical expert roles. Candidates' skills, knowledge, and attitudes in the areas of patient focus, clinical expertise, teamwork, and leadership were assessed using a clinical simulation. Candidates achieving advancement were assessed at 6 months to validate the efficacy of the process.

  6. Epiphyte communities on Thalassia testudinum from Grand Cayman, British West Indies: Their composition, structure, and contribution to lagoonal sediments

    Science.gov (United States)

    Corlett, Hilary; Jones, Brian

    2007-02-01

    Thalassia testudinum, the most common seagrass found in lagoons around Grand Cayman, influences sedimentation by baffling currents, binding sediment on the seafloor, and providing substrates for a diverse epiphytic biota. About 85% of the epiphytic biota is formed of at least 3 species of coralline algae, 72 species of foraminifera, and 61 species of diatoms. The rest of the biota is formed of sponges, gastropods, ostracods, coccoliths, dinoflagellates, brown algae, and worms. The epiphytes are organized in three communities that are part of an organized tripartite community succession. The basal diatom community is overlain by the coralline algae community, which is then overlain by a community composed of a variety of taxa. The coralline algae community, which is the most extensive, typically covers ˜ 75% of the leaf's surface. Potentially, the skeletons of these epiphytes can make a significant contribution to the fine-grained sediment budget of these lagoons. Surprisingly, only a few of the epiphytes were found in the lagoonal sediment. It appears, therefore, that the epiphytes are lost through skeletal dissolution or transported out of the lagoon following storms. Irrespective of the cause, the epiphytes do not form a significant part of the lagoon sediment in Grand Cayman.

  7. Contribution of Universities to The Economy of Provinces and Consumption Structure of Students: The Case of Muş Alparslan University

    Directory of Open Access Journals (Sweden)

    Mücahit Çayın

    2015-12-01

    Full Text Available AbstractThe main purpose of this study is to analyze the impact of the Muş Alparslan University on the economy of the province in terms of income, employment and expenditure structure of students by using the data set obtained from surveys applied to the students of Muş Alparslan University. It has been observed that Muş Alparslan University has a contribution of 894 personnel recruitment in total, 417 direct and 477 indirect recruitment; besides, it has a contribution of 40.662.570 TL income in total, 11.075.394 TL direct and 29.587.176 TL indirect income. In general, average propensity to consume of the students is found high with the rate of 97,1% (average propensity to save 2,9%.Keywords: Muş Alparslan University,Marginal Propensity to Consume, Average Propensity to ConsumeJEL Classification Codes: D12, R11

  8. Synaptic Contributions to Receptive Field Structure and Response Properties in the Rodent Lateral Geniculate Nucleus of the Thalamus.

    Science.gov (United States)

    Suresh, Vandana; Çiftçioğlu, Ulaş M; Wang, Xin; Lala, Brittany M; Ding, Kimberly R; Smith, William A; Sommer, Friedrich T; Hirsch, Judith A

    2016-10-26

    Comparative physiological and anatomical studies have greatly advanced our understanding of sensory systems. Many lines of evidence show that the murine lateral geniculate nucleus (LGN) has unique attributes, compared with other species such as cat and monkey. For example, in rodent, thalamic receptive field structure is markedly diverse, and many cells are sensitive to stimulus orientation and direction. To explore shared and different strategies of synaptic integration across species, we made whole-cell recordings in vivo from the murine LGN during the presentation of visual stimuli, analyzed the results with different computational approaches, and compared our findings with those from cat. As for carnivores, murine cells with classical center-surround receptive fields had a "push-pull" structure of excitation and inhibition within a given On or Off subregion. These cells compose the largest single population in the murine LGN (∼40%), indicating that push-pull is key in the form vision pathway across species. For two cell types with overlapping On and Off responses, which recalled either W3 or suppressed-by-contrast ganglion cells in murine retina, inhibition took a different form and was most pronounced for spatially extensive stimuli. Other On-Off cells were selective for stimulus orientation and direction. In these cases, retinal inputs were tuned and, for oriented cells, the second-order subunit of the receptive field predicted the preferred angle. By contrast, suppression was not tuned and appeared to sharpen stimulus selectivity. Together, our results provide new perspectives on the role of excitation and inhibition in retinothalamic processing. We explored the murine lateral geniculate nucleus from a comparative physiological perspective. In cat, most retinal cells have center-surround receptive fields and push-pull excitation and inhibition, including neurons with the smallest (highest acuity) receptive fields. The same is true for thalamic relay cells

  9. Synaptic Contributions to Receptive Field Structure and Response Properties in the Rodent Lateral Geniculate Nucleus of the Thalamus

    Science.gov (United States)

    Suresh, Vandana; Çiftçioğlu, Ulaş M.; Wang, Xin; Lala, Brittany M.; Ding, Kimberly R.; Smith, William A.; Sommer, Friedrich T.

    2016-01-01

    Comparative physiological and anatomical studies have greatly advanced our understanding of sensory systems. Many lines of evidence show that the murine lateral geniculate nucleus (LGN) has unique attributes, compared with other species such as cat and monkey. For example, in rodent, thalamic receptive field structure is markedly diverse, and many cells are sensitive to stimulus orientation and direction. To explore shared and different strategies of synaptic integration across species, we made whole-cell recordings in vivo from the murine LGN during the presentation of visual stimuli, analyzed the results with different computational approaches, and compared our findings with those from cat. As for carnivores, murine cells with classical center-surround receptive fields had a “push-pull” structure of excitation and inhibition within a given On or Off subregion. These cells compose the largest single population in the murine LGN (∼40%), indicating that push-pull is key in the form vision pathway across species. For two cell types with overlapping On and Off responses, which recalled either W3 or suppressed-by-contrast ganglion cells in murine retina, inhibition took a different form and was most pronounced for spatially extensive stimuli. Other On-Off cells were selective for stimulus orientation and direction. In these cases, retinal inputs were tuned and, for oriented cells, the second-order subunit of the receptive field predicted the preferred angle. By contrast, suppression was not tuned and appeared to sharpen stimulus selectivity. Together, our results provide new perspectives on the role of excitation and inhibition in retinothalamic processing. SIGNIFICANCE STATEMENT We explored the murine lateral geniculate nucleus from a comparative physiological perspective. In cat, most retinal cells have center-surround receptive fields and push-pull excitation and inhibition, including neurons with the smallest (highest acuity) receptive fields. The same is

  10. Defining Life: Synthesis and Conclusions

    Science.gov (United States)

    Gayon, Jean

    2010-04-01

    The first part of the paper offers philosophical landmarks on the general issue of defining life. §1 defends that the recognition of “life” has always been and remains primarily an intuitive process, for the scientist as for the layperson. However we should not expect, then, to be able to draw a definition from this original experience, because our cognitive apparatus has not been primarily designed for this. §2 is about definitions in general. Two kinds of definition should be carefully distinguished: lexical definitions (based upon current uses of a word), and stipulative or legislative definitions, which deliberately assign a meaning to a word, for the purpose of clarifying scientific or philosophical arguments. The present volume provides examples of these two kinds of definitions. §3 examines three traditional philosophical definitions of life, all of which have been elaborated prior to the emergence of biology as a specific scientific discipline: life as animation (Aristotle), life as mechanism, and life as organization (Kant). All three concepts constitute a common heritage that structures in depth a good deal of our cultural intuitions and vocabulary any time we try to think about “life”. The present volume offers examples of these three concepts in contemporary scientific discourse. The second part of the paper proposes a synthesis of the major debates developed in this volume. Three major questions have been discussed. A first issue (§4) is whether we should define life or not, and why. Most authors are skeptical about the possibility of defining life in a strong way, although all admit that criteria are useful in contexts such as exobiology, artificial life and the origins of life. §5 examines the possible kinds of definitions of life presented in the volume. Those authors who have explicitly defended that a definition of life is needed, can be classified into two categories. The first category (or standard view) refers to two conditions

  11. Defining life: synthesis and conclusions.

    Science.gov (United States)

    Gayon, Jean

    2010-04-01

    The first part of the paper offers philosophical landmarks on the general issue of defining life. Section 1 defends that the recognition of "life" has always been and remains primarily an intuitive process, for the scientist as for the layperson. However we should not expect, then, to be able to draw a definition from this original experience, because our cognitive apparatus has not been primarily designed for this. Section 2 is about definitions in general. Two kinds of definition should be carefully distinguished: lexical definitions (based upon current uses of a word), and stipulative or legislative definitions, which deliberately assign a meaning to a word, for the purpose of clarifying scientific or philosophical arguments. The present volume provides examples of these two kinds of definitions. Section 3 examines three traditional philosophical definitions of life, all of which have been elaborated prior to the emergence of biology as a specific scientific discipline: life as animation (Aristotle), life as mechanism, and life as organization (Kant). All three concepts constitute a common heritage that structures in depth a good deal of our cultural intuitions and vocabulary any time we try to think about "life". The present volume offers examples of these three concepts in contemporary scientific discourse. The second part of the paper proposes a synthesis of the major debates developed in this volume. Three major questions have been discussed. A first issue (Section 4) is whether we should define life or not, and why. Most authors are skeptical about the possibility of defining life in a strong way, although all admit that criteria are useful in contexts such as exobiology, artificial life and the origins of life. Section 5 examines the possible kinds of definitions of life presented in the volume. Those authors who have explicitly defended that a definition of life is needed, can be classified into two categories. The first category (or standard view) refers

  12. World Health Organization Estimates of the Relative Contributions of Food to the Burden of Disease Due to Selected Foodborne Hazards: A Structured Expert Elicitation

    DEFF Research Database (Denmark)

    Hald, Tine; Aspinall, Willy; Devleesschauwer, Brecht

    2016-01-01

    to the global burden of diseases commonly transmitted through the consumption of food.Methods and FindingsWe applied structured expert judgment using Cooke's Classical Model to obtain estimates for 14 subregions for the relative contributions of different transmission pathways for eleven diarrheal diseases......, seven other infectious diseases and one chemical (lead). Experts were identified through international networks followed by social network sampling. Final selection of experts was based on their experience including international working experience. Enrolled experts were scored on their ability to judge...

  13. The $\\alpha^2(Z\\alpha)^4m$ contributions to the Lamb shift and the fine structure in light muonic atoms

    CERN Document Server

    Korzinin, Evgeny Yu; Karshenboim, Savely G

    2013-01-01

    Corrections to energy levels in light muonic atoms are investigated in order $\\alpha^2(Z\\alpha)^4m$. We pay attention to corrections which are specific for muonic atoms and include the electron vacuum polarization loop. In particular, we calculate relativistic and relativistic-recoil two-loop electron vacuum polarization contributions. The results are obtained for the levels with $n=1,2$ and in particular for the Lamb shift ($2p_{1/2}-2s_{1/2}$) and fine-structure intervals ($2p_{3/2}-2p_{1/2}$) in muonic hydrogen, deuterium, and muonic helium ions.

  14. Expression of the aryl hydrocarbon receptor contributes to the establishment of intestinal microbial community structure in mice

    Science.gov (United States)

    Murray, Iain A.; Nichols, Robert G.; Zhang, Limin; Patterson, Andrew D.; Perdew, Gary H.

    2016-01-01

    Environmental and genetic factors represent key components in the establishment/maintenance of the intestinal microbiota. The aryl hydrocarbon receptor (AHR) is emerging as a pleiotropic factor, modulating pathways beyond its established role as a xenobiotic sensor. The AHR is known to regulate immune surveillance within the intestine through retention of intraepithelial lymphocytes, functional redistribution of Th17/Treg balance. Consequently, environmental/genetic manipulation of AHR activity likely influences host-microbe homeostasis. Utilizing C57BL6/J Ahr−/+ and Ahr−/− co-housed littermates followed by 18 days of genotypic segregation, we examined the influence of AHR expression upon intestinal microbe composition/functionality and host physiology. 16S sequencing/quantitative PCR (qPCR) revealed significant changes in phyla abundance, particularly Verrucomicrobia together with segmented filamentous bacteria, and an increase in species diversity in Ahr−/− mice following genotypic segregation. Metagenomics/metabolomics indicate microbial composition is associated with functional shifts in bacterial metabolism. Analysis identified Ahr−/−-dependent increases in ileal gene expression, indicating increased inflammatory tone. Transfer of Ahr−/− microbiota to wild-type germ-free mice recapitulated the increase Verrucomicrobia and inflammatory tone, indicating Ahr−/−-microbial dependence. These data suggest a role for the AHR in influencing the community structure of the intestinal microbiota. PMID:27659481

  15. Symphyotrichum ciliatum an Invasive Species in the Romanian Flora – Contributions to the Knowledge of the Vegetative Organs Structure

    Directory of Open Access Journals (Sweden)

    Sârbu Anca

    2015-11-01

    Full Text Available Symphyotrichum ciliatum (Ledeb. G.L. Nesom is an adventive plant first reported in Romania in 1967, which has spread rapidly over the last few decades in Moldova, Muntenia and, more recently, in Transylvania. Although the species has been known for a while in Europe and Romania, there is no information about the anatomy of the vegetative organs of this invasive taxon. This paper presents a series of structural aspects of the vegetative body, of Symphyotrichum ciliatum collected from a sandy and salty substrate (Sacalin Island - Danube Delta. These demonstrate the ability of this plant to adapt to the environment and its capacity to achieve a wide spread. As such, although this plant is an annual species, the root and stem achieve secondary growth in their width, which offers robustness to the corm; the palisade tissue has an ecvifacial disposition which enhances efficiency in capturing light, especially on sandy soil that reflects light; there are aeriferous and aquiferous formations that ensure efficiency in adapting to a wet and relatively salty environment. These results are documented by original photographs of optical microscopy and a distribution map of the taxon in Romania as at 2011.

  16. The contribution of off-shell gluons to the structure functions F{sub 2} and F{sub L}{sup c} and the unintegrated gluon distributions

    Energy Technology Data Exchange (ETDEWEB)

    Kotikov, A.V. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Lipatov, A.V. [Department of Physics, M.V. Lomonosov Moscow State University, 119899 Moscow (Russian Federation); Parente, G. [Departamento de Fisica de Particulas, Universidade de Santiago de Compostela, 15706 Santiago de Compostela (Spain); Zotov, N.P. [D.V. Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, 119899 Moscow (Russian Federation)

    2002-11-01

    We calculate the perturbative parts of the structure functions F{sub 2}{sup c} and F{sub L}{sup c} for a gluon target having non-zero transverse momentum squared at order {alpha}{sub s}. The results of the double convolution (with respect to the Bjorken variable x{sub B} and the transverse momentum) of the perturbative part and the unintegrated gluon densities are compared with the HERA experimental data for F{sub 2}{sup c}. The contribution from the F{sub L}{sup c} structure function ranges in 10-30% of that of F{sub 2}{sup c} at the kinematical range of the HERA experiments. (orig.)

  17. Mutations in HCV non-structural genes do not contribute to resistance to nitazoxanide in replicon-containing cells.

    Science.gov (United States)

    Yon, Changsuek; Viswanathan, Prasanth; Rossignol, Jean-François; Korba, Brent

    2011-09-01

    Nitazoxanide (NTZ) exhibits potent antiviral activity against hepatitis C virus (HCV) in cell culture. Previously, HCV replicon-containing cell lines resistant to NTZ were selected, but transfer the HCV NTZ-resistance phenotype was not observed following transfection of whole cell RNA. To further explore the nature of the resistance of HCV to NTZ, full length HCV replicon sequences were obtained from two NTZ-resistant (NTZ-11, TIZ-9), and the parental (RP7) cell lines. Numerous nucleotide changes were observed in individual HCV genomes relative to the RP7 HCV consensus sequence, but no common mutations in the HCV non-structural genes or 3'-UTR were detected. A cluster of single nucleotide mutations was found within a 5-base portion of the 5'-UTR in 20/21 HCV replicon sequences from both resistant cell lines. Three mutations (5'-UTR G17A, G18A, C20U) were individually inserted into CON1 ('wild-type') HCV replicons, showed reduced replication (5 to 50-fold), but none conferred resistance to NTZ. RP7, NTZ-11, and TIZ-9 were cured of HCV genomes by serial passage under interferon. Transfection of cured NTZ-11 and TIZ-9 with either whole cell RNAs from RP7, NTZ-11, or TIZ-9, 'wild-type' or the 5'-UTR mutation-containing replicon RNAs exhibited an NTZ-resistance phenotype. TIZ (the active metabolite of NTZ) was found to be inactive against the activity of HCV polymerase, protease, and helicase in enzymatic assays. These data confirm previous speculations that HCV resistance to NTZ is not due to mutations in the virus, and demonstrate that HCV resistance and most likely the antiviral activity of TIZ are due to interactions with cellular target(s).

  18. The 3-loop non-singlet heavy flavor contributions and anomalous dimensions for the structure function F2(x,Q2) and transversity

    Science.gov (United States)

    Ablinger, J.; Behring, A.; Blümlein, J.; De Freitas, A.; Hasselhuhn, A.; von Manteuffel, A.; Round, M.; Schneider, C.; Wißbrock, F.

    2014-09-01

    We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F2(x,Q2) in the asymptotic region Q2≫m2 and the associated operator matrix element Aqq,Q(3),NS(N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This matrix element is associated with the vector current and axial vector current for the even and the odd moments N, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(NF) and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in N space and harmonic polylogarithms in x-space. Numerical results are presented for the non-singlet charm quark contribution to F2(x,Q2).

  19. The 3-loop non-singlet heavy flavor contributions and anomalous dimensions for the structure function F2(x,Q2 and transversity

    Directory of Open Access Journals (Sweden)

    J. Ablinger

    2014-09-01

    Full Text Available We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F2(x,Q2 in the asymptotic region Q2≫m2 and the associated operator matrix element Aqq,Q(3,NS(N to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This matrix element is associated with the vector current and axial vector current for the even and the odd moments N, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(NF and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in N space and harmonic polylogarithms in x-space. Numerical results are presented for the non-singlet charm quark contribution to F2(x,Q2.

  20. The 3-loop non-singlet heavy flavor contributions and anomalous dimensions for the structure function F{sub 2}(x,Q{sup 2}) and transversity

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, J.; Hasselhuhn, A.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Behring, A.; Bluemlein, J.; Freitas, A. de [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Manteuffel, A. von [Mainz Univ. (Germany). PRISMA Cluster of Excellence; Mainz Univ. (Germany). Inst. fuer Physik; Round, M.; Wissbrock, F. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2014-06-15

    We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F{sub 2}(x,Q{sup 2}) in the asymptotic region Q{sup 2}>>m{sup 2} and the associated operator matrix element A{sup (3),NS}{sub qq,Q} (N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This matrix element is associated to the vector current and axial vector current for the even and the odd moments N, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(N{sub F}) and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in N space and harmonic polylogarithms in x-space. Numerical results are presented for the non-singlet charm quark contribution to F{sub 2}(x,Q{sup 2}).

  1. The 3-loop non-singlet heavy flavor contributions and anomalous dimensions for the structure function F{sub 2}(x,Q{sup 2}) and transversity

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, J. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Behring, A.; Blümlein, J.; De Freitas, A. [Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Hasselhuhn, A. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Manteuffel, A. von [PRISMA Cluster of Excellence and Institute of Physics, J. Gutenberg University, D-55099 Mainz (Germany); Round, M. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Schneider, C. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Wißbrock, F. [Research Institute for Symbolic Computation (RISC), Johannes Kepler University, Altenbergerstraße 69, A-4040 Linz (Austria); Deutsches Elektronen-Synchrotron, DESY, Platanenallee 6, D-15738 Zeuthen (Germany)

    2014-09-15

    We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F{sub 2}(x,Q{sup 2}) in the asymptotic region Q{sup 2}≫m{sup 2} and the associated operator matrix element A{sub qq,Q}{sup (3),NS}(N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable N. This matrix element is associated with the vector current and axial vector current for the even and the odd moments N, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(N{sub F}) and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in N space and harmonic polylogarithms in x-space. Numerical results are presented for the non-singlet charm quark contribution to F{sub 2}(x,Q{sup 2})

  2. The 3-Loop Non-Singlet Heavy Flavor Contributions and Anomalous Dimensions for the Structure Function $F_2(x,Q^2)$ and Transversity

    CERN Document Server

    Ablinger, J; Blümlein, J; De Freitas, A; Hasselhuhn, A; von Manteuffel, A; Round, M; Schneider, C; Wißbrock, F

    2014-01-01

    We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function $F_2(x,Q^2)$ in the asymptotic region $Q^2 \\gg m^2$ and the associated operator matrix element $A_{qq,Q}^{(3), \\rm NS}(N)$ to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable $N$. This matrix element is associated to the vector current and axial vector current for the even and the odd moments $N$, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to $O(N_F)$ and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in $N$ space and harmonic polylogarithms in $x$-space. Numerical results are presented for the non-singlet charm quark contribution to $F_2(x,Q^2)$.

  3. Comparison of the oral bioavailability of silymarin-loaded lipid nanoparticles with their artificial lipolysate counterparts: implications on the contribution of integral structure.

    Science.gov (United States)

    Shangguan, Mingzhu; Qi, Jianping; Lu, Yi; Wu, Wei

    2015-07-15

    Both solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) were artificially broken down into lipolysates. Their oral bioavailability, with silymarin as a model drug, was compared in dogs to highlight the contribution of their integral structure. The lipid nanoparticles were prepared using a conventional hot homogenization method, whereas the lipolysates were obtained through lipolysis in phospholipid- and bile salt-enriched simulated intestinal fluid. More than 80% of vehicle-associated drugs could be transformed into the water-soluble form of mixed micelles. Pharmacokinetics analysis in dogs showed a decrease in bioavailability of 74.86% and 59.09% for lipolysates compared to integral NLCs and SLNs, respectively. It was indicated that lipolysates contributed to a majority of drug absorption. Integral nanoparticles were superior to their lipolysate counterparts, but only marginally; if the approximately 20% of the drug that precipitated during in vitro lipolysis was deducted from the overall absorption amount, the superiority of integral nanoparticles would be significantly compromised. In conclusion, lipolysis was the predominant in vivo absorption mechanism, and the contribution of intact lipid nanoparticles was limited. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. The contribution of spatial analysis to understanding HIV/TB mortality in children: a structural equation modelling approach

    Directory of Open Access Journals (Sweden)

    Eustasius Musenge

    2013-01-01

    Full Text Available Background: South Africa accounts for more than a sixth of the global population of people infected with HIV and TB, ranking her highest in HIV/TB co-infection worldwide. Remote areas often bear the greatest burden of morbidity and mortality, yet there are spatial differences within rural settings. Objectives: The primary aim was to investigate HIV/TB mortality determinants and their spatial distribution in the rural Agincourt sub-district for children aged 1–5 years in 2004. Our secondary aim was to model how the associated factors were interrelated as either underlying or proximate factors of child mortality using pathway analysis based on a Mosley-Chen conceptual framework. Methods: We conducted a secondary data analysis based on cross-sectional data collected in 2004 from the Agincourt sub-district in rural northeast South Africa. Child HIV/TB death was the outcome measure derived from physician assessed verbal autopsy. Modelling used multiple logit regression models with and without spatial household random effects. Structural equation models were used in modelling the complex relationships between multiple exposures and the outcome (child HIV/TB mortality as relayed on a conceptual framework. Results: Fifty-four of 6,692 children aged 1–5 years died of HIV/TB, from a total of 5,084 households. Maternal death had the greatest effect on child HIV/TB mortality (adjusted odds ratio=4.00; 95% confidence interval=1.01–15.80. A protective effect was found in households with better socio-economic status and when the child was older. Spatial models disclosed that the areas which experienced the greatest child HIV/TB mortality were those without any health facility. Conclusion: Low socio-economic status and maternal deaths impacted indirectly and directly on child mortality, respectively. These factors are major concerns locally and should be used in formulating interventions to reduce child mortality. Spatial prediction maps can guide policy

  5. Next-to-next-to-leading order QCD analysis of the revised CCFR data for $xF_3$ structure function and the higher twist contributions

    CERN Document Server

    Kataev, A L; Parente, G; Sidorov, A V

    1998-01-01

    We present the results of the next-to-next-to-leading order QCD analysis of the recently revised experimental data of the CCFR collaboration for the $xF_3$ structure function using the Jacobi polynomial expansion method. The effects of the higher twist contributions are included into the fits following the infrared renormalon motivated model. The special attention is paid to the checks of the predictive abilities of the infrared renormalon model and to the independent extraction of the $x$-shape of the twist-4 contributions to the $xF_3$ structure function in the process of the leading order, next-to-leading order and next-to-next-to-leading order fits of the revised CCFR data. We stress that at the next-to-next-to-leading order the results for We obtain the following result $\\alpha_s(M_Z)^{NNLO}=0.117 \\pm 0.002(stat) \\pm 0.005 (syst)\\pm 0.003 (theory)$. The comparison of the outcomes of our next-to-leading order and next-to-next-to-leading order analysis indicate that the theoretical QCD uncertainties were u...

  6. Structure-Dependent Anchoring of Organic Molecules to Atomically Defined Oxide Surfaces: Phthalic Acid on Co3O4(111), CoO(100), and CoO(111).

    Science.gov (United States)

    Xu, Tao; Schwarz, Matthias; Werner, Kristin; Mohr, Susanne; Amende, Max; Libuda, Jörg

    2016-04-04

    We have performed a model study to explore the influence of surface structure on the anchoring of organic molecules on oxide materials. Specifically, we have investigated the adsorption of phthalic acid (PA) on three different, well-ordered, and atomically defined cobalt oxide surfaces, namely 1) Co3O4(111), 2) CoO(111), and 3) CoO(100) on Ir(100). PA was deposited by physical vapor deposition (PVD). The formation of the PA films and interfacial reactions were monitored in situ during growth by isothermal time-resolved IR reflection absorption spectroscopy (TR-IRAS) under ultrahigh vacuum (UHV) conditions. We observed a pronounced structure dependence on the three surfaces with three distinctively different binding geometries and characteristic differences depending on the temperature and coverage. 1) PA initially binds to Co3O4(111) through the formation of a chelating bis-carboxylate with the molecular plane oriented perpendicularly to the surface. Similar species were observed both at low temperature (130 K) and at room temperature (300 K). With increasing exposure, chelating mono-carboxylates became more abundant and partially replaced the bis-carboxylate. 2) PA binds to CoO(100) in the form of a bridging bis-carboxylate for low coverage. Upon prolonged deposition of PA at low temperature, the bis-carboxylates were converted into mono-carboxylate species. In contrast, the bis-carboxylate layer was very stable at 300 K. 3) For CoO(111) we observed a temperature-dependent change in the adsorption mechanism. Although PA binds as a mono-carboxylate in a bridging bidentate fashion at low temperature (130 K), a strongly distorted bis-carboxylate was formed at 300 K, possibly as a result of temperature-dependent restructuring of the surface. The results show that the adsorption geometry of PA depends on the atomic structure of the oxide surface. The structure dependence can be rationalized by the different arrangements of cobalt ions at the three surfaces.

  7. 7 CFR 51.2 - Terms defined.

    Science.gov (United States)

    2010-01-01

    ... Definitions § 51.2 Terms defined. Words in the regulations in this part in the singular form shall be deemed.... “Federal-State Inspection Agency” means any State agency, business association or trade organization... plant. “Packing plant” means the premises, buildings, structures, and equipment including but...

  8. Defining Grammatical Difficulty: A Student Teacher Perspective

    Science.gov (United States)

    Graus, Johan; Coppen, Peter-Arno

    2015-01-01

    Numerous second language acquisition (SLA) researchers have tried to define grammatical difficulty in second and foreign language acquisition--often as part of an attempt to relate the efficacy of different types of instruction to the degree of difficulty of grammatical structures. The resulting proliferation of definitions and the lack of a…

  9. 东亚三国的公共养老金制度改革:名义账户制的应用前景评析%Public Pension Reform in Three East Asian Countries: Assessing the Potential Utility of the Notional Defined Contribution (NDC) Model

    Institute of Scientific and Technical Information of China (English)

    John B. Williamson; 申策; 房连泉

    2011-01-01

    在人口老龄化形势下,东亚国家的老年人口赡养率迅速攀升。如何改革公共养老金制度,建立与人口、经济社会形势相适应的养老保障体系,是摆在这些国家面前的一个难题。本文将比较中国、韩国和新加坡的公共养老制度,探讨名义账户制(NDC)在三国的应用前景。通过分析名义账户制化解各国现实问题的潜在能力,作者认为中国适用名义账户制的可行性最强,新加坡较低,而韩国介于二者之间。%In East Asia the rate of increase in the major factor behind old-age dependency ratio is particularly rapid and is a search by pension policy experts in many of these nations for new ideas about how to reform their existing public pension schemes so as to make them more suitable for the demographic and economic pressures they are facing. In this article we ask whether or not the notional defined contribution (NDC) model has potential utility and deserves greater attention than it has been getting in current public pension policy debates in three countries in East and South East Asia. We conclude that the NDC model has a great deal to offer China, but much less to offer to Singapore with South Korea located between the other two.

  10. First report on the contribution of small-sized species to the copepod community structure of the southern Patagonian shelf (Argentina, 47-55°S

    Directory of Open Access Journals (Sweden)

    Julieta Carolina Antacli

    2014-03-01

    Full Text Available The copepod community structure, with special emphasis on small-sized species, was studied over the southern Patagonian shelf in late summer 2004, applying the first plankton sampling in the region with a fine-mesh (66 μm net. The key role of the copepods Drepanopus forcipatus and Calanus australis was confirmed, but also the high abundance and frequency of occurrence of the microcopepods Oithona helgolandica and Microsetella norvegica and of the medium-sized copepod Ctenocalanus vanus were revealed. Copepod community structure was nearly homogenous over the entire study area. Drepanopus forcipatus, O. helgolandica and M. norvegica were identified as the typical species of the region, although secondarily C. australis and Oithona atlantica also contributed significantly to community similarity across the area. The study of interspecific relationships of dominant copepods indicated that D. forcipatus and C. australis were associated positively with O. helgolandica, while C. vanus, and M. norvegica constituted a separate assemblage with Clausocalanus brevipes and O. atlantica. The importance of fine-mesh-size nets for collecting the smaller size fractions of mesozooplankton and for accurately portraying the mesozooplankton assemblage structure in the area is stressed by this study.

  11. Insights into the molecular mechanisms underlying mammalian P2X7 receptor functions and contributions in diseases, revealed by structural modeling and single nucleotide polymorphisms

    Directory of Open Access Journals (Sweden)

    Lin-Hua eJiang

    2013-05-01

    Full Text Available The mammalian P2X7 receptors (P2X7Rs, a member of the ionotropic P2X receptor family with distinctive functional properties, play an important part in mediating extracellular ATP signaling in health and disease. A clear delineation of the molecular mechanisms underlying the key receptor properties, such as ATP-binding, ion permeation, and large pore formation of the mammalian P2X7Rs, is still lacking, but such knowledge is crucial for a better understanding of their physiological functions and contributions in diseases and for development of therapeutics. The recent breakthroughs in determining the atomic structures of the zebrafish P2X4.1R in the closed and ATP-bound open states have provided the long-awaited structural information. The human P2RX7 gene is abundant with non-synonymous single nucleotide polymorphisms (NS-SNPs, which generate a repertoire of human P2X7Rs with point mutations. Characterizations of the NS-SNPs identified in patients of various disease conditions and the resulting mutations have informed previously unknown molecular mechanisms determining the mammalian P2X7R functions and diseases. In this review, we will discuss the new insights into such mechanisms provided by structural modeling and recent functional and genetic linkage studies of NS-SNPs.

  12. Defining asthma in genetic studies

    NARCIS (Netherlands)

    Koppelman, GH; Postma, DS; Meijer, G.

    1999-01-01

    Genetic studies have been hampered by the lack of a gold standard to diagnose asthma. The complex nature of asthma makes it more difficult to identify asthma genes. Therefore, approaches to define phenotypes, which have been successful in other genetically complex diseases, may be applied to define

  13. Defining asthma in genetic studies

    NARCIS (Netherlands)

    Koppelman, GH; Postma, DS; Meijer, G.

    1999-01-01

    Genetic studies have been hampered by the lack of a gold standard to diagnose asthma. The complex nature of asthma makes it more difficult to identify asthma genes. Therefore, approaches to define phenotypes, which have been successful in other genetically complex diseases, may be applied to define

  14. Korean contribution to the IAEA coordinated research programme (CRP-IV) on assuring structural integrity of PRV's (II)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Sang; Hong, J.H.; Byun, T.S.; Kim, J.H.; Yang, W.J

    1998-11-01

    This report summarize the results obtained from the second year contribution of KAERI to the IAEA CRP-IV on Assuring Structural Integrity of Reactor Pressure Vessels. The mandatory part of this programme is to perform fracture toughness (K{sub JC}) tests using pre-cracked Charpy specimens on the IAEA reference material JRQ (ASTM A533-B1 steel). The results will be used to validate the small specimens for surveillance tests. In this report, three different heats of reactor pressure vessel materials are characterized by the ASTM E 1921-97 Standard Test Method for Determination of Reference Temperature, T{sub 0}, for Ferritic Steels in the TRansition Range. The materials are the IAEA reference plate (JRQ), a Japanese forging (JFL), and a Korean forging (KFY5). A special emphasis is focused on the loading rate effect and the limit of the validity range for T{sub 0} determination. (author). 5 refs., 5 tabs., 16 figs.

  15. TiO2 anatase's bulk and (001) surface, structural and electronic properties: A DFT study on the importance of Hubbard and van der Waals contributions

    Science.gov (United States)

    Araujo-Lopez, Eduard; Varilla, Luis Alcala; Seriani, Nicola; Montoya, Javier A.

    2016-11-01

    Theoretical ab initio studies done so far on the structural properties of the titanium dioxide anatase (001) surface, have not reported simultaneously the complete set of cell and interatomic parameters for this system or its bulk. Here we present a complete report of these quantities within a spin polarized Density Functional Theory calculation, including also the Hubbard term and the van der Waals dispersion contribution. We show that within this approach it is possible to find a description of TiO2 anatase using DFT, that correlates better with experimental results than most theoretical studies reported previously. This good level of agreement has an advantage with respect to other very accurate studies which have performed computationally expensive calculations involving hybrid functionals, in that our method tends to be faster while also including the van der Waals dispersion contributions in addition to the treatment of correlations. The observed high-quality description of a system like TiO2 within this approach is important and encouraging; specially because it treats properly a d-shell element that is possibly going to have, for many applications of interest, long-range interaction with molecules, e.g. in studies of photocatalysis, where one needs all the relevant physics of the system to be included. We support this claim with an example of the effects that long-range interactions have on a CO2 molecule at the (001) surface.

  16. Zero-valent iron treatment of dark brown colored coffee effluent: Contributions of a core-shell structure to pollutant removals.

    Science.gov (United States)

    Tomizawa, Mayuka; Kurosu, Shunji; Kobayashi, Maki; Kawase, Yoshinori

    2016-12-01

    The decolorization and total organic carbon (TOC) removal of dark brown colored coffee effluent by zero-valent iron (ZVI) have been systematically examined with solution pH of 3.0, 4.0, 6.0 and 8.0 under oxic and anoxic conditions. The optimal decolorization and TOC removal were obtained at pH 8.0 with oxic condition. The maximum efficiencies of decolorization and TOC removal were 92.6 and 60.2%, respectively. ZVI presented potential properties for pollutant removal at nearly neutral pH because of its core-shell structure in which shell or iron oxide/hydroxide layer on ZVI surface dominated the decolorization and TOC removal of coffee effluent. To elucidate the contribution of the core-shell structure to removals of color and TOC at the optimal condition, the characterization of ZVI surface by scanning electron microscopy (SEM) with an energy dispersive X-ray spectroscope (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) was conducted. It was confirmed that the core-shell structure was formed and the shell on ZVI particulate surface and the precipitates formed during the course of ZVI treatment consisted of iron oxides and hydroxides. They were significantly responsible for decolorization and TOC removal of coffee effluent via adsorption to shell on ZVI surface and inclusion into the precipitates rather than the oxidative degradation by OH radicals and the reduction by emitted electrons. The presence of dissolved oxygen (DO) enhanced the formation of the core-shell structure and as a result improved the efficiency of ZVI treatment for the removal of colored components in coffee effluents. ZVI was found to be an efficient material toward the treatment of coffee effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The structure of Aquifex aeolicus ribosomal protein S8 reveals a unique subdomain that contributes to an extremely tight association with 16S rRNA.

    Science.gov (United States)

    Menichelli, Elena; Edgcomb, Stephen P; Recht, Michael I; Williamson, James R

    2012-01-20

    The assembly of ribonucleoprotein complexes occurs under a broad range of conditions, but the principles that promote assembly and allow function at high temperature are poorly understood. The ribosomal protein S8 from Aquifex aeolicus (AS8) is unique in that there is a 41-residue insertion in the consensus S8 sequence. In addition, AS8 exhibits an unusually high affinity for the 16S ribosomal RNA, characterized by a picomolar dissociation constant that is approximately 26,000-fold tighter than the equivalent interaction from Escherichia coli. Deletion analysis demonstrated that binding to the minimal site on helix 21 occurred at the same nanomolar affinity found for other bacterial species. The additional affinity required the presence of a three-helix junction between helices 20, 21, and 22. The crystal structure of AS8 was solved, revealing the helix-loop-helix geometry of the unique AS8 insertion region, while the core of the molecule is conserved with known S8 structures. The AS8 structure was modeled onto the structure of the 30S ribosomal subunit from E. coli, suggesting the possibility that the unique subdomain provides additional backbone and side-chain contacts between the protein and an unpaired base within the three-way junction of helices 20, 21, and 22. Point mutations in the protein insertion subdomain resulted in a significantly reduced RNA binding affinity with respect to wild-type AS8. These results indicate that the AS8-specific subdomain provides additional interactions with the three-way junction that contribute to the extremely tight binding to ribosomal RNA.

  18. A study of genetic and environmental contributions to structural brain changes over time in twins concordant and discordant for bipolar disorder.

    Science.gov (United States)

    Bootsman, F; Brouwer, R M; Schnack, H G; Kemner, S M; Hillegers, M H J; Sarkisyan, G; van der Schot, A C; Vonk, R; Hulshoff Pol, H E; Nolen, W A; Kahn, R S; van Haren, N E M

    2016-08-01

    This is the first longitudinal twin study examining genetic and environmental contributions to the association between liability to bipolar disorder (BD) and changes over time in global brain volumes, and global and regional measures of cortical surface area, cortical thickness and cortical volume. A total of 50 twins from pairs discordant or concordant for BD (monozygotic: 8 discordant and 3 concordant pairs, and 1 patient and 3 co-twins from incomplete pairs; dizygotic: 6 discordant and 2 concordant pairs, and 1 patient and 7 co-twins from incomplete pairs) underwent magnetic resonance imaging twice. In addition, 57 twins from healthy twin pairs (15 monozygotic and 10 dizygotic pairs, and 4 monozygotic and 3 dizygotic subjects from incomplete pairs) were also scanned twice. Mean follow-up duration for all twins was 7.5 years (standard deviation: 1.5 years). Data were analyzed using structural equation modeling software OpenMx. The liability to BD was not associated with global or regional structural brain changes over time. Although we observed a subtle increase in cerebral white matter in BD patients, this effect disappeared after correction for multiple comparisons. Heritability of brain changes over time was generally low to moderate. Structural brain changes appear to follow similar trajectories in BD patients and healthy controls. Existing brain abnormalities in BD do not appear to progressively change over time, but this requires additional confirmation. Further study with large cohorts is recommended to assess genetic and environmental influences on structural brain abnormalities in BD, while taking into account the influence of lithium on the brain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Defining and Classifying Interest Groups

    DEFF Research Database (Denmark)

    Baroni, Laura; Carroll, Brendan; Chalmers, Adam;

    2014-01-01

    The interest group concept is defined in many different ways in the existing literature and a range of different classification schemes are employed. This complicates comparisons between different studies and their findings. One of the important tasks faced by interest group scholars engaged...... in large-N studies is therefore to define the concept of an interest group and to determine which classification scheme to use for different group types. After reviewing the existing literature, this article sets out to compare different approaches to defining and classifying interest groups with a sample...

  20. Trabecular Structure Quantified With the MRI-Based Virtual Bone Biopsy in Postmenopausal Women Contributes to Vertebral Deformity Burden Independent of Areal Vertebral BMD

    Science.gov (United States)

    Ladinsky, Glenn A; Vasilic, Branimir; Popescu, Andra M; Wald, Michael; Zemel, Babette S; Snyder, Peter J; Loh, Louise; Song, Hee Kwon; Saha, Punam K; Wright, Alexander C; Wehrli, Felix W

    2008-01-01

    In postmenopausal women with a wide range of vertebral deformities, MRI-based structural measures of topology and scale at the distal radius are shown to account for as much as 30% of vertebral deformity, independent of integral vertebral BMD. Introduction Trabecular bone architecture has been postulated to contribute to overall bone strength independent of vertebral BMD measured by DXA. However, there has thus far been only sparse in vivo evidence to support this hypothesis. Materials and Methods Postmenopausal women, 60–80 yr of age, were screened by DXA, and those with T-scores at either the hip or spine falling within the range of −2.5 ± 1.0 were studied with the MRI-based virtual bone biopsy, along with heel broadband ultrasound absorption and pQCT of the tibia. The data from 98 subjects meeting the enrollment criteria were subjected to μMRI at the distal tibia and radius, and measures of topology and scale of the trabecular bone network were computed. A spinal deformity index (SDI) was obtained from morphometric measurements in midline sagittal MR images of the thoracic and lumbar spine to evaluate associations between structure and deformity burden. Results A number of structural indices obtained at the distal radius were correlated with the SDI. Among these were the topological surface density (a measure of trabecular plates) and trabecular bone volume fraction, which were inversely correlated with SDI (p < 0.0001). Combinations of two structural parameters accounted for up to 30% of the variation in SDI (p < 0.0001) independent of spinal BMD, which was not significantly correlated. pQCT trabecular BMD was also weakly associated, whereas broadband ultrasound absorption was not. No significant association between SDI and structural indices were found at the tibia. Conclusions Structural measures at the distal radius obtained in vivo by μMRI explained a significant portion of the variation in total spinal deformity burden in postmenopausal women

  1. Structural Basis of IgE Binding to α- and γ-Gliadins: Contribution of Disulfide Bonds and Repetitive and Nonrepetitive Domains.

    Science.gov (United States)

    Mameri, Hamza; Brossard, Chantal; Gaudin, Jean-Charles; Gohon, Yann; Paty, Evelyne; Beaudouin, Etienne; Moneret-Vautrin, Denise-Anne; Drouet, Martine; Solé, Véronique; Wien, Frank; Lupi, Roberta; Larré, Colette; Snégaroff, Jacques; Denery-Papini, Sandra

    2015-07-29

    Wheat products cause IgE-mediated allergies. The present study aimed to decipher the molecular basis of α- and γ-gliadin allergenicity. Gliadins and their domains, the repetitive N-terminal and the nonrepetitive C-terminal domains, were cloned and expressed in Escherichia coli. Their secondary structures and their IgE binding capacity were compared with those of natural proteins before and after reduction/alkylation. Allergenicity was evaluated with sera from patients who had a wheat food allergy or baker's asthma. The secondary structures of natural and recombinant proteins were slightly different. Compared with natural gliadins, recombinant proteins retained IgE binding but with reduced reactivity. Reduction/alkylation decreased IgE binding for both natural and recombinant gliadins. Although more continuous epitopes were identified in the N-terminal domains of α- and γ-gliadins, both the N-terminal and C-terminal domains contributed to IgE binding. As for other members of the prolamin superfamily, disulfide bonds appear to be of high importance for IgE binding.

  2. Theoretical approaches to elections defining

    Directory of Open Access Journals (Sweden)

    Natalya V. Lebedeva

    2011-01-01

    Full Text Available Theoretical approaches to elections defining develop the nature, essence and content of elections, help to determine their place and a role as one of the major national law institutions in democratic system.

  3. Defining, constructing and assessing learning outcomes.

    Science.gov (United States)

    Taylor, R M

    2009-08-01

    Learning outcomes define the veterinary curriculum and inform students about what they must be able to demonstrate to succeed. Stakeholder consultation during their development ensures that programme learning outcomes equip graduates to contribute to the veterinary profession. Effective learning outcomes form a hierarchy linking the programme, its courses and tasks. Clear outcomes direct students towards higher quality learning by indicating the achievements intended, but leave scope for emergent learning outcomes. Defined technical competencies fit within this overarching framework, complementing higher order learning. Mapping is used to align learning outcomes horizontally and vertically so students are systematically guided towards entry-level competence and professional independence. Constructively aligned learning and assessment tasks ensure learners spend the focused time required to sequentially develop programme outcomes. Assessment by staff, peers and other stakeholders certifies achievement of intended outcomes. Effective assessment also empowers students to define and achieve their own learning outcomes, so they develop the habits of autonomous life-long learning. Evaluation of the quality and consistency of achieved outcomes informs ongoing programme improvement. If we are going to achieve the objectives of this set of papers, i.e. to improve public health education globally (Rev. sci. tech. Off. int. Epiz. 28 [2] 2009), then it is essential that they be well defined in the learning outcomes statement of all veterinary schools.

  4. Defining Modules, Modularity and Modularization

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth; Pedersen, Per Erik Elgård

    The paper describes the evolution of the concept of modularity in a historical perspective. The main reasons for modularity are: create variety, utilize similarities, and reduce complexity. The paper defines the terms: Module, modularity, and modularization.......The paper describes the evolution of the concept of modularity in a historical perspective. The main reasons for modularity are: create variety, utilize similarities, and reduce complexity. The paper defines the terms: Module, modularity, and modularization....

  5. Cocrystal Structures of Antibody N60-i3 and Antibody JR4 in Complex with gp120 Define More Cluster A Epitopes Involved in Effective Antibody-Dependent Effector Function against HIV-1.

    Science.gov (United States)

    Gohain, Neelakshi; Tolbert, William D; Acharya, Priyamvada; Yu, Lei; Liu, Tongyun; Zhao, Pingsen; Orlandi, Chiara; Visciano, Maria L; Kamin-Lewis, Roberta; Sajadi, Mohammad M; Martin, Loïc; Robinson, James E; Kwong, Peter D; DeVico, Anthony L; Ray, Krishanu; Lewis, George K; Pazgier, Marzena

    2015-09-01

    Accumulating evidence indicates a role for Fc receptor (FcR)-mediated effector functions of antibodies, including antibody-dependent cell-mediated cytotoxicity (ADCC), in prevention of human immunodeficiency virus type 1 (HIV-1) acquisition and in postinfection control of viremia. Consequently, an understanding of the molecular basis for Env epitopes that constitute effective ADCC targets is of fundamental interest for humoral anti-HIV-1 immunity and for HIV-1 vaccine design. A substantial portion of FcR effector function of potentially protective anti-HIV-1 antibodies is directed toward nonneutralizing, transitional, CD4-inducible (CD4i) epitopes associated with the gp41-reactive region of gp120 (cluster A epitopes). Our previous studies defined the A32-like epitope within the cluster A region and mapped it to the highly conserved and mobile layers 1 and 2 of the gp120 inner domain within the C1-C2 regions of gp120. Here, we elucidate additional cluster A epitope structures, including an A32-like epitope, recognized by human monoclonal antibody (MAb) N60-i3, and a hybrid A32-C11-like epitope, recognized by rhesus macaque MAb JR4. These studies define for the first time a hybrid A32-C11-like epitope and map it to elements of both the A32-like subregion and the seven-layered β-sheet of the gp41-interactive region of gp120. These studies provide additional evidence that effective antibody-dependent effector function in the cluster A region depends on precise epitope targeting--a combination of epitope footprint and mode of antibody attachment. All together these findings help further an understanding of how cluster A epitopes are targeted by humoral responses. HIV/AIDS has claimed the lives of over 30 million people. Although antiretroviral drugs can control viral replication, no vaccine has yet been developed to prevent the spread of the disease. Studies of natural HIV-1 infection, simian immunodeficiency virus (SIV)- or simian-human immunodeficiency virus (SHIV

  6. FINANCIAL ACCOUNTING QUALITY AND ITS DEFINING CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    Andra M. ACHIM

    2014-11-01

    Full Text Available The importance ofhigh-quality financial statements is highlighted by the main standard-setting institutions activating in the field of accounting and reporting. These have issued Conceptual Frameworks which state and describe the qualitative characteristics of accounting information. In this qualitative study, the research methodology consists of reviewing the literature related to the definition of accounting quality and striving for understanding how it can be explained. The main objective of the study is to identify the characteristics information should possess in order to be of high quality. These characteristics also contribute to the way of defining financial accounting quality. The main conclusions that arise from this research are represented by the facts that indeed financial accounting quality cannot be uniquely defined and that financial information is of good quality when it enhances the characteristics incorporated in the conceptual frameworks issued by both International Accounting Standards Board and Financial Accounting Standards Board.

  7. Defining life or bringing biology to life.

    Science.gov (United States)

    Ruiz-Mirazo, Kepa; Peretó, Juli; Moreno, Alvaro

    2010-04-01

    In the present, post-genomic times, systemic or holistic approaches to living phenomena are compulsory to overcome the limits of traditional strategies, such as the methodological reductionism of molecular biology. In this paper, we propose that theoretical and philosophical efforts to define life also contribute to those integrative approaches, providing a global theoretical framework that may help to deal with or interpret the huge amount of data being collected by current high-throughput technologies, in this so-called 'omics' revolution. We claim that two fundamental notions can capture the core of the living, (basic) autonomy and open-ended evolution, and that only the complementary combination of these two theoretical constructs offers an adequate solution to the problem of defining the nature of life in specific enough-but also encompassing enough-terms. This tentative solution should also illuminate, in its most elementary version, the leading steps towards living beings on Earth.

  8. Defining professional nursing accountability: a literature review.

    Science.gov (United States)

    Krautscheid, Lorretta C

    2014-01-01

    Professional nursing accountability is described by both professional nursing organizations and nursing education credentialing agencies as a core aspect that underpins professional nursing practice. Although accountability is foundational to professional practice, a review of the literature revealed no consistent language or definition regarding professional nursing accountability. Instead, the literature itself reveals that professional nursing accountability is challenging to both describe and define. The ambiguity surrounding how to define professional nursing accountability contributes to challenges associated with both teaching and evaluating student nurse accountability within nursing education curricula. This article provides a reliable and comprehensive definition of professional nursing accountability derived from a synthesis of the literature. Recommendations for nursing education practice and recommendations for nursing education research are proposed.

  9. Quantitative analysis of artifacts in 4D DSA: the relative contributions of beam hardening and scatter to vessel dropout behind highly attenuating structures

    Science.gov (United States)

    Hermus, James; Szczykutowicz, Timothy P.; Strother, Charles M.; Mistretta, Charles

    2014-03-01

    When performing Computed Tomographic (CT) image reconstruction on digital subtraction angiography (DSA) projections, loss of vessel contrast has been observed behind highly attenuating anatomy, such as dental implants and large contrast filled aneurysms. Because this typically occurs only in a limited range of projection angles, the observed contrast time course can potentially be altered. In this work, we have developed a model for acquiring DSA projections that models both the polychromatic nature of the x-ray spectrum and the x-ray scattering interactions to investigate this problem. In our simulation framework, scatter and beam hardening contributions to vessel dropout can be analyzed separately. We constructed digital phantoms with large clearly defined regions containing iodine contrast, bone, soft issue, titanium (dental implants) or combinations of these materials. As the regions containing the materials were large and rectangular, when the phantoms were forward projected, the projections contained uniform regions of interest (ROI) and enabled accurate vessel dropout analysis. Two phantom models were used, one to model the case of a vessel behind a large contrast filled aneurysm and the other to model a vessel behind a dental implant. Cases in which both beam hardening and scatter were turned off, only scatter was turned on, only beam hardening was turned on, and both scatter and beam hardening were turned on, were simulated for both phantom models. The analysis of this data showed that the contrast degradation is primarily due to scatter. When analyzing the aneurysm case, 90.25% of the vessel contrast was lost in the polychromatic scatter image, however only 50.5% of the vessel contrast was lost in the beam hardening only image. When analyzing the teeth case, 44.2% of the vessel contrast was lost in the polychromatic scatter image and only 26.2% of the vessel contrast was lost in the beam hardening only image.

  10. Multivariate analysis of structure and contribution per shares made by potential risk factors at malignant neoplasms in trachea, bronchial tubes and lung

    Directory of Open Access Journals (Sweden)

    G.T. Aydinov

    2017-03-01

    Full Text Available The article gives the results of multivariate analysis of structure and contribution per shares made by potential risk factors at malignant neoplasms in trachea, bronchial tubes and lung. The authors used specialized databases comprising personified records on oncologic diseases in Taganrog, Rostov region, over 1986-2015 (30,684 registered cases of malignant neoplasms, including 3,480 cases of trachea cancer, bronchial tubes cancer, and lung cancer. When carrying out analytical research we applied both multivariate statistical techniques (factor analysis and hierarchical cluster correlation analysis and conventional techniques of epidemiologic analysis including etiologic fraction calculation (EF, as well as an original technique of assessing actual (epidemiologic risk. Average long-term morbidity with trachea, bronchial tubes and lung cancer over 2011-2015 amounts to 46.64 o / oooo . Over the last 15 years a stable decreasing trend has formed, annual average growth being – 1.22 %. This localization holds the 3rd rank place in oncologic morbidity structure, its specific weight being 10.02 %. We determined etiological fraction (EF for smoking as a priority risk factor causing trachea, bronchial tubes and lung cancer; this fraction amounts to 76.19 % for people aged 40 and older, and to 81.99 % for those aged 60 and older. Application of multivariate statistical techniques (factor analysis and cluster correlation analysis in this research enabled us to make factor structure more simple; namely, to highlight, interpret, give a quantitative estimate of self-descriptiveness and rank four group (latent potential risk factors causing lung cancer.

  11. Contribution to a probabilistic safety analysis for the dismantling of slender reinforced-concrete structures; Ein Beitrag zur probabilistischen Sicherheitsanalyse von Abbruchvorgaengen turmartiger Bauwerke aus Stahlbeton

    Energy Technology Data Exchange (ETDEWEB)

    Lehnen, D.J.

    1997-12-31

    In the present work a concept of probabilistic safety-analysis for the dismantling of slender concrete-structures by tilting is developed. Based on requirements, that define a regular dismantling process, models describing characteristic limit-states of the building are derived. The connection of these limit-states allows rating the whole process. Uncertainties in the model-input are caught by using stochastic variables. Uncertainties in the model itself are caught by using inferior and superior modelling. With the help of two concluding examples it is shown, how the obtained probability of failure can be used to enhance objectiveness of safety-considerations. The numeric simulation is based on a Monte-Carlo method. (orig.) [Deutsch] In der vorliegenden Arbeit wird ein Konzept zur probabilistischen Sicherheitsanalyse des Fallrichtungsabbruchs turmartiger Bauwerke aus Stahlbeton entwickelt. Ausgehend von einem definierten Anforderungsprofil an den ordnungsgemaessen Ablauf eines Fallrichtungsabbruchs werden Modellvorstellungen herausgearbeitet, die einzelne Bauwerksgrenzzustaende abbilden, welche sich zur Beurteilung des Gesamtvorgangs eignen. Unsicherheiten in den Eingangsgroessen werden durch deren Auffassung als Wahrschlichkeitsdichten erfasst. Unsicherheiten in den Modellbildungen werden durch den jeweiligen Einsatz unterschaetzender und ueberschaetzender Betrachtungen, sogenannter Minoranten und Majoranten, beruecksichtigt. Anhand zweier Beispiele wird abschliessend demonstriert, wie die erhaltene operative Versagenswahrscheinlichkeit zur Objektivierung von Sicherheitsbetrachtungen herangezogen werden kann. Dabei beruht die numerische Umsetzung auf einer Monte-Carlo Simulation. (orig.)

  12. 26 CFR 53.4942(a)-3 - Qualifying distributions defined.

    Science.gov (United States)

    2010-04-01

    ... contribution to: (a) A private foundation which is not an operating foundation (as defined in section 4942(j)(3... distribution, since it is a contribution for section 170(c)(2)(B) purposes to an organization which is not... month period for paying the amount set aside may, for good cause shown, be extended by the Commissioner...

  13. Healthcare Engineering Defined: A White Paper.

    Science.gov (United States)

    Chyu, Ming-Chien; Austin, Tony; Calisir, Fethi; Chanjaplammootil, Samuel; Davis, Mark J; Favela, Jesus; Gan, Heng; Gefen, Amit; Haddas, Ram; Hahn-Goldberg, Shoshana; Hornero, Roberto; Huang, Yu-Li; Jensen, Øystein; Jiang, Zhongwei; Katsanis, J S; Lee, Jeong-A; Lewis, Gladius; Lovell, Nigel H; Luebbers, Heinz-Theo; Morales, George G; Matis, Timothy; Matthews, Judith T; Mazur, Lukasz; Ng, Eddie Yin-Kwee; Oommen, K J; Ormand, Kevin; Rohde, Tarald; Sánchez-Morillo, Daniel; Sanz-Calcedo, Justo García; Sawan, Mohamad; Shen, Chwan-Li; Shieh, Jiann-Shing; Su, Chao-Ton; Sun, Lilly; Sun, Mingui; Sun, Yi; Tewolde, Senay N; Williams, Eric A; Yan, Chongjun; Zhang, Jiajie; Zhang, Yuan-Ting

    2015-01-01

    Engineering has been playing an important role in serving and advancing healthcare. The term "Healthcare Engineering" has been used by professional societies, universities, scientific authors, and the healthcare industry for decades. However, the definition of "Healthcare Engineering" remains ambiguous. The purpose of this position paper is to present a definition of Healthcare Engineering as an academic discipline, an area of research, a field of specialty, and a profession. Healthcare Engineering is defined in terms of what it is, who performs it, where it is performed, and how it is performed, including its purpose, scope, topics, synergy, education/training, contributions, and prospects.

  14. Healthcare Engineering Defined: A White Paper

    Directory of Open Access Journals (Sweden)

    Ming-Chien Chyu

    2015-01-01

    Full Text Available Engineering has been playing an important role in serving and advancing healthcare. The term “Healthcare Engineering” has been used by professional societies, universities, scientific authors, and the healthcare industry for decades. However, the definition of “Healthcare Engineering” remains ambiguous. The purpose of this position paper is to present a definition of Healthcare Engineering as an academic discipline, an area of research, a field of specialty, and a profession. Healthcare Engineering is defined in terms of what it is, who performs it, where it is performed, and how it is performed, including its purpose, scope, topics, synergy, education/training, contributions, and prospects.

  15. Polymer property modeling using grid technology for design of structured products

    DEFF Research Database (Denmark)

    Chelakara Satyanarayana, Kavitha; Gani, Rafiqul; Abildskov, Jens

    2007-01-01

    Property prediction for a given polymer structure using group contribution models require that the structure can be fully represented by groups with well-defined contributions for that particular property. Frequently this cannot be accomplished. To overcome this limitation a group contribution(+)...

  16. Defining the states of consciousness.

    Science.gov (United States)

    Tassi, P; Muzet, A

    2001-03-01

    Consciousness remains an elusive concept due to the difficulty to define what has been regarded for many years as a subjective experience, therefore irrelevant for scientific study. Recent development in this field of research has allowed to provide some new insight to a possible way to define consciousness. Going through the extensive literature in this domain, several perspectives are proposed to define this concept. (1) Consciousness and Attention may not reflect the same process. (2) Consciousness during wake and sleep may not involve the same mechanisms. (3) Besides physiological states of consciousness, human beings can experience modified states of consciousness either by self-training (transcendental meditation, hypnosis, etc.) or by drug intake (hallucinogens, anaesthetics, etc.). Altogether, we address the question of a more precise terminology, given the theoretical weight words can convey. To this respect, we propose different definitions for concepts like consciousness, vigilance, arousal and alertness as candidates to separate functional entities.

  17. Modular Software-Defined Radio

    Directory of Open Access Journals (Sweden)

    Rhiemeier Arnd-Ragnar

    2005-01-01

    Full Text Available In view of the technical and commercial boundary conditions for software-defined radio (SDR, it is suggestive to reconsider the concept anew from an unconventional point of view. The organizational principles of signal processing (rather than the signal processing algorithms themselves are the main focus of this work on modular software-defined radio. Modularity and flexibility are just two key characteristics of the SDR environment which extend smoothly into the modeling of hardware and software. In particular, the proposed model of signal processing software includes irregular, connected, directed, acyclic graphs with random node weights and random edges. Several approaches for mapping such software to a given hardware are discussed. Taking into account previous findings as well as new results from system simulations presented here, the paper finally concludes with the utility of pipelining as a general design guideline for modular software-defined radio.

  18. Defining the Internet of Things

    OpenAIRE

    Benghozi, Pierre-Jean; Bureau, Sylvain; Massit-Folléa, Françoise

    2012-01-01

    How can a definition be given to what does not yet exist ? The Internet of Things, as it is conceptualized by researchers or imagined by science-fiction writers such as Bruce Sterling, is not yet reality and if we try to define it accurately we risk rash predictions. In order to better comprehend this notion, let us first define the main principles of the IoT as given in research papers and reports on the subject. Definitions gradually established Almost all agree that the Internet of Things...

  19. Defining the Internet of Things

    OpenAIRE

    Benghozi, Pierre-Jean; Bureau, Sylvain; Massit-Folléa, Françoise

    2012-01-01

    How can a definition be given to what does not yet exist ? The Internet of Things, as it is conceptualized by researchers or imagined by science-fiction writers such as Bruce Sterling, is not yet reality and if we try to define it accurately we risk rash predictions. In order to better comprehend this notion, let us first define the main principles of the IoT as given in research papers and reports on the subject. Definitions gradually established Almost all agree that the Internet of Things...

  20. A defined system for in vitro lambda DNA packaging.

    Science.gov (United States)

    Hwang, Y; Feiss, M

    1995-08-20

    We constructed a defined in vitro system for packaging lambda DNA which is composed of purified proheads, the noncapsid proteins terminase and gpFI, and the Escherichia coli DNA binding/bending protein IHF. The defined packaging system: (i) is free from endogenous ATP, DNAs, and DNases and (ii) packages 30% of the input mature lambda DNA efficiently. In this defined packaging system, IHF and gpFI make modest contributions to packaging efficiency. The defined packaging reactions showed that DNA packaging gave a linear response to the concentration of mature lambda DNA and terminase. DNA packaging showed a sigmoidal relationship with respect to the concentration of ATP and proheads.

  1. Beyond the Schoolyard: The Contributions of Parenting Logics, Financial Resources, and Social Institutions to the Social Class Gap in Structured Activity Participation.

    Science.gov (United States)

    Bennett, Pamela R; Lutz, Amy; Jayaram, Lakshmi

    2012-01-01

    We investigate cultural and structural sources of class differences in youth activity participation with interview, survey, and archival data. We find working- and middle-class parents overlap in parenting logics about participation, though differ in one respect: middle-class parents are concerned with customizing children's involvement in activities, while working-class parents are concerned with achieving safety and social mobility for children through participation. Second, because of financial constraints, working-class families rely on social institutions for participation opportunities, but few are available. Schools act as an equalizing institution by offering low-cost activities, allowing working-class children to resemble middle-class youth in school activities, but they remain disadvantaged in out-of-school activities. School influences are complex, however, as they also contribute to class differences by offering different activities to working- and middle-class youth. Findings raise questions about the extent to which differences in participation reflect class culture rather than the objective realities parents face.

  2. Defined medium for Moraxella bovis.

    OpenAIRE

    Juni, E; Heym, G A

    1986-01-01

    A defined medium (medium MB) for Moraxella bovis was formulated. Nineteen strains grew well on medium MB. One strain was auxotrophic for asparagine, and another was auxotrophic for methionine. Strains of M. equi and M. lacunata also grew on medium MB. All strains had an absolute requirement for thiamine and were stimulated by or actually required the other growth factors in the medium.

  3. Indico CONFERENCE: Define the Programme

    CERN Document Server

    CERN. Geneva; Ferreira, Pedro

    2017-01-01

    In this tutorial you are going to learn how to define the programme of a conference in Indico. The program of your conference is divided in different “tracks”. Tracks represent the subject matter of the conference, such as “Online Computing”, “Offline Computing”, and so on.

  4. Defining and Measuring User Experience

    DEFF Research Database (Denmark)

    Stage, Jan

    2006-01-01

    on the intrinsic relation between definition and measurement. In the area of usability, this relation has been developed over several years. It is described how usability is defined and measured in contemporary approaches. Based on that, it is discussed to what extent we can employ experience from the conceptual...

  5. Defining sphincter of oddi dysfunction

    DEFF Research Database (Denmark)

    Funch-Jensen, P

    1996-01-01

    Sphincter of Oddi (SO) dysmotility may give rise to pain. The golden standard for the demonstration of SO dysfunction is endoscopic manometry. A number of abnormalities are observed in patients with postcholecystectomy pain and in patients with idiopathic recurrent pancreatitis. Criteria for defi...... for defining SO dysfunction and the possible mechanisms for the precipitation of pain are discussed....

  6. Defined medium for Moraxella bovis.

    Science.gov (United States)

    Juni, E; Heym, G A

    1986-10-01

    A defined medium (medium MB) for Moraxella bovis was formulated. Nineteen strains grew well on medium MB. One strain was auxotrophic for asparagine, and another was auxotrophic for methionine. Strains of M. equi and M. lacunata also grew on medium MB. All strains had an absolute requirement for thiamine and were stimulated by or actually required the other growth factors in the medium.

  7. Defined medium for Moraxella bovis.

    OpenAIRE

    1986-01-01

    A defined medium (medium MB) for Moraxella bovis was formulated. Nineteen strains grew well on medium MB. One strain was auxotrophic for asparagine, and another was auxotrophic for methionine. Strains of M. equi and M. lacunata also grew on medium MB. All strains had an absolute requirement for thiamine and were stimulated by or actually required the other growth factors in the medium.

  8. Network Coded Software Defined Networking

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Roetter, Daniel Enrique Lucani

    2015-01-01

    Software Defined Networking (SDN) and Network Coding (NC) are two key concepts in networking that have garnered a large attention in recent years. On the one hand, SDN's potential to virtualize services in the Internet allows a large flexibility not only for routing data, but also to manage buffe...

  9. X-ray Spectroscopic Characterization of Co(IV) and Metal-Metal Interactions in Co4O4: Electronic Structure Contributions to the Formation of High-Valent States Relevant to the Oxygen Evolution Reaction.

    Science.gov (United States)

    Hadt, Ryan G; Hayes, Dugan; Brodsky, Casey N; Ullman, Andrew M; Casa, Diego M; Upton, Mary H; Nocera, Daniel G; Chen, Lin X

    2016-08-31

    The formation of high-valent states is a key factor in making highly active transition-metal-based catalysts of the oxygen evolution reaction (OER). These high oxidation states will be strongly influenced by the local geometric and electronic structures of the metal ion, which are difficult to study due to spectroscopically active and complex backgrounds, short lifetimes, and limited concentrations. Here, we use a wide range of complementary X-ray spectroscopies coupled to DFT calculations to study Co(III)4O4 cubanes and their first oxidized derivatives, which provide insight into the high-valent Co(IV) centers responsible for the activity of molecular and heterogeneous OER catalysts. The combination of X-ray absorption and 1s3p resonant inelastic X-ray scattering (Kβ RIXS) allows Co(IV) to be isolated and studied against a spectroscopically active Co(III) background. Co K- and L-edge X-ray absorption data allow for a detailed characterization of the 3d-manifold of effectively localized Co(IV) centers and provide a direct handle on the t2g-based redox-active molecular orbital. Kβ RIXS is also shown to provide a powerful probe of Co(IV), and specific spectral features are sensitive to the degree of oxo-mediated metal-metal coupling across Co4O4. Guided by the data, calculations show that electron-hole delocalization can actually oppose Co(IV) formation. Computational extension of Co4O4 to CoM3O4 structures (M = redox-inactive metal) defines electronic structure contributions to Co(IV) formation. Redox activity is shown to be linearly related to covalency, and M(III) oxo inductive effects on Co(IV) oxo bonding can tune the covalency of high-valent sites over a large range and thereby tune E(0) over hundreds of millivolts. Additionally, redox-inactive metal substitution can also switch the ground state and modify metal-metal and antibonding interactions across the cluster.

  10. Consideration of modal structural properties with sensor grids and methods of Operational Modal Analysis. A contribution of state monitoring of great structures; Erfassung modaler Struktureigenschaften mit Sensornetzwerken und den Methoden der Operational Modal Analysis. Ein Beitrag zur Zustandsueberwachung grosser Strukturen

    Energy Technology Data Exchange (ETDEWEB)

    Friedmann, A.; Mayer, D.; Koch, M.; Kauba, M.; Melz, T. [Fraunhofer-Institut fuer Betriebsfestigkeit und Systemzuverlaessigkeit LBF, Darmstadt (Germany)

    2010-07-01

    A state monitoring of mechanical structures is possible based on the modal parameters natural frequency, self-oscillation form and modal damping. Beyond the damage recognition such a monitoring also can be used to the localization of damages. During the monitoring of large structures (such as blades or towers of wind power plants) problems arise with the instrumentation realization: However the execution of a unique data acquisition requires an expenditure which goes beyond logistic questions such as sensor assembly, grid connection and excitation. The presented solution covers two components whose combination can overcome the described problem definition. On the one hand a network of intelligent sensors will be used, on the other hand the received data are evaluated according to the methods of operational modal analysis. So the temporal development of the modal parameters can be supervised with a firmly installed sensor network based on the data received in the normal operation of the structure. The contribution under consideration contains a description of the Random Decrement Method used for the spectral estimation in the sensors. Subsequently, the function mode of the sensor network is presented from the data capture up to the modal dismantling with the help of a numeric system simulation. The realization of the sensor network at a mechanical, wind-excited test-structure is described. The results of the investigation of the test-structure with the sensor network are presented and compared with the results of conventional procedures. The innovation of the presented technology exists in the combination of known methods of random decrement and operational modal analysis with the possibilities of a network of intelligent sensors.

  11. Two factors defining humus as a key structural component of soil organic matter and as a physicochemical speciation of carbon in its turnover wending its way through the micro environment of soil, sediments and natural waters

    Science.gov (United States)

    Aleksandrova, Olga

    2016-04-01

    on a change in the partitioning of roaming H-bonds, and in turn, define components, into which non-humified SOM can be disintegrated. Therefore, some physicochemical species of SOM, which can be observed in physicochemical processes of carbon turnover in soil, originate from disintegrated SOM bulged at the seams of weak H-bonds, and doesn't reveal strong properties of humus because humus structure is still bound to SOM via stronger H-bonds. Also, SL EPR examination of native and labeled soil samples revealed the substantial influence of hydrophobic interaction on physicochemical speciation of carbon in soil, and this interaction is mediated by humus [3]. Among different effects of hydrophobic interaction, the formation of condensed matter is of great interest. Condensed matter mediated by humic acids is shown to reveal specific quantum properties and invoke hydrodynamic instability on the surface of plant roots that results in uptake of the whole nano-pieces of humus by plant roots, as it was observed in [6, 7]. Considered effects of H-bonds with different bonding energy and hydrophobic interaction in SOM show that a carbon turnover in soil is mediated by humus, and humus play a substantial role as the physicochemical speciation in carbon turnover. Thus, model of 'humus' is still an up-to-date model. 1.Lehmann J. &Kleber H. (2015). Nature, 528, Issue 7580, 60 - 68. 2. M. Hutta, R. Gora, R. Halko, et al., (2011). J. Chromatogr. A., 1218, 8946. 3. Alexanderova O.N. (2015). J Soils Sediments, DOI 10.1007/s11368-015-1195-2 4. Aleksandrova O.N., Kholodov V.A., Perminova I.V. (2015). Russian Journal of Physical Chemistry A, 2015, Vol. 89, No. 8, pp. 1407-1413. 5. Aleksandrova O.N. (2013). J Geochem Explor 129:6-13. 6. Smirnov A.I. et al. (1991). J. of Magnetic Resonance 91, 386-391 7. Kulikova N.V. et al. (2012). Conference HIT-2012.

  12. Social entrepreneurship. The contribution of individual entrepreneurs to sustainable development

    OpenAIRE

    Seelos, Christian; Mair, Johanna

    2004-01-01

    Social entrepreneurship is a phenomenon that has resisted attempts to establish a clear definition. A focus on organizational structures and/or what constitutes a worthy social cause has created a diverse set of terminology. Observing the positive social impact of entrepreneurs catering to basic needs, this paper recognizes their unique role in efficiently contributing to the achievement of sustainable development goals. From this perspective, the term "social" can be much better defined. The...

  13. Proposal of a new indicator to define ductility applied to corroded steel reinforcement on concrete structures = Propuesta de un nuevo indicador para definir la ductilidad aplicada a la corrosión del acero de refuerzo en estructuras de hormigón

    OpenAIRE

    Moreno Fernández, María Esther; Prieto Barrio, Maria Isabel; González García, Nieves; Llauradó Pérez, Nuria

    2015-01-01

    The carbonation of concrete or the chlorides ingress in such quantity to reach the level of bars is triggers of reinforcement corrosion. One of the most significant effects of reinforcing steel corrosion on reinforced concrete structures is the decline in the ductility-related properties of the steel. Reinforcement ductility has a decisive effect on the overall ductility of reinforced concrete structures. Different Codes classify the type of steel depending on their ductility defined by the m...

  14. Software defined radio architectures evaluation

    OpenAIRE

    Palomo, Alvaro; Villing, Rudi; Farrell, Ronan

    2008-01-01

    This paper presents an performance evaluation of GNU Radio and OSSIE, two open source Software Defined Radio (SDR) architectures. The two architectures were compared by running implementations of a BPSK waveform utilising a software loopback channel on each. The upper bound full duplex throughput was found to be around 700kbps in both cases, though OSSIE was slightly faster than GNU Radio. CPU and memory loads did not differ significantly.

  15. AIDS defining disease: Disseminated cryptococcosis

    Directory of Open Access Journals (Sweden)

    Roshan Anupama

    2006-01-01

    Full Text Available Disseminated cryptococcosis is one of the acquired immune deficiency syndrome defining criteria and the most common cause of life threatening meningitis. Disseminated lesions in the skin manifest as papules or nodules that mimic molluscum contagiosum (MC. We report here a human immunodeficiency virus positive patient who presented with MC like lesions. Disseminated cryptococcosis was confirmed by India ink preparation and histopathology. The condition of the patient improved with amphotercin B.

  16. How to define green adjuvants.

    Science.gov (United States)

    Beck, Bert; Steurbaut, Walter; Spanoghe, Pieter

    2012-08-01

    The concept 'green adjuvants' is difficult to define. This paper formulates an answer based on two approaches. Starting from the Organisation for Economic Cooperation and Development (OECD) definition for green chemistry, production-based and environmental-impact-based definitions for green adjuvants are proposed. According to the production-based approach, adjuvants are defined as green if they are manufactured using renewable raw materials as much as possible while making efficient use of energy, preferably renewable energy. According to the environmental impact approach, adjuvants are defined as green (1) if they have a low human and environmental impact, (2) if they do not increase active ingredient environmental mobility and/or toxicity to humans and non-target organisms, (3) if they do not increase the exposure to these active substances and (4) if they lower the impact of formulated pesticides by enhancing the performance of active ingredients, thus potentially lowering the required dosage of active ingredients. Based on both approaches, a tentative definition for 'green adjuvants' is given, and future research and legislation directions are set out.

  17. SOCIAL ROBOT: DEFINING THE CONCEPT

    Directory of Open Access Journals (Sweden)

    Nadezhda Nikolaevna Zilberman

    2016-11-01

    Practical implications. The results of the study contribute toьthe theoretical basis of the cross-disciplinary research field of social robotics and may be used by researchers. They may also be used as educational aid in teaching academic courses in social studies, robotics, ethics of technology, artificial intelligence, etc.

  18. Defining an Industry: What is the Size and Scope of the Australian Building and Construction Industry

    Directory of Open Access Journals (Sweden)

    Gerard de Valence

    2011-08-01

    Full Text Available The analysis and understanding of the conduct and performance of an industry beginswith a study of its structure. However, before analysing an industry's structure it isnecessary to define the industry and identify its size, scope and scale to establish itstrue economic contribution. This paper discusses the size and scope of the Australianbuilding and construction industry, firstly, from a traditional industry economics approachby firm size and business characteristics using data from three construction industrysurveys done over 15 years by the ABS. Secondly, data from an industry 'cluster'perspective is shown. The objective of the paper is to compare the differences found inindustry size and scope in the structure-conduct-performance approach and thealternative industry cluster approach. Each model reveals different characteristics of theindustry. The conclusion finds that the building and construction industry is a casewhere the traditional structure-conduct-performance model cannot be easily applied.53

  19. Poster contributions; Contributions par affiches

    Energy Technology Data Exchange (ETDEWEB)

    Allegraud, K.; Gatilova, I.; Guaitella, O.; Ionikh, Y.; Roepcke, J.; Rousseau, A.; Aranchuk, L.E.; Larour, J.; Asad, S.; Tendero, C.; Tixier, C.; Jaoul, C.; Tristant, P.; Boisse-Laporte, C.; Leprince, P.; Leniniven, C.; Assouar, M.B.; Jimenez Rioboo, R.J.; Aubert, X.; Rousseau, A.; Sadeghi, N.; Bekstein, A.; Benhenni, M.; Yousfi, M.; Bousquet, A.; Granier, A.; Cartry, G.; Calafat, M.; Escaich, D.; Raynaud, P.; Clergereaux, R.; Cardoso, R.P.; Belmonte, T.; Henrion, G.; Sadeghi, N.; Cavarroc, M.; Mikikian, M.; Tessier, Y.; Boufendi, I.; Celestin, S.; Guaitella, O.; Bourdon, A.; Rousseau, A.; Cernogora, G.; Szopa, C.; Cavarroc, M.; Boufendi, I.; Commaux, N.; Geraud, A.; Pegourie, B.; Clairet, F.; Gil, C.; Gros, G.; Gunn, J.; Joffrin, E.; Hertout, P.; Costin, C.; Choimet, J.B.; Minea, T.; Couedel, L.; Mikikian, M.; Tessier, Y.; Boufendi, I.; Samarian, A.A.; Cousin, R.; Larour, J.; Gouard, P.; Raymond, P.; Curley, G.A.; Booth, J.P.; Corr, C.S.; Foldes, T.; Guillon, J.; Czarny, O.; Huysmans, G.; Daniel, A.; Belmonte, T.; Poucques, L. de; Imbert, J.C.; Teule-Gay, L.; Boisse-Laporte, C.; Devaux, S.; Manfredi, G.; Dif-Pradalier, G.; Grandgirard, V.; Sarazin, Y.; Garbet, X.; Ghendrih, Ph.; Dong, B.; Bauchire, J.M.; Pouvesle, J.M.; Magnier, P.; Hong, D.; Duluard, C.; Tillocher, T.; Mekkakia Maaza, N.; Dussart, R.; Mellhaoui, X.; Lefaucheux, P.; Puech, M.; Ranson, P.; Faudot, E.; Heuraux, S.; Colas, L.; Fubiani, G.; Boilson, D.; Hemsworth, R.S.; Gatilova, L.; Allegraud, K.; Ionikh, Y.; Roepcke, J.; Cartry, G.; Rousseau, A.; Gauthier, J.C.; Fourment, C.; Schurtz, G.; Nicolai, Ph.; Peyrusse, O.; Feugeas, J.L

    2006-07-01

    This document gathers the poster contributions among which 11 are relevant for fusion plasmas or particle acceleration: 1) the spectral study of a micro plasma from an X-pinch explosion; 2) experiments with a plasma density greater than the Greenwald value via the injection of icicles in Tore-Supra; 3) Bezier's surfaces and finite elements method for non-linear MHD; 4) 2-dimensional simulation of the RF casings before the ICRF antennas in tokamaks; 5) negative ion sources for ITER; 6) experimental characterization of electron heat transport on the laser integration line; 7) comparison of fluctuation measurement methods of plasma density via reflectometry in mode-o and mode-x in Tore-Supra; 8) water-bag model applied to kinetics equations of magnetic fusion plasmas; 9) computerized simulation of electron acceleration in plasma waves generated in a capillary pipe through laser wakefield; 10) the slowing-down of an alpha particle in a strongly magnetized dense plasma; and 11) stochastic processes of particle trapping by a wave in a magnetized plasma. (A.C.)

  20. Defining Starch Binding by Glucan Phosphatases

    DEFF Research Database (Denmark)

    Auger, Kyle; Raththagala, Madushi; Wilkens, Casper

    2015-01-01

    phosphatases. The main objective of this study was to quantify the binding affinity of different enzymes that are involved in this cyclic process. We established a protocol to quickly, reproducibly, and quantitatively measure the binding of the enzymes to glucans utilizing Affinity Gel Electrophoresis (AGE...... glucan phosphatases showed similar affinities for the short oligosaccharide β-cyclodextrin. We performed structure-guided mutagenesis to define the mechanism of these differences. We found that the carbohydrate binding module (CBM) domain provided a stronger binding affinity compared to surface binding...

  1. UNIQLO, Define Your Own Fashion

    Institute of Scientific and Technical Information of China (English)

    Wang Ting

    2009-01-01

    @@ Yes,women like and enjoy shopping.Always,they want to buy some well-designed clothes with the most 'in'factors; and what's of the great importance,they would like to hear the words:"wow! You fit the wear well!"However,the most satisfied right things could not be always waiting for you there or you would not help complaining the so-fast changing trends day by day.At that time,why not to seek some delights from the basic classic collections?UNIQLO maybe is a choice for you to define your own fashion.

  2. Defining and Measuring User Experience

    DEFF Research Database (Denmark)

    Stage, Jan

    2006-01-01

    User experience is being used to denote what a user goes through while using a computerized system. The concept has gained momentum as a means to distinguish new types of applications such as games and entertainment software from more traditional work-related applications. This paper focuses...... on the intrinsic relation between definition and measurement. In the area of usability, this relation has been developed over several years. It is described how usability is defined and measured in contemporary approaches. Based on that, it is discussed to what extent we can employ experience from the conceptual...... definition of usability to develop the notion of user experience....

  3. Self-defining memories and self-defining future projections in hypomania-prone individuals.

    Science.gov (United States)

    Lardi Robyn, Claudia; Ghisletta, Paolo; Van der Linden, Martial

    2012-06-01

    Mania and hypomania involve dysfunctional beliefs about the self, others, and the world, as well about affect regulation. The present study explored the impact of these beliefs on self-defining memories and self-defining future projections of individuals with a history of hypomanic symptoms. The main findings showed that a history of hypomanic symptoms was related to enhanced retrieval of memories describing positive relationships and to reduced future projections about relationships, suggesting both a need for social bonding and a striving for autonomy. Moreover, hypomania-prone individuals tended to describe more recent events and to produce self-defining memories with references to tension that were more integrated in their self-structure. All of these findings support the presence of conflicting dysfunctional beliefs and the importance of memories containing references to tension in hypomania.

  4. Defining Life: The Virus Viewpoint

    Science.gov (United States)

    Forterre, Patrick

    2010-04-01

    Are viruses alive? Until very recently, answering this question was often negative and viruses were not considered in discussions on the origin and definition of life. This situation is rapidly changing, following several discoveries that have modified our vision of viruses. It has been recognized that viruses have played (and still play) a major innovative role in the evolution of cellular organisms. New definitions of viruses have been proposed and their position in the universal tree of life is actively discussed. Viruses are no more confused with their virions, but can be viewed as complex living entities that transform the infected cell into a novel organism—the virus—producing virions. I suggest here to define life (an historical process) as the mode of existence of ribosome encoding organisms (cells) and capsid encoding organisms (viruses) and their ancestors. I propose to define an organism as an ensemble of integrated organs (molecular or cellular) producing individuals evolving through natural selection. The origin of life on our planet would correspond to the establishment of the first organism corresponding to this definition.

  5. Defining life: the virus viewpoint.

    Science.gov (United States)

    Forterre, Patrick

    2010-04-01

    Are viruses alive? Until very recently, answering this question was often negative and viruses were not considered in discussions on the origin and definition of life. This situation is rapidly changing, following several discoveries that have modified our vision of viruses. It has been recognized that viruses have played (and still play) a major innovative role in the evolution of cellular organisms. New definitions of viruses have been proposed and their position in the universal tree of life is actively discussed. Viruses are no more confused with their virions, but can be viewed as complex living entities that transform the infected cell into a novel organism-the virus-producing virions. I suggest here to define life (an historical process) as the mode of existence of ribosome encoding organisms (cells) and capsid encoding organisms (viruses) and their ancestors. I propose to define an organism as an ensemble of integrated organs (molecular or cellular) producing individuals evolving through natural selection. The origin of life on our planet would correspond to the establishment of the first organism corresponding to this definition.

  6. Oscillator metrology with software defined radio

    CERN Document Server

    Sherman, Jeff A

    2016-01-01

    Analog electrical elements such as mixers, filters, transfer oscillators, isolating buffers, dividers, and even transmission lines contribute technical noise and unwanted environmental coupling in time and frequency measurements. Software defined radio (SDR) techniques replace many of these analog components with digital signal processing (DSP) on rapidly sampled signals. We demonstrate that, generically, commercially available multi-channel SDRs are capable of time and frequency metrology, outperforming purpose-built devices by as much as an order-of-magnitude. For example, for signals at 10 MHz and 6 GHz, we observe SDR time deviation noise floors of about 20 fs and 1 fs, respectively, in under 10 ms of averaging. Examining the other complex signal component, we find a relative amplitude measurement instability of 3e-7 at 5 MHz. We discuss the scalability of a SDR-based system for simultaneous measurement of many clocks. SDR's frequency agility allows for comparison of oscillators at widely different freque...

  7. The Defining Characteristics of Urban Living Labs

    Directory of Open Access Journals (Sweden)

    Kris Steen

    2017-07-01

    Full Text Available The organization of supported and sustainable urban interventions is challenging, with multiple actors involved, fragmented decision-making powers, and multiple values at stake. Globally, urban living labs have become a fashionable phenomenon to tackle this challenge, fostering the development and implementation of innovation, experimentation, and knowledge in urban, real-life settings while emphasizing the important role of participation and co-creation. However, although urban living labs could in this way help cities to speed up the sustainable transition, urban living lab experts agree that, in order to truly succeed in these ambitious tasks, the way urban living labs are being shaped and steered needs further research. Yet, they also confirm the existing variation and opaqueness in the definition of the concept. This article contributes to conceptual clarity by developing an operationalized definition of urban living labs, which has been used to assess 90 sustainable urban innovation projects in the city of Amsterdam. The assessment shows that the majority of the projects that are labelled as living labs do not include one or more of the defining elements of a living lab. In particular, the defining co-creation and development activities were found to be absent in many of the projects. This article makes it possible to categorize alleged living lab projects and distill the “true” living labs from the many improperly labelled or unlabelled living labs, allowing more specific analyses and, ultimately, better targeted methodological recommendations for urban living labs.

  8. Introducing and modeling inefficiency contributions

    DEFF Research Database (Denmark)

    Asmild, Mette; Kronborg, Dorte; Matthews, Kent

    2016-01-01

    Whilst Data Envelopment Analysis (DEA) is the most commonly used non-parametric benchmarking approach, the interpretation and application of DEA results can be limited by the fact that radial improvement potentials are identified across variables. In contrast, Multi-directional Efficiency Analysis......-called inefficiency contributions, which are defined as the relative contributions from specific variables to the overall levels of inefficiencies. A statistical model for distinguishing the inefficiency contributions between subgroups is proposed and the method is illustrated on a data set on Chinese banks....

  9. Contribution des trois emplois de à la fin à la structuration du discours : le temporel, l’aspectuel, le « reformulatif »

    Directory of Open Access Journals (Sweden)

    Christiane Marque-Pucheu

    2011-07-01

    Full Text Available Nous distinguons trois fonctionnements de à la fin dans des suites de phrases coordonnées ou juxtaposées, P0 P1, où P1 comporte l’adverbial à la fin. Dans la première partie, nous opposons sur la base de propriétés (portée, type de phrase, position dans la phrase, un emploi temporel (à la fin1 un emploi aspectuel (à la fin2 et un emploi pragmatique (à la fin3 exprimant une attitude du locuteur qui intervient pour mettre fin à un état de fait. Dans la deuxième partie, nous montrons comment, malgré ces différences, les trois emplois servent la structuration du discours. À la fin1 introduit une énumération externe (en impliquant un balancement avec au début ; à la fin2 introduit une énumération interne, la répétition du procès dans P0 ayant pour résultat un autre procès dans P1, ce que traduisent la paraphrase avec finir par et la possibilité d’introduire une relation de subordination consécutive entre P0 et P1 ; à la fin3 vise à agir sur l’allocutaire pour qu’il mette un terme à un dire ou un faire (finissons-en exprimé ou non dans P0.We can distinguish three functions of à la fin in the second parts of coordinated and juxtaposed phrases, P0, P1 in which P1 contains the adverbial à la fin. We first compare three uses of the adverbial on the basis of qualities (scope, type of sentence, position in the sentence: a temporal use (à la fin1, an aspectual use (à la fin2 and a pragmatic use (à la fin3 expressing an attitude on the part of the speaker who intervenes to put an end to a state of affairs. We then show how, in spite of these differences, the three uses contribute to structuring the discourse. À la fin1 introduces an external enumeration (implying opposition to au début; à la fin2 introduces an internal enumeration, the repetition of the process in P0 that results in another process in P1 which can be translated by the paraphrase finir par and the possibility of introducing a relation of

  10. Network Coded Software Defined Networking

    DEFF Research Database (Denmark)

    Hansen, Jonas; Roetter, Daniel Enrique Lucani; Krigslund, Jeppe

    2015-01-01

    Software defined networking has garnered large attention due to its potential to virtualize services in the Internet, introducing flexibility in the buffering, scheduling, processing, and routing of data in network routers. SDN breaks the deadlock that has kept Internet network protocols stagnant...... for decades, while applications and physical links have evolved. This article advocates for the use of SDN to bring about 5G network services by incorporating network coding (NC) functionalities. The latter constitutes a major leap forward compared to the state-of-the- art store and forward Internet paradigm....... The inherent flexibility of both SDN and NC provides fertile ground to envision more efficient, robust, and secure networking designs, which may also incorporate content caching and storage, all of which are key challenges of the upcoming 5G networks. This article not only proposes the fundamentals...

  11. Network Coded Software Defined Networking

    DEFF Research Database (Denmark)

    Krigslund, Jeppe; Hansen, Jonas; Roetter, Daniel Enrique Lucani;

    2015-01-01

    Software Defined Networking (SDN) and Network Coding (NC) are two key concepts in networking that have garnered a large attention in recent years. On the one hand, SDN's potential to virtualize services in the Internet allows a large flexibility not only for routing data, but also to manage...... buffering, scheduling, and processing over the network. On the other hand, NC has shown great potential for increasing robustness and performance when deployed on intermediate nodes in the network. This new paradigm changes the dynamics of network protocols, requiring new designs that exploit its potential....... This paper advocates for the use of SDN to bring about future Internet and 5G network services by incorporating network coding (NC) functionalities. The inherent flexibility of both SDN and NC provides a fertile ground to envision more efficient, robust, and secure networking designs, that may also...

  12. Defining biocultural approaches to conservation.

    Science.gov (United States)

    Gavin, Michael C; McCarter, Joe; Mead, Aroha; Berkes, Fikret; Stepp, John Richard; Peterson, Debora; Tang, Ruifei

    2015-03-01

    We contend that biocultural approaches to conservation can achieve effective and just conservation outcomes while addressing erosion of both cultural and biological diversity. Here, we propose a set of guidelines for the adoption of biocultural approaches to conservation. First, we draw lessons from work on biocultural diversity and heritage, social-ecological systems theory, integrated conservation and development, co-management, and community-based conservation to define biocultural approaches to conservation. Second, we describe eight principles that characterize such approaches. Third, we discuss reasons for adopting biocultural approaches and challenges. If used well, biocultural approaches to conservation can be a powerful tool for reducing the global loss of both biological and cultural diversity.

  13. Miniature EVA Software Defined Radio

    Science.gov (United States)

    Pozhidaev, Aleksey

    2012-01-01

    As NASA embarks upon developing the Next-Generation Extra Vehicular Activity (EVA) Radio for deep space exploration, the demands on EVA battery life will substantially increase. The number of modes and frequency bands required will continue to grow in order to enable efficient and complex multi-mode operations including communications, navigation, and tracking applications. Whether conducting astronaut excursions, communicating to soldiers, or first responders responding to emergency hazards, NASA has developed an innovative, affordable, miniaturized, power-efficient software defined radio that offers unprecedented power-efficient flexibility. This lightweight, programmable, S-band, multi-service, frequency- agile EVA software defined radio (SDR) supports data, telemetry, voice, and both standard and high-definition video. Features include a modular design, an easily scalable architecture, and the EVA SDR allows for both stationary and mobile battery powered handheld operations. Currently, the radio is equipped with an S-band RF section. However, its scalable architecture can accommodate multiple RF sections simultaneously to cover multiple frequency bands. The EVA SDR also supports multiple network protocols. It currently implements a Hybrid Mesh Network based on the 802.11s open standard protocol. The radio targets RF channel data rates up to 20 Mbps and can be equipped with a real-time operating system (RTOS) that can be switched off for power-aware applications. The EVA SDR's modular design permits implementation of the same hardware at all Network Nodes concept. This approach assures the portability of the same software into any radio in the system. It also brings several benefits to the entire system including reducing system maintenance, system complexity, and development cost.

  14. Asymptomatic Alzheimer disease: Defining resilience.

    Science.gov (United States)

    Hohman, Timothy J; McLaren, Donald G; Mormino, Elizabeth C; Gifford, Katherine A; Libon, David J; Jefferson, Angela L

    2016-12-06

    To define robust resilience metrics by leveraging CSF biomarkers of Alzheimer disease (AD) pathology within a latent variable framework and to demonstrate the ability of such metrics to predict slower rates of cognitive decline and protection against diagnostic conversion. Participants with normal cognition (n = 297) and mild cognitive impairment (n = 432) were drawn from the Alzheimer's Disease Neuroimaging Initiative. Resilience metrics were defined at baseline by examining the residuals when regressing brain aging outcomes (hippocampal volume and cognition) on CSF biomarkers. A positive residual reflected better outcomes than expected for a given level of pathology (high resilience). Residuals were integrated into a latent variable model of resilience and validated by testing their ability to independently predict diagnostic conversion, cognitive decline, and the rate of ventricular dilation. Latent variables of resilience predicted a decreased risk of conversion (hazard ratio 0.02, p < 0.001), and slower rates of ventricular dilation (β < -4.7, p < 2 × 10(-15)). These results were significant even when analyses were restricted to clinically normal individuals. Furthermore, resilience metrics interacted with biomarker status such that biomarker-positive individuals with low resilience showed the greatest risk of subsequent decline. Robust phenotypes of resilience calculated by leveraging AD biomarkers and baseline brain aging outcomes provide insight into which individuals are at greatest risk of short-term decline. Such comprehensive definitions of resilience are needed to further our understanding of the mechanisms that protect individuals from the clinical manifestation of AD dementia, especially among biomarker-positive individuals. © 2016 American Academy of Neurology.

  15. Intact Protein Analysis at 21 Tesla and X-Ray Crystallography Define Structural Differences in Single Amino Acid Variants of Human Mitochondrial Branched-Chain Amino Acid Aminotransferase 2 (BCAT2)

    Science.gov (United States)

    Anderson, Lissa C.; Håkansson, Maria; Walse, Björn; Nilsson, Carol L.

    2017-09-01

    Structural technologies are an essential component in the design of precision therapeutics. Precision medicine entails the development of therapeutics directed toward a designated target protein, with the goal to deliver the right drug to the right patient at the right time. In the field of oncology, protein structural variants are often associated with oncogenic potential. In a previous proteogenomic screen of patient-derived glioblastoma (GBM) tumor materials, we identified a sequence variant of human mitochondrial branched-chain amino acid aminotransferase 2 as a putative factor of resistance of GBM to standard-of-care-treatments. The enzyme generates glutamate, which is neurotoxic. To elucidate structural coordinates that may confer altered substrate binding or activity of the variant BCAT2 T186R, a 45 kDa protein, we applied combined ETD and CID top-down mass spectrometry in a LC-FT-ICR MS at 21 T, and X-Ray crystallography in the study of both the variant and non-variant intact proteins. The combined ETD/CID fragmentation pattern allowed for not only extensive sequence coverage but also confident localization of the amino acid variant to its position in the sequence. The crystallographic experiments confirmed the hypothesis generated by in silico structural homology modeling, that the Lys59 side-chain of BCAT2 may repulse the Arg186 in the variant protein (PDB code: 5MPR), leading to destabilization of the protein dimer and altered enzyme kinetics. Taken together, the MS and novel 3D structural data give us reason to further pursue BCAT2 T186R as a precision drug target in GBM. [Figure not available: see fulltext.

  16. Intact Protein Analysis at 21 Tesla and X-Ray Crystallography Define Structural Differences in Single Amino Acid Variants of Human Mitochondrial Branched-Chain Amino Acid Aminotransferase 2 (BCAT2)

    Science.gov (United States)

    Anderson, Lissa C.; Håkansson, Maria; Walse, Björn; Nilsson, Carol L.

    2017-07-01

    Structural technologies are an essential component in the design of precision therapeutics. Precision medicine entails the development of therapeutics directed toward a designated target protein, with the goal to deliver the right drug to the right patient at the right time. In the field of oncology, protein structural variants are often associated with oncogenic potential. In a previous proteogenomic screen of patient-derived glioblastoma (GBM) tumor materials, we identified a sequence variant of human mitochondrial branched-chain amino acid aminotransferase 2 as a putative factor of resistance of GBM to standard-of-care-treatments. The enzyme generates glutamate, which is neurotoxic. To elucidate structural coordinates that may confer altered substrate binding or activity of the variant BCAT2 T186R, a 45 kDa protein, we applied combined ETD and CID top-down mass spectrometry in a LC-FT-ICR MS at 21 T, and X-Ray crystallography in the study of both the variant and non-variant intact proteins. The combined ETD/CID fragmentation pattern allowed for not only extensive sequence coverage but also confident localization of the amino acid variant to its position in the sequence. The crystallographic experiments confirmed the hypothesis generated by in silico structural homology modeling, that the Lys59 side-chain of BCAT2 may repulse the Arg186 in the variant protein (PDB code: 5MPR), leading to destabilization of the protein dimer and altered enzyme kinetics. Taken together, the MS and novel 3D structural data give us reason to further pursue BCAT2 T186R as a precision drug target in GBM.

  17. Cyberbullying: the challenge to define.

    Science.gov (United States)

    Langos, Colette

    2012-06-01

    Cyberbullying is a reality of the digital age. To address this phenomenon, it becomes imperative to understand exactly what cyberbullying is. Thus, establishing a workable and theoretically sound definition is essential. This article contributes to the existing literature in relation to the definition of cyberbullying. The specific elements of repetition, power imbalance, intention, and aggression, regarded as essential criteria of traditional face-to-face bullying, are considered in the cyber context. It is posited that the core bullying elements retain their importance and applicability in relation to cyberbullying. The element of repetition is in need of redefining, given the public nature of material in the online environment. In this article, a clear distinction between direct and indirect cyberbullying is made and a model definition of cyberbullying is offered. Overall, the analysis provided lends insight into how the essential bullying elements have evolved and should apply in our parallel cyber universe.

  18. Software Defined Common Processing System (SDCPS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Coherent Logix, Incorporated proposes the Software Defined Common Processing System (SDCPS) program to facilitate the development of a Software Defined Radio...

  19. Defining Platelet Function During Polytrauma

    Science.gov (United States)

    2013-02-01

    using calibrated automated thrombography ( CAT ). 3. Platelet-induced clot contraction and using viscoelastic measures such as TEG with Platelet Mapping...using calibrated automated thrombography ( CAT ) in platelet-rich plasma. 3. Platelet-induced clot contraction and effect on clot structure by platelet...if injury with stable vital signs on initial evaluation.  Pregnancy (confirmed with urine pregnancy testing)  Documented do not resuscitate order

  20. Contribution to the study of the structure and reactivity of ketones using deuterium substitution of the {alpha} - ketone hydrogens; Contribution a l'etude de la structure et de la reactivite des cetones, par utilisation de la substitution deuteriee des hydrogenes {alpha}-cetoniques

    Energy Technology Data Exchange (ETDEWEB)

    Frejaville, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-02-01

    This work is an attempt to obtain more knowledge about the structure and the reactivity of ketones; it is also a contribution to conformational analysis based on infrared signals associated with the C-D vibration in mono-deuterated compounds. In the first chapter the various dosage and synthetic methods used in this work are described. In the second chapter the infrared spectra in the 2100-2200 cm{sup -1} region for mono-deuterated ketones are interpreted on the basis of a simple model. This model is then studied in detail, and also critically and precisely, in the case of the mono deuterated acetone molecule. In the third chapter is studied the mechanism of the Favorskii reaction and the reactivity of all the {alpha}-ketonic hydrogens of 2 chloro-cyclohexanone are classified. In a technical appendix is described a counter-current exchange method for obtaining a great variety of solvents and deuterated pure raw materials under advantageous conditions. (author) [French] Ce travail est un effort vers une meilleure connaissance de la structure et de la reactivite des cetones; c'est egalement une contribution a l'analyse conformationnelle d'apres l'etude des signaux infrarouges associes a la vibration C-D dans les composes monodeuteries. Dans le premier chapitre sont decrites les differentes methodes de dosage et de synthese qui ont ete utilisees dans ce travail. Dans le deuxieme chapitre, les spectres infrarouges dans la region 2100-2200 cm{sup -1} de cetones monodeuteriees sont interpretes sur la base d'un modele simple. Ce modele est ensuite etudie de facon detaillee, critique et precise sur la molecule d'acetone monodeuteriee. Dans le troisieme chapitre on etudie le mecanisme de la reaction de FAWORSKII et l'on classe la reactivite de tous les hydrogenes {alpha}-cetoniques de la chloro-2-cyclohexanone. Dons l'appendice technique on decrit la mise en oeuvre d'un appareil d'echange a contre-courant qui permet d

  1. Structural Biology Guides Antibiotic Discovery

    Science.gov (United States)

    Polyak, Steven

    2014-01-01

    Modern drug discovery programs require the contribution of researchers in a number of specialist areas. One of these areas is structural biology. Using X-ray crystallography, the molecular basis of how a drug binds to its biological target and exerts its mode of action can be defined. For example, a drug that binds into the active site of an…

  2. Structural Biology Guides Antibiotic Discovery

    Science.gov (United States)

    Polyak, Steven

    2014-01-01

    Modern drug discovery programs require the contribution of researchers in a number of specialist areas. One of these areas is structural biology. Using X-ray crystallography, the molecular basis of how a drug binds to its biological target and exerts its mode of action can be defined. For example, a drug that binds into the active site of an…

  3. Defining Tobacco Regulatory Science Competencies.

    Science.gov (United States)

    Wipfli, Heather L; Berman, Micah; Hanson, Kacey; Kelder, Steven; Solis, Amy; Villanti, Andrea C; Ribeiro, Carla M P; Meissner, Helen I; Anderson, Roger

    2017-02-01

    In 2013, the National Institutes of Health and the Food and Drug Administration funded a network of 14 Tobacco Centers of Regulatory Science (TCORS) with a mission that included research and training. A cross-TCORS Panel was established to define tobacco regulatory science (TRS) competencies to help harmonize and guide their emerging educational programs. The purpose of this paper is to describe the Panel's work to develop core TRS domains and competencies. The Panel developed the list of domains and competencies using a semistructured Delphi method divided into four phases occurring between November 2013 and August 2015. The final proposed list included a total of 51 competencies across six core domains and 28 competencies across five specialized domains. There is a need for continued discussion to establish the utility of the proposed set of competencies for emerging TRS curricula and to identify the best strategies for incorporating these competencies into TRS training programs. Given the field's broad multidisciplinary nature, further experience is needed to refine the core domains that should be covered in TRS training programs versus knowledge obtained in more specialized programs. Regulatory science to inform the regulation of tobacco products is an emerging field. The paper provides an initial list of core and specialized domains and competencies to be used in developing curricula for new and emerging training programs aimed at preparing a new cohort of scientists to conduct critical TRS research. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Prediction of biodegradation kinetics using a nonlinear group contribution method

    Energy Technology Data Exchange (ETDEWEB)

    Tabak, H.H. (Environmental Protection Agency, Cincinnati, OH (United States)); Govind, R. (Univ. of Cincinnati, OH (United States))

    1993-02-01

    The fate of organic chemicals in the environment depends on their susceptibility to biodegradation. Hence, development of regulations concerning their manufacture and use requires information on the extent and rate of biodegradation. Recent studies have attempted to correlate the kinetics of biodegradation with the molecular structure of the compound. This has led to the development of structure-biodegradation relationships (SBRs) using the group contribution approach. Each defined group present in the chemical structure of the compound is assigned a unique numerical contribution toward the calculation of the biodegradation kinetic constants. In this paper, a nonlinear group contribution method has been developed using neural networks; it is trained using literature data on the first-order biodegradation kinetic rate constant for a number of priority pollutants. The trained neural network is then used to predict the biodegradation kinetic constant for a new list of compounds, and results have been compared with the experimental values and the predictions obtained from a linear group contribution method. It has been shown that the nonlinear group contribution method using neural networks is able to provide a superior fit to the training set data and test data set and produce a lower prediction error than the previous linear method.

  5. Defining fish community structure in Lake Winnipeg using stable isotopes (δ{sup 13}C, δ{sup 15}N, δ{sup 34}S): Implications for monitoring ecological responses and trophodynamics of mercury and other trace elements

    Energy Technology Data Exchange (ETDEWEB)

    Ofukany, Amy F.A. [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3 (Canada); Wassenaar, Leonard I. [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada); Bond, Alexander L., E-mail: alex.bond@rspb.org.uk [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada); Hobson, Keith A. [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada)

    2014-11-01

    The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km{sup 2} watershed and the arrival of non-native zooplankters and fishes. We measured δ{sup 13}C, δ{sup 15}N, and δ{sup 34}S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ{sup 13}C and δ{sup 34}S, and lower δ{sup 15}N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations. - Highlights: • Anthropogenic eutrophication and non-native species affect Lake Winnipeg’s ecosystem. • We measured stable isotopes and trace elements in 15 native fish species. • There was more evidence for growth dilution than biomagnification for most elements. • The trophic structures of the north and south basins were different. • These results will help determine the effects of recent arrival of zebra mussels.

  6. Neotectonics and structure of the Himalayan deformation front in the Kashmir Himalaya, India: Implication in defining what controls a blind thrust front in an active fold-thrust belt

    Science.gov (United States)

    Gavillot, Y. G.; Meigs, A.; Yule, J. D.; Rittenour, T. M.; Malik, M. O. A.

    2014-12-01

    Active tectonics of a deformation front constrains the kinematic evolution and structural interaction between the fold-thrust belt and most-recently accreted foreland basin. In Kashmir, the Himalayan Frontal thrust (HFT) is blind, characterized by a broad fold, the Suruin-Mastargh anticline (SMA), and displays no emergent faults cutting either limb. A lack of knowledge of the rate of shortening and structural framework of the SMA hampers quantifying the earthquake potential for the deformation front. Our study utilized the geomorphic expression of dated deformed terraces on the Ujh River in Kashmir. Six terraces are recognized, and three yield OSL ages of 53 ka, 33 ka, and 0.4 ka. Vector fold restoration of long terrace profiles indicates a deformation pattern characterized by regional uplift across the anticlinal axis and back-limb, and by fold limb rotation on the forelimb. Differential uplift across the fold trace suggests localized deformation. Dip data and stratigraphic thicknesses suggest that a duplex structure is emplaced at depth along the basal décollement, folding the overlying roof thrust and Siwalik-Muree strata into a detachment-like fold. Localized faulting at the fold axis explains the asymmetrical fold geometry. Folding of the oldest dated terrace, suggest that rock uplift rates across the SMA range between 2.0-1.8 mm/yr. Assuming a 25° dipping ramp for the blind structure on the basis of dip data constraints, the shortening rate across the SMA ranges between 4.4-3.8 mm/yr since ~53 ka. Of that rate, ~1 mm/yr is likely absorbed by minor faulting in the near field of the fold axis. Given that Himalaya-India convergence is ~18.8-11 mm/yr, internal faults north of the deformation front, such as the Riasi thrust absorbs more of the Himalayan shortening than does the HFT in Kashmir. We attribute a non-emergent thrust at the deformation front to reflect deformation controlled by pre-existing basin architecture in Kashmir, in which the thick succession

  7. Defining professional pharmacy services in community pharmacy.

    Science.gov (United States)

    Moullin, Joanna C; Sabater-Hernández, Daniel; Fernandez-Llimos, Fernando; Benrimoj, Shalom I

    2013-01-01

    Multiple terms and definitions exist to describe specific aspects of pharmacy practice and service provision, yet none encompass the full range of professional services delivered by community pharmacy. The majority of current pharmacy service definitions and nomenclature refer to either the professional philosophy of pharmaceutical care or to specific professional pharmacy services; particularly pharmaceutical services provided by pharmacists with a focus on drug safety, effectiveness and health outcomes. The objective of this paper is therefore to define a professional pharmacy service within the context of the community pharmacy model of service provision. A professional pharmacy service is defined as "an action or set of actions undertaken in or organised by a pharmacy, delivered by a pharmacist or other health practitioner, who applies their specialised health knowledge personally or via an intermediary, with a patient/client, population or other health professional, to optimise the process of care, with the aim to improve health outcomes and the value of healthcare." Based on Donabedian's framework, the professional pharmacy service definition incorporates the concepts of organizational structure, process indicators and outcome measures. The definition will assist in many areas including recognition of the full range of services provided by community pharmacy and facilitating the identification of indicators of professional pharmacy service implementation and sustainable provision. A simple conceptual model for incorporating all services provided by community pharmacy is proposed. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Defining 'surveillance' in drug safety.

    Science.gov (United States)

    Aronson, Jeffrey K; Hauben, Manfred; Bate, Andrew

    2012-05-01

    The concept of surveillance in pharmacovigilance and pharmacoepidemiology has evolved from the concept of surveillance in epidemiology, particularly of infectious diseases. We have surveyed the etymology, usages, and previous definitions of 'surveillance' and its modifiers, such as 'active' and 'passive'. The following essential definitional features of surveillance emerge: (i) surveillance and monitoring are different--surveillance involves populations, while monitoring involves individuals; (ii) surveillance can be performed repeatedly and at any time during the lifetime of a medicinal product or device; (iii) although itself non-interventional, it can adduce any types of evidence (interventional, observational, or anecdotal, potentially at different times); (iv) it encompasses data collection, management, analysis, and interpretation; (v) it includes actions to be taken after signal detection, including initial evaluation and communication; and (vi) it should contribute to the classification of adverse reactions and their prevention or mitigation and/or to the harnessing of beneficial effects. We conclude that qualifiers add ambiguity and uncertainty without enhancing the idea of surveillance. We propose the following definition of surveillance of health-care products, which embraces all the surveyed ideas and reflects real-world pharmacovigilance processes: 'a form of non-interventional public health research, consisting of a set of processes for the continued systematic collection, compilation, interrogation, analysis, and interpretation of data on benefits and harms (including relevant spontaneous reports, electronic medical records, and experimental data).' As a codicil, we note that the purposes of surveillance are to identify, evaluate, understand, and communicate previously unknown effects of health-care products, or new aspects of known effects, in order to harness such effects (if beneficial) or prevent or mitigate them (if harmful).

  9. Defining Starch Binding by Glucan Phosphatases

    DEFF Research Database (Denmark)

    Auger, Kyle; Raththagala, Madushi; Wilkens, Casper;

    2015-01-01

    Starch is a vital energy molecule in plants that has a wide variety of uses in industry, such as feedstock for biomaterial processing and biofuel production. Plants employ a three enzyme cyclic process utilizing kinases, amylases, and phosphatases to degrade starch in a diurnal manner. Starch...... is comprised of the branched glucan amylopectin and the more linear glucan amylose. Our lab has determined the first structures of these glucan phosphatases and we have defined their enzymatic action. Despite this progress, we lacked a means to quickly and efficiently quantify starch binding to glucan...... phosphatases. The main objective of this study was to quantify the binding affinity of different enzymes that are involved in this cyclic process. We established a protocol to quickly, reproducibly, and quantitatively measure the binding of the enzymes to glucans utilizing Affinity Gel Electrophoresis (AGE...

  10. O(α{sup 3}{sub s}) contributions to the heavy flavor Wilson coefficients of the structure function F{sub 2}(x,Q{sup 2}) at Q{sup 2}>>m{sup 2}

    Energy Technology Data Exchange (ETDEWEB)

    Wissbrock, Fabian Philipp

    2015-10-15

    At O(α{sub s}{sup 3}) the contribution of a single heavy quark to the unpolarized structure function F{sub 2}(x,Q{sup 2}) in the asymptotic region Q{sup 2}>>m{sup 2} is written as a convolution of the light flavor Wilson coefficients and the process independent massive operator matrix elements. This thesis extends the present description to allow for the presence of two heavy quark flavors and presents the respective renormalization prescription and first analytic results for these contributions. Furthermore the remaining O(C{sub A,F} T{sub F}{sup 2} N{sub F}) contributions and various diagrams of more complex topologies have been computed analytically. On the mathematical side different evaluation techniques based on representations in terms of special functions, Mellin-Barnes representations and Hyperlogarithms have been worked out.

  11. Relation of large-scale coronal X-ray structure and cosmic rays. I - Sources of solar wind streams as defined by X-ray emission and H-alpha absorption features

    Science.gov (United States)

    Krieger, A. S.; Nolte, J. T.; Sullivan, J. D.; Lazarus, A. J.; Mcintosh, P. S.; Gold, R. E.; Roelof, E. C.

    1975-01-01

    The large-scale structure of the corona and the interplanetary medium during Carrington rotations 1601-1607 is discussed relative to recurrent high-speed solar wind streams and their coronal sources. Only streams A, C, D, and F recur on more than one rotation. Streams A and D are associated with coronal holes, while C and F originate in the high corona (20-50 solar radii) over faint X-ray emissions. The association of the streams with holes is confirmed by earlier findings that there are no large equatorial holes without an associated high-speed stream and that the area of the equatorial region of coronal holes is highly correlated with the maximum velocity observed in the associated stream near 1 AU.

  12. Defining dysbiosis and its influence on host immunity and disease.

    Science.gov (United States)

    Petersen, Charisse; Round, June L

    2014-07-01

    Mammalian immune system development depends on instruction from resident commensal microorganisms. Diseases associated with abnormal immune responses towards environmental and self antigens have been rapidly increasing over the last 50 years. These diseases include inflammatory bowel disease (IBD), multiple sclerosis (MS), type I diabetes (T1D), allergies and asthma. The observation that people with immune mediated diseases house a different microbial community when compared to healthy individuals suggests that pathogenesis arises from improper training of the immune system by the microbiota. However, with hundreds of different microorganisms on our bodies it is hard to know which of these contribute to health and more importantly how? Microbiologists studying pathogenic organisms have long adhered to Koch's postulates to directly relate a certain disease to a specific microbe, raising the question of whether this might be true of commensal-host relationships as well. Emerging evidence supports that rather than one or two dominant organisms inducing host health, the composition of the entire community of microbial residents influences a balanced immune response. Thus, perturbations to the structure of complex commensal communities (referred to as dysbiosis) can lead to deficient education of the host immune system and subsequent development of immune mediated diseases. Here we will overview the literature that describes the causes of dysbiosis and the mechanisms evolved by the host to prevent these changes to community structure. Building off these studies, we will categorize the different types of dysbiosis and define how collections of microorganisms can influence the host response. This research has broad implications for future therapies that go beyond the introduction of a single organism to induce health. We propose that identifying mechanisms to re-establish a healthy complex microbiota after dysbiosis has occurred, a process we will refer to as rebiosis

  13. Sociometabolic transitions defining the Anthropocene

    Science.gov (United States)

    Fischer-Kowalski, Prof; Krausmann, Prof; Pallua, Mag

    2014-05-01

    growth and metabolic rates carry about equal weight in increasing human pressure on the environment approximately fivefold from the year AD 1 onwards. From then on, fossil fuel use gradually raises the socially disposable energy to unprecedented levels and introduces a take off in population and technology. From then on, the overall pressure of humanity upon Earth increases by one order of magnitude; energy intensity contributes to this rise by roughly tripling the impact of population growth. Technology, because it is based upon a shift from biomass to fossil fuels (and other "modern" energy carriers), does not moderate this impact, but enhances it by a factor of 1.5. Finally, we also draw critical conclusions concerning the applied IPAT model: apparently, there are strong interactions between the components of the equation: in particular, population dynamics depend upon energy in the agrarian, but paradoxically much less so in the industrial regime.

  14. Structural and sensory characterization of compounds contributing to the bitter off-taste of carrots (Daucus carota L.) and carrot puree.

    Science.gov (United States)

    Czepa, Andreas; Hofmann, Thomas

    2003-06-18

    Sequential application of solvent extraction, gel permeation chromatography, and HPLC in combination with taste dilution analyses revealed that not a sole compound but a multiplicity of bitter tastants contribute to the bitter off-taste of cold-stored carrots and commercial carrot puree, respectively. Among these bitter compounds, 3-methyl-6-methoxy-8-hydroxy-3,4-dihydroisocoumarin (6-methoxymellein), 5-hydroxy-7-methoxy-2-methylchromone (eugenin), 2,4,5-trimethoxybenzaldehyde (gazarin), (Z)-heptadeca-1,9-diene-4,6-diin-3,8-diol (falcarindiol), (Z)-heptadeca-1,9-diene-4,6-diin-3-ol (falcarinol), and (Z)-3-acetoxy-heptadeca-1,9-diene-4,6-diin-8-ol (falcarindiol 3-acetate) could be identified on the basis of MS as well as 1D- and 2D-NMR experiments. Due to the low concentrations of <0.1 mg/kg and the high taste thresholds found for eugenin and gazarin, these compounds could be unequivocally excluded as important contributors to the bitter taste of carrots. Calculation of bitter activity values as the ratio of their concentration to their bitter detection threshold clearly demonstrated that neither in fresh and stored carrots nor in commercial carrot puree did 6-methoxymellein contribute to the bitter off-taste. In contrast, the concentrations of falcarindiol in stored carrots and, even more pronounced, in carrot puree were found to be 9- and 13-fold above its low bitter detection concentration of 0.04 mmol/kg, thus demonstrating that this acetylenic diol significantly contributes to the bitter taste of the carrot products investigated.

  15. CREATIVITY AND INNOVATION AS DEFINED BY WORKER

    Directory of Open Access Journals (Sweden)

    Sônia Maria Guedes Gondim

    2015-12-01

    Full Text Available ABSTRACT Creativity and innovation are now required given the new configurations in work processes, in organizational formats, in physical and intangible technologies, as well as in products and markets. In parallel with the growing centrality and interest in the phenomena of creativity and innovation, a broadening of its concepts is observed. The inflation and trivialization of uses tend to make them self-explanatory and not very enlightening regarding situations to which they apply and the associated effects. The lack of conceptual clarity thus contributes both to undermining policies to promote creativity and innovation in organizations, as well as to hinder the employees' adherence to such policies. The study aimed to characterize the key elements of workers' informal definitions of creativity and innovation, and identify their alignment with definitions and theoretical perspectives. The study included 231 workers from Portuguese-, Spanish-, and Basque-speaking countries, aged 22-75 years. The qualitative data analysis software ATLAS.ti 7 was used for coding and categorization. One point of convergence with the specialized literature was that creativity and innovation strongly associated with novelty in the development of an idea / product / process / service. Creativity, however, is defined more in terms of dispositional factors rather than contextual and situational factors, diverging from current theoretical perspectives. Planning as a key aspect for organizational innovation development is practically absent from the workers' definitions. It discusses some impacts of these settings for organizational management practices.

  16. Defining Ecosystem Assets for Natural Capital Accounting.

    Science.gov (United States)

    Hein, Lars; Bagstad, Ken; Edens, Bram; Obst, Carl; de Jong, Rixt; Lesschen, Jan Peter

    2016-01-01

    In natural capital accounting, ecosystems are assets that provide ecosystem services to people. Assets can be measured using both physical and monetary units. In the international System of Environmental-Economic Accounting, ecosystem assets are generally valued on the basis of the net present value of the expected flow of ecosystem services. In this paper we argue that several additional conceptualisations of ecosystem assets are needed to understand ecosystems as assets, in support of ecosystem assessments, ecosystem accounting and ecosystem management. In particular, we define ecosystems' capacity and capability to supply ecosystem services, as well as the potential supply of ecosystem services. Capacity relates to sustainable use levels of multiple ecosystem services, capability involves prioritising the use of one ecosystem service over a basket of services, and potential supply considers the ability of ecosystems to generate services regardless of demand for these services. We ground our definitions in the ecosystem services and accounting literature, and illustrate and compare the concepts of flow, capacity, capability, and potential supply with a range of conceptual and real-world examples drawn from case studies in Europe and North America. Our paper contributes to the development of measurement frameworks for natural capital to support environmental accounting and other assessment frameworks.

  17. Oscillator metrology with software defined radio.

    Science.gov (United States)

    Sherman, Jeff A; Jördens, Robert

    2016-05-01

    Analog electrical elements such as mixers, filters, transfer oscillators, isolating buffers, dividers, and even transmission lines contribute technical noise and unwanted environmental coupling in time and frequency measurements. Software defined radio (SDR) techniques replace many of these analog components with digital signal processing (DSP) on rapidly sampled signals. We demonstrate that, generically, commercially available multi-channel SDRs are capable of time and frequency metrology, outperforming purpose-built devices by as much as an order-of-magnitude. For example, for signals at 10 MHz and 6 GHz, we observe SDR time deviation noise floors of about 20 fs and 1 fs, respectively, in under 10 ms of averaging. Examining the other complex signal component, we find a relative amplitude measurement instability of 3 × 10(-7) at 5 MHz. We discuss the scalability of a SDR-based system for simultaneous measurement of many clocks. SDR's frequency agility allows for comparison of oscillators at widely different frequencies. We demonstrate a novel and extreme example with optical clock frequencies differing by many terahertz: using a femtosecond-laser frequency comb and SDR, we show femtosecond-level time comparisons of ultra-stable lasers with zero measurement dead-time.

  18. A Methodology to Define Flood Resilience

    Science.gov (United States)

    Tourbier, J.

    2012-04-01

    Flood resilience has become an internationally used term with an ever-increasing number of entries on the Internet. The SMARTeST Project is looking at approaches to flood resilience through case studies at cities in various countries, including Washington D.C. in the United States. In light of U.S. experiences a methodology is being proposed by the author that is intended to meet ecologic, spatial, structural, social, disaster relief and flood risk aspects. It concludes that: "Flood resilience combines (1) spatial, (2) structural, (3) social, and (4) risk management levels of flood preparedness." Flood resilience should incorporate all four levels, but not necessarily with equal emphasis. Stakeholders can assign priorities within different flood resilience levels and the considerations they contain, dividing 100% emphasis into four levels. This evaluation would be applied to planned and completed projects, considering existing conditions, goals and concepts. We have long known that the "road to market" for the implementation of flood resilience is linked to capacity building of stakeholders. It is a multidisciplinary enterprise, involving the integration of all the above aspects into the decision-making process. Traditional flood management has largely been influenced by what in the UK has been called "Silo Thinking", involving constituent organizations that are responsible for different elements, and are interested only in their defined part of the system. This barrier to innovation also has been called the "entrapment effect". Flood resilience is being defined as (1) SPATIAL FLOOD RESILIENCE implying the management of land by floodplain zoning, urban greening and management to reduce storm runoff through depression storage and by practicing Sustainable Urban Drainage (SUD's), Best Management Practices (BMP's, or Low Impact Development (LID). Ecologic processes and cultural elements are included. (2) STRUCTURAL FLOOD RESILIENCE referring to permanent flood defense

  19. Contribution to the study of electronic structure of crystalline semiconductors (Si, Ge, GaAs, Gap, ZnTe, ZnSe

    Directory of Open Access Journals (Sweden)

    Bouhafs B.

    2012-06-01

    Full Text Available The band structure of semiconductors was described by several theorists since the Fifties. The main objective of the present paper is to do a comparative study between various families of semi-conductors IV (Si,Ge, III-V (GaAs, GaP and II-VI (ZnSe, ZnTe with both methods; tight Binding1 method and pseudo potential method2. This work enables us to understand as well as the mechanism of conduction process in these semiconductors and powers and limits of the above methods. The obtained results allow to conclude that both methods are in a good agreement to describe the morphology of band structures of the cited semiconductors. This encourages us to study in the future the electronic behaviour through the structure of bands for more complex systems such as the heterostructures.

  20. Assessing many-body contributions to intermolecular interactions of the AMOEBA force field using energy decomposition analysis of electronic structure calculations

    Science.gov (United States)

    Demerdash, Omar; Mao, Yuezhi; Liu, Tianyi; Head-Gordon, Martin; Head-Gordon, Teresa

    2017-10-01

    In this work, we evaluate the accuracy of the classical AMOEBA model for representing many-body interactions, such as polarization, charge transfer, and Pauli repulsion and dispersion, through comparison against an energy decomposition method based on absolutely localized molecular orbitals (ALMO-EDA) for the water trimer and a variety of ion-water systems. When the 2- and 3-body contributions according to the many-body expansion are analyzed for the ion-water trimer systems examined here, the 3-body contributions to Pauli repulsion and dispersion are found to be negligible under ALMO-EDA, thereby supporting the validity of the pairwise-additive approximation in AMOEBA's 14-7 van der Waals term. However AMOEBA shows imperfect cancellation of errors for the missing effects of charge transfer and incorrectness in the distance dependence for polarization when compared with the corresponding ALMO-EDA terms. We trace the larger 2-body followed by 3-body polarization errors to the Thole damping scheme used in AMOEBA, and although the width parameter in Thole damping can be changed to improve agreement with the ALMO-EDA polarization for points about equilibrium, the correct profile of polarization as a function of intermolecular distance cannot be reproduced. The results suggest that there is a need for re-examining the damping and polarization model used in the AMOEBA force field and provide further insights into the formulations of polarizable force fields in general.

  1. Precise Determination of the Deuteron Spin Structure at Low to Moderate $Q^2$ with CLAS and Extraction of the Neutron Contribution

    CERN Document Server

    Guler, N; Kuhn, S E; Bosted, P; Griffioen, K A; Keith, C; Minehart, R; Prok, Y; Adhikari, K P; Adikaram, D; Amaryan, M J; Anderson, M D; Pereira, S Anefalos; Ball, J; Battaglieri, M; Batourine, V; Bedlinskiy, I; Briscoe, W J; Brooks, W K; Bultmann, S; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Contalbrigo, M; Crabb, D; Crede, V; Angelo, A D; Dashyan, N; Deur, A; Djalali, C; Dodge, G E; Dupre, R; Alaoui, A El; Fassi, L El; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Filippi, A; Fleming, J A; Forest, T A; Garillon, B; Garcon, M; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Golovatch, E; Gothe, R W; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Harrison, N; Hattawy, M; Hicks, K; Ho, D; Holtrop, M; Hughes, S M; Hyde, C E; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jo, H S; Joo, K; Joosten, S; Keller, D; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, F J; Kubarovsky, V; Kuleshov, S V; Livingston, K; Lu, H Y; MacGregor, I J D; McKinnon, B; Mirazita, M; Mokeev, V; Montgomery, R A; Movsisyan, A; Camacho, C Munoz; Nadel-Turonski, P; Net, L A; Niculescu, I; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatie, F; Salgado, C; Schott, D; Schumacher, R A; Seder, E; Simonyan, A; Skorodumina, Iu; Sokhan, D; Sparveris, N; Strakovsky, I I; Strauch, S; Sytnik, V; Tian, Ye; Tkachenko, S; Ungaro, M; Voutier, E; Walford, N K; Wei, X; Weinstein, L B; Wood, M H; Zachariou, N; Zana, L; Zhang, J; Zhao, Z W; Zonta, I

    2015-01-01

    We present the final results for the deuteron spin structure functions obtained from the full data set collected with Jefferson Lab's CLAS in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2 and 5.8 GeV were scattered from deuteron ($^{15}$ND$_3$) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double spin asymmetry, the virtual photon absorption asymmetry $A_1^d$ and the polarized structure function $g_1^d$ were extracted over a wide kinematic range (0.05 GeV$^2 < Q^2 <$ 5 GeV$^2$ and 0.9 GeV $< W <$ 3 GeV). We use an unfolding procedure and a parametrization of the corresponding proton results to extract from these data the polarized structure functions $A_1^n$ and $g_1^n$ of the (bound) neutron, which are so far unknown in the resonance region, $W < 2$ GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations as well as para...

  2. Contribution of landscape metrics to the assessment of scenic quality – the example of the landscape structure plan Havelland/Germany

    Directory of Open Access Journals (Sweden)

    H. Herbst

    2009-03-01

    Full Text Available The scenic quality of a landscape is a natural resource that is to be preserved according to German and international law. One important indicator for the evaluation of this value is the structural diversity of the landscape. Although Landscape Metrics (LM represent a well-known instrument for the quantification of landscape patterns, they are hardly used in applied landscape and environmental planning. This study shows possibilities for the integration of LM into a commonly used method to assess scenic quality by the example of a Landscape Structure Plan. First results indicate that especially Shannon’s Diversity Index and Edge Density are suitable to achieve an objective evaluation of the structural diversity as indicator for scenic quality. The addition of qualitative parameters to the objective structural analysis is discussed. Moreover, the use of landscape scenery units and raster cells as basic geometry has been compared. It shows that LM can support the evaluation of the aesthetic quality in environmental planning, especially when integrated into commonly used evaluation methods.

  3. A 1.9 Å Crystal Structure of the HDV Ribozyme Precleavage Suggests both Lewis Acid and General Acid Mechanisms Contribute to Phosphodiester Cleavage

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jui-Hui; Yajima, Rieko; Chadalavada, Durga M.; Chase, Elaine; Bevilacqua, Philip C.; Golden, Barbara L. (Purdue); (Penn)

    2010-11-01

    The hepatitis delta virus (HDV) ribozyme and HDV-like ribozymes are self-cleaving RNAs found throughout all kingdoms of life. These RNAs fold into a double-nested pseudoknot structure and cleave RNA, yielding 2{prime},3{prime}-cyclic phosphate and 5{prime}-hydroxyl termini. The active site nucleotide C75 has a pK{sub a} shifted >2 pH units toward neutrality and has been implicated as a general acid/base in the cleavage reaction. An active site Mg{sup 2+} ion that helps activate the 2{prime}-hydroxyl for nucleophilic attack has been characterized biochemically; however, this ion has not been visualized in any previous structures. To create a snapshot of the ribozyme in a state poised for catalysis, we have crystallized and determined the structure of the HDV ribozyme bound to an inhibitor RNA containing a deoxynucleotide at the cleavage site. This structure includes the wild-type C75 nucleotide and Mg{sup 2+} ions, both of which are required for maximal ribozyme activity. This structure suggests that the position of C75 does not change during the cleavage reaction. A partially hydrated Mg{sup 2+} ion is also found within the active site where it interacts with a newly resolved G {center_dot} U reverse wobble. Although the inhibitor exhibits crystallographic disorder, we modeled the ribozyme-substrate complex using the conformation of the inhibitor strand observed in the hammerhead ribozyme. This model suggests that the pro-RP oxygen of the scissile phosphate and the 2{prime}-hydroxyl nucleophile are inner-sphere ligands to the active site Mg{sup 2+} ion. Thus, the HDV ribozyme may use a combination of metal ion Lewis acid and nucleobase general acid strategies to effect RNA cleavage.

  4. Defining nodes in complex brain networks

    Directory of Open Access Journals (Sweden)

    Matthew Lawrence Stanley

    2013-11-01

    Full Text Available Network science holds great promise for expanding our understanding of the human brain in health, disease, development, and aging. Network analyses are quickly becoming the method of choice for analyzing functional MRI data. However, many technical issues have yet to be confronted in order to optimize results. One particular issue that remains controversial in functional brain network analyses is the definition of a network node. In functional brain networks a node represents some predefined collection of brain tissue, and an edge measures the functional connectivity between pairs of nodes. The characteristics of a node, chosen by the researcher, vary considerably in the literature. This manuscript reviews the current state of the art based on published manuscripts and highlights the strengths and weaknesses of three main methods for defining nodes. Voxel-wise networks are constructed by assigning a node to each, equally sized brain area (voxel. The fMRI time-series recorded from each voxel is then used to create the functional network. Anatomical methods utilize atlases to define the nodes based on brain structure. The fMRI time-series from all voxels within the anatomical area are averaged and subsequently used to generate the network. Functional activation methods rely on data from traditional fMRI activation studies, often from databases, to identify network nodes. Such methods identify the peaks or centers of mass from activation maps to determine the location of the nodes. Small (~10-20 millimeter diameter spheres located at the coordinates of the activation foci are then applied to the data being used in the network analysis. The fMRI time-series from all voxels in the sphere are then averaged, and the resultant time series is used to generate the network. We attempt to clarify the discussion and move the study of complex brain networks forward. While the correct method to be used remains an open, possibly unsolvable question that

  5. On defining semantics of extended attribute grammars

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1980-01-01

    Knuth has introduced attribute grammars (AGs) as a tool to define the semanitcs of context-free languages. The use of AGs in connection with programming language definitions has mostly been to define the context-sensitive syntax of the language and to define a translation in code for a hypothetical...

  6. Defining moments in leadership character development.

    Science.gov (United States)

    Bleich, Michael R

    2015-06-01

    Critical moments in life define one's character and clarify true values. Reflective leadership is espoused as an important practice for transformational leaders. Professional development educators can help surface and explore defining moments, strengthen leadership behavior with defining moments as a catalyst for change, and create safe spaces for leaders to expand their leadership capacity.

  7. Recent advances on green concrete for structural purposes the contribution of the EU-FP7 project EnCoRe

    CERN Document Server

    Ferrara, Liberato; Martinelli, Enzo

    2017-01-01

    This book is mainly based on the results of the EU-funded UE-FP7 Project EnCoRe, which aimed to characterize the key physical and mechanical properties of a novel class of advanced cement-based materials incorporating recycled powders and aggregates and/or natural ingredients in order to allow partial or even total replacement of conventional constituents. More specifically, the project objectives were to predict the physical and mechanical performance of concrete with recycled aggregates; to understand the potential contribution of recycled fibers as a dispersed reinforcement in concrete matrices; and to demonstrate the feasibility and possible applications of natural fibers as a reinforcement in cementitious composites. All of these aspects are fully covered in the book. The opening chapters explain the material concept and design and discuss the experimental characterization of the physical, chemical, and mechanical properties of the recycled raw constituents, as well as of the cementitious composite incor...

  8. PREPARATION OF CHEMICALLY WELL-DEFINED CARBOHYDRATE DENDRIMER CONJUGATES

    DEFF Research Database (Denmark)

    2004-01-01

    A method for the synthesis of dendrimer conjugates having a well-defined chemical structure, comprising one or more carbohydrate moieties and one or more immunomodulating substances coupled to a dendrimer, is presented. First, the carbohydrate is bound to the dendrimer in a chemoselective manner....... Subsequently, the immunomodulating substance is also bound in a chemoselective manner, to give a dendrimer conjugate with a well-defined structure and connectivity and containing a precise, pre-determined ratio of carbohydrate to immunomodulating substance. The invention also relates to novel dendrimer...

  9. Disconnection mechanism and regional cortical atrophy contribute to impaired processing of facial expressions and theory of mind in multiple sclerosis: a structural MRI study.

    Directory of Open Access Journals (Sweden)

    Andrea Mike

    Full Text Available Successful socialization requires the ability of understanding of others' mental states. This ability called as mentalization (Theory of Mind may become deficient and contribute to everyday life difficulties in multiple sclerosis. We aimed to explore the impact of brain pathology on mentalization performance in multiple sclerosis. Mentalization performance of 49 patients with multiple sclerosis was compared to 24 age- and gender matched healthy controls. T1- and T2-weighted three-dimensional brain MRI images were acquired at 3Tesla from patients with multiple sclerosis and 18 gender- and age matched healthy controls. We assessed overall brain cortical thickness in patients with multiple sclerosis and the scanned healthy controls, and measured the total and regional T1 and T2 white matter lesion volumes in patients with multiple sclerosis. Performances in tests of recognition of mental states and emotions from facial expressions and eye gazes correlated with both total T1-lesion load and regional T1-lesion load of association fiber tracts interconnecting cortical regions related to visual and emotion processing (genu and splenium of corpus callosum, right inferior longitudinal fasciculus, right inferior fronto-occipital fasciculus, uncinate fasciculus. Both of these tests showed correlations with specific cortical areas involved in emotion recognition from facial expressions (right and left fusiform face area, frontal eye filed, processing of emotions (right entorhinal cortex and socially relevant information (left temporal pole. Thus, both disconnection mechanism due to white matter lesions and cortical thinning of specific brain areas may result in cognitive deficit in multiple sclerosis affecting emotion and mental state processing from facial expressions and contributing to everyday and social life difficulties of these patients.

  10. Survey of linear structural features from remote sensing – a contribution to the geotechnical mapping in Baturité Mountain, Ceará

    Directory of Open Access Journals (Sweden)

    Clístenes Teixeira Batista

    2014-06-01

    Full Text Available The use of techniques of digital image processing remote sensing allows applications of great importance for the geosciences. One of the possible fields of application of these resources is the geotechnical mapping. Filtering techniques for radar and optical images emphasize natural linear structures that can be interpreted as fractures, drainages, ridges, valley bottoms and foliation. With the lifting of these data, combined with field work, the geotechnical mapping gains in precision and agility. The high incidence of slope instability events recently occurred in some parts of Brazil, especially in the Southeast, has attracted the interest of researchers in engineering and geoscience areas in the preparation of monographs, dissertations, theses and academic articles that address this issue. For subsequent generation of a diagram rosettes and visualization of regional trend of the structures and preparation of lineament density map, the vectors corresponding to the guidelines direction were measured in azimuth, and the length was measured in meters. The importance of applying frequency spectrum filters is therefore to quantify and qualify these geological and geomorphological structures, which are among the main components of conditions of mass movements and erosion.

  11. Contribution to assessing the stiffness reduction of structural elements in the global stability analysis of precast concrete multi-storey buildings

    Directory of Open Access Journals (Sweden)

    M. C. Marin

    Full Text Available This study deals with the reduction of the stiffness in precast concrete structural elements of multi-storey buildings to analyze global stability. Having reviewed the technical literature, this paper present indications of stiffness reduction in different codes, standards, and recommendations and compare these to the values found in the present study. The structural model analyzed in this study was constructed with finite elements using ANSYS® software. Physical Non-Linearity (PNL was considered in relation to the diagrams M x N x 1/r, and Geometric Non-Linearity (GNL was calculated following the Newton-Raphson method. Using a typical precast concrete structure with multiple floors and a semi-rigid beam-to-column connection, expressions for a stiffness reduction coefficient are presented. The main conclusions of the study are as follows: the reduction coefficients obtained from the diagram M x N x 1/r differ from standards that use a simplified consideration of PNL; the stiffness reduction coefficient for columns in the arrangements analyzed were approximately 0.5 to 0.6; and the variation of values found for stiffness reduction coefficient in concrete beams, which were subjected to the effects of creep with linear coefficients from 0 to 3, ranged from 0.45 to 0.2 for positive bending moments and 0.3 to 0.2 for negative bending moments.

  12. Contributions on ecotoxicology. Proceedings; Beitraege zur Oekotoxikologie. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, A.; Brueggemann, R. [eds.

    1997-11-01

    Ecotoxicological effects can be defined in terms of changes in reaction patterns, processes, structures, and functions of ecosystems. At an all-day workshop at GSF on 10. November 1995 various working groups presented their reports on this subject. Taken together the contributions provide good coverage of the present state of knowledge on ecotoxicology. (orig./SR) [Deutsch] Oekotoxikologische Wirkungen lassen sich als Aenderungen hinsichtlich auftretender Reaktionsmuster, Prozesse, Strukturen und Funktionen von Oekosystemen definieren. 1. Molekulare, noxenbezogene Ebene; 2. Zellebene; 3. Organismenebene; 4. Modellsysteme; 5. Systemebene; Oekotoxikologische Bewertung; Im Rahmen eines ganztaegigen Workshops am 10. November 1995 in der GSF wurden Berichte verschiedener Arbeitsgruppe allen Themenbereichen vorgestellt. (orig./SR)

  13. Low Left Atrial Compliance Contributes to the Clinical Recurrence of Atrial Fibrillation after Catheter Ablation in Patients with Structurally and Functionally Normal Heart.

    Directory of Open Access Journals (Sweden)

    Junbeom Park

    Full Text Available Stiff left atrial (LA syndrome was initially reported in post-cardiac surgery patients and known to be associated with low LA compliance. We investigated the physiological and clinical implications of LA compliance by estimating LA pulse pressure (LApp among patients with atrial fibrillation (AF and structurally and functionally normal heart. Among 1038 consecutive patients with LA pressure measurements before AF ablation, we included 334 patients with structurally and functionally normal heart (81.7% male, 54.1±10.6 years, 77.0% paroxysmal AF after excluding those with hypertension, diabetes, and previous ablation or cardiac surgery. We measured LApp (peak-nadir LA pressure at the beginning of the ablation procedure and compared the values with clinical parameters and the AF recurrence rate. AF patients with normal heart were younger and more frequently male and had paroxysmal AF, a lower body mass index, and a lower LApp compared to others (all p<0.05. Based on the median value, the low LA compliance group (LApp≥13 mmHg had a smaller LA volume index and lower LA voltage (all p<0.05 compared to the high LA compliance group. During a mean follow-up of 16.7±11.8 months, low LA compliance was independently associated with two fold-higher risk of clinical AF recurrence (HR:2.202; 95%CI:1.077-4.503; p = 0.031. Low LA compliance, as determined by an elevated LApp, was associated with a smaller LA volume index and lower LA voltage and independently associated with higher clinical recurrence after catheter ablation in AF patients with structurally and functionally normal heart.

  14. Low Left Atrial Compliance Contributes to the Clinical Recurrence of Atrial Fibrillation after Catheter Ablation in Patients with Structurally and Functionally Normal Heart.

    Science.gov (United States)

    Park, Junbeom; Yang, Pil-sung; Kim, Tae-Hoon; Uhm, Jae-Sun; Kim, Joung-Youn; Joung, Boyoung; Lee, Moon-Hyoung; Hwang, Chun; Pak, Hui-Nam

    2015-01-01

    Stiff left atrial (LA) syndrome was initially reported in post-cardiac surgery patients and known to be associated with low LA compliance. We investigated the physiological and clinical implications of LA compliance by estimating LA pulse pressure (LApp) among patients with atrial fibrillation (AF) and structurally and functionally normal heart. Among 1038 consecutive patients with LA pressure measurements before AF ablation, we included 334 patients with structurally and functionally normal heart (81.7% male, 54.1±10.6 years, 77.0% paroxysmal AF) after excluding those with hypertension, diabetes, and previous ablation or cardiac surgery. We measured LApp (peak-nadir LA pressure) at the beginning of the ablation procedure and compared the values with clinical parameters and the AF recurrence rate. AF patients with normal heart were younger and more frequently male and had paroxysmal AF, a lower body mass index, and a lower LApp compared to others (all p<0.05). Based on the median value, the low LA compliance group (LApp≥13 mmHg) had a smaller LA volume index and lower LA voltage (all p<0.05) compared to the high LA compliance group. During a mean follow-up of 16.7±11.8 months, low LA compliance was independently associated with two fold-higher risk of clinical AF recurrence (HR:2.202; 95%CI:1.077-4.503; p = 0.031). Low LA compliance, as determined by an elevated LApp, was associated with a smaller LA volume index and lower LA voltage and independently associated with higher clinical recurrence after catheter ablation in AF patients with structurally and functionally normal heart.

  15. Spatial analysis of carbon isotopes reveals seagrass contribution to fishery food web

    National Research Council Canada - National Science Library

    Connolly, Rod M; Waltham, Nathan J

    2015-01-01

    .... Pooling of modelled contributions from sources with similar isotope values indicated a role for organic matter from seagrass meadows or saltmarshes, but still did not define contributions well...

  16. Self-dual Codes Defined on Factor Graphs

    Institute of Scientific and Technical Information of China (English)

    WANG Hui-song; WANG Jun; DU Qun; ZENG Gui-hua

    2007-01-01

    A definition of a self-dual code on graph and a procedure based on factor graphs to judge a self-dual code were presented.Three contributions of this paper were described as follows.To begin with, transform TR→L were defined, which was the basis of self-dual codes defined on graphs and played a key role in the paper.The second were that a self-dual code could be defined on factor graph, which was much different from conventional algebraic method.The third was that a factor graph approach to judge a self-dual code was illustrated, which took advantage of duality properties of factor graphs and our proposed transform TR→L to offer a convenient and geometrically intuitive process to judge a self-dual code.

  17. High Resolution Software Defined Radar System for Target Detection

    Directory of Open Access Journals (Sweden)

    S. Costanzo

    2013-01-01

    Full Text Available The Universal Software Radio Peripheral USRP NI2920, a software defined transceiver so far mainly used in Software Defined Radio applications, is adopted in this work to design a high resolution L-Band Software Defined Radar system. The enhanced available bandwidth, due to the Gigabit Ethernet interface, is exploited to obtain a higher slant-range resolution with respect to the existing Software Defined Radar implementations. A specific LabVIEW application, performing radar operations, is discussed, and successful validations are presented to demonstrate the accurate target detection capability of the proposed software radar architecture. In particular, outdoor and indoor test are performed by adopting a metal plate as reference structure located at different distances from the designed radar system, and results obtained from the measured echo are successfully processed to accurately reveal the correct target position, with the predicted slant-range resolution equal to 6 m.

  18. Host resistance, population structure and the long-term persistence of bubonic plague: contributions of a modelling approach in the Malagasy focus.

    Science.gov (United States)

    Gascuel, Fanny; Choisy, Marc; Duplantier, Jean-Marc; Débarre, Florence; Brouat, Carine

    2013-01-01

    Although bubonic plague is an endemic zoonosis in many countries around the world, the factors responsible for the persistence of this highly virulent disease remain poorly known. Classically, the endemic persistence of plague is suspected to be due to the coexistence of plague resistant and plague susceptible rodents in natural foci, and/or to a metapopulation structure of reservoirs. Here, we test separately the effect of each of these factors on the long-term persistence of plague. We analyse the dynamics and equilibria of a model of plague propagation, consistent with plague ecology in Madagascar, a major focus where this disease is endemic since the 1920s in central highlands. By combining deterministic and stochastic analyses of this model, and including sensitivity analyses, we show that (i) endemicity is favoured by intermediate host population sizes, (ii) in large host populations, the presence of resistant rats is sufficient to explain long-term persistence of plague, and (iii) the metapopulation structure of susceptible host populations alone can also account for plague endemicity, thanks to both subdivision and the subsequent reduction in the size of subpopulations, and extinction-recolonization dynamics of the disease. In the light of these results, we suggest scenarios to explain the localized presence of plague in Madagascar.

  19. Host resistance, population structure and the long-term persistence of bubonic plague: contributions of a modelling approach in the Malagasy focus.

    Directory of Open Access Journals (Sweden)

    Fanny Gascuel

    Full Text Available Although bubonic plague is an endemic zoonosis in many countries around the world, the factors responsible for the persistence of this highly virulent disease remain poorly known. Classically, the endemic persistence of plague is suspected to be due to the coexistence of plague resistant and plague susceptible rodents in natural foci, and/or to a metapopulation structure of reservoirs. Here, we test separately the effect of each of these factors on the long-term persistence of plague. We analyse the dynamics and equilibria of a model of plague propagation, consistent with plague ecology in Madagascar, a major focus where this disease is endemic since the 1920s in central highlands. By combining deterministic and stochastic analyses of this model, and including sensitivity analyses, we show that (i endemicity is favoured by intermediate host population sizes, (ii in large host populations, the presence of resistant rats is sufficient to explain long-term persistence of plague, and (iii the metapopulation structure of susceptible host populations alone can also account for plague endemicity, thanks to both subdivision and the subsequent reduction in the size of subpopulations, and extinction-recolonization dynamics of the disease. In the light of these results, we suggest scenarios to explain the localized presence of plague in Madagascar.

  20. Host Resistance, Population Structure and the Long-Term Persistence of Bubonic Plague: Contributions of a Modelling Approach in the Malagasy Focus

    Science.gov (United States)

    Gascuel, Fanny; Choisy, Marc; Duplantier, Jean-Marc; Débarre, Florence; Brouat, Carine

    2013-01-01

    Although bubonic plague is an endemic zoonosis in many countries around the world, the factors responsible for the persistence of this highly virulent disease remain poorly known. Classically, the endemic persistence of plague is suspected to be due to the coexistence of plague resistant and plague susceptible rodents in natural foci, and/or to a metapopulation structure of reservoirs. Here, we test separately the effect of each of these factors on the long-term persistence of plague. We analyse the dynamics and equilibria of a model of plague propagation, consistent with plague ecology in Madagascar, a major focus where this disease is endemic since the 1920s in central highlands. By combining deterministic and stochastic analyses of this model, and including sensitivity analyses, we show that (i) endemicity is favoured by intermediate host population sizes, (ii) in large host populations, the presence of resistant rats is sufficient to explain long-term persistence of plague, and (iii) the metapopulation structure of susceptible host populations alone can also account for plague endemicity, thanks to both subdivision and the subsequent reduction in the size of subpopulations, and extinction-recolonization dynamics of the disease. In the light of these results, we suggest scenarios to explain the localized presence of plague in Madagascar. PMID:23675291