WorldWideScience

Sample records for alpha-nucleus interaction potential

  1. alpha-nucleus potentials, alpha-decay half-lives, and shell closures for superheavy nuclei

    OpenAIRE

    Mohr, Peter

    2006-01-01

    Systematic alpha-nucleus folding potentials are used to analyze alpha-decay half-lives of superheavy nuclei. Preformation factors of about several per cent are found for all nuclei under study. The systematic behavior of the preformation factors and the volume integrals of the potentials allows to predict alpha-decay energies and half-lives for unknown nuclei. Shell closures can be determined from measured alpha-decay energies using the discontinuity of the volume integral at shell closures. ...

  2. Nuclear structure approach to the calculation of the imaginary alpha-nucleus optical potential

    International Nuclear Information System (INIS)

    A microscopic calculation of the second-order imaginary optical potential for 40(Ca(α,α) is made for incident energies of 31 and 100 MeV using RPA transition densities for intermediate excited states. The projectile is treated as an elementary particle, and the alpha-nucleon interaction is normalized by fitting 3- inelastic cross sections with a folded M3Y potential. The use of an optical Green's function for the intermediate propagator is found to be important. Equivalent local potentials are obtained and used to calculate elastic scattering cross sections. Agreement with low-angle experimental data is fair at 31 MeV, but at 100 MeV the calculated cross sections indicate much too little absorption. 9 figures, 1 table

  3. Sensitivity of alpha-decay to the real alpha-nucleus potential

    International Nuclear Information System (INIS)

    The information which can be obtained from studies of low energy alpha-particle scattering from heavy nuclei and from alpha-decay is discussed. The sensitivity of calculated widths and lifetimes for alpha-decay to the real nuclear potential is examined in detail using a formalism based on the unified theory of nuclear reactions. It is shown that a combined study of alpha-decay and alpha-particle scattering at energies near the Coulomb barrier should give a very precise determination of the barrier height and radius, although there is a more uniquely defined separation distance some way beyond the barrier. (orig.)

  4. Comparative study of alpha + nucleus elastic scattering using different models

    International Nuclear Information System (INIS)

    The alpha (α) elastic scattering from different targets potential over the energy range 10–240 MeV has been analyzed in the framework of the single-folding (SF) optical model. Four targets are considered, namely, 24Mg, 28Si, 32S and 40Ca. The SF calculations for the real central part of the nuclear optical potential are performed by folding an effective α–α interaction with the α-cluster distribution density in the target nucleus. The imaginary part of the optical potential is expressed in the phenomenological Woods–Saxon (WS) form. The calculated angular distributions of the elastic scattering differential cross-section using the derived semimicroscopic potentials successfully reproduce 36 sets of data all over the measured angular ranges. The obtained results confirm the validity of the α-cluster structure of the considered nuclei. For the sake of comparison, the same sets of data are reanalyzed using microscopic double-folded optical potentials based upon the density-dependent Jeukenne–Lejeune–Mahaux (JLM) effective nucleon–nucleon interaction. (author)

  5. A microscopic description for the alpha decay of nuclei using a realistic effective interaction

    CERN Document Server

    Basu, D N

    2002-01-01

    The process of alpha disintegration has been studied theoretically in the framework of a microscopic superasymmetric fission model (MSAFM). The nuclear interaction potential required for the alpha decay process has been calculated by folding in the density distribution functions of the alpha nucleus and the daughter nucleus with a realistic effective interaction. The nuclear microscopic alpha-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently results in a parameter free calculation for the half lives of the alpha decays of nuclei. The model is successful in calculating the half lives of the alpha disintegration processes of nuclei.

  6. Diatomic interaction potential theory applications

    CERN Document Server

    Goodisman, Jerry

    2013-01-01

    Diatomic Interaction Potential Theory, Volume 2: Applications discusses the variety of applicable theoretical material and approaches in the calculations for diatomic systems in their ground states. The volume covers the descriptions and illustrations of modern calculations. Chapter I discusses the calculation of the interaction potential for large and small values of the internuclear distance R (separated and united atom limits). Chapter II covers the methods used for intermediate values of R, which in principle means any values of R. The Hartree-Fock and configuration interaction schemes des

  7. Few interacting particles in a random potential

    OpenAIRE

    Shepelyansky, D. L.; Sushkov, O. P.

    1996-01-01

    We study the localization length of few interacting particles in a random potential. Concentrating on the case of three particles we show that their localization length is strongly enhanced comparing to the enhancement for two interacting particles.

  8. Potential interactions between alternative therapies and warfarin.

    Science.gov (United States)

    Heck, A M; DeWitt, B A; Lukes, A L

    2000-07-01

    Potential and documented interactions between alternative therapy agents and warfarin are discussed. An estimated one third of adults in the United States use alternative therapies, including herbs. A major safety concern is potential interactions of alternative medicine products with prescription medications. This issue is especially important with respect to drugs with narrow therapeutic indexes, such as warfarin. Herbal products that may potentially increase the risk of bleeding or potentiate the effects of warfarin therapy include angelica root, arnica flower, anise, asafoetida, bogbean, borage seed oil, bromelain, capsicum, celery, chamomile, clove, fenugreek, feverfew, garlic, ginger ginkgo, horse chestnut, licorice root, lovage root, meadowsweet, onion, parsley, passionflower herb, poplar, quassia, red clover, rue, sweet clover, turmeric, and willow bark. Products that have been associated with documented reports of potential interactions with warfarin include coenzyme Q10, danshen, devil's claw, dong quai, ginseng, green tea, papain, and vitamin E. Interpretation of the available information on herb-warfarin interactions is difficult because nearly all of it is based on in vitro data, animal studies, or individual case reports. More study is needed to confirm and assess the clinical significance of these potential interactions. There is evidence that a wide range of alternative therapy products have the potential to interact with warfarin. Pharmacists and other health care professionals should question all patients about use of alternative therapies and report documented interactions to FDA's MedWatch program. PMID:10902065

  9. A new interaction potential for swarming models

    CERN Document Server

    Carrillo, J A; Panferov, V

    2012-01-01

    We consider a self-propelled particle system which has been used to describe certain types of collective motion of animals, such as fish schools and bird flocks. Interactions between particles are specified by means of a pairwise potential, repulsive at short ranges and attractive at longer ranges. The exponentially decaying Morse potential is a typical choice, and is known to reproduce certain types of collective motion observed in nature, particularly aligned flocks and rotating mills. We introduce a class of interaction potentials, that we call Quasi-Morse, for which flock and rotating mills states are also observed numerically, however in that case the corresponding macroscopic equations allow for explicit solutions in terms of special functions, with coefficients that can be obtained numerically without solving the particle evolution. We compare thus obtained solutions with long-time dynamics of the particle systems and find a close agreement for several types of flock and mill solutions.

  10. A new interaction potential for swarming models

    Science.gov (United States)

    Carrillo, J. A.; Martin, S.; Panferov, V.

    2013-10-01

    We consider a self-propelled particle system which has been used to describe certain types of collective motion of animals, such as fish schools and bird flocks. Interactions between particles are specified by means of a pairwise potential, repulsive at short ranges and attractive at longer ranges. The exponentially decaying Morse potential is a typical choice, and is known to reproduce certain types of collective motion observed in nature, particularly aligned flocks and rotating mills. We introduce a class of interaction potentials, that we call Quasi-Morse, for which flock and rotating mills states are also observed numerically, however in that case the corresponding macroscopic equations allow for explicit solutions in terms of special functions, with coefficients that can be obtained numerically without solving the particle evolution. We compare the obtained solutions with long-time dynamics of the particle systems and find a close agreement for several types of flock and mill solutions.

  11. Statistical systems with nonintegrable interaction potentials

    Science.gov (United States)

    Yukalov, V. I.

    2016-07-01

    Statistical systems composed of atoms interacting with each other trough nonintegrable interaction potentials are considered. Examples of these potentials are hard-core potentials and long-range potentials, for instance, the Lennard-Jones and dipolar potentials. The treatment of such potentials is known to confront several problems, e.g., the impossibility of using the standard mean-field approximations, such as Hartree and Hartree-Fock approximations, the impossibility of directly introducing coherent states, the difficulty in breaking the global gauge symmetry, which is required for describing Bose-Einstein condensed and superfluid systems, the absence of a correctly defined Fourier transform, which hampers the description of uniform matter as well as the use of local-density approximation for nonuniform systems. A novel iterative procedure for describing such systems is developed, starting from a correlated mean-field approximation, allowing for a systematic derivation of higher orders, and meeting no problems listed above. The procedure is applicable to arbitrary systems, whether equilibrium or nonequilibrium. The specification for equilibrium systems is presented. The method of extrapolating the expressions for observable quantities from weak coupling to strong coupling is described.

  12. Developing interaction potentials from first principles

    OpenAIRE

    Foy, Lindsay

    2009-01-01

    Interaction potentials for the double-perovskite cryolite, Na3AlF6, have been developed for use in classical Molecular Dynamics (MD) simulations using a method whereby ionic configurations are generated with empirical pair potentials, the multipoles and forces on the ions and the stress tensor of the cell are extracted from ab initio single-point DFT calculations, and then the multipoles, forces and stresses from the MD simulations are ‘fit’ to the ab initio quantities in a ser...

  13. PRESENTATION POTENTIAL USING IN PEDAGOGICAL INTERACTION PROCESS

    Directory of Open Access Journals (Sweden)

    Olga V. Ershova

    2016-01-01

    Full Text Available The given article is aimed at considering multimedia presentation potential and its influence on strengthening classroom teacher-student interaction. In the article the importance of using this kind of activity in the study process is pointed in connection with educational state policy on the one hand. On the other hand, gained students’ skills as a final result of work with presentations met employers’ demand for both parent and world labour-markets and bring competitive benefit to the candidates. Scientific novelty and results. Multimedia presentation is considered as a specific complex of classroom activities. The students are oriented on the self analysis and presentation assessment. It is shown that well-organized process of peer students’ assessment allows to simultaneously helping in solving the didactic and methodical problems. To this purpose the system of assessment criteria should be developed. It has to be clear for students for making assessment feasible and time-saving. The example of a possible variant of criteria system is described; quality of the presentations prepared by students can be defined based on such system criteria. The author also analyzed software products of the three main platforms (Windows, Linux, MacOs which have different tools and allow to follow users’ needs for creating presentations. In the article there is a comparative table of the two most popular software development: the program Microsoft PowerPoint and the web-service Prezi for realizing the relevance of their use in the study process. Practical significance of the present article concludes in author’s suggestions of some recommendations for presentation potential use as a tool of improving pedagogical interaction process with contemporary students. 

  14. Relativistic point interactions: Approximation by smooth potentials

    Science.gov (United States)

    Hughes, Rhonda J.

    1997-06-01

    We show that the four-parameter family of one-dimensional relativistic point interactions studied by Benvegnu and Dąbrowski may be approximated in the strong resolvent sense by smooth, local, short-range perturbations of the Dirac Hamiltonian. In addition, we prove that the nonrelativistic limits correspond to the Schrödinger point interactions studied extensively by the author and Paul Chernoff.

  15. Potential Flow Interactions With Directional Solidification

    Science.gov (United States)

    Buddhavarapu, Sudhir S.; Meiburg, Eckart

    1999-01-01

    The effect of convective melt motion on the growth of morphological instabilities in crystal growth has been the focus of many studies in the past decade. While most of the efforts have been directed towards investigating the linear stability aspects, relatively little attention has been devoted to experimental and numerical studies. In a pure morphological case, when there is no flow, morphological changes in the solid-liquid interface are governed by heat conduction and solute distribution. Under the influence of a convective motion, both heat and solute are redistributed, thereby affecting the intrinsic morphological phenomenon. The overall effect of the convective motion could be either stabilizing or destabilizing. Recent investigations have predicted stabilization by a flow parallel to the interface. In the case of non-parallel flows, e.g., stagnation point flow, Brattkus and Davis have found a new flow-induced morphological instability that occurs at long wavelengths and also consists of waves propagating against the flow. Other studies have addressed the nonlinear aspects (Konstantinos and Brown, Wollkind and Segel)). In contrast to the earlier studies, our present investigation focuses on the effects of the potential flow fields typically encountered in Hele-Shaw cells. Such a Hele-Shaw cell can simulate a gravity-free environment in the sense that buoyancy-driven convection is largely suppressed, and hence negligible. Our interest lies both in analyzing the linear stability of the solidification process in the presence of potential flow fields, as well as in performing high-accuracy nonlinear simulations. Linear stability analysis can be performed for the flow configuration mentioned above. It is observed that a parallel potential flow is stabilizing and gives rise to waves traveling downstream. We have built a highly accurate numerical scheme which is validated at small amplitudes by comparing with the analytically predicted results for the pure

  16. Large potential steps at weakly interacting metal-insulator interfaces

    OpenAIRE

    Bokdam, Menno; Brocks, Geert; Kelly, Paul J.

    2014-01-01

    Potential steps exceeding 1 eV are regularly formed at metal|insulator interfaces, even when the interaction between the materials at the interface is weak physisorption. From first-principles calculations on metal|h-BN interfaces we show that these potential steps are only indirectly sensitive to the interface bonding through the dependence of the binding energy curves on the van der Waals interaction. Exchange repulsion forms the main contribution to the interface potential step in the weak...

  17. Prospective study on microscopic potential with Gogny interaction

    International Nuclear Information System (INIS)

    We present our current studies and future plans on microscopic potential based on effective nucleon-nucleon interaction and many-body theory. This framework treats in an unified way nuclear structure and reaction. It offers the opportunity to link the underlying effective interaction to nucleon scattering observables. The more consistently connected to a variety of reaction and structure experimental data the framework is, the more constrained the effective interaction will be. As a proof of concept, we present some recent results for both neutron and proton scattered from spherical target nucleus, namely 40Ca, using the Gogny D1S interaction. Possible fruitful cross-talks between microscopic potential, phenomenological potential and effective interaction are exposed. We then draw some prospective plans for the forthcoming years including scattering from spherical nuclei experiencing pairing correlations, scattering from axially deformed nuclei, and new effective interaction with reaction constraints. (orig.)

  18. Prospective study on microscopic potential with Gogny interaction

    Energy Technology Data Exchange (ETDEWEB)

    Blanchon, G.; Dupuis, M. [DAM, DIF, CEA, Arpajon (France); Arellano, H.F. [University of Chile, Department of Physics - FCFM, Santiago (Chile); DAM, DIF, CEA, Arpajon (France)

    2015-12-15

    We present our current studies and future plans on microscopic potential based on effective nucleon-nucleon interaction and many-body theory. This framework treats in an unified way nuclear structure and reaction. It offers the opportunity to link the underlying effective interaction to nucleon scattering observables. The more consistently connected to a variety of reaction and structure experimental data the framework is, the more constrained the effective interaction will be. As a proof of concept, we present some recent results for both neutron and proton scattered from spherical target nucleus, namely {sup 40}Ca, using the Gogny D1S interaction. Possible fruitful cross-talks between microscopic potential, phenomenological potential and effective interaction are exposed. We then draw some prospective plans for the forthcoming years including scattering from spherical nuclei experiencing pairing correlations, scattering from axially deformed nuclei, and new effective interaction with reaction constraints. (orig.)

  19. Discrete Time Markovian Agents Interacting Through a Potential

    CERN Document Server

    Budhiraja, Amarjit; Rubenthaler, Sylvain

    2011-01-01

    A discrete time stochastic model for a multiagent system given in terms of a large collection of interacting Markov chains is studied. The evolution of the interacting particles is described through a time inhomogeneous transition probability kernel that depends on the 'gradient' of the potential field. The particles, in turn, dynamically modify the potential field through their cumulative input. Interacting Markov processes of the above form have been suggested as models for active biological transport in response to external stimulus such as a chemical gradient. One of the basic mathematical challenges is to develop a general theory of stability for such interacting Markovian systems and for the corresponding nonlinear Markov processes that arise in the large agent limit. Such a theory would be key to a mathematical understanding of the interactive structure formation that results from the complex feedback between the agents and the potential field. It will also be a crucial ingredient in developing simulat...

  20. Helium-3 Microscopic Optical Model Potential Based on Skyrme Interaction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The helium-3 microscopic optical potential is obtained by Green function method through nuclear matter approximation and local density approximation based on the effective Skyrme interaction. The reaction cross

  1. Calculation of Interaction Potentials between Spherical and Deformed Nuclei

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gao-Long; XU Xin-Xing; BAI Chun-Lin; YU Ning; ZHANG Huan-Qiao; LIU Zu-Hua; ZHANG Chun-Lei; LIN Cheng-Jian; YANG Feng; AN Guang-Peng; JIA Hui-Ming; WU Zhen-Dong

    2007-01-01

    The interaction potential for spherical-deformed reaction partners is calculated. The shape, separation and orientation dependence of the interaction potential and fusion cross section of the system 32S+154Sm are investigated within the double-folding model of the deformed nuclei. The effective nucleon-nucleon interaction is taken to be the M3Y-Reid potential. The density is considered for three terms of the expansion using the truncated multipole expansion method, which is a deformed Fermi shape with quadrupole and hexadecapole for the density distribution of 154Sm. It is found for the interaction potential that the height and the position of barrier strongly depend on the deformations, the orientation angle of the deformed nucleus, and hence produce great effects on fusion cross section. The integrated fusion cross section is in good agreement with the experimental data.

  2. Complex separable potential for the α-α interaction

    International Nuclear Information System (INIS)

    A non-local complex separable potential is used to fit l = 0, 2, 4, 6, 8, 10 α-α scattering phase shifts (real and imaginary) up to an incident energy of 100 MeV. The calculations takes into account the Coulomb interaction exactly, so that the separable potential can be expressed in a Coulomb wave representation. (author)

  3. Risk factors for potential drug interactions in general practice

    DEFF Research Database (Denmark)

    Bjerrum, Lars; Gonzalez Lopez-Valcarcel, Beatriz; Petersen, Gert

    2008-01-01

    Pharmacoepidemiologic Database, OPED) covering prescriptions to all inhabitants in the county of Funen, Denmark. All individuals exposed to concurrent use of two or more drugs (polypharmacy) were identified. Combinations of drugs with potential interactions were registered and classified as major, moderate, or minor......, depending on the severity of outcome and the quality of documentation. A two-level random coefficient logistic regression model was used to investigate factors related to potential drug interactions. Results: One-third of the population was exposed to polypharmacy, and 6% were exposed to potential drug...

  4. Interaction potential between discrete solitons in waveguide arrays.

    Science.gov (United States)

    Al Khawaja, U; Al-Marzoug, S M; Bahlouli, H; Baizakov, B

    2016-08-01

    Using a variational approach, we obtained the interaction potential between two discrete solitons in optical waveguide arrays. The resulting potential bears the two features of soliton-soliton and soliton-waveguide interaction potentials where the former is similar to that of the continuum case and the latter is similar to the effective Pierls-Nabarro potential. The interplay between the two interaction potentials is investigated by studying its effect on the soliton molecule formation. It is found that the two solitons bind if their initial separation equals an odd number of waveguides, while they do not bind if their separation is an even number, which is a consequence of the two solitons being both either at the intersites (unstable) or being onsite (stable). We derived the equations of motion for the solitons' centre of mass and relative separation and provided analytic solutions for some specific cases. Favourable agreement between the analytical and numerical interaction potentials is obtained. Possible applications of our results to all-optical logic gates are pointed out. PMID:27505780

  5. The interaction between potential criminals' and victims' demands for guns

    OpenAIRE

    Baç, Mehmet; Bac, Mehmet

    2009-01-01

    I develop a model with endogenous gun ownership and study the interaction between the demands for guns by heterogeneous potential offenders and victims. I show that the interaction depends on pervasiveness of guns, injury probabilities and, in particular, the impact of the gun on the probability of success against armed relative to unarmed adversaries. While the sanction on armed offense is maximal under plausible conditions, the sanction on unarmed offense balances direct deterrence benef...

  6. Scattering with absorptive interaction: Energy-dependent potentials

    Science.gov (United States)

    Cassing, W.; Stingl, M.; Weiguny, A.

    1983-05-01

    The energy dependence and analytic structure of the effective interaction for elastic scattering of composite particles are investigated using Feshbach's projection technique. A generalized Levinson theorem is established for complex, nonlocal, and energy-dependent interactions. The analytical results are illustrated by means of Argand diagrams for a solvable model and the effect of energy averaging is discussed. NUCLEAR REACTIONS Scattering theory, S matrix for absorptive, energy-dependent potentials, Levinson theorem.

  7. Localization of weakly interacting Bose gas in quasiperiodic potential

    Science.gov (United States)

    Ray, Sayak; Pandey, Mohit; Ghosh, Anandamohan; Sinha, Subhasis

    2016-01-01

    We study the localization properties of weakly interacting Bose gas in a quasiperiodic potential. The Hamiltonian of the non-interacting system reduces to the well known ‘Aubry-André model’, which shows the localization transition at a critical strength of the potential. In the presence of repulsive interaction we observe multi-site localization and obtain a phase diagram of the dilute Bose gas by computing the superfluid fraction and the inverse participation ratio. We construct a low-dimensional classical Hamiltonian map and show that the onset of localization is manifested by the chaotic phase space dynamics. The level spacing statistics also identify the transition to localized states resembling a Poisson distribution that are ubiquitous for both non-interacting and interacting systems. We also study the quantum fluctuations within the Bogoliubov approximation and compute the quasiparticle energy spectrum. Enhanced quantum fluctuation and multi-site localization phenomenon of non-condensate density are observed above the critical coupling of the potential. We briefly discuss the effect of the trapping potential on the localization of matter wave.

  8. Interactions between delta-like sources and potentials

    CERN Document Server

    Camilo, G T; Barone, F A

    2014-01-01

    The modified scalar boson propagator due to the presence of a hyperplane semi-transparent mirror is computed. From this, the classical interaction between static charges and the mirror is investigated employing delta-like potentials and sources. Although the calculations for hyperplane mirrors are performed in arbitrary dimensions, and in a completely general way, it is shown that the results give rise to the usual image method as a particular case. The interaction between a point-like mirror and a point-like source is also considered in $3+1$ dimensions, where a central $1/R^{2}$ attractive potential is also obtained as a special case.

  9. Study of interaction in silica glass via model potential approach

    Science.gov (United States)

    Mann, Sarita; Rani, Pooja

    2016-05-01

    Silica is one of the most commonly encountered substances in daily life and in electronics industry. Crystalline SiO2 (in several forms: quartz, cristobalite, tridymite) is an important constituent of many minerals and gemstones, both in pure form and mixed with related oxides. Cohesive energy of amorphous SiO2 has been investigated via intermolecular potentials i.e weak Van der Waals interaction and Morse type short-range interaction. We suggest a simple atom-atom based Van der Waals as well as Morse potential to find cohesive energy of glass. It has been found that the study of silica structure using two different model potentials is significantly different. Van der Waals potential is too weak (P.E =0.142eV/molecule) to describe the interaction between silica molecules. Morse potential is a strong potential, earlier given for intramolecular bonding, but if applied for intermolecular bonding, it gives a value of P.E (=-21.92eV/molecule) to appropriately describe the structure of silica.

  10. Optimizing Interacting Potentials to Form Targeted Materials Structures

    Energy Technology Data Exchange (ETDEWEB)

    Torquato, Salvatore [Princeton Univ., NJ (United States)

    2015-09-28

    Conventional applications of the principles of statistical mechanics (the "forward" problems), start with particle interaction potentials, and proceed to deduce local structure and macroscopic properties. Other applications (that may be classified as "inverse" problems), begin with targeted configurational information, such as low-order correlation functions that characterize local particle order, and attempt to back out full-system configurations and/or interaction potentials. To supplement these successful experimental and numerical "forward" approaches, we have focused on inverse approaches that make use of analytical and computational tools to optimize interactions for targeted self-assembly of nanosystems. The most original aspect of our work is its inherently inverse approach: instead of predicting structures that result from given interaction potentials among particles, we determine the optimal potential that most robustly stabilizes a given target structure subject to certain constraints. Our inverse approach could revolutionize the manner in which materials are designed and fabricated. There are a number of very tangible properties (e.g. zero thermal expansion behavior), elastic constants, optical properties for photonic applications, and transport properties.

  11. Potential electrode/electrolyte interactions in solid oxide fuel cells

    International Nuclear Information System (INIS)

    Yttria-stabilized zirconia and strontium-doped lanthanum manganite are the prime candidates for the electrolyte and the air electrode material, respectively, for the solid oxide fuel cell. In this study, the potential high temperature interactions, including intrinsic reactivity and interdiffusion, between these two fuel cell components have been investigated

  12. Interaction between the skyrmions LS potential of nuclear force and potential between the octet

    International Nuclear Information System (INIS)

    Investigations of the spin-orbital (LS) interaction of nuclear force in SU(2)-model are carried out. It is well-known that in LS potential is very important in nuclear force. LS potential is created by means of light π, ρ, σ and ω mesons for the pattern of meson exchange. Adiabatic potential reproduces well the property of π- and ρ-meson exchange within the Skyrme standard model. But the attraction in the intermediate region which corresponds to σ-meson exchange disappears. Adiabatic potential between the baryon octet in SU(3)-model is discussed. The advantage of Skyrme model is in the possibility to investigate systematically the properties and interactions of baryon. There are still many investigated intresting problems in baryon physics. For example interaction between nucleon and hyperon as well as problem of the existance of H-states are still open. 12 refs.; 1 fig.; 1 tab

  13. Potential disruption of protein-protein interactions by graphene oxide

    Science.gov (United States)

    Feng, Mei; Kang, Hongsuk; Yang, Zaixing; Luan, Binquan; Zhou, Ruhong

    2016-06-01

    Graphene oxide (GO) is a promising novel nanomaterial with a wide range of potential biomedical applications due to its many intriguing properties. However, very little research has been conducted to study its possible adverse effects on protein-protein interactions (and thus subsequent toxicity to human). Here, the potential cytotoxicity of GO is investigated at molecular level using large-scale, all-atom molecular dynamics simulations to explore the interaction mechanism between a protein dimer and a GO nanosheet oxidized at different levels. Our theoretical results reveal that GO nanosheet could intercalate between the two monomers of HIV-1 integrase dimer, disrupting the protein-protein interactions and eventually lead to dimer disassociation as graphene does [B. Luan et al., ACS Nano 9(1), 663 (2015)], albeit its insertion process is slower when compared with graphene due to the additional steric and attractive interactions. This study helps to better understand the toxicity of GO to cell functions which could shed light on how to improve its biocompatibility and biosafety for its wide potential biomedical applications.

  14. Finite-range model potentials for resonant interactions

    Science.gov (United States)

    Deb, Bimalendu

    2016-03-01

    We show that it is possible to model two-body resonant interactions at low energy with a class of finite-range potentials based on the methods of Jost and Kohn. These potentials are expressed in terms of the effective range r0 and the s-wave scattering length as. We derive continuum solutions of these potentials. By writing V±(r) = V0(r) + V±ɛ(r), where the sign + (‑) refers to positive(negative) scattering length, V0(r) is of the form of Pöschl-Teller potential and V±ɛ is expressed as a power series of the small parameter ɛ = (1 ‑ 2r0 /as)‑1 ‑ 1 when as is large, we derive Green’s function of V0(r). Using the Green’s function, solutions of V±(r) for |as|≫ r0 can be obtained numerically by treating V±ɛ(r) as a perturbation. We describe the threshold behavior of scattering phase shift for V0(r). This study may be important for developing a better understanding of physics of strongly interacting ultracold atomic gases with tunable interactions.

  15. Interaction Potential between Parabolic Rotator and an Outside Particle

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2014-01-01

    Full Text Available At micro/nanoscale, the interaction potential between parabolic rotator and a particle located outside the rotator is studied on the basis of the negative exponential pair potential 1/Rn between particles. Similar to two-dimensional curved surfaces, we confirm that the potential of the three-dimensional parabolic rotator and outside particle can also be expressed as a unified form of curvatures; that is, it can be written as the function of curvatures. Furthermore, we verify that the driving forces acting on the particle may be induced by the highly curved micro/nano-parabolic rotator. Curvatures and the gradient of curvatures are the essential elements forming the driving forces. Through the idealized numerical experiments, the accuracy of the curvature-based potential is preliminarily proved.

  16. Cosmological solutions in string theory with dilaton self interaction potential

    CERN Document Server

    Mora, C

    2003-01-01

    In this work we present homogeneous and isotropic cosmological solutions for the low energy limit of string theory with a self interacting potential for the scalar field. For a potential that is a linear combination of two exponential, a family of exact solutions are found for the different spatial curvatures. Among this family a non singular accelerating solution for positive curvature is singled out and the violation of the energy conditions for that solution is studied, and also its astrophysical consequences. The string coupling for this solution is finite. (Author)

  17. Cosmological solutions in string theory with dilaton self interaction potential

    International Nuclear Information System (INIS)

    In this work we present homogeneous and isotropic cosmological solutions for the low energy limit of string theory with a self interacting potential for the scalar field. For a potential that is a linear combination of two exponential, a family of exact solutions are found for the different spatial curvatures. Among this family a non singular accelerating solution for positive curvature is singled out and the violation of the energy conditions for that solution is studied, and also its astrophysical consequences. The string coupling for this solution is finite. (Author)

  18. Potential interaction and potential investigation of science center exhibits and visitors' interest

    Science.gov (United States)

    Busque, Laurier

    This research consisted of studying the characteristics of interaction and investigation potential present in museum or science center exhibits. Categories (strong and weak) for the characteristics of interaction potential and investigation potential were established. Fifteen exhibits were chosen from the Museum of Science (Ottawa) and from two science centers (Sudbury and Toronto); these were representative of the established characteristics and categories. A test was constructed that measured the interest in an exhibit in a museum or a science center. The final analysis of the test (20 items) reflects a coefficient of homogeneity (Cronbach alpha) of 0.97 (n = 278). In terms of the characteristics of interaction potential and investigation potential, a significant difference among the ranks of interest was not found once they were regrouped under the categories of strong and weak. The hypothesis of a relationship between the interaction potential and visitors' interest in an exhibit in a museum or science center and the hypothesis of a relationship between the investigation potential and the interest aroused were both rejected. In regards to the interaction potential, median ranks of interest in exhibits of 8.6 for the strong category and of 7.5 for the weak category were observed. In terms of the investigation potential, median ranks of interest of 7.0 for the strong category and of 9.1 for the weak category were observed. In the case of investigation potential, even if the difference is not significant, there is an indication that the strong investigation potential seems to have the effect of creating disinterest in the presentation of an exhibit in a museum or in a science center. In the context of new museum and science centers, the view of developing exhibits which are primarily objects which stimulate interest must be maintained. If this is done with exhibits that arc interactive and have an investigative approach, it is necessary for those in charge of

  19. Measuring three-dimensional interaction potentials using optical interference

    OpenAIRE

    Mojarad, Nassiredin; Sandoghdar, Vahid; Krishnan, Madhavi

    2013-01-01

    We describe the application of three-dimensional (3D) scattering interferometric (iSCAT) imaging to the measurement of spatial interaction potentials for nano-objects in solution. We study electrostatically trapped gold particles in a nanofluidic device and present details on axial particle localization in the presence of a strongly reflecting interface. Our results demonstrate high-speed (~kHz) particle tracking with subnanometer localization precision in the axial and average 2.5 nm in the ...

  20. The interaction time of a packet with a potential barrier

    International Nuclear Information System (INIS)

    They study the evolution of a wave packet impinging onto a one-dimensional potential barrier. The transmission and reflection times discussed in the literature for stationary states do not correspond to the times required for the emergence of a transmitted or a reflected packet. They propose new definitions for the interaction time and the transmission and reflection times which are suitable for packets and fit better the actual time evolution of the packet

  1. POTENTIALS OF INTERACTIVE TEACHING TECHNIQUES TO TRAIN EXPERTS IN PHARMACY

    Directory of Open Access Journals (Sweden)

    A. V. Krikova

    2016-01-01

    Full Text Available Various interactive teaching methods and techniques are extensively used in modern higher schools. Their implementation is considered to be one of the most significant and efficient ways to improve quality of pharmaceutical professional training. Efficiency of these interactive techniques applied at the Department of Economics and Management of Pharmaceutical Business of Smolensk State Medical University has been comprehensively investigated and assessed. Obtained results are presented in the paper, as well as students’ survey data as consumers of educational services. Fifth year full-time students were involved into the study. Students’ awareness on potentials and significance of applied interactive teaching methods, as well as their interest in innovative forms to gain professional knowledge comprised 93.3%. Potentials of interactive techniques to teach students to deal with a diversity of real life practical professional tasks and problems are particularly emphasized in the study (86.7% students.

  2. Asynchronous Variational Integration of Interaction Potentials for Contact Mechanics

    CERN Document Server

    Vouga, Etienne; Tamstorf, Rasmus; Grinspun, Eitan

    2009-01-01

    Asynchronous Variational Integrators (AVIs) have demonstrated long-time good energy behavior. It was previously conjectured that this remarkable property is due to their geometric nature: they preserve a discrete multisymplectic form. Previous proofs of AVIs' multisymplecticity assume that the potentials are of an elastic type, i.e., specified by volume integration over the material domain, an assumption violated by interaction-type potentials, such as penalty forces used to model mechanical contact. We extend the proof of AVI multisymplecticity, showing that AVIs remain multisymplectic under relaxed assumptions on the type of potential. The extended theory thus accommodates the simulation of mechanical contact in elastica (such as thin shells) and multibody systems (such as granular materials) with no drift of conserved quantities (energy, momentum) over long run times, using the algorithms in [3]. We present data from a numerical experiment measuring the long time energy behavior of simulated contact, compa...

  3. Gender differences, polypharmacy, and potential pharmacological interactions in the elderly

    Directory of Open Access Journals (Sweden)

    Carina Duarte Venturini

    2011-01-01

    Full Text Available OBJECTIVE: This study aims to analyze pharmacological interactions among drugs taken by elderly patients and their age and gender differences in a population from Porto Alegre, Brazil. METHODS: We retrospectively analyzed the database provided by the Institute of Geriatric and Gerontology, Porto Alegre, Brazil. The database was composed of 438 elderly and includes information about the patients' disease, therapy regimens, utilized drugs. All drugs reported by the elderly patients were classified using the Anatomical Therapeutic and Chemical Classification System. The drug-drug interactions and their severity were assessed using the Micromedex® Healthcare Series. RESULTS: Of the 438 elderly patients in the data base, 376 (85.8% used pharmacotherapy, 274 were female, and 90.4% of females used drugs. The average number of drugs used by each individual younger than 80 years was 3.2±2.6. Women younger than 80 years old used more drugs than men in the same age group whereas men older than 80 years increased their use of drugs in relation to other age groups. Therefore, 32.6% of men and 49.2% of women described at least one interaction, and 8.1% of men and 10.6% of women described four or more potential drug-drug interactions. Two-thirds of drug-drug interactions were moderate in both genders, and most of them involved angiotensin-converting enzyme inhibitor, non-steroidal anti-inflammatory, loop and thiazide diuretics, and β-blockers. CONCLUSION: Elderly patients should be closely monitored, based on drug class, gender, age group and nutritional status.

  4. Microscopic positive-energy potential based on Gogny interaction

    CERN Document Server

    Blanchon, G; Arellano, H F; Mau, N Vinh

    2014-01-01

    We present nucleon elastic scattering calculation based on Green's function formalism in the Random-Phase Approximation. For the first time, the Gogny effective interaction is used consistently throughout the whole calculation to account for the complex, non-local and energy-dependent optical potential. Effects of intermediate single-particle resonances are included and found to play a crucial role in the account for measured reaction cross section. Double counting of the particle-hole second-order contribution is carefully addressed. The resulting integro-differential Schr\\"odinger equation for the scattering process is solved without localization procedures. The method is applied to neutron and proton elastic scattering from $^{40}$Ca. A successful account for differential and integral cross sections, including analyzing powers, is obtained for incident energies up to 30 MeV. Discrepancies at higher energies are related to much too high volume integral of the real potential for large partial waves. Moreover...

  5. Potential interaction between proton pump inhibitor and clopidogrel

    Directory of Open Access Journals (Sweden)

    Indra Kurniawan

    2013-02-01

    Full Text Available Clopidogrel is an anti-platelet agent commonly used in patients with atherosclerotic cardiovascular (CV disease. Although formerly considered safe, several studies reported that the use of clopidogrel may cause a significant increase in the rate of gastrointestinal (GI bleeding. This adverse effect could be minimized by coadministration of proton pump inhibitor (PPI. However, since PPI and clopidogrel share the same metabolic pathway, it has been hypothesized that the administration of PPI following clopidogrel therapy may cause a reduction in its anti-platelet effect, thereby increasing the risk of CV events. Recent studies found no significant inhibition in the activation of clopidogrel by CYP2C19 with administration of PPI in vitro. Pharmacokinetic and pharmacodynamic studies, as well as clinical studies, reported conflicting results regarding the potential interaction between PPI and clopidogrel. Until now, the available study investigated the PPI-clopidogrel interaction are primarily observational. The COGENT study is the only prospective, placebo-controlled trial examined the PPI-clopidogrel interaction. This study revealed no significant increase in CV events in patients receiving PPI following clopidogrel therapy, compared to the control group. Though remains controversial, current expert consensus recommended the administration of PPI in patients receiving clopidogrel, particularly in high-risk patients. (Med J Indones. 2013;22:57-62Keywords: Cardiovascular, clopidogrel, gastrointestinal, proton pump inhibitor

  6. Mineral-microbe interactions: biotechnological potential of bioweathering.

    Science.gov (United States)

    Mapelli, Francesca; Marasco, Ramona; Balloi, Annalisa; Rolli, Eleonora; Cappitelli, Francesca; Daffonchio, Daniele; Borin, Sara

    2012-02-20

    Mineral-microbe interaction has been a key factor shaping the lithosphere of our planet since the Precambrian. Detailed investigation has been mainly focused on the role of bioweathering in biomining processes, leading to the selection of highly efficient microbial inoculants for the recovery of metals. Here we expand this scenario, presenting additional applications of bacteria and fungi in mineral dissolution, a process with novel biotechnological potential that has been poorly investigated. The ability of microorganisms to trigger soil formation and to sustain plant establishment and growth are suggested as invaluable tools to counteract the expansion of arid lands and to increase crop productivity. Furthermore, interesting exploitations of mineral weathering microbes are represented by biorestoration and bioremediation technologies, innovative and competitive solutions characterized by economical and environmental advantages. Overall, in the future the study and application of the metabolic properties of microbial communities capable of weathering can represent a driving force in the expanding sector of environmental biotechnology. PMID:22138043

  7. Interactions among endophytic bacteria and fungi: effects and potentials

    Indian Academy of Sciences (India)

    W M M S Bandara; Gamini Seneviratne; S A Kulasooriya

    2006-12-01

    Plants benefit extensively by harbouring endophytic microbes. They promote plant growth and confer enhanced resistance to various pathogens. However, the way the interactions among endophytes influence the plant productivity has not been explained. Present study experimentally showed that endophytes isolated from rice (Oryza sativa) used as the test plant produced two types of interactions; biofilms (bacteria attached to mycelia) and mixed cultures with no such attachments. Acidity, as measured by pH in cultures with biofilms was higher than that of fungi alone, bacteria alone or the mixed cultures. Production of indoleacetic acid like substances (IAAS) of biofilms was higher than that of mixed cultures, fungi or bacteria. Bacteria and fungi produced higher quantities of IAAS than mixed cultures. In mixed cultures, the potential of IAAS production of resident microbes was reduced considerably. There was a negative relationship between IAAS and pH of the biofilms, indicating that IAAS was the main contributor to the acidity. However, such a relationship was not observed in mixed cultures. Microbial acid production is important for suppressing plant pathogens. Thus the biofilm formation in endophytic environment seems to be very important for healthy and improved plant growth. However, it is unlikely that an interaction among endophytes takes place naturally in the endophytic environment, due to physical barriers of plant tissues. Further, critical cell density dependant quorum sensing that leads to biofilm formation may not occur in the endophytic environment as there is a limited space. As such in vitro production and application of beneficial biofilmed inocula of endophytes are important for improved plant production in any agro-ecosystem. The conventional practice of plant inoculation with monocultures or mixed cultures of effective microbes may not give the highest microbial effect, which may only be achieved by biofilm formation.

  8. Global Optocal Potential for 6He Interactions at Low Energies

    International Nuclear Information System (INIS)

    A set of global optical potential has been derived to describe the interactions of 6He nucleus at energies near the Coulomb barrier. The elastic scattering angular distribution data for many systems ranging from 12C to 209Bi have been considered within the framework of the optical model by using the derived potential set and very good agreement has been obtained between theoretical results and experimental data. In the same study, we have also attempted to understand the reason why the elastic scattering of the halo nucleus 6He from heavy targets at incident energies near the Coulomb barrier displays a deviation from the standard Fresnel-type diffraction behavior due to the strong Coulomb dipole breakup coupling produced by the Coulomb field of the heavy target. In order to address this problem, we have also performed Continuum Discretized Coupled Channels calculations for the elastic scattering of 6He on 12C, 68Ni, 120Sn, 144Sm and 184Ta targets in order to determine the range of ZT where these large breakup coupling effect begins to be dominant. In our calculations, we find that the strong Coulomb dipole breakup coupling effect starts to be seen at around ZT=60.(author)

  9. Asymptotic near-nucleus structure of the electron-interaction potential in local effective potential theories

    International Nuclear Information System (INIS)

    In local effective potential theories of electronic structure, the electron correlations due to the Pauli exclusion principle, Coulomb repulsion, and correlation-kinetic effects, are all incorporated in the local electron-interaction potential vee(r). In previous work, it has been shown that for spherically symmetric or sphericalized systems, the asymptotic near-nucleus expansion of this potential is vee(r)=vee(0)+βr+O(r2), with vee(0) being finite. By assuming that the Schroedinger and local effective potential theory wave functions are analytic near the nucleus of atoms, we prove the following via quantal density functional theory (QDFT): (i) Correlations due to the Pauli principle and Coulomb correlations do not contribute to the linear structure; (ii) these Pauli and Coulomb correlations contribute quadratically; (iii) the linear structure is solely due to correlation-kinetic effects, the contributions of these effects being determined analytically. We also derive by application of adiabatic coupling constant perturbation theory via QDFT (iv) the asymptotic near-nucleus expansion of the Hohenberg-Kohn-Sham theory exchange vx(r) and correlation vc(r) potentials. These functions also approach the nucleus linearly with the linear term of vx(r) being solely due to the lowest-order correlation kinetic effects, and the linear term of vc(r) being due solely to the higher-order correlation kinetic contributions. The above conclusions are equally valid for systems of arbitrary symmetry, provided spherical averages of the properties are employed

  10. Commercially available interactive video games in burn rehabilitation: therapeutic potential.

    Science.gov (United States)

    Parry, Ingrid S; Bagley, Anita; Kawada, Jason; Sen, Soman; Greenhalgh, David G; Palmieri, Tina L

    2012-06-01

    Commercially available interactive video games (IVG) like the Nintendo Wii™ (NW) and PlayStation™II Eye Toy (PE) are increasingly used in the rehabilitation of patients with burn. Such games have gained popularity in burn rehabilitation because they encourage range of motion (ROM) while distracting from pain. However, IVGs were not originally designed for rehabilitation purposes but rather for entertainment and may lack specificity for achieving rehabilitative goals. Objectively evaluating the specific demands of IVGs in relation to common burn therapy goals will determine their true therapeutic benefit and guide their use in burn rehabilitation. Upper extremity (UE) motion of 24 normal children was measured using 3D motion analysis during play with the two types of IVGs most commonly described for use after burn: NW and PE. Data was analyzed using t-tests and One-way Analysis of Variance. Active range of motion for shoulder flexion and abduction during play with both PE and NW was within functional range, thus supporting the idea that IVGs offer activities with therapeutic potential to improve ROM. PE resulted in higher demands and longer duration of UE motion than NW, and therefore may be the preferred tool when UE ROM or muscular endurance are the goals of rehabilitation. When choosing a suitable IVG for application in rehabilitation, the user's impairment together with the therapeutic attributes of the IVG should be considered to optimize outcome. PMID:22385641

  11. Induced gravity with Higgs potential. Elementary interactions and quantum processes

    Energy Technology Data Exchange (ETDEWEB)

    Bezares Roder, Nils Manuel

    2010-07-01

    This work is intended to first serve as introduction in fundamental subjects of physics in order to be then able to review the mechanism of symmetry breakdown and its essential character in physics. It introduces the concept of scalar-tensor theories of gravity based on Bergmann-Wagoner models with a Higgs potential. The main physical context aimed is the problem of Dark Matter and Dark Energy. On the one hand, there is gravitation. Within this context, we have Dark Matter as an especially relevant concept. This work entails the following main contributions: - General features of Einstein's theory are introduced together with generalities of the different elementary interactions of physics from which the concepts of dark sectors and Higgs Mechanism are derived. - The concept of symmetry breaking and especially the Higgs Mechanism of mass generation are discussed in their relevance for the most different subjects of physics, especially in relation to the Standard Model of elementary particle physics with elementary Higgs fields. - Scalar-Tensor Theories are introduced in order to build in them the process of Higgs Mechanism. This is then fulfilled with a theory of induced gravity with a Higgs potential which seems renormalizable according to deWitt's power counting criterion, and with mass-generating Higgs fields which only couple gravitationally as well as with Higgs fields which act analogously to cosmon fields. - Further, the energy density of the gravitational field is derived for the specific model of induced gravity from an analogy to electrodynamics. It is shown that a nonvanishing value of pressure related to the scalar field is necessary in order to reproduce standard linear solar-relativistic dynamics. Within astrophysical considerations for flat rotation curves of galaxies, a possible dark-matter behavior is concluded within spherical symmetry. The scalar field and the dark-matter profile of total energy density are derived. An analogous

  12. Induced gravity with Higgs potential. Elementary interactions and quantum processes

    International Nuclear Information System (INIS)

    This work is intended to first serve as introduction in fundamental subjects of physics in order to be then able to review the mechanism of symmetry breakdown and its essential character in physics. It introduces the concept of scalar-tensor theories of gravity based on Bergmann-Wagoner models with a Higgs potential. The main physical context aimed is the problem of Dark Matter and Dark Energy. On the one hand, there is gravitation. Within this context, we have Dark Matter as an especially relevant concept. This work entails the following main contributions: - General features of Einstein's theory are introduced together with generalities of the different elementary interactions of physics from which the concepts of dark sectors and Higgs Mechanism are derived. - The concept of symmetry breaking and especially the Higgs Mechanism of mass generation are discussed in their relevance for the most different subjects of physics, especially in relation to the Standard Model of elementary particle physics with elementary Higgs fields. - Scalar-Tensor Theories are introduced in order to build in them the process of Higgs Mechanism. This is then fulfilled with a theory of induced gravity with a Higgs potential which seems renormalizable according to deWitt's power counting criterion, and with mass-generating Higgs fields which only couple gravitationally as well as with Higgs fields which act analogously to cosmon fields. - Further, the energy density of the gravitational field is derived for the specific model of induced gravity from an analogy to electrodynamics. It is shown that a nonvanishing value of pressure related to the scalar field is necessary in order to reproduce standard linear solar-relativistic dynamics. Within astrophysical considerations for flat rotation curves of galaxies, a possible dark-matter behavior is concluded within spherical symmetry. The scalar field and the dark-matter profile of total energy density are derived. An analogous relation between

  13. Anticoagulant Medicine: Potential for Drug-Food Interactions

    Science.gov (United States)

    ... AerobiKa® Cardiology Medications Anticoagulant Medicine Anticoagulants and Drug-Food Interactions COPD Medications Bronchodilators Anti-Inflammatories Antibiotics Managing Your Medications Devices ...

  14. Effective potentials for atom-atom interaction at low temperatures

    OpenAIRE

    Gao, Bo

    2002-01-01

    We discuss the concept and design of effective atom-atom potentials that accurately describe any physical processes involving only states around the threshold. The existence of such potentials gives hope to a quantitative, and systematic, understanding of quantum few-atom and quantum many-atom systems at relatively low temperatures.

  15. The Stability of Icosahedral Cluster and the Range of Interaction Potential

    Institute of Scientific and Technical Information of China (English)

    DING Feng; WANG Jin-Lan; SHEN Wei-Feng; WANG Bao-Lin; LI Hui; WANG Guang-Hou

    2001-01-01

    The relation between the stability of icosahedral clusters and the range of interaction potential is discussed.We found that the stability of icosahedral clusters nay decrease with decreasing range of interaction potential. A simple formula about the critical number of icosahedral clusters and the range of interaction potential (M1/3c = A1 + A2r2eff)was proposed. The calculation of the stability of icosahedral fullerence molecular clusters shows that our idea is right.``

  16. Studies on pharmacokinetic drug interaction potential of vinpocetine

    Science.gov (United States)

    Background: Vinpocetine, a semi-synthetic derivative of vincamine, is a popular dietary supplement used for the treatment of several central nervous system related disorders. Despite its wide use, no pharmacokinetic drug interaction studies are reported in literature. Due to increasing use of dietar...

  17. Potential risk related consequences of core-concrete interactions

    International Nuclear Information System (INIS)

    In those severe-accident scenarios in which the primary vessel fails, high-temperature core debris falls into the reactor cavity where it interacts with structural concrete. This presentation outlines three aspects of core-concrete interaction analysis that must be considered in the prediction of radiological source terms: (1) the risk-related physical and chemical phenomena, (2) the NRC computer codes, CORCON and VANESA, used to predict the source-term and containment-loading parameters, and (3) possible causes of uncertainties in code predictions. Finally, to illustrate the range of problems encountered in determining code prediction uncertainties, a number of sensitivity studies and code comparisons with experimental data are reviewed

  18. MicroRNAs and potential target interactions in psoriasis

    DEFF Research Database (Denmark)

    Zibert, John R; Løvendorf, Marianne B; Litman, Thomas;

    2010-01-01

    BACKGROUND: Psoriasis is a chronic inflammatory skin disease often seen in patients with a genetic susceptibility. MicroRNAs (miRNA) are endogenous, short RNA molecules that can bind to parts of mRNA target genes, thus inhibiting their translation and causing accelerated turnover or transcript......: Biopsies were obtained from PP, PN and NN, the miRNA and mRNA expression was analyzed by microarray techniques and a subset of miRNAs and mRNAs were validated by q-RT-PCR. Novel target interactions in psoriasis were found using PubMed, miRBase and RNAhybrid. In addition, TIMP3 protein expression was...... for miRNAs in psoriasis and in particular the miR-221/2-TIMP3 target interaction could among others play a role in the psoriasis pathogenesis....

  19. Solution of the Dirac Equation for Potential Interaction

    OpenAIRE

    A. D. Alhaidari

    2002-01-01

    An effective approach for solving the three-dimensional Dirac equation for spherically symmetric local interactions, which we have introduced recently, is reviewed and consolidated. The merit of the approach is in producing Schrodinger-like equation for the spinor components that could simply be solved by correspondence with well-known exactly solvable non-relativistic problems. Taking the nonrelativistic limit will reproduce the nonrelativistic problem. The approach has been used successfull...

  20. Gender differences, polypharmacy, and potential pharmacological interactions in the elderly

    OpenAIRE

    Carina Duarte Venturini; Paula Engroff; Luísa Scheer Ely; Luísa Faria de Araújo Zago; Guilherme Schroeter; Irenio Gomes; Geraldo Attilio De Carli,; Fernanda Bueno Morrone

    2011-01-01

    OBJECTIVE: This study aims to analyze pharmacological interactions among drugs taken by elderly patients and their age and gender differences in a population from Porto Alegre, Brazil. METHODS: We retrospectively analyzed the database provided by the Institute of Geriatric and Gerontology, Porto Alegre, Brazil. The database was composed of 438 elderly and includes information about the patients' disease, therapy regimens, utilized drugs. All drugs reported by the elderly patients were classif...

  1. Theoretical studies of interaction potential and scattering cross section for He-CO system

    International Nuclear Information System (INIS)

    A new anisotropic interaction potential surface be fitted for He-CO system according to Maitland-Smith(MS) potential model. The scattering cross sections for the collision of CO with ground-state helium atom have been calculated by employing the fitting potential surface at collision energy of 27.7 meV. The results of the calculation indicate that the fitting potential surface can describe exactly the characteristic of interaction between CO and He. (authors)

  2. The fusion of heavy ions in an interaction potential model

    International Nuclear Information System (INIS)

    The paper contains the problems connected with fusion processes in heavy ions collision. Results of experimental fusion data for reactions: 9Be + 12C, 6Li + 28Si, 9Be + 28Si, 12C + 28Si, 12C + 16O and 16O + 16O are presented. Comparison of measured fusion cross sections with predictions of the fusion potential model have been made. The validity of this model for both light systems, like 9Be + 12C and heavy systems, like 35Cl + 62Ni, have been discussed. In conclusion, it should be stated that fusion cross sections could be correctly predicted by the potential model with a potential describing the elastic scattering data. (author)

  3. A MOLECULAR-DYNAMICS STUDY OF B2O3 GLASS USING DIFFERENT INTERACTION POTENTIALS

    NARCIS (Netherlands)

    VERHOEF, AH; DENHARTOG, HW

    1992-01-01

    Molecular dynamics calculations of B2O3 glass were carried out, using seven different interaction potential schemes. Two-body Born-Mayer-Huggins potentials and in some samples a[so three-body bond-angle interactions were applied. Structural and dynamical properties of the simulated systems were eval

  4. A constructive model potential method for atomic interactions

    Science.gov (United States)

    Bottcher, C.; Dalgarno, A.

    1974-01-01

    A model potential method is presented that can be applied to many electron single centre and two centre systems. The development leads to a Hamiltonian with terms arising from core polarization that depend parametrically upon the positions of the valence electrons. Some of the terms have been introduced empirically in previous studies. Their significance is clarified by an analysis of a similar model in classical electrostatics. The explicit forms of the expectation values of operators at large separations of two atoms given by the model potential method are shown to be equivalent to the exact forms when the assumption is made that the energy level differences of one atom are negligible compared to those of the other.

  5. A simple contact mapping algorithm for identifying potential peptide mimetics in protein–protein interaction partners

    OpenAIRE

    Krall, Alex; Brunn, Jonathan; Kankanala, Spandana; Michael H. Peters

    2014-01-01

    A simple, static contact mapping algorithm has been developed as a first step at identifying potential peptide biomimetics from protein interaction partner structure files. This rapid and simple mapping algorithm, “OpenContact” provides screened or parsed protein interaction files based on specified criteria for interatomic separation distances and interatomic potential interactions. The algorithm, which uses all-atom Amber03 force field models, was blindly tested on several unrelated cases f...

  6. Technological Dangers and the Potential of Human-Robot Interaction

    DEFF Research Database (Denmark)

    Nørskov, Marco

    positioning with regard to HRI. It is argued that the process itself is an artifact with moral significance, and consequently tantamount to discrimination. Furthermore, influenced by Heidegger’s warnings concerning technology, this chapter explores the possibilities of HRI with respect to the accompanying...... technological dangers and opportunities. Finally, aiming for the very limits of the theory, I discuss the contours of a praxis facilitating being-with-robots beyond conceptualization. Basically, this mode of being, pertaining to non-technological HRI, bypasses Heidegger’s warnings, and potentially facilitates a...... certain kind of self-realization for the human involved....

  7. Correlations between potentials and observables in the NN interaction

    Science.gov (United States)

    Pauss, F.; Mathelitsch, L.; Côté, J.; Lacombe, M.; Loiseau, B.; Vinh Mau, R.

    1981-08-01

    We study the effects of the components of the soft-core and velocity-dependent Paris nucleon-nucleon potential on the scattering observables for laboratory energies, TL, between 10 and 350 MeV. Knowledge of these correlations is useful to indicate constraints on components of the nucléon-nucléon force. The velocity-dependent component, attractive at low energy and repulsive at high energy, plays a role at all energies. The polarisation P, the depolarisation D and the parameters Dt, A, R, CKP and CNN are good tests for the tensor, spin-orbit and, to a smaller extent, quadratic spin-orbit forces. The isovector tensor force contribution is important at low energy and that of the isovector spin-orbit at high energy. The isoscalar tensor force effect is large at all energies and that of the isoscalar spin-orbit force rather small. The potential without quadratic spin-orbit term reproduces well the experimental data for TL < 150 MeV.

  8. No enhancement of the localization length for two interacting particles in a random potential

    OpenAIRE

    Römer, R. A.; Schreiber, M.

    1998-01-01

    We study two interacting particles in a random potential chain by means of the transfer matrix method. The dependence of the two-particle localization length $\\lambda_2$ on disorder and interaction strength is investigated. Our results demonstrate that the recently proposed enhancement of $\\lambda_2$ as compared to the results for single particles is entirely due to the finite size of the systems considered. This is shown for a Hubbard-like onsite interaction and also a long-range interaction.

  9. Dactinomycin potentiation of radiation pneumonitis: A forgotten interaction

    International Nuclear Information System (INIS)

    No mention of dactinomycin potentiation of pulmonary radiation was found in a review of the literature of the past 12 years. Before that, this complication was well described and investigators had calculated that dactinomycin increased the toxic effect of lung radiation by a factor of 1.3 and reduced the radiation tolerance of the lung by at least 20%. An example of such a toxic effect is described in the treatment of a 7-year-old girl with lung metastases from Ewing's sarcoma. The chemotherapy protocol followed contained cyclophosphamide, vincristine, dactinomycin, adriamycin, cisplatinum, VP16, and radiotherapy. The treatment was associated with fatal pulmonary fibrosis following the reintroduction of dactinomycin after radiotherapy. The authors experience suggests that there is clinical significance to this complication in sarcoma therapy when dactinomycin-containing protocols are used with radiation in the treatment of pulmonary metastases. 20 references

  10. Orchid-pollinator interactions and potential vulnerability to biological invasion.

    Science.gov (United States)

    Chupp, Adam D; Battaglia, Loretta L; Schauber, Eric M; Sipes, Sedonia D

    2015-01-01

    an indirect threat to plant-pollinator interactions. PMID:26286221

  11. Evaluation of a Potential Clinical Interaction between Ceftriaxone and Calcium▿

    Science.gov (United States)

    Steadman, Emily; Raisch, Dennis W.; Bennett, Charles L.; Esterly, John S.; Becker, Tischa; Postelnick, Michael; McKoy, June M.; Trifilio, Steve; Yarnold, Paul R.; Scheetz, Marc H.

    2010-01-01

    In April 2009, the FDA retracted a warning asserting that ceftriaxone and intravenous calcium products should not be coadministered to any patient to prevent precipitation events leading to end-organ damage. Following that announcement, we sought to evaluate if the retraction was justified. A search of the FDA Adverse Event Reporting System was conducted to identify any ceftriaxone-calcium interactions that resulted in serious adverse drug events. Ceftazidime-calcium was used as a comparator agent. One hundred four events with ceftriaxone-calcium and 99 events with ceftazidime-calcium were identified. Adverse drug events were recorded according to the listed description of drug involvement (primary or secondary suspect) and were interpreted as probable, possible, unlikely, or unrelated. For ceftriaxone-calcium-related adverse events, 7.7% and 20.2% of the events were classified as probable and possible for embolism, respectively. Ceftazidime-calcium resulted in fewer probable embolic events (4%) but more possible embolic events (30.3%). Among cases that considered ceftriaxone or ceftazidime and calcium as the primary or secondary drug, one case was classified as a probable embolic event. That patient received ceftriaxone-calcium and died, although an attribution of causality was not possible. Our analysis suggests a lack of support for the occurrence of ceftriaxone-calcium precipitation events in adults. The results of the current analysis reinforce the revised FDA recommendations suggesting that patients >28 days old may receive ceftriaxone and calcium sequentially and provide a transparent and reproducible methodology for such evaluations. PMID:20086152

  12. Membrane interactions of synthetic peptides with antimicrobial potential: effect of electrostatic interactions and amphiphilicity.

    Science.gov (United States)

    Fillion, Matthieu; Valois-Paillard, Geneviève; Lorin, Aurélien; Noël, Mathieu; Voyer, Normand; Auger, Michèle

    2015-03-01

    Cationic antimicrobial peptides are considered promising candidates to complement currently used antibiotics, which are less effective against increasingly resistant pathogens. To determine the mechanism of action of these peptides, a better understanding of each molecular determinant involved in their membrane interactions is of great importance. In this study, we have focused on the role of electrostatic interactions and amphiphilicity on the membrane interactions since the large majority of natural antimicrobial peptides are cationic. Therefore, cationic and anionic peptides have been prepared based on a model 14-mer peptide. The latter is a synthetic peptide composed of ten leucines and four phenylalanines, which are modified by the addition of the crown ether. Infrared spectroscopy results indicate that the position of substitution is the main determinant involved in the secondary structure adopted by the peptides, and not the charge of the substituted residues. Fluorescence vesicle leakage assays indicate, however, differences between the ability of cationic and anionic peptides to induce calcein release in zwitterionic and anionic lipid vesicles, suggesting an importance of electrostatic interactions and repulsions. Finally, (31)P NMR results indicate that the vesicle morphologies is not significantly affected by the interactions with both cationic and anionic peptides but that their effect on lipid bilayers is mainly determined by their secondary structure. This study therefore indicates that the membrane interactions of model 14-mer peptides are mainly governed by their secondary structure, which depends on the position of substitution, and not the charge of the residues. PMID:25422123

  13. Expanding Interaction Potentials within Virtual Environments: Investigating the Usability of Speech and Manual Input Modes for Decoupled Interaction

    OpenAIRE

    Alex Stedmon; Victor Bayon; Gareth Griffiths

    2011-01-01

    Distributed technologies and ubiquitous computing now support users who may be detached or decoupled from traditional interactions. In order to investigate the potential usability of speech and manual input devices, an evaluation of speech input across different user groups and a usability assessment of independent-user and collaborative-user interactions was conducted. Whilst the primary focus was on a formative usability evaluation, the user group evaluation provided a formal basis to under...

  14. Effective potentials in concentrated colloid-polymer mixtures with competing interactions

    Science.gov (United States)

    Laurati, Marco; Valadez Perez, Nestor; Capellmann, Ronja; Egelhaaf, Stefan; Castañeda-Priego, Ramon

    We determine the effective potentials describing the interactions between colloidal particles in concentrated colloid-polymer mixtures in which depletion attraction competes with electrostatic repulsion. To obtain the potentials, the method of Monte-Carlo inversion is applied to experimental pair distribution functions obtained by confocal microscopy. Both fluid and gel states are investigated. We compare the results of the inversion method with those obtained by describing the interactions using a combination of a square well potential for the attractive component and a Yukawa potential for the repulsive component. This allows us to test the validity range of the one-component pair-potential.

  15. Phase transition of strongly interacting matter with a chemical potential dependent Polyakov loop potential

    Science.gov (United States)

    Shao, Guo-yun; Tang, Zhan-duo; Di Toro, Massimo; Colonna, Maria; Gao, Xue-yan; Gao, Ning

    2016-07-01

    We construct a hadron-quark two-phase model based on the Walecka-quantum hadrodynamics and the improved Polyakov-Nambu-Jona-Lasinio (PNJL) model with an explicit chemical potential dependence of Polyakov loop potential (μ PNJL model). With respect to the original PNJL model, the confined-deconfined phase transition is largely affected at low temperature and large chemical potential. Using the two-phase model, we investigate the equilibrium transition between hadronic and quark matter at finite chemical potentials and temperatures. The numerical results show that the transition boundaries from nuclear to quark matter move towards smaller chemical potential (lower density) when the μ -dependent Polyakov loop potential is taken. In particular, for charge asymmetric matter, we compute the local asymmetry of u , d quarks in the hadron-quark coexisting phase, and analyze the isospin-relevant observables possibly measurable in heavy-ion collision (HIC) experiments. In general new HIC data on the location and properties of the mixed phase would bring relevant information on the expected chemical potential dependence of the Polyakov loop contribution.

  16. On the theory of interaction potentials in ionic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, Roberto [Departamento de Ciencia de los Materiales, Facultad de Ciencias Fisicas y Matematicas, Beauchef 850, Santiago (Chile); Soto-Bubert, Andres [Instituto de Ciencias Basicas, Facultad de Ingenieria, Universidad Diego Portales, Avenida Ejercito 441, Santiago (Chile)], E-mail: roberto.acevedo@umayor.cl

    2008-11-01

    The aim of this research work is to report a more comprehensive and detailed study of both, the intermolecular and intramolecular potencial functions with reference to the various families of the elpasolite type crystals. The cohesive energy has been thought as a sum of three terms; the long range (Coulombic), the Born and the van der Waals contributions to the total energy. The Born-Mayer-Buckingham potential{sup 1} has been employed in all of these current studies and a number of convergence tests are analyzed from a formal viewpoint. Our work has been focused to the following systems: Cs{sub 2}NaLnF{sub 6}, Cs{sub 2}NaLnCl{sub 6}, Cs{sub 2}NaLnBr{sub 6}, Rb{sub 2}NaLnF{sub 6} and Cs{sub 2}KLnF{sub 6} in the Fm3m space group. A substantial amount of theoretical models have been analyzed and several computing simulations have been undertaken to estimate the reticular energies and the corresponding heat of formation for these crystals. To achieve this goal, a Born-Haber thermodynamic cycle has been introduced in our model. It is shown that the calculated energy values are reasonable and follow the expected trend along the lanthanide series in the periodic chart. We also discuss the advantages and disadvantages of the current and proposed generalized model. The most likely sources for improvement are discussed in detail. New convergence tests as well as some master equations have been introduced to study the various diagonal contributions to the total energy.

  17. Controlling Soliton Collisions of Condensates by Time-Dependence of Both Interactions and External Potential

    Institute of Scientific and Technical Information of China (English)

    何章明; 王登龙; 丁建文; 颜晓红

    2012-01-01

    Considering time-dependence of both interactions and external potential,we analytically study the collisional behaviors of two bright solitons in Bose-Einstein condensates by using Darboux transformation.It is found that for a closed external potential,the soliton-soliton distance is decreased with nonlinearly increased interactions,while the amplitude of each soliton increases and its width decreases.For linearly increased interactions but nonlinearly decreased external potential,especially,the atom transfer between two solitons is observed,different from previous theory of no atom transfer in solitons collision in a fixed external potential.In addition,it is shown that the collisional type,such as head-on,"chase",or collision period between two solitons,can be controlled by tuning both interactions and external potential.The predicted phenomena can be observed under the condition of the current experiments and open possibilities for future application in atoms transport.

  18. Phase transition of strongly interacting matter with a chemical potential dependent Polyakov loop potential

    CERN Document Server

    Shao, Guo-yun; Di Toro, Massimo; Colonna, Maria; Gao, Xue-yan; Gao, Ning

    2016-01-01

    We construct a hadron-quark two-phase model based on the Walecka-quantum hadrodynamics and the improved Polyakov-Nambu--Jona-Lasinio model with an explicit chemical potential dependence of Polyakov-loop potential ($\\mu$PNJL model). With respect to the original PNJL model, the confined-deconfined phase transition is largely affected at low temperature and large chemical potential. Using the two-phase model, we investigate the equilibrium transition between hadronic and quark matter at finite chemical potentials and temperatures. The numerical results show that the transition boundaries from nuclear to quark matter move towards smaller chemical potential (lower density) when the $\\mu$-dependent Polyakov loop potential is taken. In particular, for charge asymmetric matter, we compute the local asymmetry of $u, d$ quarks in the hadron-quark coexisting phase, and analyse the isospin-relevant observables possibly measurable in heavy-ion collision (HIC) experiments. In general new HIC data on the location and proper...

  19. Student Interactions with CD-ROM Storybooks: A Look at Potential Relationships between Multiple Intelligence Strengths and Levels of Interaction

    Science.gov (United States)

    Huffman, Celia A.

    2012-01-01

    This study looked at the potential relationship that may exist between students' intelligence strengths, in particular their spatial and kinesthetic strengths, and their combined cognitive and metacognitive levels of interaction with a CD-ROM storybook. The multiple intelligence strengths of a sample of students, measured via the MIDAS/My…

  20. Velocity dependence of angular distributions in gas/solid--surface collisions: Relationship to the interaction potential

    Energy Technology Data Exchange (ETDEWEB)

    Brady, J.W. Jr.; Doll, J.D.; Thompson, D.L.

    1978-10-15

    The angular and velocity distributions for gas/solid-surface collisions are examined. It is shown that the envelope of the scattered phase-space distribution is quite sensitive to the gas/surface interaction potential.

  1. Stability of stationary states of non-local equations with singular interaction potentials

    KAUST Repository

    Fellner, Klemens

    2011-04-01

    We study the large-time behaviour of a non-local evolution equation for the density of particles or individuals subject to an external and an interaction potential. In particular, we consider interaction potentials which are singular in the sense that their first derivative is discontinuous at the origin.For locally attractive singular interaction potentials we prove under a linear stability condition local non-linear stability of stationary states consisting of a finite sum of Dirac masses. For singular repulsive interaction potentials we show the stability of stationary states of uniformly bounded solutions under a convexity condition.Finally, we present numerical simulations to illustrate our results. © 2010 Elsevier Ltd.

  2. Potential of the neutron lloyd's mirror interferometer for the search for new interactions

    Energy Technology Data Exchange (ETDEWEB)

    Pokotilovski, Yu. N., E-mail: pokot@nf.jinr.ru [Joint Institute for Nuclear Research (Russian Federation)

    2013-04-15

    We discuss the potential of the neutron Lloyd's mirror interferometer in a search for new interactions at small scales. We consider three hypothetical interactions that may be tested using the interferometer. The chameleon scalar field proposed to solve the enigma of accelerating expansion of the Universe produces interaction between particles and matter. The axion-like spin-dependent coupling between a neutron and nuclei or/and electrons may result in a P- and T-noninvariant interaction with matter. Hypothetical non-Newtonian gravitational interactions mediates an additional short-range potential between neutrons and bulk matter. These interactions between the neutron and the mirror of a Lloyd-type neutron interferometer cause a phase shift of neutron waves. We estimate the sensitivity and systematic effects of possible experiments.

  3. Potential of the neutron Lloyd's mirror interferometer for the search for new interactions

    CERN Document Server

    Pokotilovski, Yu N

    2013-01-01

    We discuss the potential of the neutron Lloyd's mirror interferometer in a search for new interactions at small scales. We consider three hypothetical interactions that may be tested using the interferometer. The chameleon scalar field proposed to solve the enigma of accelerating expansion of the Universe produces interaction between particles and matter. The axion-like spin-dependent coupling between neutron and nuclei or/and electrons may cause P- and T-non-invariant interaction with matter. Hypothetical non-Newtonian gravitational interactions mediates additional short-range potential between neutrons and bulk matter. These interactions between the neutron and the mirror of the Lloyd's type neutron interferometer cause phase shift of neutron waves. We estimate the sensitivity and systematic effects of possible experiments.

  4. Peculiar features of the interaction potential between hydrogen and antihydrogen at intermediate separations

    Institute of Scientific and Technical Information of China (English)

    Lee Teck-Ghee; Wong Cheuk-Yin; Wang Lee-Shien

    2008-01-01

    This paper evaluates the interaction potential between a hydrogen and an antihydrogen using the second-order perturbation theory within the framework of the four-body system in a separable two-body basis. It finds that the H-H interaction potential possesses the peculiar features of a shallow local minimum located around interatomic separations of r ~ 6a.u. and a barrier rising at r<~ 5a.u.

  5. Nuclear Physics without High-Momentum Potentials: Direct Construction of the Effective Interaction from Scattering Observables

    CERN Document Server

    McElvain, Kenneth S

    2016-01-01

    The standard approach to nuclear physics encodes phase shift information in an NN potential, then decodes that information in forming an effective interaction, appropriate to a low-momentum Hilbert space. Here we show that it is instead possible to construct the effective interaction directly from continuum phase shifts and mixing angles, eliminating all reference to a high momentum potential. The theory is rapidly convergent and well behaved, yielding sub-keV accuracy.

  6. Potential of Drug Interactions among Hospitalized Cancer Patients in a Developing Country

    OpenAIRE

    Tavakoli-Ardakani, Maria; Kazemian, Kaveh; Salamzadeh, Jamshid; Mehdizadeh, Mahshid

    2013-01-01

    Cancer patients are more susceptible to adverse drug-drug interactions (DDIs) due to receiving multiple medications especially chemotherapy medications, hormonal agents and supportive care drugs. The aim of this study is to describe the prevalence of potential DDIs and to identify risk factors for these potential interactions in hospitalized cancer patients in a developing country. A cross-sectional study conducted by reviewing charts of 224 consecutive in hospitalized patients in hematology-...

  7. Spin and Pseudospin Symmetries of Hellmann Potential with Three Tensor Interactions Using Nikiforov-Uvarov Method

    Science.gov (United States)

    Akpan, N. Ikot; Hassan, Hassanabadi; Tamunoimi, M. Abbey

    2015-12-01

    The Dirac equation with Hellmann potential is presented in the presence of Coulomb-like tensor (CLT), Yukawa-like tensor (YLT), and Hulthen-type tensor (HLT) interactions by using Nikiforov-Uvarov method. The bound state energy spectra and the radial wave functions are obtained approximately within the framework of spin and pseudospin symmetries limit. We have also reported some numerical results and figures to show the effects of the tensor interactions. Special cases of the potential are also discussed.

  8. Potential drug interactions : exposure and management in hospital and ambulatory settings

    OpenAIRE

    Indermitte, Jörg Lorenz

    2006-01-01

    Health care professionals are responsible to ensure safe dispensing and use of drug regimens involving the use of drug combinations that may interact and cause serious adverse events. In the last 40 years an enormous amount of data on drug interactions has been published. But, although potential drug interactions are probably common only few of them manifest serious adverse events and often only in predisposed patients. Therefore, health care professionals feel inundated with h...

  9. Dirac Hamiltonian with Coulomb potential and spherically symmetric shell contact interaction

    International Nuclear Information System (INIS)

    Spherically symmetric Hamiltonians describing a Dirac particle in Coulomb potential combined with contact interaction on a sphere (typically, a δ-shell interaction) are constructed. The point spectrum is studied numerically for the case of scalar δ-shell. A comparison of two possible definitions of δ-shell coupling constants is also given. 17 refs.; 3 figs

  10. Reactive Boundary Conditions as Limits of Interaction Potentials for Brownian and Langevin Dynamics

    CERN Document Server

    Chapman, S Jonathan; Isaacson, Samuel A

    2015-01-01

    A popular approach to modeling bimolecular reactions between diffusing molecules is through the use of reactive boundary conditions. One common model is the Smoluchowski partial absorption condition, which uses a Robin boundary condition in the separation coordinate between two possible reactants. This boundary condition can be interpreted as an idealization of a reactive interaction potential model, in which a potential barrier must be surmounted before reactions can occur. In this work we show how the reactive boundary condition arises as the limit of an interaction potential encoding a steep barrier within a shrinking region in the particle separation, where molecules react instantly upon reaching the peak of the barrier. The limiting boundary condition is derived by the method of matched asymptotic expansions, and shown to depend critically on the relative rate of increase of the barrier height as the width of the potential is decreased. Limiting boundary conditions for the same interaction potential in b...

  11. Vector solitons in two-component Bose-Einstein condensates with tunable interactions and harmonic potential

    Science.gov (United States)

    Zhang, Xiao-Fei; Hu, Xing-Hua; Liu, Xun-Xu; Liu, W. M.

    2009-03-01

    We present a family of exact vector-soliton solutions for the coupled nonlinear Schrödinger equations with tunable interactions and harmonic potential, and then apply the model to investigate the dynamics of solitons and collisions between two orthogonal solitons in the case with equal interaction parameters. Our results show that the exact vector-soliton solutions can be obtained with arbitrary tunable interactions as long as a proper harmonic potential is applied. The dynamics of solitons can be controlled by the Feshbach resonance and the collisions are essentially elastic and do not depend on the initial conditions.

  12. Expanding Interaction Potentials within Virtual Environments: Investigating the Usability of Speech and Manual Input Modes for Decoupled Interaction

    Directory of Open Access Journals (Sweden)

    Alex Stedmon

    2011-01-01

    Full Text Available Distributed technologies and ubiquitous computing now support users who may be detached or decoupled from traditional interactions. In order to investigate the potential usability of speech and manual input devices, an evaluation of speech input across different user groups and a usability assessment of independent-user and collaborative-user interactions was conducted. Whilst the primary focus was on a formative usability evaluation, the user group evaluation provided a formal basis to underpin the academic rigor of the exercise. The results illustrate that using a speech interface is important in understanding user acceptance of such technologies. From the usability assessment it was possible to translate interactions and make them compatible with innovative input devices. This approach to interaction is still at an early stage of development, and the potential or validity of this interfacing concept is still under evaluation; however, as a concept demonstrator, the results of these initial evaluations demonstrate the potential usability issues of both input devices as well as highlighting their suitability for advanced virtual applications.

  13. Chemical Potential Dependence of the Dressed-Quark Propagator from an Effective Quark-Quark Interaction

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; PING Jia-Lun; SUN Wei-Min; CHANG Chao-Hsi; WANG Fan

    2002-01-01

    We exhibit a method for obtaining the low chemical potential dependence of the dressed quark propagatorfrom an effective quark-quark interaction model. Within this approach we explore the chemical potential dependenceof the dressed-quark propagator, which provides a means of determining the behavior of the chiral and deconfinementorder parameters. A comparison with the results of previous researches is given.

  14. Interaction potential and repulsive force between atoms whose internuclear separations are small

    International Nuclear Information System (INIS)

    The Thomas-Fermi equation is solved for the homonuclear diatomic molecule. The electronic density and electrostatic potential at each point are used to calculate energies and interaction potentials for very small internuclear separation distances. The repulsive force between atoms is derived by means of the virial theorem. (author)

  15. Hydrogen Bonding between Metal-Ion Complexes and Noncoordinated Water: Electrostatic Potentials and Interaction Energies.

    Science.gov (United States)

    Andrić, Jelena M; Misini-Ignjatović, Majda Z; Murray, Jane S; Politzer, Peter; Zarić, Snežana D

    2016-07-01

    The hydrogen bonding of noncoordinated water molecules to each other and to water molecules that are coordinated to metal-ion complexes has been investigated by means of a search of the Cambridge Structural Database (CSD) and through quantum chemical calculations. Tetrahedral and octahedral complexes that were both charged and neutral were studied. A general conclusion is that hydrogen bonds between noncoordinated water and coordinated water are much stronger than those between noncoordinated waters, whereas hydrogen bonds of water molecule in tetrahedral complexes are stronger than in octahedral complexes. We examined the possibility of correlating the computed interaction energies with the most positive electrostatic potentials on the interacting hydrogen atoms prior to interaction and obtained very good correlation. This study illustrates the fact that electrostatic potentials computed for ground-state molecules, prior to interaction, can provide considerable insight into the interactions. PMID:26989883

  16. Choice of single-particle potential and the convergence of the effective interaction

    International Nuclear Information System (INIS)

    The convergence of the expansion for the effective interaction is studied considering as example the shell model for the nuclei 18O and 18F. In this work the effective interaction is computed through third order in the Brueckner G matrix, using both a harmonic-oscillator (HO) basis and a Brueckner-Hartree-Fock (BHF) basis. The significant differences in the convergence behavior of the effective interaction in these two cases are reported. The results indicate that the choice of the BHF single-particle potential facilitates the convergence of the effective interaction in low-orders of the expansion, whereas the HO results exhibit a non-convergent behavior. The implications for the HO approach are discussed. All calculations have been performed considering a modern version of the Bonn one-boson-exchange potential for the nucleon-nucleon interaction. 23 refs., 4 figs., 2 tabs

  17. Thermodynamics of a two-dimensional interacting Bose gas trapped in a quartic potential

    International Nuclear Information System (INIS)

    We have studied the Bose-Einstein condensation (BEC) of an interacting Bose gas confined in a two-dimensional (2D) quartic potential by using a mean-field, semiclassical two-fluid model. A thermodynamic analysis including the chemical potential, condensate fraction, total energy, and specific heat has been carried out by considering different values of the interaction strength. Finally, we have found that the behaviour of the condensate fraction and specific heat of quartically trapped bosons differs from those of bosons trapped in a harmonic potential.

  18. Interaction potentials for multiquark states from instantons and other background gauge field configurations

    International Nuclear Information System (INIS)

    A simple rule is presented for calculating the contributions to the interaction potentials between constituent particles for a family of multiquark states, due to the presence of a semi-classical gauge field configuration which exists in a single SU(2) subgroup of colour SU(3). In multiquark states beyond the baryon many-body potential terms are found. The static (Wilson loop) limit is sufficient to elucidate the dependence of the potential on the colour structure of the multiquark state

  19. Effective interactions through third order for mass-18 nuclei with the Paris potential

    International Nuclear Information System (INIS)

    The behaviour of the effective interaction in the (sd)-shell through third order for mass-18 has been studied with the meson-theoretical Paris potential. All JT states were considered. The results are compared with those obtained with the G-matrix of Kuo and Brown, based on the phenomenological Hamada-Johnston potential. The excitation spectra obtained with both these potentials are rather similar. The Paris potential gives, however, a better fit through third order, whereas it produces more binding for low-lying states through second order. Still, evidence for non-convergent behavior is found in T=0 states for the Paris potential

  20. Equation of state and interaction potential of helium under high temperatures and high densities

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the thermodynamics statistic method, the improved variational perturbation theory and the modified quantum mechanics correction model have been used to calculate the equation of state of liquid helium at pressure from 0.7 to 108 GPa. The calculation results are in good agreement with the experimental data. The EXP-6 potential (α = 13.1) can more accurately describe the interaction of helium atoms than other potentials in the scheme. Finally, a comparison is shown between our interatomic potentials and other potentials.

  1. Equation of state and interaction potential of helium under high temperatures and high densities

    Institute of Scientific and Technical Information of China (English)

    YANG JinWen; YAN YuanHong

    2009-01-01

    Based on the thermodynamics statistic method, the improved variational perturbation theory and the modified quantum mechanics correction model have been used to calculate the equation of state of liquid helium at pressure from 0.7 to 108 GPa. The calculation results are in good agreement with the experimental data. The EXP-6 potential (α=13.1) can more accurately describe the interaction of helium atoms than other potentials in the scheme. Finally, s comparison is shown between our interatomic potentials and other potentials.

  2. Study of various models of nuclear interaction potentials: nucleon-nucleus and nucleus-nucleus systems

    International Nuclear Information System (INIS)

    Several models, performed within a mean field theory, are developed for the calculation of nucleon-nucleus interaction potentials. The first part of the thesis deals with the nucleon-nucleus average interaction. It is mainly devoted to the calculation of dynamical corrections to the Hartree-Fock approximation. Two approaches are used: a microscopic model performed in the framework of the nuclear structure approach and a semi-phenomenological one, based on the application of the dispersion relations to the empirical imaginary potential. Both models take into account finite size effects like collectivity or threshold effects which are important at low energy. The Green's function properties are used for both models. The second part of this work is devoted to the interaction potential between two heavy ions. This calculation, which is performed in the framework of the sudden approximation, uses the energy density formalism (Thomas-Fermi approximation). It has been extended to finite temperature. At T=0 the experimental fusion barriers of heavy systems are reproduced within 4%. Their temperature dependence is studied. The proximity scaling is checked and a universal function is obtained at T=0 and at finite temperature. It is found that the proximity theorem is well satisfied on the average. The dispersion around the mean behaviour increases with increasing temperature. At last, P+A* and α+A* interaction potentials are calculated within a double folding model using a schematic effective interaction

  3. Nucleon-nucleon interaction with a flat bottom linear confinement potential in the quark model

    International Nuclear Information System (INIS)

    Nucleon-nucleon interaction is studied in the non-relativistic quark model with a flat bottom linear confinement potential. The results are consistent with the calculated ones from the lattice quantum chromodynamics. The quark-quark interaction also consists of those caused by the one gluon exchange and the one pion exchange. The phenomenological sigma meson exchange between two nucleons is also included to fit the S-wave N-N scattering data. The calculated NN channel S-wave phase shifts show that the flat bottom linear confinement potential can provide part of the medium range attraction

  4. Temperature-dependent optical potential and mean free path based on Skyrme interactions

    International Nuclear Information System (INIS)

    Optical potentials and mean free paths of nucleons at finite temperatures are studied by utilizing effective Skyrme interactions which yield 'good' optical potentials at zero temperature. The results for nuclear matter (symmetric and asymmetric) are applied within the local density approximation of finite nuclei at various temperatures. Because of the limitation due to zero-range forces used and the assumptions of temperature independent nuclear densities and effective Skyrme interactions made, the calculations are expected to be limited to nucleon energies between 10 and 50 MeV above the Fermi energy and to nuclear temperatures of less than 8 MeV. (orig.)

  5. Intermolecular interaction of thiosemicarbazone derivatives to solvents and a potential Aedes aegypti target

    Science.gov (United States)

    da Silva, João Bosco P.; Hallwass, Fernando; da Silva, Aluizio G.; Moreira, Diogo Rodrigo; Ramos, Mozart N.; Espíndola, José Wanderlan P.; de Oliveira, Ana Daura T.; Brondani, Dalci José; Leite, Ana Cristina L.; Merz, Kenneth M.

    2015-08-01

    DFT calculations were used to access information about structure, energy and electronic properties of series of phenyl- and phenoxymethyl-(thio)semicarbazone derivatives with demonstrated activity against the larvae of Aedes aegypti in stage L4. The way as the thiosemicarbazone derivatives can interact with solvents like DMSO and water were analyzed from the comparison between calculated and experimental 1H NMR chemical shifts. The evidences of thiosemicarbazone derivatives making H-bond interaction to solvent have provide us insights on how they can interact with a potential A. aegypti's biological target, the Sterol Carrier Protein-2.

  6. Mean field propagation of infinite dimensional Wigner measures with a singular two-body interaction potential

    OpenAIRE

    AMMARI, Zied; Nier, Francis

    2015-01-01

    49 pages International audience We consider the quantum dynamics of many bosons systems in the mean field limit with a singular pair-interaction potential, including the attractive or repulsive Coulombic case in three dimensions. By using a measure transportation technique, we show that Wigner measures propagate along the nonlinear Hartree flow. Such property was previously proved only for bounded potentials in our previous works with a slightly different strategy.

  7. Mean field propagation of infinite dimensional Wigner measures with a singular two-body interaction potential

    CERN Document Server

    Ammari, Zied

    2011-01-01

    We consider the quantum dynamics of many bosons systems in the mean field limit with a singular pair-interaction potential, including the attractive or repulsive Coulombic case in three dimensions. By using a measure transportation technique, we show that Wigner measures propagate along the nonlinear Hartree flow. Such property was previously proved only for bounded potentials in our previous works with a slightly different strategy.

  8. Interacting particles in a periodically moving potential: Traveling wave and transport

    OpenAIRE

    Chatterjee, Rakesh; Chatterjee, Sakuntala; Pradhan, Punyabrata; Manna, S.S.

    2014-01-01

    We study a system of interacting particles in a periodically moving external potential, within the simplest possible description of paradigmatic symmetric exclusion process on a ring. The model describes diffusion of hardcore particles where the diffusion dynamics is locally modified at a uniformly moving defect site, mimicking the effect of the periodically moving external potential. The model, though simple, exhibits remarkably rich features in particle transport, such as polarity reversal ...

  9. A review of potential harmful interactions between anticoagulant/antiplatelet agents and Chinese herbal medicines.

    Directory of Open Access Journals (Sweden)

    Hsin-Hui Tsai

    Full Text Available BACKGROUND: The risks attributed to drug-herb interactions, even when known, are often ignored or underestimated, especially for those involving anti-clotting drugs and Chinese medicines. The aim of this study was to structurally search and evaluate the existing evidence-based data associated with potential drug interactions between anticoagulant/antiplatelet drugs and Chinese herbal medicines (CHMs and evaluate the documented mechanisms, consequences, and/or severity of interactions. METHODOLOGY AND FINDINGS: Information related to anticoagulant/antiplatelet drug-CHM interactions was retrieved from eight interaction-based textbooks, four web resources and available primary biomedical literature. The primary literature searches were conducted in English and/or Chinese from January 2000 through December 2011 using the secondary databases (e.g., PubMed, Airiti Library, China Journal full-text database. The search terms included the corresponding medical subject headings and key words. Herbs or natural products not used as a single entity CHM or in Chinese Medicinal Prescriptions were excluded from further review. The corresponding mechanisms and severity ratings of interactions were retrieved using MicroMedex®, Lexicomp® and Natural Medicines Comprehensive Database®. Finally, we found 90 single entity CHMs contributed to 306 documented drug-CHM interactions. A total of 194 (63.4% interactions were verified for its evidence describing possible mechanisms and severity. Of them, 155 interactions (79.9% were attributable to pharmacodynamic interactions, and almost all were rated as moderate to severe interactions. The major consequences of these interactions were increased bleeding risks due to the additive anticoagulant or antiplatelet effects of the CHMs, specifically danshen, dong quai, ginger, ginkgo, licorice, and turmeric. CONCLUSIONS/SIGNIFICANCE: Conventional anticoagulants and antiplatelet drugs were documented to have harmful interactions

  10. Variance heterogeneity analysis for detection of potentially interacting genetic loci: method and its limitations

    Directory of Open Access Journals (Sweden)

    van Duijn Cornelia

    2010-10-01

    Full Text Available Abstract Background Presence of interaction between a genotype and certain factor in determination of a trait's value, it is expected that the trait's variance is increased in the group of subjects having this genotype. Thus, test of heterogeneity of variances can be used as a test to screen for potentially interacting single-nucleotide polymorphisms (SNPs. In this work, we evaluated statistical properties of variance heterogeneity analysis in respect to the detection of potentially interacting SNPs in a case when an interaction variable is unknown. Results Through simulations, we investigated type I error for Bartlett's test, Bartlett's test with prior rank transformation of a trait to normality, and Levene's test for different genetic models. Additionally, we derived an analytical expression for power estimation. We showed that Bartlett's test has acceptable type I error in the case of trait following a normal distribution, whereas Levene's test kept nominal Type I error under all scenarios investigated. For the power of variance homogeneity test, we showed (as opposed to the power of direct test which uses information about known interacting factor that, given the same interaction effect, the power can vary widely depending on the non-estimable direct effect of the unobserved interacting variable. Thus, for a given interaction effect, only very wide limits of power of the variance homogeneity test can be estimated. Also we applied Levene's approach to test genome-wide homogeneity of variances of the C-reactive protein in the Rotterdam Study population (n = 5959. In this analysis, we replicate previous results of Pare and colleagues (2010 for the SNP rs12753193 (n = 21, 799. Conclusions Screening for differences in variances among genotypes of a SNP is a promising approach as a number of biologically interesting models may lead to the heterogeneity of variances. However, it should be kept in mind that the absence of variance heterogeneity for

  11. The potential of protein-nanomaterial interaction for advanced drug delivery.

    Science.gov (United States)

    Peng, Qiang; Mu, Huiling

    2016-03-10

    Nanomaterials, like nanoparticles, micelles, nano-sheets, nanotubes and quantum dots, have great potentials in biomedical fields. However, their delivery is highly limited by the formation of protein corona upon interaction with endogenous proteins. This new identity, instead of nanomaterial itself, would be the real substance the organs and cells firstly encounter. Consequently, the behavior of nanomaterials in vivo is uncontrollable and some undesired effects may occur, like rapid clearance from blood stream; risk of capillary blockage; loss of targeting capacity; and potential toxicity. Therefore, protein-nanomaterial interaction is a great challenge for nanomaterial systems and should be inhibited. However, this interaction can also be used to functionalize nanomaterials by forming a selected protein corona. Unlike other decoration using exogenous molecules, nanomaterials functionalized by selected protein corona using endogenous proteins would have greater promise for clinical use. In this review, we aim to provide a comprehensive understanding of protein-nanomaterial interaction. Importantly, a discussion about how to use such interaction is launched and some possible applications of such interaction for advanced drug delivery are presented. PMID:26812004

  12. Critical temperature of Bose-Einstein condensation for weakly interacting bose gas in a potential trap

    Institute of Scientific and Technical Information of China (English)

    YU; Xuecai; YE; Yutang; WU; Yunfeng; XIE; Kang; CHENG; Lin

    2005-01-01

    The critical temperature of Bose-Einstein condensation at minimum momentum state for weakly interacting Bose gases in a power-law potential and the deviation of the critical temperature from ideal bose gas are studied. The effect of interaction on the critical temperature is ascribed to the ratiao α/λc, where α is the scattering length for s wave and λc is de Broglie wavelength at critical temperature. As α/λc<<1/(2π)2, the interaction is negligible. The presented deviation of the critical temperature for three dimensional harmonic potential is well in agreement with recent measurement of critical temperature for 87Rb bose gas trapped in a harmonic well.

  13. The potential of protein-nanomaterial interaction for advanced drug delivery

    DEFF Research Database (Denmark)

    Peng, Qiang; Mu, Huiling

    2016-01-01

    Nanomaterials, like nanoparticles, micelles, nano-sheets, nanotubes and quantum dots, have great potentials in biomedical fields. However, their delivery is highly limited by the formation of protein corona upon interaction with endogenous proteins. This new identity, instead of nanomaterial itself......, would be the real substance the organs and cells firstly encounter. Consequently, the behavior of nanomaterials in vivo is uncontrollable and some undesired effects may occur, like rapid clearance from blood stream; risk of capillary blockage; loss of targeting capacity; and potential toxicity....... Therefore, protein-nanomaterial interaction is a great challenge for nanomaterial systems and should be inhibited. However, this interaction can also be used to functionalize nanomaterials by forming a selected protein corona. Unlike other decoration using exogenous molecules, nanomaterials functionalized...

  14. Behaviour of interatomic interaction potentials in metal in the track area of heavy charged particles

    International Nuclear Information System (INIS)

    The computational technique of interatomic interaction potentials in the presence of ionized states is developed. Using aluminium as an example, they are obtained for atoms with different ionization degree. The molecular-dynamic modeling of atom transfer in crystal lattice has shown that ion emission from fast charged particle track near surface (coulomb explosion) is possible if the life time of ionized states is 10-13 s or more. On the base of pseudopotential approach behaviour of interaction potentials in conditions of electron subsystem excitation is analyzed. It has been found out that thermal tailing of Fermi surface does not result in essential change of interatomic interaction forces, and the local increase of conduction electrons concentration induces softening of crystal lattice when configuration with lesser interatomic distance becomes equilibrium

  15. Evaluation of screening length corrections for interaction potentials in impact-collision ion scattering spectroscopy

    Science.gov (United States)

    Takeuchi, Wataru

    2013-10-01

    Since in impact-collision ion scattering spectroscopy (ICISS) data analysis the interaction potential represented by the screening length as the screening effect is not satisfactorily established up to the present, we introduce commonly the correction factor in the screening length. Previously, Yamamura, Takeuchi and Kawamura (YTK) have suggested the theory taking the shell effect of electron distributions into account for the correction factor to Firsov screening length in the Moliere potential. The application of YTK theory to the evaluation of screening length corrections for the interaction potentials in ICISS manifested that the screening length corrections calculated by the YTK theory agree almost with those determined by simulations or numerical calculations in ICISS and its variants data analyses, being superior to the evaluation of screening length corrections with the O'Connor and Biersack (OB) formula.

  16. Evaluation of screening length corrections for interaction potentials in impact-collision ion scattering spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Wataru, E-mail: take@sp.ous.ac.jp

    2013-10-15

    Since in impact-collision ion scattering spectroscopy (ICISS) data analysis the interaction potential represented by the screening length as the screening effect is not satisfactorily established up to the present, we introduce commonly the correction factor in the screening length. Previously, Yamamura, Takeuchi and Kawamura (YTK) have suggested the theory taking the shell effect of electron distributions into account for the correction factor to Firsov screening length in the Moliere potential. The application of YTK theory to the evaluation of screening length corrections for the interaction potentials in ICISS manifested that the screening length corrections calculated by the YTK theory agree almost with those determined by simulations or numerical calculations in ICISS and its variants data analyses, being superior to the evaluation of screening length corrections with the O’Connor and Biersack (OB) formula.

  17. Reconstruction of the Tip-Surface Interaction Potential by Analysis of the Brownian Motion of an Atomic Force Microscope Tip

    NARCIS (Netherlands)

    Willemsen, Oscar H.; Kuipers, Laurens; Werf, van der Kees O.; Grooth, de Bart G.; Greve, Jan

    2000-01-01

    The thermal movement of an atomic force microscope (AFM) tip is used to reconstruct the tip-surface interaction potential. If a tip is brought into the vicinity of a surface, its movement is governed by the sum of the harmonic cantilever potential and the tip-surface interaction potential. By simula

  18. Association of COMT and COMT-DRD2 interaction with creative potential

    Directory of Open Access Journals (Sweden)

    Shun eZhang

    2014-04-01

    Full Text Available Several lines of evidence suggest that genes involved in dopamine (DA transmission may contribute to creativity. Among these genes, the catechol-O-methyltransferase gene (COMT and the dopamine D2 receptor gene (DRD2 are the most promising candidates. Our previous study has revealed evidence for the involvement of DRD2 in creative potential. The present study extended our previous study by systematically exploring the association of COMT with creative potential as well as the interaction between COMT and DRD2. Twelve single nucleotide polymorphisms (SNPs covering COMT were genotyped in 543 healthy Chinese college students whose creative potentials were assessed by divergent thinking tests. Single SNP analysis showed that rs174697 was nominally associated with verbal originality, two SNPs (rs737865 and rs5993883 were nominally associated with figural fluency, and two SNPs (rs737865 and rs4680 were nominally associated with figural originality. Haplotype analysis showed that, the TCT and CCT haplotype (rs737865-rs174675-rs5993882 were nominally associated with figural originality, and the TATGCAG and CGCGGGA haplotype (rs4646312-rs6269-rs4633-rs6267-rs4818-rs4680-rs769224 were nominally associated with figural originality and verbal flexibility, respectively. However, none of these nominal findings survived correction for multiple testing. Gene-gene interaction analysis identified one significant four-way interaction of rs174675 (COMT, rs174697 (COMT, rs1076560 (DRD2 and rs4436578 (DRD2 on verbal fluency, one significant four-way interaction of rs174675 (COMT, rs4818 (COMT, rs1076560 (DRD2 and rs4648317 (DRD2 on verbal flexibility, and one significant three-way interaction of rs5993883 (COMT, rs4648319 (DRD2 and rs4648317 (DRD2 on figural flexibility. In conclusion, the present study provides nominal evidence for the involvement of COMT in creative potential and suggests that DA related genes may act in coordination to contribute to creativity.

  19. A Study on Potential of Integrating Multimodal Interaction into Musical Conducting Education

    CERN Document Server

    Siang, Gilbert Phuah Leong; Yong, Pang Yee

    2010-01-01

    With the rapid development of computer technology, computer music has begun to appear in the laboratory. Many potential utility of computer music is gradually increasing. The purpose of this paper is attempted to analyze the possibility of integrating multimodal interaction such as vision-based hand gesture and speech interaction into musical conducting education. To achieve this purpose, this paper is focus on discuss some related research and the traditional musical conducting education. To do so, six musical conductors had been interviewed to share their musical conducting learning/ teaching experience. These interviews had been analyzed in this paper to show the syllabus and the focus of musical conducting education for beginners.

  20. Charged patchy particle models in explicit salt: Ion distributions, electrostatic potentials, and effective interactions

    International Nuclear Information System (INIS)

    We introduce a set of charged patchy particle models (CPPMs) in order to systematically study the influence of electrostatic charge patchiness and multipolarity on macromolecular interactions by means of implicit-solvent, explicit-ion Langevin dynamics simulations employing the Gromacs software. We consider well-defined zero-, one-, and two-patched spherical globules each of the same net charge and (nanometer) size which are composed of discrete atoms. The studied mono- and multipole moments of the CPPMs are comparable to those of globular proteins with similar size. We first characterize ion distributions and electrostatic potentials around a single CPPM. Although angle-resolved radial distribution functions reveal the expected local accumulation and depletion of counter- and co-ions around the patches, respectively, the orientation-averaged electrostatic potential shows only a small variation among the various CPPMs due to space charge cancellations. Furthermore, we study the orientation-averaged potential of mean force (PMF), the number of accumulated ions on the patches, as well as the CPPM orientations along the center-to-center distance of a pair of CPPMs. We compare the PMFs to the classical Derjaguin-Verwey-Landau-Overbeek theory and previously introduced orientation-averaged Debye-Hückel pair potentials including dipolar interactions. Our simulations confirm the adequacy of the theories in their respective regimes of validity, while low salt concentrations and large multipolar interactions remain a challenge for tractable theoretical descriptions

  1. Charged patchy particle models in explicit salt: Ion distributions, electrostatic potentials, and effective interactions

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, Cemil; Dzubiella, Joachim, E-mail: joachim.dzubiella@helmholtz-berlin.de [Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, 14109 Berlin (Germany); Helmholtz Virtual Institute “Multifunctional Biomaterials for Medicine,” 14513 Teltow (Germany); Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Heyda, Jan [Department of Physical Chemistry, University of Chemistry and Technology, Prague, 166 28 Praha 6 (Czech Republic)

    2015-08-14

    We introduce a set of charged patchy particle models (CPPMs) in order to systematically study the influence of electrostatic charge patchiness and multipolarity on macromolecular interactions by means of implicit-solvent, explicit-ion Langevin dynamics simulations employing the Gromacs software. We consider well-defined zero-, one-, and two-patched spherical globules each of the same net charge and (nanometer) size which are composed of discrete atoms. The studied mono- and multipole moments of the CPPMs are comparable to those of globular proteins with similar size. We first characterize ion distributions and electrostatic potentials around a single CPPM. Although angle-resolved radial distribution functions reveal the expected local accumulation and depletion of counter- and co-ions around the patches, respectively, the orientation-averaged electrostatic potential shows only a small variation among the various CPPMs due to space charge cancellations. Furthermore, we study the orientation-averaged potential of mean force (PMF), the number of accumulated ions on the patches, as well as the CPPM orientations along the center-to-center distance of a pair of CPPMs. We compare the PMFs to the classical Derjaguin-Verwey-Landau-Overbeek theory and previously introduced orientation-averaged Debye-Hückel pair potentials including dipolar interactions. Our simulations confirm the adequacy of the theories in their respective regimes of validity, while low salt concentrations and large multipolar interactions remain a challenge for tractable theoretical descriptions.

  2. Assessment of potential drug-drug interactions and its associated factors in the hospitalized cardiac patients.

    Science.gov (United States)

    Murtaza, Ghulam; Khan, Muhammad Yasir Ghani; Azhar, Saira; Khan, Shujaat Ali; Khan, Tahir M

    2016-03-01

    Drug-drug interactions (DDIs) may result in the alteration of therapeutic response. Sometimes they may increase the untoward effects of many drugs. Hospitalized cardiac patients need more attention regarding drug-drug interactions due to complexity of their disease and therapeutic regimen. This research was performed to find out types, prevalence and association between various predictors of potential drug-drug interactions (pDDIs) in the Department of Cardiology and to report common interactions. This study was performed in the hospitalized cardiac patients at Ayub Teaching Hospital, Abbottabad, Pakistan. Patient charts of 2342 patients were assessed for pDDIs using Micromedex® Drug Information. Logistic regression was applied to find predictors of pDDIs. The main outcome measure in the study was the association of the potential drug-drug interactions with various factors such as age, gender, polypharmacy, and hospital stay of the patients. We identified 53 interacting-combinations that were present in total 5109 pDDIs with median number of 02 pDDIs per patient. Overall, 91.6% patients had at least one pDDI; 86.3% were having at least one major pDDI, and 84.5% patients had at least one moderate pDDI. Among 5109 identified pDDIs, most were of moderate (55%) or major severity (45%); established (24.2%), theoretical (18.8%) or probable (57%) type of scientific evidence. Top 10 common pDDIs included 3 major and 7 moderate interactions. Results obtained by multivariate logistic regression revealed a significant association of the occurrence of pDDIs in patient with age of 60 years or more (p Older patients, patients with longer hospital stay and with elevated number of prescribed drugs were at higher risk of pDDIs. PMID:27013915

  3. Medicinal plant reported with adverse reactions in Cuba: potential interactions with conventional drugs

    Directory of Open Access Journals (Sweden)

    Ioanna Martínez

    2015-04-01

    Full Text Available Context: Herbal drugs are a mixture of active compounds and the chemical complexity of each formulation increase with the possibility of interactions between them and conventional drugs. Many mechanisms are implicated in the interactions; scientific community has dedicated the attentions to enzymes as P-gp and CYP450. Aims: To investigate in the literature the principal plants with suspicions of adverse reactions in Cuba and their potential interactions with conventional drugs. Methods: PubMed was the database used as source of information until February 2014. Key words: Herb-Drug, Drug-Plant, Herbal–Drug, Interactions with scientific names of plants was used. Information was structured and analysed with EndNote X4. Analysis and integration of the information: Allium sativum L. (garlic was the plant with the high number of studies related with CYP450 and P-gp. Plants with great demand as Morinda citrifolia L. (noni, Psidium guajava L. (guayaba, Zingiber officinale Roscoe (ginger and Eucalyptus spp. (eucalyptus have a very small number of studies. The professionals of the health should keep in mind the possibility of interactions between herbal products and conventional drugs to increase the effectiveness of phytotherapy. Conclusions: It is necessary enhance reports and investigations and to put to disposition of the system of health information on the interactions of plants and to stimulate the investigation that offers information for the rational use of our medicinal plants.

  4. Electrostatic potential profile and nonlinear current in an interacting one-dimensional molecular wire

    Indian Academy of Sciences (India)

    S Lakshmi; Swapan K Pati

    2003-10-01

    We consider an interacting one-dimensional molecular wire attached to two metal electrodes on either side of it. The electrostatic potential profile across the wire-electrode interface has been deduced solving the Schrodinger and Poisson equations self-consistently. Since the Poisson distribution crucially depends on charge densities, we have considered different Hamiltonian parameters to model the nanoscale wire. We find that for very weak electron correlations, the potential gradient is almost zero in the middle of the wire but are large near the chain ends. However, for strong correlations, the potential is essentially a ramp function. The nonlinear current, obtained from the scattering formalism, is found to be less with the ramp potential than for weak correlations. Some of the interesting features in current-voltage characteristics have been explained using one-electron formalism and instabilities in the system.

  5. An effective interaction derived from HJ potential for use in TDA and RPA calculations

    International Nuclear Information System (INIS)

    An effective interaction is derived by fitting the matrix elements of a sum of Yukawa terms to the G-matrix elements of a sum of Yukawa terms to the G-matrix elements derived from the Hamada-Johnston potential. Central, spin-orbit and tensor components are taken into account. Numerical results are given and compared with those obtained from the Paris and Reid potentials. As an application, the excitation spectra in 16O are investigated in the framework of the TDA and RPA. (author). 12 refs, 3 tabs

  6. Reconstructing interaction potentials in thin films from real-space images

    Science.gov (United States)

    Gienger, Jonas; Severin, Nikolai; Rabe, Jürgen P.; Sokolov, Igor M.

    2016-04-01

    We demonstrate that an inverse Monte Carlo approach allows one to reconstruct effective interaction potentials from real-space images. The method is exemplified on monomolecular ethanol-water films imaged with scanning force microscopy, which provides the spatial distribution of the molecules. Direct Monte Carlo simulations with the reconstructed potential allow for obtaining characteristics of the system which are unavailable in the experiment, such as the heat capacity of the monomolecularly thin film, and for a prediction of the critical temperature of the demixing transition.

  7. The interaction potential of NO-H2 in ground and A Rydberg state

    Science.gov (United States)

    Pajón-Suárez, Pedro; Valentín-Rodríguez, Mónica; Hernández-Lamoneda, Ramón

    2016-08-01

    The interaction potential for the ground and A Rydberg state of NO-H2 has been calculated using high level ab initio methods. The complex is very floppy in nature and large amplitude motions are expected to characterize its dynamics. The ground state is characterized by two very close-lying states which exhibit crossings. By analogy with other complexes the Rydberg state is characterized by much smaller well depth and larger intermolecular distance. We compare with model potentials used in previous molecular dynamics simulations of photoexcitation and relaxation and conclude on the importance of performing new studies.

  8. Multireference configuration interaction calculations of the first six ionization potentials of the uranium atom

    International Nuclear Information System (INIS)

    The first 6 ionization potentials (IPs) of the uranium atom have been calculated using multireference configuration interaction (MRCI+Q) with extrapolations to the complete basis set limit using new all-electron correlation consistent basis sets. The latter was carried out with the third-order Douglas-Kroll-Hess Hamiltonian. Correlation down through the 5s5p5d electrons has been taken into account, as well as contributions to the IPs due to the Lamb shift. Spin-orbit coupling contributions calculated at the 4-component Kramers restricted configuration interaction level, as well as the Gaunt term computed at the Dirac-Hartree-Fock level, were added to the best scalar relativistic results. The final ionization potentials are expected to be accurate to at least 5 kcal/mol (0.2 eV) and thus more reliable than the current experimental values of IP3 through IP6

  9. Potential of lateral interactions of CO on Pt (111) fitted to recent STM images

    Science.gov (United States)

    Myshlyavtsev, Alexander V.; Stishenko, Pavel V.

    2015-12-01

    Monolayers of carbon monoxide (CO) on Pt(111) surfaces are one of the most studied adsorption systems. However, molecular models of this system still do not take into account the reliable potential of lateral interactions between adsorbed CO molecules. Recent advances in experimental technique have brought high-resolution real-space images of CO/Pt(111) monolayers. For example, Yang et al. (J. Phys. Chem. C 117 (2013) 16429-16437) found island structures for coverages from 0.11 to 0.25 ML. In this study we have shown that these island structures can be explained with long-range oscillating lateral interactions. Parameters of the proposed potential were fitted to experimental scanning tunneling microscopy images with a series of Monte Carlo simulations.

  10. Multiple scattering of low energy ions in matter: Influence of energy loss and interaction potential

    International Nuclear Information System (INIS)

    In this paper, the effect of inelastic energy loss and interaction potential on transmitted ions at low energy is studied. For this purpose, angular distributions of slow He+ ions transmitted through thin Ag films are calculated using the theory of multiple scattering. Thin films (20–50 Å at 2 keV and 50–200 Å at 10 keV) are considered so that the total path length of transmitted ions can be approximated by the value of the target thickness in this calculation. The corresponding values of the relative energy loss ΔE/E are comprised between 0.04 and 0.17. We show that even if low values of the thickness are considered, the total energy loss of ions in the target should be included in the calculation. These calculated angular distributions are also influenced by the potential used to describe the interaction between the incident ion and the target atom

  11. Multiple scattering of low energy ions in matter: Influence of energy loss and interaction potential

    Energy Technology Data Exchange (ETDEWEB)

    Mekhtiche, A. [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria); Faculté des Sciences et de la Technologie, Université Yahia Farès de Médéa (Algeria); Khalal-Kouache, K., E-mail: kkouache@yahoo.fr [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria)

    2015-07-01

    In this paper, the effect of inelastic energy loss and interaction potential on transmitted ions at low energy is studied. For this purpose, angular distributions of slow He{sup +} ions transmitted through thin Ag films are calculated using the theory of multiple scattering. Thin films (20–50 Å at 2 keV and 50–200 Å at 10 keV) are considered so that the total path length of transmitted ions can be approximated by the value of the target thickness in this calculation. The corresponding values of the relative energy loss ΔE/E are comprised between 0.04 and 0.17. We show that even if low values of the thickness are considered, the total energy loss of ions in the target should be included in the calculation. These calculated angular distributions are also influenced by the potential used to describe the interaction between the incident ion and the target atom.

  12. Cation-π interactions: accurate intermolecular potential from symmetry-adapted perturbation theory.

    Science.gov (United States)

    Ansorg, Kay; Tafipolsky, Maxim; Engels, Bernd

    2013-09-01

    Symmetry-adapted perturbation theory (SAPT) is used to decompose the total intermolecular interaction energy between the ammonium cation and a benzene molecule into four physically motivated individual contributions: electrostatics, exchange, dispersion, and induction. Based on this rigorous decomposition, it is shown unambiguously that both the electrostatic and the induction energy components contribute almost equally to the attractive forces stabilizing the dimer with a nonnegligible contribution coming from the dispersion term. A polarizable potential model for the interaction of ammonium cation with benzene is parametrized by fitting these four energy components separately using the functional forms of the AMOEBA force field augmented with the missing charge penetration energy term calculated as a sum over pairwise electrostatic energies between spherical atoms. It is shown that the proposed model is able to produce accurate intermolecular interaction energies as compared to ab initio results, thus avoiding error compensation to a large extent. PMID:23924321

  13. Mach-Zehnder interferometry with interacting Bose-Einstein condensates in a double-well potential

    International Nuclear Information System (INIS)

    Mach-Zehnder interferometry with interacting Bose-Einstein condensates in a double-well potential Particle-wave duality has enabled the construction of interferometers for massive particles such as electrons, neutrons, atoms or molecules. Implementing atom interferometry has required the development of analogues to the optical beam-splitters, phase shifters or recombiners to enable the coherent, i.e. phase-preserving manipulation of quantum superpositions. While initially demonstrating the wave nature of particles, atom interferometers have evolved into some of the most advanced devices for precision measurement, both for technological applications and tests of the fundamental laws of nature. Bose- Einstein condensates (BEC) of ultracold atoms are particular matter waves: they exhibit a collective many-body wave function and macroscopic coherence properties. As such, they have often been considered as an analogue to optical laser elds and it is natural to wonder whether BECs can provide to atom interferometry a similar boost as the laser brought to optical interferometry. One fundamental dierence between atomic BECs and lasers elds is the presence of atomic interactions, yielding an intrinsic non-linearity. On one hand, interactions can lead to eects destroying the phase coherence and limiting the interrogation time of trapped BEC interferometers. On the other hand, they can be used to generate nonclassical (e.g. squeezed) states to improve the sensitivity of interferometric measurements beyond the standard quantum limit (SQL). In this thesis, we present the realization of a full Mach-Zehnder interferometric sequence with trapped, interacting BECs con ned on an atom chip. Our interferometer relies on the coherent manipulation of a BEC in a magnetic double-well potential. For this purpose, we developed a novel type of matter-wave recombiner, an element which so far was missing in BEC atom optics. We have been able to exploit interactions to generate a squeezed

  14. Herbal Medicines in Brazil: Pharmacokinetic Profile and Potential Herb-Drug Interactions

    OpenAIRE

    JoseMariaPrieto

    2014-01-01

    A plethora of active compounds found in herbal medicines can serve as substrate for enzymes involved in the metabolism of xenobiotics. When a medicinal plant is co-administered with a conventional drug and little or no information is known about the pharmacokinetics of the plant metabolites, there is an increased risk of potential herb-drug interactions. Moreover, genetic polymorphisms in a population may act to predispose individuals to adverse reactions. The use of herbal medicines is rapid...

  15. The effective potential and fixed point of QED with four-fermion interaction

    International Nuclear Information System (INIS)

    We consider quantum electrodynamics in the quenched approximation including a four-fermion interaction with coupling constant g. The effective potential at stationary points is computed as a function of the coupling constant α and g. We find a minimum of energy in the (α,g) plane for α sub(c) = π/3 and g>Ο(1), arguing that this is an indication of the existence of a fixed point in this theory. (author)

  16. Combining genomic sequencing methods to explore viral diversity and reveal potential virus-host interactions

    OpenAIRE

    Chow, Cheryl-Emiliane T.; Danielle M Winget; White, Richard A.; Steven J Hallam; Suttle, Curtis A.

    2015-01-01

    Viral diversity and virus-host interactions in oxygen-starved regions of the ocean, also known as oxygen minimum zones (OMZs), remain relatively unexplored. Microbial community metabolism in OMZs alters nutrient and energy flow through marine food webs, resulting in biological nitrogen loss and greenhouse gas production. Thus, viruses infecting OMZ microbes have the potential to modulate community metabolism with resulting feedback on ecosystem function. Here, we describe viral communities in...

  17. SEROTONERGIC/GLUTAMATERGIC INTERACTIONS: POTENTIATION OF PHENCYCLIDINE-INDUCED STIMULUS CONTROL BY CITALOPRAM

    OpenAIRE

    Winter, J. C.; Eckler, J.R.; Rice, K. C.; Rabin, R. A.

    2005-01-01

    Previous investigations in our laboratory have found that the stimulus effects of the hallucinogenic serotonergic agonists DOM and LSD are potentiated by phencyclidine [PCP], a non-competitive NMDA antagonist. Also suggestive of behaviorally significant serotonergic/glutamatergic interactions is our finding that stimulus control by both PCP and LSD is partially antagonized by the mGlu2/3 agonist, LY 379268. These observations coupled with the fact that the stimulus effects of LSD and DOM are ...

  18. Experimenting with ecosystem interaction networks in search of threshold potentials in real-world marine ecosystems

    OpenAIRE

    Thrush, S. F.; Hewitt, J E; Parkes, S; Lohrer, A.M.; Pilditch, C.A.; Woodin, S.A.; Wethey, D. S.; Chiantore, M.; Asnaghi, V; de Juan, S.; Kraan, C.; Rodil, I.; Savage, C; Van Colen, C.

    2014-01-01

    Thresholds profoundly affect our understanding and management of ecosystem dynamics, but we have yet to develop practical techniques to assess the risk that thresholds will be crossed. Combining ecological knowledge of critical system interdependencies with a large-scale experiment, we tested for breaks in the ecosystem interaction network to identify threshold potential in real-world ecosystem dynamics. Our experiment with the bivalves Macomona liliana and Austrovenus stutchburyi on marine s...

  19. Multi-time Schrödinger equations cannot contain interaction potentials

    International Nuclear Information System (INIS)

    Multi-time wave functions are wave functions that have a time variable for every particle, such as ϕ(t1,x1,...,tN,xN). They arise as a relativistic analog of the wave functions of quantum mechanics but can be applied also in quantum field theory. The evolution of a wave function with N time variables is governed by N Schrödinger equations, one for each time variable. These Schrödinger equations can be inconsistent with each other, i.e., they can fail to possess a joint solution for every initial condition; in fact, the N Hamiltonians need to satisfy a certain commutator condition in order to be consistent. While this condition is automatically satisfied for non-interacting particles, it is a challenge to set up consistent multi-time equations with interaction. We prove for a wide class of multi-time Schrödinger equations that the presence of interaction potentials (given by multiplication operators) leads to inconsistency. We conclude that interaction has to be implemented instead by creation and annihilation of particles, which, in fact, can be done consistently [S. Petrat and R. Tumulka, “Multi-time wave functions for quantum field theory,” Ann. Physics (to be published)]. We also prove the following result: When a cut-off length δ > 0 is introduced (in the sense that the multi-time wave function is defined only on a certain set of spacelike configurations, thereby breaking Lorentz invariance), then the multi-time Schrödinger equations with interaction potentials of range δ are consistent; however, in the desired limit δ → 0 of removing the cut-off, the resulting multi-time equations are interaction-free, which supports the conclusion expressed in the title

  20. Skyrme-type effective forces in nuclei and properties of ion-ion interactions potentials

    International Nuclear Information System (INIS)

    The ion-ion interaction potentials between three pairs of colliding nuclei: O-O, O-Ca and Ca-Ca have been analyzed within the extended Local-Scale Transformation method with various Skyrme-type effective forces using the known sudden approximation with Thomas-Fermi term for the kinetic energy density functional. It turns out that the interaction potentials do not depend significantly on the particular variational parameters used but their properties are strongly affected by the choice of effective interaction. It has been demonstrated that in the physically significant region of the distance R between the two colliding nuclei, the volume term (∝ ρ2) dominates together with the three-body term (∝ ρσ+2), the kinetic energy terms (∝ τ and ∝ τ.ρ) are smaller while the surface term (∝ (∇ρ)2) is ignorable in any case. This allows to relate the properties of the ion-ion interaction potential to the characteristics of the infinitive nuclear matter associated with the Skyrme-type forces used. One has particularly in mind the nuclear incompressibility coefficient K ∞, asymmetry energy J∞ and the effective mass ratio m*∞/m. The main conclusion is that the ion-ion interaction potential gives possibilities to make a clear difference between the forces with one-third and one-sixth power density dependence (σ = 1/3 or 1/6) and the forces with a linear one (σ = 1). In both cases the depth of the potential Vmin = V(Rmin) has a constant behaviour as a function of K∞, J∞ and m*∞/m. The deeper potentials uniquely support the forces with σ = 1/3 or 1/6. At the same time different almost linear dependencies are obtained for the distance Rmin as a function of K∞, J∞ and m*∞/m in both cases: σ = 1/3 or 1/6 and σ = 1. 1 tab., 6 figs., 11 refs. (author)

  1. Effective interactions for valence-hole nuclei with modern meson-exchange potential models

    International Nuclear Information System (INIS)

    Within the framework of the folded-diagram theory, the authors have studied the effective interaction appropriate for hole-hole nuclei in the mass regions of 16O and 40Ca, using the Bonn and Paris potential models. To sum up the folded diagrams the renormalization procedure of Lee and Suzuki has been employed, using a so-called Q-box in which were included all one-body and two-body irreducible valence-linked diagrams through third order in perturbation theory. Discrepancies for the mass dependence of the effective interaction for several JT configurations with respect to empirically deduced mass dependencies is reported. The role of core polarization processes through third order were found to be one of the mechanisms behind these discrepancies. Compared to the results obtained with the Paris potential, more attraction is introduced by the Bonn potential for all matrix elements of concerns, a result which agrees well with previous findings for the particle-particle interaction in the same mass regions. A qualitative agreements with experimental data is obtained. 31 refs., 6 figs., 8 tabs

  2. Improving intermolecular interactions in DFTB3 using extended polarization from chemical-potential equalization

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Anders S., E-mail: andersx@chem.wisc.edu, E-mail: cui@chem.wisc.edu; Cui, Qiang, E-mail: andersx@chem.wisc.edu, E-mail: cui@chem.wisc.edu [Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706 (United States); Elstner, Marcus [Theoretische Chemische Biologie, Universität Karlsruhe, Kaiserstr. 12, 76131 Karlsruhe (Germany)

    2015-08-28

    Semi-empirical quantum mechanical methods traditionally expand the electron density in a minimal, valence-only electron basis set. The minimal-basis approximation causes molecular polarization to be underestimated, and hence intermolecular interaction energies are also underestimated, especially for intermolecular interactions involving charged species. In this work, the third-order self-consistent charge density functional tight-binding method (DFTB3) is augmented with an auxiliary response density using the chemical-potential equalization (CPE) method and an empirical dispersion correction (D3). The parameters in the CPE and D3 models are fitted to high-level CCSD(T) reference interaction energies for a broad range of chemical species, as well as dipole moments calculated at the DFT level; the impact of including polarizabilities of molecules in the parameterization is also considered. Parameters for the elements H, C, N, O, and S are presented. The Root Mean Square Deviation (RMSD) interaction energy is improved from 6.07 kcal/mol to 1.49 kcal/mol for interactions with one charged species, whereas the RMSD is improved from 5.60 kcal/mol to 1.73 for a set of 9 salt bridges, compared to uncorrected DFTB3. For large water clusters and complexes that are dominated by dispersion interactions, the already satisfactory performance of the DFTB3-D3 model is retained; polarizabilities of neutral molecules are also notably improved. Overall, the CPE extension of DFTB3-D3 provides a more balanced description of different types of non-covalent interactions than Neglect of Diatomic Differential Overlap type of semi-empirical methods (e.g., PM6-D3H4) and PBE-D3 with modest basis sets.

  3. Improving intermolecular interactions in DFTB3 using extended polarization from chemical-potential equalization

    International Nuclear Information System (INIS)

    Semi-empirical quantum mechanical methods traditionally expand the electron density in a minimal, valence-only electron basis set. The minimal-basis approximation causes molecular polarization to be underestimated, and hence intermolecular interaction energies are also underestimated, especially for intermolecular interactions involving charged species. In this work, the third-order self-consistent charge density functional tight-binding method (DFTB3) is augmented with an auxiliary response density using the chemical-potential equalization (CPE) method and an empirical dispersion correction (D3). The parameters in the CPE and D3 models are fitted to high-level CCSD(T) reference interaction energies for a broad range of chemical species, as well as dipole moments calculated at the DFT level; the impact of including polarizabilities of molecules in the parameterization is also considered. Parameters for the elements H, C, N, O, and S are presented. The Root Mean Square Deviation (RMSD) interaction energy is improved from 6.07 kcal/mol to 1.49 kcal/mol for interactions with one charged species, whereas the RMSD is improved from 5.60 kcal/mol to 1.73 for a set of 9 salt bridges, compared to uncorrected DFTB3. For large water clusters and complexes that are dominated by dispersion interactions, the already satisfactory performance of the DFTB3-D3 model is retained; polarizabilities of neutral molecules are also notably improved. Overall, the CPE extension of DFTB3-D3 provides a more balanced description of different types of non-covalent interactions than Neglect of Diatomic Differential Overlap type of semi-empirical methods (e.g., PM6-D3H4) and PBE-D3 with modest basis sets

  4. Optical interaction potentials from differential cross section measurements at thermal energies

    International Nuclear Information System (INIS)

    Differential cross sections for He(23S) + Ar have been measured in the relative kinetic energy range from 20 to 480 MeV. At low kinetic energies the small-angle oscillations are resolved, so that it was possible to derive an accurate complex or optical interaction potential. The velocity dependence of the ionization and total cross sections calculated from this optical potential is in good agreement with experimental results. Orbiting resonances are predicted at low velocities. The derived potential is unusually soft for large internuclear distances, where the argon atom penetrates only the diffuse He(2s) orbital. The repulsion becomes much harder when the argon atom starts to overlap the He(1s) orbital. (author)

  5. Dirac equation for the Hulthén potential within the Yukawa-type tensor interaction

    Institute of Scientific and Technical Information of China (English)

    Oktay Aydo(g)du; Elham Maghsoodi; Hassan Hassanabadi

    2013-01-01

    Using the Nikiforov-Uvarov (NU) method,pseudospin and spin symmetric solutions of the Dirac equation for the scalar and vector Hulthén potentials with the Yukawa-type tensor potential are obtained for an arbitrary spin-orbit coupling quantum number κ.We deduce the energy eigenvalue equations and corresponding upper-and lower-spinor wave functions in both the pseudospin and spin symmetry cases.Numerical results of the energy eigenvalue equations and the upper-and lower-spinor wave functions are presented to show the effects of the external potential and particle mass parameters as well as pseudospin and spin symmetric constants on the bound-state energies and wave functions in the absence and presence of the tensor interaction.

  6. Optical interaction potentials from high-resolution differential cross section measurements at thermal energies

    International Nuclear Information System (INIS)

    Differential cross sections for He(21S) + Ar have been measured for six relative kinetic energies between 21 and 180 meV. At low kinetic energies the small-angle oscillations are clearly resolved. Except for the lowest energy (21 meV) a well resolved rainbow peak is observed in the differential cross sections. The real and imaginary parts of the interaction potential are obtained from the data. The real part has an intermediate maximum in the potential (ΔE = 25 meV, rsub(max) = 7 au) which causes the rainbow peaks. The imaginary part can be expressed by an exponential plus a Gaussian. The velocity dependence of the total and ionization cross sections is calculated and the possibility of an energy-dependent width of the potential is indicated. Good agreement is obtained with the measured temperature dependence of the ionization rate constant and the velocity dependence of the ionization cross section. The observed peculiarities of the Penning electron energy distributions can be explained naturally from the proposed potential. Quantum-mechanical deflection functions are calculated and it is shown that the width of the potential has only a small influence on them. Classical trajectories are calculated to illuminate certain features of the scattering process. The qualitative similarity of the proposed potential to that used for heavy-ion scattering at energies of about 100 MeV is discussed. (author)

  7. Microorganisms in potential host rocks for geological disposal of nuclear waste and their interactions with radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Cherkouk, A.; Liebe, M.; Luetke, L.; Moll, H.; Stumpf, T. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

    2015-07-01

    The long-term safety of nuclear waste in a deep geological repository is an important issue in our society. Microorganisms indigenous to potential host rocks are able to influence the oxidation state, speciation and therefore the mobility of radionuclides as well as gas generation or canister corrosion. Therefore, for the safety assessment of such a repository it is necessary to know which microorganisms are present in the potential host rocks (e.g. clay, salt) and if these microorganisms can influence the performance of a repository. Microbial diversity in potential host rocks for geological disposal of nuclear waste was analyzed by culture-independent molecular biological methods (e.g. 16S rRNA gene retrieval) as well as enrichment and isolation of indigenous microbes. Among other isolates, a Paenibacillus strain, as a representative of Firmicutes, was recovered in R2A media under anaerobic conditions from Opalinus clay from the Mont Terri in Switzerland. Accumulation experiments and potentiometric titrations showed a strong interaction of Paenibacillus sp. cells with U(VI) within a broad pH range (3-7). Additionally, the interactions of the halophilic archaeal strain Halobacterium noricense DSM 15987, a salt rock representative reference strain, with U(VI) at high ionic strength was investigated. After 48 h the cells were still alive at uranium concentrations up to 60 μM, which demonstrates that Halobacterium noricense can tolerate uranium concentrations up to this level. The formed uranium sorption species were examined with time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results about the microbial communities present in potential host rocks for nuclear waste repositories and their interactions with radionuclides contribute to the safety assessment of a prospective nuclear waste repository.

  8. Microorganisms in potential host rocks for geological disposal of nuclear waste and their interactions with radionuclides

    International Nuclear Information System (INIS)

    The long-term safety of nuclear waste in a deep geological repository is an important issue in our society. Microorganisms indigenous to potential host rocks are able to influence the oxidation state, speciation and therefore the mobility of radionuclides as well as gas generation or canister corrosion. Therefore, for the safety assessment of such a repository it is necessary to know which microorganisms are present in the potential host rocks (e.g. clay, salt) and if these microorganisms can influence the performance of a repository. Microbial diversity in potential host rocks for geological disposal of nuclear waste was analyzed by culture-independent molecular biological methods (e.g. 16S rRNA gene retrieval) as well as enrichment and isolation of indigenous microbes. Among other isolates, a Paenibacillus strain, as a representative of Firmicutes, was recovered in R2A media under anaerobic conditions from Opalinus clay from the Mont Terri in Switzerland. Accumulation experiments and potentiometric titrations showed a strong interaction of Paenibacillus sp. cells with U(VI) within a broad pH range (3-7). Additionally, the interactions of the halophilic archaeal strain Halobacterium noricense DSM 15987, a salt rock representative reference strain, with U(VI) at high ionic strength was investigated. After 48 h the cells were still alive at uranium concentrations up to 60 μM, which demonstrates that Halobacterium noricense can tolerate uranium concentrations up to this level. The formed uranium sorption species were examined with time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results about the microbial communities present in potential host rocks for nuclear waste repositories and their interactions with radionuclides contribute to the safety assessment of a prospective nuclear waste repository.

  9. The study of interaction potentials and differential cross sections for collisions between He atoms and hydrogen halide molecules

    Institute of Scientific and Technical Information of China (English)

    孙桂华; 杨向东; 朱俊; 王彩霞

    2002-01-01

    In this paper, we present the uniform interaction potentials for helium atoms and halogen hydride molecules (HF,HC1 and HBr). The differential cross sections are calculated using the above interaction potentials for the He-HF,HCl and HBr systems, respectively, and the results of the calculations are found to be in agreement with the existingtheoretical results and experimental data.

  10. Accuracy of simple folding model in the calculation of the direct part of real − interaction potential

    Indian Academy of Sciences (India)

    Keshab C Panda; Binod C Sahu; Jhasaketan Bhoi

    2014-05-01

    The direct part of real − interaction potential is calculated in the simple folding model using density-dependent Brink–Boeker effective interaction. The simple folding potentials calculated from the short- and finite-range components of this effective interaction are compared with their corresponding double folding results obtained from the oscillator model wave function to establish the relative accuracy of the model. It is found that the direct part of real – interaction potential calculated in the simple folding model is reliable.

  11. Medication use and potential drug interactions in pediatric patients with infectious diseases.

    Science.gov (United States)

    Lisby, S M; Nahata, M C

    1987-04-01

    Infectious diseases are the most common type of illness in pediatric patients. Limited data are available, however, about the most frequently prescribed drugs for children in pediatric infectious diseases units. The authors prospectively evaluated medication records of 493 children over a 5-month period to determine the pattern of drug prescribing and incidence of potential drug interactions in children admitted to the infectious diseases unit in a pediatric hospital. Antimicrobial agents were the most frequently prescribed class of drugs, comprising 60% of all drug orders. Of all antibiotics used during this period, ampicillin was the most common (24% of antibiotic orders). Ceftriaxone, cefuroxime, and gentamicin were also used frequently and consisted of 15%, 10%, and 14% of all orders for anti-infective agents, respectively. Other classes of drugs frequently given to patients on the infectious disease unit were antipyretics (14%), bronchodilators (10%), and anticonvulsants (7%). The incidence of potential drug interactions was 3.5%, the majority involving anticonvulsants. A clinically significant drug interaction was not documented in any of these cases. Observations made from this study may assist in developing clinical pharmacy services and educational programs for pharmacy students. In addition, knowledge of drug use patterns may aid in conducting antibiotic use reviews. PMID:10281735

  12. Interaction grand potential between calcium-silicate-hydrate nanoparticles at the molecular level.

    Science.gov (United States)

    Bonnaud, Patrick A; Labbez, Christophe; Miura, Ryuji; Suzuki, Ai; Miyamoto, Naoto; Hatakeyama, Nozomu; Miyamoto, Akira; Van Vliet, Krystyn J

    2016-02-21

    Calcium-silicate-hydrate (or C-S-H), an inosilicate, is the major binding phase in cement pastes and concretes and a porous hydrated material made up of a percolated and dense network of crystalline nanoparticles of a mean apparent spherical diameter of ∼5 nm that are each stacks of multiple C-S-H layers. Interaction forces between these nanoparticles are at the origin of C-S-H chemical, physical, and mechanical properties at the meso- and macroscales. These particle interactions and the resulting properties may be affected significantly by nanoparticle density and environmental conditions such as the temperature, relative humidity, or concentration of chemical species in the bulk solution. In this study, we combined grand canonical Monte Carlo simulations and an extension of the mean force integration method to derive the pair potentials. This approach enables realistic simulation of the physical environment surrounding the C-S-H particles. We thus constructed the pair potentials for C-S-H nanoparticles of defined chemical stoichiometry at 10% relative humidity (RH), varying the relative crystallographic orientations at a constant particle density of ρpart ∼ 2.21 mmol L(-1). We found that cohesion between nanoparticles is affected strongly by both the aspect ratio and the crystallographic misorientation of interacting particles. This method and the findings underscore the importance of accounting for relative dimensions and orientation among C-S-H nanoparticles in descriptions of physical and simulated multiparticle aggregates or mesoscale systems. PMID:26866999

  13. A method for computing the inter-residue interaction potentials for reduced amino acid alphabet

    Indian Academy of Sciences (India)

    Abhinav Luthra; Anupam Nath Jha; G K Ananthasuresh; Saraswathi Vishveswara

    2007-08-01

    Inter-residue potentials are extensively used in the design and evaluation of protein structures. However, dealing with all (20×20) interactions becomes computationally difficult in extensive investigations. Hence, it is desirable to reduce the alphabet of 20 amino acids to a smaller number. Currently, several methods of reducing the residue types exist; however a critical assessment of these methods is not available. Towards this goal, here we review and evaluate different methods by comparing with the complete (20×20) matrix of Miyazawa-Jernigan potential, including a method of grouping adopted by us, based on multi dimensional scaling (MDS). The second goal of this paper is the computation of inter-residue interaction energies for the reduced amino acid alphabet, which has not been explicitly addressed in the literature until now. By using a least squares technique, we present a systematic method of obtaining the interaction energy values for any type of grouping scheme that reduces the amino acid alphabet. This can be valuable in designing the protein structures.

  14. Assessment of potential drug–drug interactions and its associated factors in the hospitalized cardiac patients

    Directory of Open Access Journals (Sweden)

    Ghulam Murtaza

    2016-03-01

    Full Text Available Drug–drug interactions (DDIs may result in the alteration of therapeutic response. Sometimes they may increase the untoward effects of many drugs. Hospitalized cardiac patients need more attention regarding drug–drug interactions due to complexity of their disease and therapeutic regimen. This research was performed to find out types, prevalence and association between various predictors of potential drug–drug interactions (pDDIs in the Department of Cardiology and to report common interactions. This study was performed in the hospitalized cardiac patients at Ayub Teaching Hospital, Abbottabad, Pakistan. Patient charts of 2342 patients were assessed for pDDIs using Micromedex® Drug Information. Logistic regression was applied to find predictors of pDDIs. The main outcome measure in the study was the association of the potential drug–drug interactions with various factors such as age, gender, polypharmacy, and hospital stay of the patients. We identified 53 interacting-combinations that were present in total 5109 pDDIs with median number of 02 pDDIs per patient. Overall, 91.6% patients had at least one pDDI; 86.3% were having at least one major pDDI, and 84.5% patients had at least one moderate pDDI. Among 5109 identified pDDIs, most were of moderate (55% or major severity (45%; established (24.2%, theoretical (18.8% or probable (57% type of scientific evidence. Top 10 common pDDIs included 3 major and 7 moderate interactions. Results obtained by multivariate logistic regression revealed a significant association of the occurrence of pDDIs in patient with age of 60 years or more (p < 0.001, hospital stay of 7 days or longer (p < 0.001 and taking 7 or more drugs (p < 0.001. We found a high prevalence for pDDIs in the Department of Cardiology, most of which were of moderate severity. Older patients, patients with longer hospital stay and with elevated number of prescribed drugs were at higher risk of pDDIs.

  15. Improving intermolecular interactions in DFTB3 using extended polarization from chemical-potential equalization

    CERN Document Server

    Christensen, Anders S; Cui, Qiang

    2015-01-01

    Semi-empirical quantum mechanical methods traditionally expand the electron density in a minimal, valence-only electron basis set. The minimal-basis approximation causes molecular polarization to be underestimated, and hence intermolecular interaction energies are also underestimated, especially for intermolecular interactions involving charged species. In this work, the third-order self-consistent charge density functional tight-binding method (DFTB3) is augmented with an auxiliary response density using the chemical-potential equalization (CPE) method and an empirical dispersion correction (D3). The parameters in the CPE and D3 models are fitted to high-level CCSD(T) reference interaction energies for a broad range of chemical species, as well as dipole moments calculated at the DFT level; the impact of including polarizabilities of molecules in the parameterization is also considered. Parameters for the elements H, C, N, O and S are presented. The RMSD interaction energy is improved from 6.07 kcal/mol to 1...

  16. Computation of Ship Hydrodynamic Interaction Forces in Restricted Waters using Potential Theory

    Institute of Scientific and Technical Information of China (English)

    Xueqian Zhou; Serge Sutulo; C. Guedes Soares

    2012-01-01

    A computer code based on the double-body potential flow model and the classic source panel method has been developed to study various problems of hydrodynamic interaction between ships and other objects with solid boundaries including the seabed.A peculiarity of the proposed implementation is the application of the so-called “moving-patch” method for simulating steady boundaries of large extensions.The method is based on an assumption that at any moment just the part of the boundary (“moving patch”) which lies close to the interacting ship is significant for the near-field interaction.For a specific case of the flat bottom,comparative computations were performed to determine optimal dimensions of the patch and of the constituting panels based on the trade-off between acceptable accuracy and reasonable efficiency.The method was applied to estimate the sway force on a ship hull moving obliquely across a dredged channel.The method was validated for a case of ship-to-ship interaction when tank data were available.This study also contains a description of a newly developed spline approximation algorithm necessary for creating consistent discretizations of ship hulls with various degrees of refinement.

  17. Entangling spin-spin interactions of ions in individually controlled potential wells

    Science.gov (United States)

    Wilson, Andrew; Colombe, Yves; Brown, Kenton; Knill, Emanuel; Leibfried, Dietrich; Wineland, David

    2014-03-01

    Physical systems that cannot be modeled with classical computers appear in many different branches of science, including condensed-matter physics, statistical mechanics, high-energy physics, atomic physics and quantum chemistry. Despite impressive progress on the control and manipulation of various quantum systems, implementation of scalable devices for quantum simulation remains a formidable challenge. As one approach to scalability in simulation, here we demonstrate an elementary building-block of a configurable quantum simulator based on atomic ions. Two ions are trapped in separate potential wells that can individually be tailored to emulate a number of different spin-spin couplings mediated by the ions' Coulomb interaction together with classical laser and microwave fields. We demonstrate deterministic tuning of this interaction by independent control of the local wells and emulate a particular spin-spin interaction to entangle the internal states of the two ions with 0.81(2) fidelity. Extension of the building-block demonstrated here to a 2D-network, which ion-trap micro-fabrication processes enable, may provide a new quantum simulator architecture with broad flexibility in designing and scaling the arrangement of ions and their mutual interactions. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), ONR, and the NIST Quantum Information Program.

  18. The prospects for producing ultracold NH$_3$ molecules by sympathetic cooling: a survey of interaction potentials

    CERN Document Server

    Zuchowski, Piotr S \\

    2008-01-01

    We investigate the possibility of producing ultracold NH3 molecules by sympathetic cooling in a bath of ultracold atoms. We consider the interactions of NH3 with alkali-metal and alkaline-earth atoms, and with Xe, using ab initio coupled-cluster calculations. For Rb-NH3 and Xe-NH3 we develop full potential energy surfaces, while for the other systems we characterize the stationary points (global and local minima and saddle points). We also calculate isotropic and anisotropic Van der Waals C6 coefficients for all the systems. The potential energy surfaces for interaction of NH3 with alkali-metal and alkaline-earth atoms all show deep potential wells and strong anisotropies. The well depths vary from 887 1/cm for Mg-NH3 to 5104 1/cm for Li-NH3. This suggests that all these systems will exhibit strong inelasticity whenever inelastic collisions are energetically allowed and that sympathetic cooling will work only when both the atoms and the molecules are already in their lowest internal states. Xe-NH3 is more wea...

  19. Assessment of Potential Herb-Drug Interactions among Nigerian Adults with Type-2 Diabetes

    Science.gov (United States)

    Ezuruike, Udoamaka; Prieto, Jose M.

    2016-01-01

    It is becoming increasingly evident that patients with diabetes do not rely only on prescription drugs for their disease management. The use of herbal medicines is one of the self-management practices adopted by these patients, often without the knowledge of their healthcare practitioners. This study assessed the potential for pharmacokinetic herb-drug interactions (HDIs) amongst Nigerian adult diabetic patients. This was done through a literature analysis of the pharmacokinetic profile of their herbal medicines and prescription drugs, based on information obtained from 112 patients with type-2 diabetes attending two secondary health care facilities in Nigeria. Fifty percent of the informants used herbal medicines alongside their prescription drugs. Worryingly, 60% of the patients taking herbal medicines did not know their identity, thus increasing the risk of unidentified HDIs. By comparing the pharmacokinetic profile of eight identified herbs taken by the patients for the management of diabetes against those of the prescription drugs, several scenarios of potential HDIs were identified and their clinical relevance is discussed. The lack of clinical predictors points toward cultural factors as the influence for herb use, making it more difficult to identify these patients and in turn monitor potential HDIs. In identifying these possible interactions, we have highlighted the need for healthcare professionals to promote a proactive monitoring of patients' use of herbal medicines. PMID:27559312

  20. Assessment of Potential Herb-Drug Interactions among Nigerian Adults with Type-2 Diabetes.

    Science.gov (United States)

    Ezuruike, Udoamaka; Prieto, Jose M

    2016-01-01

    It is becoming increasingly evident that patients with diabetes do not rely only on prescription drugs for their disease management. The use of herbal medicines is one of the self-management practices adopted by these patients, often without the knowledge of their healthcare practitioners. This study assessed the potential for pharmacokinetic herb-drug interactions (HDIs) amongst Nigerian adult diabetic patients. This was done through a literature analysis of the pharmacokinetic profile of their herbal medicines and prescription drugs, based on information obtained from 112 patients with type-2 diabetes attending two secondary health care facilities in Nigeria. Fifty percent of the informants used herbal medicines alongside their prescription drugs. Worryingly, 60% of the patients taking herbal medicines did not know their identity, thus increasing the risk of unidentified HDIs. By comparing the pharmacokinetic profile of eight identified herbs taken by the patients for the management of diabetes against those of the prescription drugs, several scenarios of potential HDIs were identified and their clinical relevance is discussed. The lack of clinical predictors points toward cultural factors as the influence for herb use, making it more difficult to identify these patients and in turn monitor potential HDIs. In identifying these possible interactions, we have highlighted the need for healthcare professionals to promote a proactive monitoring of patients' use of herbal medicines. PMID:27559312

  1. Inverse Monte Carlo study on effective interaction potential of Ag–Rh alloy from pair correlation functions

    International Nuclear Information System (INIS)

    This paper presents an inverse Monte Carlo method to reconstruct pair interaction potential from pair correlation function. This approach adopts an iterative algorithm on interaction potential to fit known pair correlation function by compelling deviations of canonical average to meet with Hamiltonian parameters on a basis of statistical mechanism. The effective interaction potential between particles in liquid Ag–Rh alloys has been calculated with the inverse Monte Carlo method. It demonstrates an effective and simple way to obtain the effective potential of complex melt systems. (the physics of elementary particles and fields)

  2. Matter-Wave Solitons in Two-Component Bose-Einstein Condensates with Tunable Interactions and Time Varying Potential

    Institute of Scientific and Technical Information of China (English)

    宣恒农; 左苗

    2011-01-01

    We present three families of exact matter-wave soliton solutions for an effective one-dimension two- component Bose-Einstein condensates (BECs) with tunable interactions, harmonic potential and gain or loss term. We investigate the dynamics of bright-bright solitons, bright-dark solitons and dark-dark solitons for the time-dependent expulsive harmonic trap potential, periodically modulated harmonic trap potential, and kinklike modulated harmonic trap potential. Through the Feshbach resonance, these dynamics can be realized in experiments by suitable control of time-dependent trap parameters, atomic interactions, and interaction with thermal cloud.

  3. Antinucleon-nucleus interaction near threshold from the Paris $\\bar NN$ potential

    CERN Document Server

    Friedman, E; Loiseau, B; Wycech, S

    2015-01-01

    A general algorithm for handling the energy dependence of hadron-nucleon amplitudes in the nuclear medium, consistently with their density dependence, has been recently applied to antikaons, eta mesons and pions interacting with nuclei. Here we apply this approach to antiprotons below threshold, analyzing experimental results for antiprotonic atoms across the periodic table. It is also applied to antiproton and antineutron interaction with nuclei up to 400~MeV/c, comparing with elastic scattering and annihilation cross sections. The underlying $\\bar pN$ scattering amplitudes are derived from the Paris $\\bar NN$ potential, including modifications in the medium. Emphasis is placed on the role of the $P$-wave amplitudes with respect to the repulsive $S$-wave amplitudes.

  4. Research on the potential use of interactive materials on astronomy education

    Science.gov (United States)

    Voelzke, Marcos Rincon; Macedo, Josue

    2016-07-01

    This study presents results of a survey conducted at the Federal Institution of Education, Science and Technology in the North of Minas Gerais (IFNMG), and aimed to investigate the potentialities of the use of interactive materials in the teaching of astronomy. An advanced training course with involved learning activities about basic concepts of astronomy was offered to thirty-two Licenciate students in Physics, Mathematics and Biological Sciences, using the mixed methodology, combined with the three pedagogical moments. Among other aspects, the viability of the use of resources was noticed, involving digital technologies and interactive materials on teaching of astronomy, which may contribute to the broadening of methodological options for future teachers and meet their training needs.

  5. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    International Nuclear Information System (INIS)

    An overview of presentations and discussions which took place at the US Department of Energy/Commission of European Communities (DOE/CEC) workshop on ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection,'' held at San Diego, California, January 21-22, 1987, is provided. The Department has traditionally supported fundamental research on interactions of ionizing radiation with different biological systems and at all levels of biological organization. The aim of this workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection

  6. Host-pathogen Interaction at the Intestinal Mucosa Correlates With Zoonotic Potential of Streptococcus suis

    DEFF Research Database (Denmark)

    Ferrando, Maria Laura; de Greeff, Astrid; van Rooijen, Willemien J. M.;

    2015-01-01

    Background. Streptococcus suis has emerged as an important cause of bacterial meningitis in adults. The ingestion of undercooked pork is a risk factor for human S. suis serotype 2 (SS2) infection. Here we provide experimental evidence indicating that the gastrointestinal tract is an entry site of...... be considered a food-borne pathogen. S. suis interaction with human and pig IEC correlates with S. suis serotype and genotype, which can explain the zoonotic potential of SS2....... of SS2 infection. Methods. We developed a noninvasive in vivo model to study oral SS2 infection in piglets. We compared in vitro interaction of S. suis with human and porcine intestinal epithelial cells (IEC). Results. Two out of 15 piglets showed clinical symptoms compatible with S. suis infection 24...

  7. In vitro and in vivo evaluation of CYP1a interaction potential of terminalia arjuna bark

    Directory of Open Access Journals (Sweden)

    Alice Varghese

    2014-01-01

    Full Text Available Terminalia arjuna Wight and Arn. (Combretaceae is a tree having an extensive medicinal potential in cardiovascular disorders. Triterpenoids are mainly responsible for cardiovascular properties. Aqueous, hydroalcoholic and alcoholic extract of T. arjuna, arjunic acid and arjungenin were examined for their potential to inhibit CYP1A enzyme in rat and human liver microsomes. IC 50 values of aqueous, hydroalcoholic and alcoholic extract of T. arjuna was found to be 11.4, 28.9 and 44.6 μg/ml in rat liver microsomes while 30.0, 29.7 and 39.0 μg/ml in human liver microsomes, respectively for CYP1A. However IC 50 values of arjunic acid and arjungenin for both rat liver microsomes and human liver microsomes were found to be >50 μM. Arjunic acid and arjungenin did not show inhibition of CYP1A enzyme up to concentrations of 50 μM. These in vitro data indicate that Terminalia arjuna extracts contain constituents that can potently inhibit the activity of CYP1A, which could in turn lead to undesirable pharmacokinetic drug-herb interactions in vivo. Based on the in vitro data, interaction potential of the aqueous extract of Terminalia arjuna orally in rats was investigated. A probe substrate, phenacetin, was used to index the activity of CYP1A. In vivo pharmacokinetic study of coadministration of aqueous extract of Terminalia arjuna and phenacetin, revealed that the aqueous extract did not lead to any significant change in the pharmacokinetic parameters of phenacetin as compared with control group. Though there was no in vivo-in vitro correlation, drug interactions could arise with drugs having a narrow therapeutic range and extensively cleared by CYP1A enzyme, which could lead to undesirable side effects.

  8. Predicting potential responses to future climate in an alpine ungulate: interspecific interactions exceed climate effects.

    Science.gov (United States)

    Mason, Tom H E; Stephens, Philip A; Apollonio, Marco; Willis, Stephen G

    2014-12-01

    The altitudinal shifts of many montane populations are lagging behind climate change. Understanding habitual, daily behavioural rhythms, and their climatic and environmental influences, could shed light on the constraints on long-term upslope range-shifts. In addition, behavioural rhythms can be affected by interspecific interactions, which can ameliorate or exacerbate climate-driven effects on ecology. Here, we investigate the relative influences of ambient temperature and an interaction with domestic sheep (Ovis aries) on the altitude use and activity budgets of a mountain ungulate, the Alpine chamois (Rupicapra rupicapra). Chamois moved upslope when it was hotter but this effect was modest compared to that of the presence of sheep, to which they reacted by moving 89-103 m upslope, into an entirely novel altitudinal range. Across the European Alps, a range-shift of this magnitude corresponds to a 46% decrease in the availability of suitable foraging habitat. This highlights the importance of understanding how factors such as competition and disturbance shape a given species' realised niche when predicting potential future responses to change. Furthermore, it exposes the potential for manipulations of species interactions to ameliorate the impacts of climate change, in this case by the careful management of livestock. Such manipulations could be particularly appropriate for species where competition or disturbance already strongly restricts their available niche. Our results also reveal the potential role of behavioural flexibility in responses to climate change. Chamois reduced their activity when it was warmer, which could explain their modest altitudinal migrations. Considering this behavioural flexibility, our model predicts a small 15-30 m upslope shift by 2100 in response to climate change, less than 4% of the altitudinal shift that would be predicted using a traditional species distribution model-type approach (SDM), which assumes that species' behaviour

  9. A new method for detecting interactions between the senses in event-related potentials

    DEFF Research Database (Denmark)

    Gondan, Matthias; Röder, B.

    2006-01-01

    Event-related potentials (ERPs) can be used in multisensory research to determine the point in time when different senses start to interact, for example, the auditory and the visual system. For this purpose, the ERP to bimodal stimuli (AV) is often compared to the sum of the ERPs to auditory (A...... not contain common activity: This activity would be subtracted twice from one ERP and would, therefore, contaminate the result. In the present study, ERPs to unimodal, bimodal, and trimodal auditory, visual, and tactile stimuli (T) were recorded. We demonstrate that (T + TAV) - (TA + TV) is equivalent...

  10. Interaction potentials and energy transfer cross sections for collisions of metastable helium and neon

    International Nuclear Information System (INIS)

    Differential cross sections for elastic and excitation transfer scattering were measured for He(21S) + Ne collisions at kinetic energies between 25 and 225 meV. A kinematic analysis and time-of-flight measurements show that Ne atoms can be excited into all energetically allowed states. From simultaneous fits of the elastic and inelastic differential cross sections information is obtained on the interaction potentials and the energy transfer cross sections. Total cross sections are in agreement with measurements in He-Ne discharges. (author)

  11. Relaxation of the distribution function tails for gases with power-law interaction potentials

    International Nuclear Information System (INIS)

    The relaxation of rarefied gases of particles with the power-law interaction potentials U=α/rs, where 1≤s<4, is considered. The formation and evolution of the distribution function tails are investigated on the basis of the one-dimensional kinetic Landau endash Fokker-Planck equation. For long times, the constructed asymptotic solutions have a propagating-wave appearance in the high velocity region. The analytical solutions are expressed explicitly in terms of the error function. The analytical consideration is accomplished by numerical calculations. The obtained analytical results are in a good agreement with the numerical simulation results. copyright 1997 The American Physical Society

  12. Relativistic symmetries in trigonometric Poschl-Teller potential plus tensor interaction

    OpenAIRE

    Falaye, Babatunde J.; Sameer M. Ikhdair

    2013-01-01

    The Dirac equation is solved to obtain its approximate bound states for a spin-1/2 particle in the presence of trigonometric Poschl-Teller (tPT) potential including a Coulomb-like tensor interaction with arbitrary spin-orbit quantum number $\\kappa$ using an approximation scheme to substitute the centrifugal terms k(k+1)/r^2. In view of spin and pseudo-spin (p-spin) symmetries, the relativistic energy eigenvalues and the corresponding two-component wave functions of a particle moving in the fi...

  13. Baryon-baryon interactions described by the WKB-RGM quark-model potential

    International Nuclear Information System (INIS)

    We investigate the baryon-baryon interactions predicted by the Kyoto-Niigata quark model, by using phase-shift equivalent local potentials obtained in the WKB-RGM method. The effect of flavor symmetry breaking is discussed by comparing the 1S0 potentials among the NN, ΣN(I=3/2), ΣΣ(I=2), ΞΣ(I=3/2) and ΞΞ(I=1) systems, which possess the simple flavor SU3 symmetry (22). It is characterized by the detailed balance between the reduction of the short-range repulsion, generated from the color-magnetic term, and the reduction of the medium-range attraction, generated from scalar-meson exchange. A special role of the Bryan-Scott term in the model fss2 is emphasized. (author)

  14. Isotropization in Bianchi type-I cosmological model with fermions and bosons interacting via Yukawa potential

    CERN Document Server

    Ribas, M O; Devecchi, F P; Kremer, G M

    2015-01-01

    In this work we investigate a model for the early Universe in a Bianchi type-I metric, where the sources of the gravitational field are a fermionic and a bosonic field, interacting through a Yukawa potential, following the standard model of elementary particles. It is shown that the fermionic field has a negative pressure, while the boson has a small positive pressure. The fermionic field is the responsible for an accelerated regime at early times, but since the total pressure tends to zero for large times, a transition to a decelerated regime occurs. Here the Yukawa potential answers for the duration of the accelerated regime, since by decreasing the value of its coupling constant the transition accelerated-decelerated occurs in later times. The isotropization which occurs for late times is due to the presence of the fermionic field as one of the sources of the gravitational field.

  15. Relativistic symmetries with the trigonometric Pöschl—Teller potential plus Coulomb-like tensor interaction

    International Nuclear Information System (INIS)

    The Dirac equation is solved to obtain its approximate bound states for a spin-1/2 particle in the presence of trigonometric Pöschl—Teller (tPT) potential including a Coulomb-like tensor interaction with arbitrary spin—orbit quantum number κ using an approximation scheme to substitute the centrifugal terms κ(κ ± 1)r−2. In view of spin and pseudo-spin (p-spin) symmetries, the relativistic energy eigenvalues and the corresponding two-component wave functions of a particle moving in the field of attractive and repulsive tPT potentials are obtained using the asymptotic iteration method (AIM). We present numerical results in the absence and presence of tensor coupling A and for various values of spin and p-spin constants and quantum numbers n and κ. The non-relativistic limit is also obtained

  16. Interaction of landscape varibles on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Plasencia–Vázquez, A. H.

    2014-12-01

    Full Text Available The loss, degradation, and fragmentation of forested areas are endangering parrot populations. In this study, we determined the influence of fragmentation in relation to vegetation cover, land use, and spatial configuration of fragments on the potential geographical distribution patterns of parrots in the Yucatan Peninsula, Mexico. We used the potential geographical distribution for eight parrot species, considering the recently published maps obtained with the maximum entropy algorithm, and we incorporated the probability distribution for each species. We calculated 71 metrics/variables that evaluate forest fragmentation, spatial configuration of fragments, the ratio occupied by vegetation, and the land use in 100 plots of approximately 29 km², randomly distributed within the presence and absence areas predicted for each species. We also considered the relationship between environmental variables and the distribution probability of species. We used a partial least squares regression to explore patterns between the variables used and the potential distribution models. None of the environmental variables analyzed alone determined the presence/absence or the probability distribution of parrots in the Peninsula. We found that for the eight species, either due to the presence/absence or the probability distribution, the most important explanatory variables were the interaction among three variables, particularly the interactions among the total forest area, the total edge, and the tropical semi–evergreen medium– height forest. Habitat fragmentation influenced the potential geographical distribution of these species in terms of the characteristics of other environmental factors that are expressed together with the geographical division, such as the different vegetation cover ratio and land uses in deforested areas.

  17. Structure and Raman spectra in cryolitic melts: simulations with an ab initio interaction potential.

    Science.gov (United States)

    Cikit, Serpil; Akdeniz, Zehra; Madden, Paul A

    2014-01-30

    The Raman spectra of cryolitic melts have been calculated from molecular dynamics computer simulations using a polarizable ionic potential obtained by force-fitting to ab initio electronic structure calculations. Simulations which made use of this ab initio derived polarizable interaction potential reproduced the structure and dynamical properties of crystalline cryolite, Na3AlF6, rather well. The transferability of the potential model from solid state to the molten state is tested by comparing results for the Raman spectra of melts of various compositions with those previously obtained with empirically developed potentials and with experimental data. The shapes of the spectra and their evolution with composition in the mixtures conform quite well to those seen experimentally, and we discuss the relationship between the bands seen in the spectra and the vibrational modes of the AlFn((3–n)) coordination complexes which are found in the NaF/AlF3 mixtures. The simulations thus enable a link between the structure of the melt as derived through Raman spectroscopy and through diffraction experiments. We report results for quantities which relate to the degree of cross-linking between these coordination complexes and the diffusive properties of ions. PMID:24432905

  18. From interatomic interaction potentials via Einstein field equation techniques to time dependent contact mechanics

    International Nuclear Information System (INIS)

    In order to understand the principle differences between rheological or simple stress tests like the uniaxial tensile test to contact mechanical tests and the differences between quasistatic contact experiments and oscillatory ones, this study resorts to effective first principles. This study will show how relatively simple models simulating bond interactions in solids using effective potentials like Lennard-Jones and Morse can be used to investigate the effect of time dependent stress-induced softening or stiffening of these solids. The usefulness of the current study is in the possibility of deriving relatively simple dependences of the bulk-modulus B on time, shear and pressure P with time t. In cases where it is possible to describe, or at least partially describe a material by Lennard-Jones potential approaches, the above- mentioned dependences are even completely free of microscopic material parameters. Instead of bond energies and length, only specific integral parameters like Young’s modulus and Poisson’s ratio are required. However, in the case of time dependent (viscose) material behavior the parameters are not constants anymore. They themselves depend on time and the actual stress field, especially the shear field. A body completely consisting of so called standard linear solid interacting particles will then phenomenologically show a completely different and usually much more complicated mechanical behavior. The influence of the time dependent pressure-shear-induced Young’s modulus change is discussed with respect to mechanical contact experiments and their analysis in the case of viscose materials. (papers)

  19. Molecular Insights into the Potential Toxicological Interaction of 2-Mercaptothiazoline with the Antioxidant Enzyme—Catalase

    Science.gov (United States)

    Huang, Zhenxing; Huang, Ming; Mi, Chenyu; Wang, Tao; Chen, Dong; Teng, Yue

    2016-01-01

    2-mercaptothiazoline (2-MT) is widely used in many industrial fields, but its residue is potentially harmful to the environment. In this study, to evaluate the biological toxicity of 2-MT at protein level, the interaction between 2-MT and the pivotal antioxidant enzyme—catalase (CAT) was investigated using multiple spectroscopic techniques and molecular modeling. The results indicated that the CAT fluorescence quenching caused by 2-MT should be dominated by a static quenching mechanism through formation of a 2-MT/CAT complex. Furthermore, the identifications of the binding constant, binding forces, and the number of binding sites demonstrated that 2-MT could spontaneously interact with CAT at one binding site mainly via Van der Waals’ forces and hydrogen bonding. Based on the molecular docking simulation and conformation dynamic characterization, it was found that 2-MT could bind into the junctional region of CAT subdomains and that the binding site was close to enzyme active sites, which induced secondary structural and micro-environmental changes in CAT. The experiments on 2-MT toxicity verified that 2-MT significantly inhibited CAT activity via its molecular interaction, where 2-MT concentration and exposure time both affected the inhibitory action. Therefore, the present investigation provides useful information for understanding the toxicological mechanism of 2-MT at the molecular level. PMID:27537873

  20. Potential-of-mean-force description of ionic interactions and structural hydration in biomolecular systems

    Energy Technology Data Exchange (ETDEWEB)

    Hummer, G.; Garcia, A.E. [Los Alamos National Lab., NM (United States). Theoretical Biology and Biophysics Group; Soumpasis, D.M. [Max-Planck-Inst for Biophysical Chemistry, Goettingen (Germany). Biocomputation Group

    1994-10-01

    To understand the functioning of living organisms on a molecular level, it is crucial to dissect the intricate interplay of the immense number of biological molecules. Most of the biochemical processes in cells occur in a liquid environment formed mainly by water and ions. This solvent environment plays an important role in biological systems. The potential-of-mean-force (PMF) formalism attempts to describe quantitatively the interactions of the solvent with biological macromolecules on the basis of an approximate statistical-mechanical representation. At its current status of development, it deals with ionic effects on the biomolecular structure and with the structural hydration of biomolecules. The underlying idea of the PMF formalism is to identify the dominant sources of interactions and incorporate these interactions into the theoretical formalism using PMF`s (or particle correlation functions) extracted from bulk-liquid systems. In the following, the authors shall briefly outline the statistical-mechanical foundation of the PMF formalism and introduce the PMF expansion formalism, which is intimately linked to superposition approximations for higher-order particle correlation functions. The authors shall then sketch applications, which describe the effects of the ionic environment on nucleic-acid structure. Finally, the authors shall present the more recent extension of the PMF idea to describe quantitatively the structural hydration of biomolecules. Results for the interface of ice and water and for the hydration of deoxyribonucleic acid (DNA) will be discussed.

  1. Cubic-quintic long-range interactions with double well potentials

    Science.gov (United States)

    Tsilifis, Panagiotis A.; Kevrekidis, Panayotis G.; Rothos, Vassilis M.

    2014-01-01

    In the present work, we examine the combined effects of cubic and quintic terms of the long-range type in the dynamics of a double well potential. Employing a two-mode approximation, we systematically develop two cubic-quintic ordinary differential equations and assess the contributions of the long-range interactions in each of the relevant prefactors, gauging how to simplify the ensuing dynamical system. Finally, we obtain a reduced canonical description for the conjugate variables of relative population imbalance and relative phase between the two wells and proceed to a dynamical systems analysis of the resulting pair of ordinary differential equations. While in the case of cubic and quintic interactions of the same kind (e.g. both attractive or both repulsive), only a symmetry-breaking bifurcation can be identified, a remarkable effect that emerges e.g. in the setting of repulsive cubic but attractive quintic interactions is a ‘symmetry-restoring’ bifurcation. Namely, in addition to the supercritical pitchfork that leads to a spontaneous symmetry breaking of the antisymmetric state, there is a subcritical pitchfork that eventually reunites the asymmetric daughter branch with the antisymmetric parent one. The relevant bifurcations, the stability of the branches and their dynamical implications are examined both in the reduced (ODE) and in the full (PDE) setting. The model is argued to be of physical relevance, especially so in the context of optical thermal media.

  2. Folding model analysis of alpha radioactivity

    CERN Document Server

    Basu, D N

    2003-01-01

    Radioactive decay of nuclei via emission of $\\alpha$ particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the $\\alpha$-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the $\\alpha$ nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic $\\alpha$-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields microscopic calculations for the half lives of $\\alpha$ decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations...

  3. Clinically Relevant Pharmacological Strategies That Reverse MDMA-Induced Brain Hyperthermia Potentiated by Social Interaction.

    Science.gov (United States)

    Kiyatkin, Eugene A; Ren, Suelynn; Wakabayashi, Ken T; Baumann, Michael H; Shaham, Yavin

    2016-01-01

    MDMA-induced hyperthermia is highly variable, unpredictable, and greatly potentiated by the social and environmental conditions of recreational drug use. Current strategies to treat pathological MDMA-induced hyperthermia in humans are palliative and marginally effective, and there are no specific pharmacological treatments to counteract this potentially life-threatening condition. Here, we tested the efficacy of mixed adrenoceptor blockers carvedilol and labetalol, and the atypical antipsychotic clozapine, in reversing MDMA-induced brain and body hyperthermia. We injected rats with a moderate non-toxic dose of MDMA (9 mg/kg) during social interaction, and we administered potential treatment drugs after the development of robust hyperthermia (>2.5 °C), thus mimicking the clinical situation of acute MDMA intoxication. Brain temperature was our primary focus, but we also simultaneously recorded temperatures from the deep temporal muscle and skin, allowing us to determine the basic physiological mechanisms of the treatment drug action. Carvedilol was modestly effective in attenuating MDMA-induced hyperthermia by moderately inhibiting skin vasoconstriction, and labetalol was ineffective. In contrast, clozapine induced a marked and immediate reversal of MDMA-induced hyperthermia via inhibition of brain metabolic activation and blockade of skin vasoconstriction. Our findings suggest that clozapine, and related centrally acting drugs, might be highly effective for reversing MDMA-induced brain and body hyperthermia in emergency clinical situations, with possible life-saving results. PMID:26105141

  4. Optical potentials for Ne*(3P2,0)-Ar, N2 interactions

    Science.gov (United States)

    Baudon, J.; Feron, P.; Miniatura, C.; Perales, F.; Reinhardt, J.; Robert, J.; Haberland, H.; Brunetti, B.; Vecchiocattivi, F.

    1991-08-01

    The differential elastic cross sections for Ne*(3P2,0)-Ar and Ne*(3P2,0)-N2 collisions have been measured in crossed beam experiments at 0.064 and 0.318 and at 0.071 and 0.295 eV, collision energies, respectively. These results have been analyzed simultaneously with integral cross sections and total ionization cross sections already available and optical spherical potentials for these two systems have been obtained. These potentials appear to be rather accurate in the distance range from 2.5 to ˜9 and from 3.0 to ˜9 Å for Ne*-Ar and Ne*-N2, respectively. The well depths and equilibrium distances are 5.12 meV and 4.9 Å for Ne*-Ar and 3.56 meV and 5.40 Å for Ne*-N2. The short-range repulsion in both cases exhibits a change in slope which can be correlated with the influence, for the interaction at shorter distances, of the Ne+ core of the metastable atom, which becomes less effective when the intermolecular distance increases. The optical potentials proposed here are given in analytical form suitable for the calculation of dynamical observables of these systems.

  5. Thermal and transport properties of a nonrelativistic quantum gas interacting through a delta-shell potential

    International Nuclear Information System (INIS)

    This work extends the seminal work of Gottfried on the two-body quantum physics of particles interacting through a delta-shell potential to many-body physics by studying a system of nonrelativistic particles when the thermal De-Broglie wavelength of a particle is larger than the range of the potential and the density is such that average distance between particles is larger than the above range. The ability of the delta-shell potential to reproduce some basic properties of the deuteron are examined. Relations for moments of bound-states are derived. The virial expansion is used to calculate the first quantum correction to the ideal gas pressure in the form of the second virial coefficient. Additionally, all thermodynamical functions are calculated up to the first-order quantum corrections. For small departures from equilibrium, the net flows of mass, energy and momentum, characterized by the coefficients of diffusion, thermal conductivity and shear viscosity, respectively, are calculated. Properties of the gas are examined for various values of physical parameters including the case of infinite scattering length when the unitary limit is achieved. (author)

  6. Plant-Microbial Interactions Define Potential Mechanisms of Organic Matter Priming in the Rhizosphere

    Science.gov (United States)

    Zhalnina, K.; Cho, H. J.; Hao, Z.; Mansoori, N.; Karaoz, U.; Jenkins, S.; White, R. A., III; Lipton, M. S.; Deng, K.; Zhou, J.; Pett-Ridge, J.; Northen, T.; Firestone, M. K.; Brodie, E.

    2015-12-01

    In the rhizosphere, metabolic processes of plants and microorganisms are closely coupled, and together with soil minerals, their interactions regulate the turnover of soil organic C (SOC). Plants provide readily assimilable metabolites for microorganisms through exudation, and it has been hypothesized that increasing concentrations of exudate C may either stimulate or suppress rates of SOC mineralization (rhizosphere priming). Both positive and negative rhizosphere priming has been widely observed, however the underlying mechanisms remain poorly understood. To begin to identify the molecular mechanisms underlying rhizosphere priming, we isolated a broad range of soil bacteria from a Mediterranean grassland dominated by annual grass. Thirty-nine heterotrophic bacteria were selected for genome sequencing and both rRNA gene analysis and metagenome coverage suggest that these isolates represent naturally abundant strain variants. We analyzed their genomes for potential metabolic traits related to life in the rhizosphere and the decomposition of polymeric SOC. While the two dominant groups, Alphaproteobacteria and Actinobacteria, were enriched in polymer degrading enzymes, Alphaproteobacterial isolates contained greater gene copies of transporters related to amino acid, organic acid and auxin uptake or export, suggesting an enhanced metabolic potential for life in the root zone. To verify this metabolic potential, we determined the enzymatic activities of these isolates and revealed preferences of strains to degrade certain polymers (xylan, cellulose or lignin). Fourier Transform Infrared spectroscopy is being used to determine which polymeric components of plant roots are targeted by specific strains and how exudates may impact their degradation. To verify the potential of isolates to assimilate root exudates and export key metabolites we are using LC-MS/MS based exometabolomic profiling. The traits hypothesized and verified here (transporters, enzymes, exudate uptake

  7. Study of potential drug-drug interactions between benzodiazepines and four commonly used antiepileptic drugs in mice

    OpenAIRE

    Kartik N. Shah; Rana, Devang A.; Patel, Varsha J.

    2014-01-01

    Background: Benzodiazepines (BZD) is one of the commonly used drug groups for certain neurological diseases. As sometimes, the anti-epileptic drugs (AEDs) may be used concomitantly with BZD there is a potential for drug-drug interactions. Study aimed to study potential drug-drug interactions between four commonly used AEDs (phenytoin, carbamazepine (CBZ), phenobarbitone, sodium valproate) and BZD (diazepam, clonazepam) in mice using maximal electroshock seizure (MES) method and pentylenetetra...

  8. Interaction with Dopamine D2 Receptor Enhances Expression of Transient Receptor Potential Channel 1 at the Cell Surface

    OpenAIRE

    Hannan, Meredith A.; Kabbani, Nadine; Paspalas, Constantinos D.; Levenson, Robert

    2008-01-01

    Receptor signaling is mediated by direct protein interaction with various types of cytoskeletal, adapter, effector, and additional receptor molecules. In brain tissue and in cultured neurons, activation of dopamine D2 receptors (D2Rs) has been found to impact cellular calcium signaling. Using a yeast two-hybrid approach, we have uncovered a direct physical interaction between the D2R and the transient receptor potential channel (TRPC) subtypes 1, 4 and 5. The TRPC/D2R interaction was further ...

  9. Analytical calculations of light ion reflection for the inverse-square interaction potential

    International Nuclear Information System (INIS)

    The linear Boltzmann transport equation for diffusion and slowing down of low-energy light ions in solids is Laplace transformed in relative path-length and solved by applying the DP0 technique. The ion-target atom interaction potential is assumed to have a form of the inverse-square law and furthermore, the collision integral of the transport equation is replaced by the P3 approximation in angular variable. The Laplace transformed solution for the reflection function is found and inverted analytically leading to the distribution of backscattered particles in the relative path-length. We have shown that this analytic procedure is in good agreement with the results of numerical Laplace inversion. Simple analytic expressions for the particle and energy reflection coefficients were derived. Our results are compared with computer simulation data and experimental results of different authors. (author)

  10. Baryon femtoscopy considering residual correlations as a tool to extract strong interaction potentials

    Directory of Open Access Journals (Sweden)

    Szymański Maciej

    2015-01-01

    Full Text Available In this article, the analysis of baryon-antibaryon femtoscopic correlations is presented. In particular, it is shown that taking into account residual correlations is crucial for the description of pΛ¯$\\bar \\Lambda $ and p̄Λ correlation functions measured by the STAR experiment in Au–Au collisions at the centre-of-mass energy per nucleon pair √sNN = 200 GeV. This approach enables to obtain pΛ¯$\\bar \\Lambda $ (p̄Λ source size consistent with the sizes extracted from correlations in pΛ (p̄Λ¯$\\bar \\Lambda $ and lighter pair systems as well as with model predictions. Moreover, with this analysis it is possible to derive the unknown parameters of the strong interaction potential for baryon-antibaryon pairs under several assumptions.

  11. In-vitro evaluation of the P-glycoprotein interactions of a series of potentially CNS-active Amaryllidaceae alkaloids

    DEFF Research Database (Denmark)

    Eriksson, André Huss; Rønsted, Nina; Jäger, Anna Katharina; Sendra, Júlia Rodríguez; Brodin, Birger

    2012-01-01

    Drug compounds interacting with the blood-brain barrier efflux transporter P-glycoprotein (P-gp) might have limited access to brain tissue. The aim of the present study was to evaluate whether nine potentially CNS-active Amaryllidaceae alkaloids of the crinine, lycorine and galanthamine types...... interact with P-gp....

  12. Final Report - Assessment of Potential Phosphate Ion-Cementitious Materials Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Naus, Dan J [ORNL; Mattus, Catherine H [ORNL; Dole, Leslie Robert [ORNL

    2007-06-01

    The objectives of this limited study were to: (1) review the potential for degradation of cementitious materials due to exposure to high concentrations of phosphate ions; (2) provide an improved understanding of any significant factors that may lead to a requirement to establish exposure limits for concrete structures exposed to soils or ground waters containing high levels of phosphate ions; (3) recommend, as appropriate, whether a limitation on phosphate ion concentration in soils or ground water is required to avoid degradation of concrete structures; and (4) provide a "primer" on factors that can affect the durability of concrete materials and structures in nuclear power plants. An assessment of the potential effects of phosphate ions on cementitious materials was made through a review of the literature, contacts with concrete research personnel, and conduct of a "bench-scale" laboratory investigation. Results of these activities indicate that: no harmful interactions occur between phosphates and cementitious materials unless phosphates are present in the form of phosphoric acid; phosphates have been incorporated into concrete as set retarders, and phosphate cements have been used for infrastructure repair; no standards or guidelines exist pertaining to applications of reinforced concrete structures in high-phosphate environments; interactions of phosphate ions and cementitious materials has not been a concern of the research community; and laboratory results indicate similar performance of specimens cured in phosphate solutions and those cured in a calcium hydroxide solution after exposure periods of up to eighteen months. Relative to the "primer," a separate NUREG report has been prepared that provides a review of pertinent factors that can affect the durability of nuclear power plant reinforced concrete structures.

  13. Final Report - Assessment of Potential Phosphate Ion-Cementitious Materials Interactions

    International Nuclear Information System (INIS)

    The objectives of this limited study were to: (1) review the potential for degradation of cementitious materials due to exposure to high concentrations of phosphate ions; (2) provide an improved understanding of any significant factors that may lead to a requirement to establish exposure limits for concrete structures exposed to soils or ground waters containing high levels of phosphate ions; (3) recommend, as appropriate, whether a limitation on phosphate ion concentration in soils or ground water is required to avoid degradation of concrete structures; and (4) provide a 'primer' on factors that can affect the durability of concrete materials and structures in nuclear power plants. An assessment of the potential effects of phosphate ions on cementitious materials was made through a review of the literature, contacts with concrete research personnel, and conduct of a 'bench-scale' laboratory investigation. Results of these activities indicate that: no harmful interactions occur between phosphates and cementitious materials unless phosphates are present in the form of phosphoric acid; phosphates have been incorporated into concrete as set retarders, and phosphate cements have been used for infrastructure repair; no standards or guidelines exist pertaining to applications of reinforced concrete structures in high-phosphate environments; interactions of phosphate ions and cementitious materials has not been a concern of the research community; and laboratory results indicate similar performance of specimens cured in phosphate solutions and those cured in a calcium hydroxide solution after exposure periods of up to eighteen months. Relative to the 'primer,' a separate NUREG report has been prepared that provides a review of pertinent factors that can affect the durability of nuclear power plant reinforced concrete structures

  14. Combining genomic sequencing methods to explore viral diversity and reveal potential virus-host interactions

    Directory of Open Access Journals (Sweden)

    Cheryl-Emiliane Tien Chow

    2015-04-01

    Full Text Available Viral diversity and virus-host interactions in oxygen-starved regions of the ocean, also known as oxygen minimum zones (OMZs, remain relatively unexplored. Microbial community metabolism in OMZs alters nutrient and energy flow through marine food webs, resulting in biological nitrogen loss and greenhouse gas production. Thus, viruses infecting OMZ microbes have the potential to modulate community metabolism with resulting feedback on ecosystem function. Here, we describe viral communities inhabiting oxic surface (10m and oxygen-starved basin (200m waters of Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island, British Columbia using viral metagenomics and complete viral fosmid sequencing on samples collected between April 2007 and April 2010. Of 6459 open reading frames (ORFs predicted across all 34 viral fosmids, 77.6% (n=5010 had no homology to reference viral genomes. These fosmids recruited a higher proportion of viral metagenomic sequences from Saanich Inlet than from nearby northeastern subarctic Pacific Ocean (Line P waters, indicating differences in the viral communities between coastal and open ocean locations. While functional annotations of fosmid ORFs were limited, recruitment to NCBI’s non-redundant ‘nr’ database and publicly available single-cell genomes identified putative viruses infecting marine thaumarchaeal and SUP05 proteobacteria to provide potential host linkages with relevance to coupled biogeochemical cycling processes in OMZ waters. Taken together, these results highlight the power of coupled analyses of multiple sequence data types, such as viral metagenomic and fosmid sequence data with prokaryotic single cell genomes, to chart viral diversity, elucidate genomic and ecological contexts for previously unclassifiable viral sequences, and identify novel host interactions in natural and engineered ecosystems.

  15. Evaluation of drug interaction potential of Labisia pumila (Kacip Fatimah) and its constituents.

    Science.gov (United States)

    Manda, Vamshi K; Dale, Olivia R; Awortwe, Charles; Ali, Zulfiqar; Khan, Ikhlas A; Walker, Larry A; Khan, Shabana I

    2014-01-01

    Labisia pumila (Kacip Fatimah) is a popular herb in Malaysia that has been traditionally used in a number of women's health applications such as to improve libido, relieve postmenopausal symptoms, and to facilitate or hasten delivery in childbirth. In addition, the constituents of this plant have been reported to possess anticancer, antioxidant, and anti-inflammatory properties. Clinical studies have indicated that cytochrome P450s (CYPs), P-glycoprotein (P-gp), and Pregnane X receptor (PXR) are the three main modulators of drug-drug interactions which alter the absorption, distribution, and metabolism of drugs. Given the widespread use of Kacip Fatimah in dietary supplements, the current study focuses on determining the potential of its constituents to affect the activities of CYPs, P-gp, or PXR using in vitro assays which may provide useful information toward the risk of herb-drug interaction with concomitantly used drugs. Six compounds isolated from the roots of L. pumila (2 saponins and 4 alkyl phenols) were tested, in addition to the methanolic extract. The extract of L. pumila showed a significant time dependent inhibition (TDI) of CYP3A4, reversible inhibition of CYP2C9 and 2C19 and a weak inhibition of 1A2 and 2D6 as well as an inhibition of P-gp and rifampicin-induced PXR activation. The alkyl phenols inhibited CYP3A4 (TDI), CYP2C9, and 2C19 (reversible) while saponins inhibited P-gp and PXR. In conclusion, L. pumila and its constituents showed significant modulation of all three regulatory proteins (CYPs, P-gp, and PXR) suggesting a potential to alter the pharmacokinetic and pharmacodynamic properties of conventional drugs if used concomitantly. PMID:25152732

  16. Evaluation of drug interaction potential of Labisia pumila (Kacip Fatimah and its constituents

    Directory of Open Access Journals (Sweden)

    Vamshikrishna eManda

    2014-08-01

    Full Text Available Labisia pumila (Kacip Fatimah is a popular herb in Malaysia that has been traditionally used in a number of women’s health applications such as to improve libido, relieve postmenopausal symptoms, and to facilitate or hasten delivery in childbirth. In addition, the constituents of this plant have been reported to possess anticancer, antioxidant, and anti-inflammatory properties. Clinical studies have indicated that cytochrome P450s (CYPs, P-glycoprotein (P-gp, and Pregnane X receptor (PXR are the three main modulators of drug-drug interactions which alter the absorption, distribution, and metabolism of drugs. Given the widespread use of Kacip Fatimah in dietary supplements, the current study focuses on determining the potential of its constituents to affect the activities of CYPs, P-gp, or PXR using in vitro assays which may provide useful information towards the risk of herb-drug interaction with concomitantly used drugs. Six compounds isolated from the roots of Labisia pumila (2 saponins and 4 alkyl phenols were tested, in addition to the methanolic extract. The extract of Labisia pumila showed a significant time dependent inhibition (TDI of CYP3A4, reversible inhibition of CYP2C9 and 2C19 and a weak inhibition of 1A2 and 2D6 as well as an inhibition of P-gp and rifampicin-induced PXR activation. The alkyl phenols inhibited CYP3A4 (TDI, CYP2C9 and 2C19 (reversible while saponins inhibited P-gp and PXR. In conclusion, Labisia pumila and its constituents showed significant modulation of all three regulatory proteins (CYPs, P-gp and PXR suggesting a potential to alter the pharmacokinetic and pharmacodynamic properties of conventional drugs if used concomitantly.

  17. Does curcumin or pindolol potentiate fluoxetine′s antidepressant effect by a pharmacokinetic or pharmacodynamic interaction?

    Directory of Open Access Journals (Sweden)

    H.A.S. Murad

    2014-01-01

    Full Text Available This study was designed to study potentiation of fluoxetine′s antidepressant effect by curcumin or pindolol. Twenty eight groups of mice (n=8 were used in three sets of experiments. In the first set, 9 groups were subjected to the forced swimming test after being treated intraperitoneally with three vehicles, fluoxetine (5 and 20 mg/kg, curcumin (20 mg/kg, pindolol (32 mg/kg, curcumin+fluoxetine (5 mg/kg and pindolol+fluoxetine (5 mg/kg. One hour after the test, serum and brain fluoxetine and norfluoxetine levels were measured in mice receiving fluoxetine (5 and 20 mg/kg, curcumin+fluoxetine (5 mg/kg and pindolol+fluoxetine (5 mg/kg. In the second set, the test was done after pretreatment with p-chlorophenylalanine. In the third set, the locomotor activity was measured. The immobility duration was significantly decreased in fluoxetine (20 mg/kg, curcumin (20 mg/kg, curcumin+fluoxetine (5 mg/kg and pindolol+fluoxetine (5 mg/kg groups. These decreases were reversed with p-chlorophenylalanine. Fluoxetine and norfluoxetine levels were significantly higher in fluoxetine (20 mg/kg group with no differences in fluoxetine (5 mg/kg, curcumin+fluoxetine (5 mg/kg and pindolol+fluoxetine (5 mg/kg groups. Moreover, drugs failed to alter the locomotor activity indicating absence of central stimulation. In conclusion, curcumin, more than pindolol enhanced the antidepressant effect of a subeffective dose of fluoxetine in mice without increasing its serum or brain levels excluding any pharmacokinetic interaction. Reversal of this potentiation with p-chlorophenylalanine suggests a pharmacodynamic interaction through involvement of presynaptic 5-HT 1A receptors.

  18. Dopamine and oxytocin interactions underlying behaviors: potential contributions to behavioral disorders.

    Science.gov (United States)

    Baskerville, Tracey A; Douglas, Alison J

    2010-06-01

    Dopamine is an important neuromodulator that exerts widespread effects on the central nervous system (CNS) function. Disruption in dopaminergic neurotransmission can have profound effects on mood and behavior and as such is known to be implicated in various neuropsychiatric behavioral disorders including autism and depression. The subsequent effects on other neurocircuitries due to dysregulated dopamine function have yet to be fully explored. Due to the marked social deficits observed in psychiatric patients, the neuropeptide, oxytocin is emerging as one particular neural substrate that may be influenced by the altered dopamine levels subserving neuropathologic-related behavioral diseases. Oxytocin has a substantial role in social attachment, affiliation and sexual behavior. More recently, it has emerged that disturbances in peripheral and central oxytocin levels have been detected in some patients with dopamine-dependent disorders. Thus, oxytocin is proposed to be a key neural substrate that interacts with central dopamine systems. In addition to psychosocial improvement, oxytocin has recently been implicated in mediating mesolimbic dopamine pathways during drug addiction and withdrawal. This bi-directional role of dopamine has also been implicated during some components of sexual behavior. This review will discuss evidence for the existence dopamine/oxytocin positive interaction in social behavioral paradigms and associated disorders such as sexual dysfunction, autism, addiction, anorexia/bulimia, and depression. Preliminary findings suggest that whilst further rigorous testing has to be conducted to establish a dopamine/oxytocin link in human disorders, animal models seem to indicate the existence of broad and integrated brain circuits where dopamine and oxytocin interactions at least in part mediate socio-affiliative behaviors. A profound disruption to these pathways is likely to underpin associated behavioral disorders. Central oxytocin pathways may serve as a

  19. Liquid chloroform structure from computer simulation with a full ab initio intermolecular interaction potential

    International Nuclear Information System (INIS)

    We have calculated the intermolecular interaction energies of the chloroform dimer in 12 orientations using the second-order Møller-Plesset perturbation theory. Single point energies of important geometries were calibrated by the coupled cluster with single and double and perturbative triple excitation method. Dunning's correlation consistent basis sets up to aug-cc-pVQZ have been employed in extrapolating the interaction energies to the complete basis set limit values. With the ab initio potential data we constructed a 5-site force field model for molecular dynamics simulations. We compared the simulation results with recent experiments and obtained quantitative agreements for the detailed atomwise radial distribution functions. Our results were also consistent with previous results using empirical force fields with polarization effects. Moreover, the calculated diffusion coefficients reproduced the experimental data over a wide range of thermodynamic conditions. To the best of our knowledge, this is the first ab initio force field which is capable of competing with existing empirical force fields for liquid chloroform

  20. Visuo-tactile interactions in the congenitally deaf: a behavioral and event-related potential study.

    Science.gov (United States)

    Hauthal, Nadine; Debener, Stefan; Rach, Stefan; Sandmann, Pascale; Thorne, Jeremy D

    2014-01-01

    Auditory deprivation is known to be accompanied by alterations in visual processing. Yet not much is known about tactile processing and the interplay of the intact sensory modalities in the deaf. We presented visual, tactile, and visuo-tactile stimuli to congenitally deaf and hearing individuals in a speeded detection task. Analyses of multisensory responses showed a redundant signals effect that was attributable to a coactivation mechanism in both groups, although the redundancy gain was less in the deaf. In line with these behavioral results, on a neural level, there were multisensory interactions in both groups that were again weaker in the deaf. In hearing but not deaf participants, somatosensory event-related potential N200 latencies were modulated by simultaneous visual stimulation. A comparison of unisensory responses between groups revealed larger N200 amplitudes for visual and shorter N200 latencies for tactile stimuli in the deaf. Furthermore, P300 amplitudes were also larger in the deaf. This group difference was significant for tactile and approached significance for visual targets. The differences in visual and tactile processing between deaf and hearing participants, however, were not reflected in behavior. Both the behavioral and electroencephalography (EEG) results suggest more pronounced multisensory interaction in hearing than in deaf individuals. Visuo-tactile enhancements could not be explained by perceptual deficiency, but could be partly attributable to inverse effectiveness. PMID:25653602

  1. The interactive potential of post-modern film narrative - Frequency, Order and Simultaneity

    Directory of Open Access Journals (Sweden)

    Carlos Sena Caires

    2009-05-01

    Full Text Available A considerable number of contemporary films are now using narrative models that allow several adaptations on digital and interactive operating systems. This trend is seen in films such as Memento by Christopher Nolan (2000, Irréversible by Gaspar Noé (2002 and Smoking / No Smoking by Alain Resnais (1993, concerning the chronological organization of their narrative parts – here it is a question of order. Or in films such as Elephant by Gus Van Sant (2003, Groundhog Day by Harold Ramis, 1993 and Rashômon by Akira Kurosawa (1950, for the diegetic repetition – a question of frequency. Or even, in films such as Magnolia by Paul Thomas Anderson (1999 and Short Cuts by Robert Altman, 1993 which use the idea of expansion or compression of the narrative – a question of simultaneity. To change the accessibility of the cinematographic experience and to constantly re-evaluate the way in which the narrative tool is used, is from now on considered the interactive potential of the contemporary film narrative.

  2. Prevalence of potential drug-drug interactions among internal medicine ward in University of Gondar Teaching Hospital, Ethiopia

    Institute of Scientific and Technical Information of China (English)

    Akshaya Srikanth Bhagavathula; Alemayehu Berhanie; Habtamu Tigistu; Yishak Abraham; Yosheph Getachew; Tahir Mehmood Khan; Chandrashekhar Unakal

    2014-01-01

    Objective: To determine the prevalence, clinical significance and the associated risk factors of potential drug-drug interactions (DDIs) at internal medicine ward of University of Gondar (UOG) hospital.Method:medicine ward of UOG hospital from April 29, 2013 to June 2, 2013. Data was collected from medical records and by interviewing the patients face to face. Descriptive analysis was conducted for back ground characteristics and logistic regression was used to determine the associated risk factors.Result:A prospective cross-sectional study was conducted on patients treated in internal interacting combinations with 4.13 potential DDIs per patient. Among 413 potential DDIs most were of moderate interactions 61.2% (n=253) followed by 26% (n=107) of minor interactions and 12.8% (n=53) of major interactions. There was significant association of occurrence of potential DDIs only with taking three or more medications.Conclusion:We have recorded a high rate of prevalence of potential DDI in the internal In our study, we have identified a total number of 413 potential DDIs and 184 types of medicine ward of UOG hospital and a high number of clinically significant DDIs which the most prevalent DDI were of moderate severity. Careful selection of drugs and active pharmaceutical care is encouraged in order to avoid negative consequences of these interactions.

  3. Microscopic optical potentials - study of charge-exchange reactions

    International Nuclear Information System (INIS)

    The present thesis is engaged in two different aspects of direct nuclear reactions, namely on the one hand in the microscopic calculation of the imaginary optical potential for the elastic alpha-nucleus scattering as well on the other hand in the microscopic analysis of giant resonance states which are excited by (p,n) and (n,p) charge-exchange reactions. In the first part in the framework of the nuclear structure approximation to the optical potential a microscopic calculation of the imaginary part of the optical potential for α40Ca scattering at Esub(α) = 31 and 100 MeV is performed. In the second part the 208Pb(p,n) and 208Pb(n,p) charge-exchange reactions are studied at low ( E 100 MeV) incident energies. (orig./HS)

  4. Potential therapeutic hazards due to drug–drug interaction between topically and systemically coadministered medications

    Directory of Open Access Journals (Sweden)

    Lan MJ

    2013-07-01

    Full Text Available Mei-Juan Lan,1 Quan Zhou21Division of Nursing, 2Department of Pharmacy, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People's Republic of ChinaWe read with great interest the study by Peniston et al1 who performed a randomized controlled trial to examine the frequency and type of adverse events (AEs in patients with osteoarthritis who received concurrent therapy of topical diclofenac sodium 1% gel (DSG, and drugs known to have potential drug–drug interactions (DDIs with diclofenac; and concluded that such co-medication had little impact on the frequency of AEs in this population.    The results of this study1 provide very useful information for clinical practice, ie, DSG may be a safe alternative to oral diclofenac when a pain reliever needs to be co-medicated with CYP2C9 substrates like warfarin antidiabetic sulfonylurea derivatives. DDIs between topically and systemically coadministered medications are easily neglected by clinicians, which brings about potential risk of patient safety. Peniston et al1 answered a scientific question in clinical therapeutics. We completely appreciate their rigorous study and original spirit of exploration. We would like to discuss and share our perspectives in the following paragraphs.View original article by Peniston and colleagues

  5. Visuo-tactile interactions in the congenitally deaf: A behavioral and event-related potential study

    Directory of Open Access Journals (Sweden)

    Nadine Hauthal

    2015-01-01

    Full Text Available Auditory deprivation is known to be accompanied by alterations in visual processing. Yet not much is known about tactile processing and the interplay of the intact sensory modalities in the deaf. We presented visual, tactile, and visuo-tactile stimuli to congenitally deaf and hearing individuals in a speeded detection task. Analyses of multisensory responses showed a redundant signals effect that was attributable to a coactivation mechanism in both groups, although the redundancy gain was less in the deaf. In hearing but not deaf participants, N200 latencies of somatosensory event-related potentials were modulated by simultaneous visual stimulation. In deaf but not hearing participants, however, there was a modulation of N200 latencies of visual event-related potentials due to simultaneous tactile stimulation. A comparison of unisensory responses between groups revealed larger N200 amplitudes for visual and shorter N200 latencies for tactile stimuli in the deaf. P300 amplitudes in response to both stimuli were larger in deaf participants. The differences in visual and tactile processing between deaf and hearing participants, however, were not reflected in behavior. The electroencephalography (EEG results suggest an asymmetry in visuo-tactile interactions between deaf and hearing individuals. Visuo-tactile enhancements could neither be fully explained by perceptual deficiency nor by inverse effectiveness. Instead, we suggest that results might be explained by a shift in the relative importance of touch and vision in deaf individuals.

  6. The role of the ion-molecule and molecule-molecule interactions in the formation of the two-ion average force interaction potential

    International Nuclear Information System (INIS)

    The effect of the ion-molecule and intermolecular interactions on the formation of inter-ion average force potentials is investigated within the framework of a classical ion-dipole model of electrolyte solutions. These potentials are shown to possess the Coulomb asymptotics at large distances while in the region of mean distances they reveal creation and disintegration of solvent-shared ion pairs. The calculation results provide a qualitatively authentic physical picture which is experimentally observed in strong electrolytes solutions. In particular, an increased interaction between an ion and a molecule enhances formation of ion pairs in which the ions are separated by one solvent molecule

  7. Convergence of the many-body expansion of interaction potentials: From van der Waals to covalent and metallic systems

    International Nuclear Information System (INIS)

    The many-body expansion of the interaction potential between atoms and molecules is analyzed in detail for different types of interactions involving up to seven atoms. Elementary clusters of Ar, Na, Si, and, in particular, Au are studied, using first-principles wave-function- and density-functional-based methods to obtain the individual n-body contributions to the interaction energies. With increasing atom number the many-body expansion converges rapidly only for long-range weak interactions. Large oscillatory behavior is observed for other types of interactions. This is consistent with the fact that Au clusters up to a certain size prefer planar structures over the more compact three-dimensional Lennard-Jones-type structures. Several Au model potentials and semiempirical PM6 theory are investigated for their ability to reproduce the quantum results. We further investigate small water clusters as prototypes of hydrogen-bonded systems. Here, the many-body expansion converges rapidly, reflecting the localized nature of the hydrogen bond and justifying the use of two-body potentials to describe water-water interactions. The question of whether electron correlation contributions can be successfully modeled by a many-body interaction potential is also addressed

  8. A potential model investigation of the low-energy antikaon-nucleon interaction and antikaon-nucleus bound states

    International Nuclear Information System (INIS)

    The parameters of separable coupled channels s-wave potentials for the strong /bar K/N interaction are determined from low energy K-p scattering data with additional constraints from π-p → πΣK0 production data. The shifts and widths of the Coulomb bound states in kaonic hydrogen are calculated with these potentials and compared with experiment. Optical potentials are constructed from /bar K/N t-matrices derived from the separable potentials, and these optical potentials are used to calculate kaonic helium and kaonic carbon shifts and widths which are also compared with experiment. 68 refs., 50 figs., 9 tabs

  9. Further insights in the ability of classical nonadditive potentials to model actinide ion-water interactions.

    Science.gov (United States)

    Réal, Florent; Trumm, Michael; Schimmelpfennig, Bernd; Masella, Michel; Vallet, Valérie

    2013-04-01

    Pursuing our efforts on the development of accurate classical models to simulate radionuclides in complex environments (Réal et al., J. Phys. Chem. A 2010, 114, 15913; Trumm et al. J. Chem. Phys. 2012, 136, 044509), this article places a large emphasis on the discussion of the influence of models/parameters uncertainties on the computed structural, dynamical, and temporal properties. Two actinide test cases, trivalent curium and tetravalent thorium, have been studied with three different potential energy functions, which allow us to account for the polarization and charge-transfer effects occurring in hydrated actinide ion systems. The first type of models considers only an additive energy term for modeling ion/water charge-transfer effects, whereas the other two treat cooperative charge-transfer interactions with two different analytical expressions. Model parameters are assigned to reproduce high-level ab initio data concerning only hydrated ion species in gas phase. For the two types of cooperative charge-transfer models, we define two sets of parameters allowing or not to cancel out possible errors inherent to the force field used to model water/water interactions at the ion vicinity. We define thus five different models to characterize the solvation of each ion. For both ions, our cooperative charge-transfer models lead to close results in terms of structure in solution: the coordination number is included within 8 and 9, and the mean ion/water oxygen distances are 2.45 and 2.49 Å, respectively, for Th(IV) and Cm(III). PMID:23233426

  10. Interaction of spirochetes with the host fibrinolytic system and potential roles in pathogenesis.

    Science.gov (United States)

    Vieira, Mônica Larucci; Nascimento, Ana Lucia T O

    2016-08-01

    The pathogenic spirochetes Borrelia burgdorferi, B. hermsii, B. recurrentis, Treponema denticola and Leptospira spp. are the etiologic agents of Lyme disease, relapsing fever, periodontitis and leptospirosis, respectively. Lyme borreliosis is a multi-systemic disorder and the most prevalent tick-borne disease in the northern hemisphere. Tick-borne relapsing fever is persistent in endemic areas worldwide, representing a significant burden in some African regions. Periodontal disease, a chronic inflammatory disorder that often leads to tooth loss, is caused by several potential pathogens found in the oral cavity including T. denticola. Leptospirosis is considered the most widespread zoonosis, and the predominant human disease in tropical, undeveloped regions. What these diseases have in common is that they are a significant burden to healthcare costs in the absence of prophylactic measures. This review addresses the interaction of these spirochetes with the fibrinolytic system, plasminogen (Plg) binding to the surface of bacteria and the generation of plasmin (Pla) on their surface. The consequences on host-pathogen interactions when the spirochetes are endowed with this proteolytic activity are discussed on the basis of the results reported in the literature. Spirochetes equipped with Pla activity have been shown to degrade extracellular matrix (ECM) components, in addition to digesting fibrin, facilitating bacterial invasion and dissemination. Pla generation triggers the induction of matrix metalloproteases (MMPs) in a cascade of events that enhances the proteolytic capacity of the spirochetes. These activities in concert with the interference exerted by the Plg/Pla on the complement system - helping the bacteria to evade the immune system - should illuminate our understanding of the mechanisms involved in host infection. PMID:25914944

  11. Hydrodynamic interactions of two nearly touching Brownian spheres in a stiff potential: Effect of fluid inertia

    International Nuclear Information System (INIS)

    The hydrodynamic interaction of two closely spaced micron-scale spheres undergoing Brownian motion was measured as a function of their separation. Each sphere was attached to the distal end of a different atomic force microscopy cantilever, placing each sphere in a stiff one-dimensional potential (0.08 Nm−1) with a high frequency of thermal oscillations (resonance at 4 kHz). As a result, the sphere’s inertial and restoring forces were significant when compared to the force due to viscous drag. We explored interparticle gap regions where there was overlap between the two Stokes layers surrounding each sphere. Our experimental measurements are the first of their kind in this parameter regime. The high frequency of oscillation of the spheres means that an analysis of the fluid dynamics would include the effects of fluid inertia, as described by the unsteady Stokes equation. However, we find that, for interparticle separations less than twice the thickness of the wake of the unsteady viscous boundary layer (the Stokes layer), the hydrodynamic interaction between the Brownian particles is well-approximated by analytical expressions that neglect the inertia of the fluid. This is because elevated frictional forces at narrow gaps dominate fluid inertial effects. The significance is that interparticle collisions and concentrated suspensions at this condition can be modeled without the need to incorporate fluid inertia. We suggest a way to predict when fluid inertial effects can be ignored by including the gap-width dependence into the frequency number. We also show that low frequency number analysis can be used to determine the microrheology of mixtures at interfaces

  12. Hydrodynamic interactions of two nearly touching Brownian spheres in a stiff potential: Effect of fluid inertia

    Energy Technology Data Exchange (ETDEWEB)

    Radiom, Milad, E-mail: milad.radiom@unige.ch; Ducker, William, E-mail: wducker@vt.edu [Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24060 (United States); Robbins, Brian; Paul, Mark [Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24060 (United States)

    2015-02-15

    The hydrodynamic interaction of two closely spaced micron-scale spheres undergoing Brownian motion was measured as a function of their separation. Each sphere was attached to the distal end of a different atomic force microscopy cantilever, placing each sphere in a stiff one-dimensional potential (0.08 Nm{sup −1}) with a high frequency of thermal oscillations (resonance at 4 kHz). As a result, the sphere’s inertial and restoring forces were significant when compared to the force due to viscous drag. We explored interparticle gap regions where there was overlap between the two Stokes layers surrounding each sphere. Our experimental measurements are the first of their kind in this parameter regime. The high frequency of oscillation of the spheres means that an analysis of the fluid dynamics would include the effects of fluid inertia, as described by the unsteady Stokes equation. However, we find that, for interparticle separations less than twice the thickness of the wake of the unsteady viscous boundary layer (the Stokes layer), the hydrodynamic interaction between the Brownian particles is well-approximated by analytical expressions that neglect the inertia of the fluid. This is because elevated frictional forces at narrow gaps dominate fluid inertial effects. The significance is that interparticle collisions and concentrated suspensions at this condition can be modeled without the need to incorporate fluid inertia. We suggest a way to predict when fluid inertial effects can be ignored by including the gap-width dependence into the frequency number. We also show that low frequency number analysis can be used to determine the microrheology of mixtures at interfaces.

  13. Interspecies interactions and potential Influenza A virus risk in small swine farms in Peru

    Directory of Open Access Journals (Sweden)

    McCune Sarah

    2012-03-01

    Full Text Available Abstract Background The recent avian influenza epidemic in Asia and the H1N1 pandemic demonstrated that influenza A viruses pose a threat to global public health. The animal origins of the viruses confirmed the potential for interspecies transmission. Swine are hypothesized to be prime "mixing vessels" due to the dual receptivity of their trachea to human and avian strains. Additionally, avian and human influenza viruses have previously been isolated in swine. Therefore, understanding interspecies contact on smallholder swine farms and its potential role in the transmission of pathogens such as influenza virus is very important. Methods This qualitative study aimed to determine swine-associated interspecies contacts in two coastal areas of Peru. Direct observations were conducted at both small-scale confined and low-investment swine farms (n = 36 and in open areas where swine freely range during the day (n = 4. Interviews were also conducted with key stakeholders in swine farming. Results In both locations, the intermingling of swine and domestic birds was common. An unexpected contact with avian species was that swine were fed poultry mortality in 6/20 of the farms in Chancay. Human-swine contacts were common, with a higher frequency on the confined farms. Mixed farming of swine with chickens or ducks was observed in 36% of all farms. Human-avian interactions were less frequent overall. Use of adequate biosecurity and hygiene practices by farmers was suboptimal at both locations. Conclusions Close human-animal interaction, frequent interspecies contacts and suboptimal biosecurity and hygiene practices pose significant risks of interspecies influenza virus transmission. Farmers in small-scale swine production systems constitute a high-risk population and need to be recognized as key in preventing interspecies pathogen transfer. A two-pronged prevention approach, which offers educational activities for swine farmers about sound hygiene and

  14. Potential impact of climate-related changes is buffered by differential responses to recruitment and interactions

    KAUST Repository

    Menge, Bruce A.

    2011-08-01

    Detection of ecosystem responsiveness to climatic perturbations can provide insight into climate change consequences. Recent analyses linking phytoplankton abundance and mussel recruitment to the North Pacific Gyre Oscillation (NPGO) revealed a paradox. Despite large increases in mussel recruitment beginning in 2000, adult mussel responses were idiosyncratic by site and intertidal zone, with no response at one long-term site, and increases in the low zone (1.5% per year) and decreases in the mid zone (1.3% per year) at the other. What are the mechanisms underlying these differential changes? Species interactions such as facilitation by barnacles and predation are potential determinants of successful mussel colonization. To evaluate these effects, we analyzed patterns of barnacle recruitment, determined if predation rate covaried with the increase in mussel recruitment, and tested facilitation interactions in a field experiment. Neither magnitude nor season of barnacle recruitment changed meaningfully with site or zone from the 1990s to the 2000s. In contrast to the relationship between NPGO and local-scale mussel recruitment, relationships between local-scale patterns of barnacle recruitment and climate indices were weak. Despite differences in rates of prey recruitment and abundance of sea stars in 1990–1991, 1999–2000, and 2007–2008, predation rates were nearly identical in experiments before, during, and after 1999–2000. The facilitation experiment showed that mussels M. trossulus only became abundant when barnacle recruitment was allowed, when abundance of barnacles reached high abundance of ∼50% cover, and when mussel recruitment was sufficiently high. Thus, in the low zone minimal changes in mussel abundance despite sharply increased recruitment rates are consistent with the hypothesis that change in adult mussel cover was buffered by the relative insensitivity of barnacle recruitment to climatic fluctuations, and a resultant lack of change in

  15. Questions of the optical potential for alpha-particles at low energies

    International Nuclear Information System (INIS)

    Among the high-priority elements for the accelerator driven systems (ADS) and fusion-reactor projects are also Zr, Mo and Li, so that the corresponding nuclear data for nucleon-, deuteron-, and α-particle interactions are of actual interest for neutron production, activation, heating, shielding requirements, and material damage estimation as well as radioactive waste transmutation projects. By using advanced nuclear models that account for details of nuclear structure and the quantum nature of the nuclear scattering, significant gains in accuracy can be achieved below 150 MeV, where intranuclear cascade calculations become less accurate. It is why this work reports on the progress of the analysis of optical potentials for nucleons, deuterons and α-particles on isotopes of these elements, and corresponding reaction cross sections calculations. The elastic-scattering angular distributions measured at deuteron energies between 3 and 50 MeV on the target nucleus 6Li, and between 1 and 14.7 MeV for the target nucleus 7Li have been thus analyzed by using the computer codes SCAT2 for pure elastic scattering processes and FRESCO for the coupled reaction channels for taking into account the effects of the elastic and inelastic alpha transfer in the d+6Li interaction. The good overall agreement obtained with the experimental data for both 6,7Li target nuclei from 1 to 50 MeV has finally proved suitable optical model potentials (OMPs). Within the double folding formalism of the alpha-nucleus optical potential, used previously for a semi-microscopic analysis of the alpha-particle elastic scattering on A∼100 nuclei at energies below 32 MeV, effects due to changes of the nuclear density at a finite temperature are considered. Parameterizations of the double-folding (DF) real potential as well as of a regional phenomenological potential have been used in the study of the (n,α) reaction cross sections for the target nuclei 92,95,98,100Mo. Taking the microscopic DF potentials

  16. Interplay between interaction and nonidentical coupling for a Bose–Einstein Condensate in a triple-well potential

    International Nuclear Information System (INIS)

    Highlights: • The interplay between interaction and nonidentical coupling gives rive to a “two negatives make a positive” effect. • In the weak interaction regime, the beating phenomenon is found. • In the strong interaction region, the collapse and revival sequences can appear instead of the beating sequences. - Abstract: We investigate the effect of interaction and nonidentical coupling on the tunneling dynamics of a Bose–Einstein Condensate trapped in a triple-well potential. In certain parameter regions, we find a “two negatives make a positive” effect. While interaction or nonidentical coupling by itself can suppress the tunneling between the wells, both together enhance the tunneling. In addition, it is shown that under appropriate conditions, the mean-field dynamics displays beating phenomenon in the weak interaction regime. We present a physical explanation for such beating phenomenon. The effect of quantum fluctuation on the beating structure is also discussed numerically

  17. Interplay between interaction and nonidentical coupling for a Bose–Einstein Condensate in a triple-well potential

    Energy Technology Data Exchange (ETDEWEB)

    Rong, Shiguang, E-mail: rong_shiguang@sina.com [Department of Physics, Hunan University of Science & Technology, Xiangtan 411201 (China); Xie, Qiongtao [College of Physics and Electronic Engineering, Hainan Normal University, Haikou 571158 (China); Hai, Wenhua [Department of Physics, Hunan Normal University, Changsha 410081 (China)

    2015-09-18

    Highlights: • The interplay between interaction and nonidentical coupling gives rive to a “two negatives make a positive” effect. • In the weak interaction regime, the beating phenomenon is found. • In the strong interaction region, the collapse and revival sequences can appear instead of the beating sequences. - Abstract: We investigate the effect of interaction and nonidentical coupling on the tunneling dynamics of a Bose–Einstein Condensate trapped in a triple-well potential. In certain parameter regions, we find a “two negatives make a positive” effect. While interaction or nonidentical coupling by itself can suppress the tunneling between the wells, both together enhance the tunneling. In addition, it is shown that under appropriate conditions, the mean-field dynamics displays beating phenomenon in the weak interaction regime. We present a physical explanation for such beating phenomenon. The effect of quantum fluctuation on the beating structure is also discussed numerically.

  18. Water structure near single and multi-layer nanoscopic hydrophobic plates of varying separation and interaction potentials

    Indian Academy of Sciences (India)

    Malay Rana; Amalendu Chandra

    2008-06-01

    We have performed a series of molecular dynamics simulations of water containing two nanoscopic hydrophobic plates to investigate the modifications of the density and hydrogen bond distributions of water in the vicinity of the surfaces. Our primary goal is to look at the effects of plate thickness, solute–solvent interaction and also interplate separation on the solvent structure in the confined region between two graphite-like plates and also near the outer surfaces of the plates. The thickness of the plates is varied by considering single and triple-layer graphite plates and the interaction potential is varied by tuning the attractive strength of the 12–6 pair interaction potential between a carbon atom of the graphite plates and a water molecule. The calculations are done for four different values of the tuning parameter ranging from fully Lennard–Jones to pure repulsive pair interactions. It is found that both the solvation characteristics and hydrogen bond distributions can depend rather strongly on the strength of the attractive part of the solute–water interaction potential. The thickness of the plates, however, is found to have only minor effects on the density profiles and hydrogen bond network. This indicates that the long range electrostatic interactions between water molecules on the two opposite sides of the same plate do not make any significant contribution to the overall solvation structure of these hydrophobic plates. The solvation characteristics are primarily determined by the balance between the loss of energy due to hydrogen bond network disruption, cavity repulsion potential and offset of the same by attractive component of the solute–water interactions. Our studies with different system sizes show that the essential features of solvation properties, e.g. wetting and dewetting characteristics for different interplate separations and interaction potentials, are also present in relatively smaller systems consisting of a few hundred

  19. Vortices in a rotating two-component Bose–Einstein condensate with tunable interactions and harmonic potential

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiao-Fei, E-mail: xfzhang@ntsc.ac.cn [Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Chinese Academy of Sciences, Xi’an 710600 (China); Du, Zhi-Jing [Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Chinese Academy of Sciences, Xi’an 710600 (China); Tan, Ren-Bing [Department of Physics, School of Mathematics and Physics, Chongqing University of Science and Technology, Chongqing 401331 (China); Dong, Rui-Fang; Chang, Hong; Zhang, Shou-Gang [Key Laboratory of Time and Frequency Primary Standards, National Time Service Center, Chinese Academy of Sciences, Xi’an 710600 (China)

    2014-07-15

    We consider a pair of coupled nonlinear Schrödinger equations modeling a rotating two-component Bose–Einstein condensate with tunable interactions and harmonic potential, with emphasis on the structure of vortex states by varying the strength of inter-component interaction, rotational frequency, and the aspect ratio of the harmonic potential. Our results show that the inter-component interaction greatly enhances the effect of rotation. For the case of isotropic harmonic potential and small inter-component interaction, the initial vortex structure remains unchanged. As the ratio of inter- to intra-component interactions increases, each component undergoes a transition from a vortex lattice (vortex line) in an isotropic (anisotropic) harmonic potential to an alternatively arranged stripe pattern, and eventually to the interwoven “serpentine” vortex sheets. Moreover, in the case of anisotropic harmonic potential the system can develop to a rotating droplet structure. -- Highlights: •Different vortex structures are obtained within the full parameter space. •Effects of system parameters on the ground state structure are discussed. •Phase transition between different vortex structures is also examined. •Present one possible way to obtain the rotating droplet structure. •Provide many possibilities to manipulate vortex in two-component BEC.

  20. Interaction of the 106-126 prion peptide with lipid membranes and potential implication for neurotoxicity

    International Nuclear Information System (INIS)

    Prion diseases are fatal neurodegenerative disorders characterized by the accumulation in the brain of an abnormally misfolded, protease-resistant, and β-sheet rich pathogenic isoform (PrPsc) of the cellular prion protein (PrPc). In the present work, we were interested to study the mode of prion protein interaction with the membrane using the 106-126 peptide and small unilamellar lipid vesicles as model. As previously demonstrated, we showed by MTS assay that PrP 106-126 induces alterations in the human neuroblastoma SH-SY5Y cell line. We demonstrated for the first time by lipid-mixing assay and by the liposome vesicle leakage test that PrP 106-126, a non-tilted peptide, induces liposome fusion thus a potential cell membrane destabilization, as supported by membrane integrity assay (LDH). By circular dichroism (CD) analysis we showed that the fusogenic property of PrP 106-126 in the presence of liposome is associated with a predominantly β-sheet structure. These data suggest that the fusogenic property associated with a predominant β-sheet structure exhibited by the prion peptides contributes to the neurotoxicity of these peptides by destabilizing cellular membranes. The latter might be attached at the membrane surface in a parallel orientation as shown by molecular modeling

  1. Spatial Interaction Modeling to Identify Potentially Exposed Populations during RDD or IND Terrorism Incidents

    International Nuclear Information System (INIS)

    Homeland Security Presidential Directive no.5 (HSPD-5) Management of Domestic Incidents and Department of Homeland Security (DHS) Planning Guidance for Protection and Recovery Following Radiological Dispersal Device (RDD) and Improvised Nuclear Device (IND) Incidents underscore the need to delineate radiological emergency guidance applicable to remedial action and recovery following an RDD or IND incident. Rapid delineation of the population potentially exposed to ionizing radiation from fallout during terrorist incidents involving RDDs or low-yield nuclear devices (≤ 20 KT) is necessary for effective medical response and incident management as part of the recovery process. This paper illustrates the application of spatial interaction models to allocate population data for a representative U.S. urban area (≅1.3M people; 1,612.27 km2 area) at a geographical scale relevant for accurately estimating risk given dose concentrations. Estimated total dose equivalents (TEDE) are calculated for isopleths moving away from the detonation point for typical release scenarios. Population is estimated within the TEDE zones using Euclidean distances between zip code polygon centroids generated in ArcGIS version 9.1 with distance decay determined by regression analysis to apportion origin-destination pairs to a population count and density matrix on a spatial basis for daytime and night-time release scenarios. (authors)

  2. Invaders eating invaders: potential trophic interactions between the amphipod Dikerogammarus villosus and juvenile crayfish Orconectes limosus

    Directory of Open Access Journals (Sweden)

    M. Buřič

    2009-01-01

    Full Text Available We investigated potential interspecific predation between two invasive crustacean species, currently widespread and co-occurring in European inland waters: the Ponto-Caspian amphipod Dikerogammarus villosus (Gammaridae and the North American spiny-cheek crayfish Orconectes limosus (Cambaridae. We evaluated interactions of adult specimens of D. villosus and juvenile O. limosus (from the 3rd developmental stage – DS under conditions with and without feeding. We used two different experimental setups: short-term (one-week rearing in aquaria each containing 30 specimens of either single-species or mixed stock, and 20-daylong rearing in small circular plates with one individual of each species. In the aquaria, a significant effect of D. villosus presence on survival of O. limosus stocks was found, with stronger influence on unfed stocks. Survival of D. villosus was not influenced by either O. limosus presence or feeding. Direct predation of D. villosus on juvenile O. limosus, predominantly on the 3rd DS, was often observed in the small plates. The 5th DS O. limosus was killed only a few times and was already able to feed on adult D. villosus. Our results show that both species are able to affect each other negatively through intra-guild predation: D. villosus may successfully feed on juvenile O. limosus (3rd and 4th DS, but larger crayfish can resist predation by the amphipod.

  3. Potential effects of ex-vessel molten core debris interactions on boiling water reactor containment integrity

    International Nuclear Information System (INIS)

    There is a steadily increasing awareness of the highly plant-specific nature of reactor safety issues. This awareness is reflected in the increasing number of research programs focused on problems limited to specific reactor or containment types. This report is limited to NRC-sponsored research on accident phenomena that may affect the integrity of boiling water reactor containment systems arising out of ex-vessel interactions of molten core debris in the reactor cavity. Some safety issues that are generic to all types of BWRs are discussed, these include: (1) effects of concrete composition, (2) dispersive effect of structures below the reactor vessel, (3) influence of unoxidized zirconium metal in the debris pool, (4) the influence of water in the reactor cavity on debris coolability and magnitude of the radiological source term, and (5) the nature of high-temperature condensed-phase chemistry and fission-product aerosol generation. Certain ex-vessel core-debris phenomena which may threaten the integrity of specific BWR containment designs include the following: (1) integrity of the BWR MARK-I steel pressure boundary, (2) potential for penetration of the MARK-II drywell floor and/or supression-pool bypass, and (3) possible failure of the MARK-III reactor support system due to thermal ablation of the reactor pedestal. Some recent experimental results derived from NRC-sponsored programs are also presented

  4. Formalizing the potential of stereoscopic 3D user experience in interactive entertainment

    Science.gov (United States)

    Schild, Jonas; Masuch, Maic

    2015-03-01

    The use of stereoscopic 3D vision affects how interactive entertainment has to be developed as well as how it is experienced by the audience. The large amount of possibly impacting factors and variety as well as a certain subtlety of measured effects on user experience make it difficult to grasp the overall potential of using S3D vision. In a comprehensive approach, we (a) present a development framework which summarizes possible variables in display technology, content creation and human factors, and (b) list a scheme of S3D user experience effects concerning initial fascination, emotions, performance, and behavior as well as negative feelings of discomfort and complexity. As a major contribution we propose a qualitative formalization which derives dependencies between development factors and user effects. The argumentation is based on several previously published user studies. We further show how to apply this formula to identify possible opportunities and threats in content creation as well as how to pursue future steps for a possible quantification.

  5. Interaction of Musicianship and Aging: A Comparison of Cortical Auditory Evoked Potentials

    Directory of Open Access Journals (Sweden)

    Jennifer L. O’Brien

    2015-01-01

    Full Text Available Objective. The goal of this study was to begin to explore whether the beneficial auditory neural effects of early music training persist throughout life and influence age-related changes in neurophysiological processing of sound. Design. Cortical auditory evoked potentials (CAEPs elicited by harmonic tone complexes were examined, including P1-N1-P2, mismatch negativity (MMN, and P3a. Study Sample. Data from older adult musicians (n=8 and nonmusicians (n=8 (ages 55–70 years were compared to previous data from young adult musicians (n=40 and nonmusicians (n=20 (ages 18–33 years. Results. P1-N1-P2 amplitudes and latencies did not differ between older adult musicians and nonmusicians; however, MMN and P3a latencies for harmonic tone deviances were earlier for older musicians than older nonmusicians. Comparisons of P1-N1-P2, MMN, and P3a components between older and young adult musicians and nonmusicians suggest that P1 and P2 latencies are significantly affected by age, but not musicianship, while MMN and P3a appear to be more sensitive to effects of musicianship than aging. Conclusions. Findings support beneficial influences of musicianship on central auditory function and suggest a positive interaction between aging and musicianship on the auditory neural system.

  6. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    The Office of Health and Environmental Research (OHER) of the US Department of Energy conducts a broad multidisciplinary research program which includes basic biophysics, biophysical chemistry, molecular and cellular biology as well as experimental animal studies and opportunistic human studies. This research is directed at understanding how low levels of radiation of various qualities produce the spectrum of biological effects that are seen for such exposures. This workshop was entitled ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection.'' It ws jointly sponsored by the Department of Energy and the Commission of European Communities. The aim of the workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection. The overview of research provided by this multidisciplinary group will be helpful to the Office in program planning. This report includes a summary of the presentations, extended abstracts, the meeting agenda, research recommendations, and a list of participants. Individual papers are processed separately for the data base.

  7. Wigner quantum systems. Two particles interacting via a harmonic potential-1: two-dimensional space

    International Nuclear Information System (INIS)

    A non-canonical quantum system, consisting of two non-relativistic particles, interacting via a harmonic potential, is considered. The centre-of-mass position and momentum operators obey the canonical commutation relations, whereas the internal variables are assumed to be the odd generators of the Lie superalgebra sl(1,2). This assumption implies a set of constraints in the phase space, which are explicitly written in the paper. All finite dimensional irreducible representations of sl(1,2) are considered. Particular attention is paid to the physical representations, i.e. the representations, corresponding to Hermitian position and momentum operators. The properties of the physical observables are investigated. In particular, the operators of the internal Hamiltonian, the relative distance, the internal momentum and the orbital momentum commute with each other. The spectrum of these operators is finite. The distance between the constituents is preserved in time. It can take no more than three different values. For any non-negative integer or half-integer l there exists a representation, where the orbital momentum is l (in unit 2 slash-h). The position of any one of the particles cannot be localized, since the operators of the coordinates do not commute with each other. The constituents are smeared with a certain probability within a finite surface, which moves with a constant velocity together with the centre of mass. (author)

  8. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    International Nuclear Information System (INIS)

    The Office of Health and Environmental Research (OHER) of the US Department of Energy conducts a broad multidisciplinary research program which includes basic biophysics, biophysical chemistry, molecular and cellular biology as well as experimental animal studies and opportunistic human studies. This research is directed at understanding how low levels of radiation of various qualities produce the spectrum of biological effects that are seen for such exposures. This workshop was entitled ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection.'' It ws jointly sponsored by the Department of Energy and the Commission of European Communities. The aim of the workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection. The overview of research provided by this multidisciplinary group will be helpful to the Office in program planning. This report includes a summary of the presentations, extended abstracts, the meeting agenda, research recommendations, and a list of participants. Individual papers are processed separately for the data base

  9. Argon Interaction with Gold Surfaces: Ab Initio-Assisted Determination of Pair Ar-Au Potentials for Molecular Dynamics Simulations.

    Science.gov (United States)

    Grenier, Romain; To, Quy-Dong; de Lara-Castells, María Pilar; Léonard, Céline

    2015-07-01

    Global potentials for the interaction between the Ar atom and gold surfaces are investigated and Ar-Au pair potentials suitable for molecular dynamics simulations are derived. Using a periodic plane-wave representation of the electronic wave function, the nonlocal van-der-Waals vdW-DF2 and vdW-OptB86 approaches have been proved to describe better the interaction. These global interaction potentials have been decomposed to produce pair potentials. Then, the pair potentials have been compared with those derived by combining the dispersionless density functional dlDF for the repulsive part with an effective pairwise dispersion interaction. These repulsive potentials have been obtained from the decomposition of the repulsive interaction between the Ar atom and the Au2 and Au4 clusters and the dispersion coefficients have been evaluated by means of ab initio calculations on the Ar+Au2 complex using symmetry adapted perturbation theory. The pair potentials agree very well with those evaluated through periodic vdW-DF2 calculations. For benchmarking purposes, CCSD(T) calculations have also been performed for the ArAu and Ar+Au2 systems using large basis sets and extrapolations to the complete basis set limit. This work highlights that ab initio calculations using very small surface clusters can be used either as an independent cross-check to compare the performance of state-of-the-art vdW-corrected periodic DFT approaches or, directly, to calculate the pair potentials necessary in further molecular dynamics calculations. PMID:26046588

  10. The potential use of SUISEKI as a protein interaction discovery tool.

    Science.gov (United States)

    Blaschke, C; Valencia, A

    2001-01-01

    Relevant information about protein interactions is stored in textual sources. This sources are commonly used not only as archives of what is already known but also as information for generating new knowledge, particularly to pose hypothesis about new possible interactions that can be inferred from the existing ones. This task is the more creative part of scientific work in experimental systems. We present a large-scale analysis for the prediction of new interactions based on the interaction network for the ones already known and detected automatically in the literature. During the last few years it has became clear that part of the information about protein interactions could be extracted with automatic tools, even if these tools are still far from perfect and key problems such as detection of protein names are not completely solved. We have developed a integrated automatic approach, called SUISEKI (System for Information Extraction on Interactions), able to extract protein interactions from collections of Medline abstracts. Previous experiments with the system have shown that it is able to extract almost 70% of the interactions present in relatively large text corpus, with an accuracy of approximately 80% (for the best defined interactions) that makes the system usable in real scenarios, both at the level of extraction of protein names and at the level of extracting interaction between them. With the analysis of the interaction map of Saccharomyces cerevisiae we show that interactions published in the years 2000/2001 frequently correspond to proteins or genes that were already very close in the interaction network deduced from the literature published before these years and that they are often connected to the same proteins. That is, discoveries are commonly done among highly connected entities. Some biologically relevant examples illustrate how interactions described in the year 2000 could have been proposed as reasonable working hypothesis with the information

  11. Deuteron - $\\alpha$ interaction by inversion of RGM S-matrix determination of spin-orbit potential for spin-1 projectile

    CERN Document Server

    MacIntosh, R S

    1997-01-01

    The iterative-perturbative (IP) procedure for S-matrix to potential inversion is applied to spin-one projectiles for the restricted case of vector spin-orbit interaction only. In order to evaluate this extension of IP inversion we have inverted the multi-channel RGM $S_{lj}$ of Kanada et al for deuterons scattering from $^4$He with deuteron distortion and then compared the central components with those derived from RGM with spin set to zero. Attention is given to the question of how well the resulting potentials are established. Reliable spin-1 inversion is demonstrated. Results relating to inversion, to deuteron-nucleus interactions and to RGM are presented and suggest the range of nuclear interaction information which the procedure makes possible. Unusual non-locality and parity dependence effects are found; these are of possible relevance to generic properties of nuclear potentials.

  12. Approximate bound-state solutions of the dirac equation for the generalized Yukawa potential plus the generalized tensor interaction

    International Nuclear Information System (INIS)

    In this paper, we obtain the approximate analytical bound-state solutions of the Dirac particle with the generalized Yukawa potential within the framework of spin and pseudospin symmetries for the arbitrary κ state with a generalized tensor interaction. The generalized parametric Nikiforov-Uvarov method is used to obtain the energy eigenvalues and the corresponding wave functions in closed form. We also report some numerical results and present figures to show the effect of the tensor interaction.

  13. Interactions of biotic and abiotic environmental factors in an ectomycorrhizal symbiosis, and the potential for selection mosaics

    OpenAIRE

    Hoeksema Jason D; Piculell Bridget J; Thompson John N

    2008-01-01

    Abstract Background Geographic selection mosaics, in which species exert different evolutionary impacts on each other in different environments, may drive diversification in coevolving species. We studied the potential for geographic selection mosaics in plant-mycorrhizal interactions by testing whether the interaction between bishop pine (Pinus muricata D. Don) and one of its common ectomycorrhizal fungi (Rhizopogon occidentalis Zeller and Dodge) varies in outcome, when different combination...

  14. Approximate bound-state solutions of the dirac equation for the generalized Yukawa potential plus the generalized tensor interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ikot, Akpan N. [University of Uyo, Uyo (Nigeria); Maghsoodi, Elham; Hassanabadi, Hassan [Islamic Azad University, Shahrood (Iran, Islamic Republic of); Obu, Joseph A. [University of Calabar, Calabar (Nigeria)

    2014-05-15

    In this paper, we obtain the approximate analytical bound-state solutions of the Dirac particle with the generalized Yukawa potential within the framework of spin and pseudospin symmetries for the arbitrary κ state with a generalized tensor interaction. The generalized parametric Nikiforov-Uvarov method is used to obtain the energy eigenvalues and the corresponding wave functions in closed form. We also report some numerical results and present figures to show the effect of the tensor interaction.

  15. On the velocity and chemical-potential dependence of the heavy-quark interaction in N=4 SYM plasmas

    CERN Document Server

    Avramis, S D; Zoakos, D; Avramis, Spyros D.; Sfetsos, Konstadinos; Zoakos, Dimitrios

    2006-01-01

    We consider the interaction of a heavy quark-antiquark pair moving in N=4 SYM plasma in the presence of non-vanishing chemical potentials. Of particular importance is the maximal length beyond which the interaction is practically turned off. We propose a simple phenomenological law that takes into account the velocity dependence of this screening length beyond the leading order and in addition its dependence on the R-charge. Our proposal is based on studies using rotating D3-branes.

  16. Potential role of lncRNA cyp2c91-protein interactions on diseases of the immune system

    OpenAIRE

    Suravajhala, Prashanth; Kogelman, Lisette J. A.; Mazzoni, Gianluca; Kadarmideen, Haja N

    2015-01-01

    With unprecedented increase in next generation sequencing technologies, there has been a persistent interest on transcript profiles of long non-coding RNAs (lncRNAs) and protein-coding genes forming an interaction network. Apart from protein–protein interaction (PPI), gene network models such as Weighted Gene Co-expression Network Analysis (WGCNA) are used to functionally annotate lncRNAs in identifying their potential disease associations. To address this, studies have led to characterizing ...

  17. Bound State Solutions of the Dirac Equation for the Eckart Potential with Coulomb-Like Yukawa-Like Tensor Interactions

    International Nuclear Information System (INIS)

    In this paper, we present the approximate bound state solutions of the Dirac equation within the framework of spin and pseudospin symmetries for Eckart potential for arbitrary κ—state using Nikiforov–Uvarov method. The tensor interactions of Coulomb-like and Yukawa-like form are considered and the effects of these tensors and the degeneracy removing role are discussed in detail. Numerical results and figures to show the effect of the tensor interactions are also reported. (author)

  18. Analysis of eigenvalues for the energy dependent potentials and NN interaction in the quark compound bag model

    International Nuclear Information System (INIS)

    The trajectories of eigenvalues of the energy dependent potentials are discussed for the case of NN interaction in the quark compound bag (QCB) model. It is shown that the asymptotic behaviour of eigenvalues for the linearly energy dependent potentials is defined by the coefficient at the linear energy term in the potential. In the QCB model this coefficient depends on the nucleon component admixture in the bag wave function. The results of eigenvalue analysis are illUstrated with the simple example of the QCB potential describing phase shifts up to T<=0.8 GeV

  19. MONITORING POTENTIAL DRUG INTERACTIONS AND REACTIONS VIA NETWORK ANALYSIS OF INSTAGRAM USER TIMELINES.

    Science.gov (United States)

    Correia, Rion Brattig; Li, Lang; Rocha, Luis M

    2016-01-01

    Much recent research aims to identify evidence for Drug-Drug Interactions (DDI) and Adverse Drug reactions (ADR) from the biomedical scientific literature. In addition to this "Bibliome", the universe of social media provides a very promising source of large-scale data that can help identify DDI and ADR in ways that have not been hitherto possible. Given the large number of users, analysis of social media data may be useful to identify under-reported, population-level pathology associated with DDI, thus further contributing to improvements in population health. Moreover, tapping into this data allows us to infer drug interactions with natural products-including cannabis-which constitute an array of DDI very poorly explored by biomedical research thus far. Our goal is to determine the potential of Instagram for public health monitoring and surveillance for DDI, ADR, and behavioral pathology at large. Most social media analysis focuses on Twitter and Facebook, but Instagram is an increasingly important platform, especially among teens, with unrestricted access of public posts, high availability of posts with geolocation coordinates, and images to supplement textual analysis. Using drug, symptom, and natural product dictionaries for identification of the various types of DDI and ADR evidence, we have collected close to 7000 user timelines spanning from October 2010 to June 2015.We report on 1) the development of a monitoring tool to easily observe user-level timelines associated with drug and symptom terms of interest, and 2) population-level behavior via the analysis of co-occurrence networks computed from user timelines at three different scales: monthly, weekly, and daily occurrences. Analysis of these networks further reveals 3) drug and symptom direct and indirect associations with greater support in user timelines, as well as 4) clusters of symptoms and drugs revealed by the collective behavior of the observed population. This demonstrates that Instagram

  20. The optimized effective potential and the self-interaction correction in density functional theory: Application to molecules

    International Nuclear Information System (INIS)

    The Krieger, Li, and Iafrate approximation to the optimized effective potential including the self-interaction correction for density functional theory has been implemented in a molecular code, NWChem, that uses Gaussian functions to represent the Kohn and Sham spin-orbitals. The differences between the implementation of the self-interaction correction in codes where planewaves are used with an optimized effective potential are discussed. The importance of the localization of the spin-orbitals to maximize the exchange-correlation of the self-interaction correction is discussed. We carried out exchange-only calculations to compare the results obtained with these approximations, and those obtained with the local spin density approximation, the generalized gradient approximation and Hartree-Fock theory. Interesting results for the energy difference (GAP) between the highest occupied molecular orbital, HOMO, and the lowest unoccupied molecular orbital, LUMO, (spin-orbital energies of closed shell atoms and molecules) using the optimized effective potential and the self-interaction correction have been obtained. The effect of the diffuse character of the basis set on the HOMO and LUMO eigenvalues at the various levels is discussed. Total energies obtained with the optimized effective potential and the self-interaction correction show that the exchange energy with these approximations is overestimated and this will be an important topic for future work. (c) 2000 American Institute of Physics

  1. Validation of an interactive map assessing the potential spread of Galba truncatula as intermediate host of Fasciola hepatica in Switzerland.

    Science.gov (United States)

    Baggenstos, Rhea; Dahinden, Tobias; Torgerson, Paul R; Bär, Hansruedi; Rapsch, Christina; Knubben-Schweizer, Gabriela

    2016-01-01

    Bovine fasciolosis, caused by Fasciola hepatica, is widespread in Switzerland. The risk regions were modelled in 2008 by an interactive map, showing the monthly potential risk of transmission of F. hepatica in Switzerland. As this map is based on a mathematical model, the aim of the present study was to evaluate the interactive map by means of a field survey taking different data sources into account. It was found that the interactive map has a sensitivity of 40.7-88.9%, a specificity of 11.4-18.8%, a positive predictive value of 26.7-51.4%, and a negative predictive value of 13.1-83.6%, depending on the source of the data. In conclusion, the grid of the interactive map (100 x 100 m) does not reflect enough detail and the underlying model of the interactive map is lacking transmission data. PMID:27245800

  2. Abnormally large neutron polarizability or long-range strong-interaction potential at fast neutron scattering by heavy nuclei?

    International Nuclear Information System (INIS)

    It is shown that the discrepancy between the results obtained for different neutron energy ranges, when neutron polarizability is derived from the neutron scattering data, can be removed if one assumes that at the fast neutron scattering a strong-interaction long-range potential of Van der Waals (∝r-6) or Casimir-Polder (∝r-7) is observed. This strong-interaction long-range potential has possibly some experimental confirmation in the elastic p-p scattering. (orig.)

  3. Interacting He and Ar atoms: Revised theoretical interaction potential, dipole moment, and collision-induced absorption spectra

    International Nuclear Information System (INIS)

    Coupled cluster quantum chemical calculations of the potential energy surface and the induced dipole surface are reported for the He–Ar van der Waals collisional complex. Spectroscopic parameters are derived from global analytical fits while an accurate value for the long-range dipole coefficient D7 is obtained by perturbation methods. Collision-induced absorption spectra are computed quantum mechanically and compared with existing measurements

  4. The Coulomb interaction in Helium-3: Interplay of strong short-range and weak long-range potentials

    Science.gov (United States)

    Kirscher, J.; Gazit, D.

    2016-04-01

    Quantum chromodynamics and the electroweak theory at low energies are prominent instances of the combination of a short-range and a long-range interaction. For the description of light nuclei, the large nucleon-nucleon scattering lengths produced by the strong interaction, and the reduction of the weak interaction to the Coulomb potential, play a crucial role. Helium-3 is the first bound nucleus comprised of more than one proton in which this combination of forces can be studied. We demonstrate a proper renormalization of Helium-3 using the pionless effective field theory as the formal representation of the nuclear regime as strongly interacting fermions. The theory is found consistent at leading and next-to-leading order without isospin-symmetry-breaking 3-nucleon interactions and a non-perturbative treatment of the Coulomb interaction. The conclusion highlights the significance of the regularization method since a comparison to previous work is contradictory if the difference in those methods is not considered. With a perturbative Coulomb interaction, as suggested by dimensional analysis, we find the Helium-3 system properly renormalized, too. For both treatments, renormalization-scheme independence of the effective field theory is demonstrated by regulating the potential and a variation of the associated cutoff.

  5. Uptake of munitions materiels (TNT, RDX) by crop plants and potential interactions of nitrogen nutrition

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, R.J.; Harvey, S.D.; Cataldo, D.A. [Pacific Northwest Lab., Richland, WA (United States); Mitchell, W. [USABRDL, Ft. Detrick, MD (United States)

    1995-12-31

    Munitions materiel such as trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and their combustion/decomposition products can accumulate/cycle in terrestrial environs. High soil organic matter and fertility have been previously shown to negatively correlate with both TNT or RDX uptake in plants such as grass, wheat, and bean. The present study was therefore conducted using low fertility soil to assess uptake and distribution patterns of C-radiolabelled TNT and RDX (15 and 30 {micro}g/g) within corn (Zea mays), spinach (Spinacea oleraceae), carrot (Daucus carota), and alfalfa (Medicago sativa) grown to maturity in growth chambers. Uptake by the plants at maturity (90- to 120-days) ranged from 1.8 to 2.7% of total amended {sup 14}C-TNT for carrots and corn respectively and 17 to 33% of total amended {sup 14}C-RDX for corn and carrots respectively. Distribution patterns of total radiolabel indicate that the TNT-derived label was primarily retained within the roots (60 to 85%) while the RDX-derived label was distributed to the shoots (85 to 97%). Less than 0.01 {micro}g/g dry wt. TNT was found in all analyzed shoot tissues with > 90% of the TNT-derived radiolabel in the form of polar metabolites. Concentrations of RDX in shoot tissues of corn exceeded 180 {micro}g/g dry wt. Alfalfa grown in unfertilized, fertilized (NO{sub 3}), or unfertilized-inoculated (Rhizobia) soil exhibited a 70 to 100% increase in dry wt. after 45 days in the TNT-amended (15 {micro}g/g) fertilized and unfertilized-inoculated plants versus the controls. A potential TNT/nitrogen interaction will be discussed.

  6. Chemistry and NMR studies of Beta-Catenin-TCF4 interaction : a potential antitumor target

    International Nuclear Information System (INIS)

    Aberrant Wnt/Beta-Catenin signaling is observed in a wide spectrum of human malignancies. Activation of this pathway is involved in colon and ovarian cancer. Therefore, inhibitors of the TCF4/Beta-Catenin interaction are of great potential as antitumor agents. We used the recently described protein meta-structure approach to identify novel small molecule compounds as binders for Beta-Catenin. The identified ligands have been tested for binding with the target protein using 1D 1H-STD, 1D AFP NOESY, 2D NOESY and 19F-NMR. The identified binders were demonstrated to compete with the authentic Beta-Catenin binding partner TCF4. In addition, a dynamic combinatorial library has been designed to synthesize new ligands for Beta-Catenin. Moreover, 2D and 3D-NMR experiments were used to assign the backbone signals of full length TCF4 and two different truncations at different pH values. The data obtained from assignment at pH=4.5 and pH=2 were compared with the predicted random coil shifts. Secondary structure propensities were also compared which allowed us to estimate changes in secondary structure propensities upon pH change. Finally, further structural insight into the TCF4/Beta-Catenin complex was provided by a combined X-ray crystallography and NMR study employing selective lysine reductive-methylation reaction. To highlight the importance of our work, the resulting prospects for the development of new powerful anticancer drugs with a high safety profile will also be discussed (author)

  7. Interaction of arbuscular mycorrhizal symbionts with arsenic and other potentially toxic elements

    International Nuclear Information System (INIS)

    The response of arbuscular mycorrhizal (AM) symbionts to arsenic, and arsenic interactions with phosphorus and potentially toxic elements (PTEs) in soils from a former arsenic mine, the Devon Great Consols, were investigated. The objective was to determine whether AM associations ameliorate arsenic toxicity in Plantago lanceolata and Agrostis capillaris, plants commonly found at abandoned mines. An exploratory investigation indicated the richness in biodiversity of AMF that colonised plants growing at the site. Arsenic was found at high concentrations and was strongly associated with copper and iron. P. lanceolata was always colonised by AMF, while colonisation of A. capillaris was variable. There was no evidence in the field of soil pH or PTEs influencing AMF colonisation and spore density. There was no strong correlation between arsenic content in plant and available arsenic, obtained through various extraction methods. Spore germination and infectivity in the mine soils were strongly influenced by the AMF genotype and to a lesser extent by the soil environment. P. lanceolata and A. capillaris root growth was inhibited at arsenic concentrations of ≥50 μg g-1 in agar. Bioavailability experiments using mine soils and Terra-GreenTM (calcined attapulgite) spiked with sodium arsenate gave no evidence that AMF-colonised plants translocated less arsenic to the shoots. Plants accumulated more arsenic in their roots than in their shoots, whether they were colonised by AMF or not. The A. capillaris genotype used in the present study translocated less of both arsenic and phosphorus to its shoots than P. lanceolata. High available phosphorus in Terra-GreenTM protected plants against arsenic toxicity, at -1 As. There was evidence for inhibition by arsenic in AMF colonisation of roots. For quantifying AMF extra radical hyphae contribution to arsenic transportation from growth medium to plant using a compartmented pot system, the use of low phosphorus medium and a longer

  8. Collisional interactions between self-interacting non-relativistic boson stars: effective potential analysis and numerical simulations

    CERN Document Server

    Cotner, Eric

    2016-01-01

    Scalar particles are a common prediction of many beyond the Standard Model theories. If they are light and cold enough, there is a possibility they may form Bose-Einstein condensates, which will then become gravitationally bound. These boson stars are solitonic solutions to the Einstein-Klein-Gordon equations, but may be approximated in the non-relativistic regime with a coupled Schr\\"odinger-Poisson system. General properties of single soliton states are derived, including the possibility of quartic self-interactions. Binary collisions between two solitons are then studied, and the effects of different mass ratios, relative phases, self-couplings, and separation distances are characterized, leading to an easy conceptual understanding of how these parameters affect the collision outcome in terms of conservation of energy. Applications to dark matter are discussed.

  9. A molecular H2 potential for heterogeneous simulations including polarization and many-body van der Waals interactions.

    Science.gov (United States)

    McLaughlin, Keith; Cioce, Christian R; Belof, Jonathan L; Space, Brian; Space, Brian B

    2012-05-21

    A highly accurate aniostropic intermolecular potential for diatomic hydrogen has been developed that is transferable for molecular modeling in heterogeneous systems. The potential surface is designed to be efficacious in modeling mixed sorbates in metal-organic materials that include sorption interactions with charged interfaces and open metal sites. The potential parameters are compatible for mixed simulations but still maintain high accuracy while deriving dispersion parameters from a proven polarizability model. The potential includes essential physical interactions including: short-range repulsions, dispersion, and permanent and induced electrostatics. Many-body polarization is introduced via a point-atomic polarizability model that is also extended to account for many-body van der Waals interactions in a consistent fashion. Permanent electrostatics are incorporated using point partial charges on atomic sites. However, contrary to expectation, the best potentials are obtained by permitting the charges to take on values that do not reproduce the first non-vanishing moment of the electrostatic potential surface, i.e., the quadrupole moment. Potential parameters are fit to match ab initio energies for a representative range of dimer geometries. The resulting potential is shown to be highly effective by comparing to electronic structure calculations for a thermal distribution of trimer geometries, and by reproducing experimental bulk pressure-density isotherms. The surface is shown to be superior to other similarly portable potential choices even in tests on homogeneous systems without strong polarizing fields. The present streamlined approach to developing such potentials allows for a simple adaptation to other molecules amenable to investigation by high-level electronic structure methods. PMID:22612090

  10. Harmonic potential as an effective limit of a discrete classical interaction

    CERN Document Server

    Segatto, B R; De Souza, M M; Segatto, Breno. R.; Azevedo, Julio S.; Souza, Manoelito M. de

    2003-01-01

    Motivated by improving the understanding of the quantum-to-classical transition we use a simple model of classical discrete interactions for studying the discrete-to-continuous transition in the classical harmonic oscilator. A parallel is traced with gravity for stressing the relevance of such discrete interaction models.

  11. Potential job facilitation benefits of "water cooler" conversations: the importance of social interactions in the workplace.

    Science.gov (United States)

    Lin, Iris Y; Kwantes, Catherine T

    2015-01-01

    This study looked at the extent to which personality and cultural factors predicted participants' perceptions of the importance private interactions played in the workplace. The 134 participants read a vignette (where a new employee socially interacted at low or high levels with co-workers) and completed the Big Five Inventory, Social Axioms Survey, and questions concerning expected workplace experiences. Results indicated employees who engaged in high levels of private interaction with co-workers were expected to be better liked, to receive better performance evaluations, were more likely to receive co-worker assistance, and were thought to be more likely chosen for future projects. However, the personality and social axiom variables studied did not significantly interact with social interaction to influence expectations of workplace outcomes. PMID:25590341

  12. A study of potential drug-drug interactions among critically ill patients at a tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Manjeeta Gupta

    2016-08-01

    Conclusions: The present study showed high concomitant administration of potentially interacting drugs. The prevalence confirmed the association of age and polypharmacy. Vigilant prescribing approach is needed to prevent hazardous outcomes of pDDI. [Int J Basic Clin Pharmacol 2016; 5(4.000: 1281-1285

  13. Sources, potentials and fields in Lorenz and Coulomb gauge: Cancellation of instantaneous interactions for moving point charges

    International Nuclear Information System (INIS)

    We investigate the coupling of the electromagnetic sources (charge and current densities) to the scalar and vector potentials in classical electrodynamics, using Green function techniques. As is well known, the scalar potential shows an action-at-a-distance behavior in Coulomb gauge. The conundrum generated by the instantaneous interaction has intrigued physicists for a long time. Starting from the differential equations that couple the sources to the potentials, we here show in a concise derivation, using the retarded Green function, how the instantaneous interaction cancels in the calculation of the electric field. The time derivative of a specific additional term in the vector potential, present only in Coulomb gauge, yields a supplementary contribution to the electric field which cancels the gradient of the instantaneous Coulomb gauge scalar potential, as required by gauge invariance. This completely eliminates the contribution of the instantaneous interaction from the electric field. It turns out that a careful formulation of the retarded Green function, inspired by field theory, is required in order to correctly treat boundary terms in partial integrations. Finally, compact integral representations are derived for the Liénard–Wiechert potentials (scalar and vector) in Coulomb gauge which manifestly contain two compensating action-at-a-distance terms. - Highlights: ► We investigate action-at-a-distance effects in electrodynamics in detail. ► We calculate the instantaneous interactions for scalar and vector potentials. ► The cancellation mechanism involves the retarded Green function. ► The mechanism is confirmed on the example of moving point charges. ► The Green function has to be treated with care for nontrivial boundary terms.

  14. Comparative aspects of spin-dependent interaction potentials for spin-1/2 and spin-1 matter fields

    CERN Document Server

    Malta, P C; Veiga, K; Helayël-Neto, J A

    2015-01-01

    This paper sets out to establish a comparative study between classes of spin- and velocity-dependent current-current interaction potentials for spin-1/2 and spin-1 matter sources in the non-relativistic regime. Both (neutral massive) scalar and vector particles are considered to mediate the interactions between scalar, pseudo-scalar, vector and pseudo-vector matter currents. We contemplate specific cases in which our results may describe the electromagnetic interaction with a massive (Proca-type) photon exchanged between two spin-1/2 or two spin-1 carriers. We highlight the similarities and peculiarities of the potentials for the two different types of charged matter and also focus our attention to the comparison between two different field representations for spin-1 matter particles. We believe that our results may contribute to a further discussion of the relation between charge, spin and extensibility.

  15. Interactions between arbuscular mycorrhizal fungi and bacteria and their potential for stimulating plant growth.

    Science.gov (United States)

    Artursson, Veronica; Finlay, Roger D; Jansson, Janet K

    2006-01-01

    Arbuscular mycorrhizal (AM) fungi and bacteria can interact synergistically to stimulate plant growth through a range of mechanisms that include improved nutrient acquisition and inhibition of fungal plant pathogens. These interactions may be of crucial importance within sustainable, low-input agricultural cropping systems that rely on biological processes rather than agrochemicals to maintain soil fertility and plant health. Although there are many studies concerning interactions between AM fungi and bacteria, the underlying mechanisms behind these associations are in general not very well understood, and their functional properties still require further experimental confirmation. Future mycorrhizal research should therefore strive towards an improved understanding of the functional mechanisms behind such microbial interactions, so that optimized combinations of microorganisms can be applied as effective inoculants within sustainable crop production systems. In this context, the present article seeks to review and discuss the current knowledge concerning interactions between AM fungi and plant growth-promoting rhizobacteria, the physical interactions between AM fungi and bacteria, enhancement of phosphorus and nitrogen bioavailability through such interactions, and finally the associations between AM fungi and their bacterial endosymbionts. Overall, this review summarizes what is known to date within the present field, and attempts to identify promising lines of future research. PMID:16343316

  16. Identifying potential survival strategies of HIV-1 through virus-host protein interaction networks

    Directory of Open Access Journals (Sweden)

    Boucher Charles AB

    2010-07-01

    Full Text Available Abstract Background The National Institute of Allergy and Infectious Diseases has launched the HIV-1 Human Protein Interaction Database in an effort to catalogue all published interactions between HIV-1 and human proteins. In order to systematically investigate these interactions functionally and dynamically, we have constructed an HIV-1 human protein interaction network. This network was analyzed for important proteins and processes that are specific for the HIV life-cycle. In order to expose viral strategies, network motif analysis was carried out showing reoccurring patterns in virus-host dynamics. Results Our analyses show that human proteins interacting with HIV form a densely connected and central sub-network within the total human protein interaction network. The evaluation of this sub-network for connectivity and centrality resulted in a set of proteins essential for the HIV life-cycle. Remarkably, we were able to associate proteins involved in RNA polymerase II transcription with hubs and proteasome formation with bottlenecks. Inferred network motifs show significant over-representation of positive and negative feedback patterns between virus and host. Strikingly, such patterns have never been reported in combined virus-host systems. Conclusions HIV infection results in a reprioritization of cellular processes reflected by an increase in the relative importance of transcriptional machinery and proteasome formation. We conclude that during the evolution of HIV, some patterns of interaction have been selected for resulting in a system where virus proteins preferably interact with central human proteins for direct control and with proteasomal proteins for indirect control over the cellular processes. Finally, the patterns described by network motifs illustrate how virus and host interact with one another.

  17. Connection of Kukulin's nucleon-nucleon deep potential with realistic repulsive core interactions

    International Nuclear Information System (INIS)

    The on-shell equivalence of the deep quantum-chromodynamically motivated realistic nucleon-nucleon interaction recently proposed by Kukulin et al. with more conventional repulsive-core forces is investigated by eliminating its unphysical deeply bound states, while preserving its scattering properties and the binding energy of the deuteron. The resulting interaction, which is built both in the singlet and triplet channels, displays a r-2 singular repulsive core followed by a shallow attraction of intermediate range, in good semiquantitative agreement with existing realistic nucleon-nucleon interactions. (orig.)

  18. Assessment of potential drug-drug interactions among outpatients receiving cardiovascular medications at Jimma University specialized hospital, South West Ethiopia

    Directory of Open Access Journals (Sweden)

    Legese Chelkeba

    2013-04-01

    Full Text Available Background: The quality of pharmacotherapy is highly dependent on the process of choosing a drug in relation to nature of the disease. Several factors should be considered in choosing optimal pharmacotherapeutics strategy including efficacy, safety, availability and cost of the drugs. The objective of this study was to assess potential drug-drug interactions and risk factors in outpatients taking cardiovascular drugs at Jimma University specialized hospital. Methods: A cross-sectional study was conducted from Feb. to April, 2011on patients visiting the cardiac clinic of Jimma University Specialized hospital. A sample of 332 outpatients who were taking cardiovascular medications at study clinic was studied. MicroMedex software was used to screen drug-drug interactions and SPSS for windows software versions-16.0 was used for data analysis. Results: A total of 1249 drugs with average of 3.76 drugs per prescription were prescribed for the 332 patients. The frequency of potential DDIs was found to be 241 (72.6%. Among these 200 (67.3% were of "moderate" severity and 164 (55.2% were delayed in onset. The most common potential DDI observed was between Enalapril and Furosemide (20%. Patients who prescribed many drugs (AOR=4.09; P=0.00 by medical intern had a higher risk of developing potential DDIs (AOR=4.6; P=0.00. Conclusions: Patients with cardiovascular disorders are subjected to high risk of potential drug-drug interactions and the number of drugs prescribed and educational level of the prescribers has a high significantly associated with the occurrence of potential drug-drug interactions. Therefore, it is imperative that further studies need to be conducted to identify reasons for and tackle the problem and provide appropriate mechanisms for management. [Int J Basic Clin Pharmacol 2013; 2(2.000: 144-152

  19. Convergence and the Potential Ban on Interactive Product Placement in Germany

    OpenAIRE

    Christian Jansen

    2003-01-01

    This paper addresses the economic impact of German advertising regulations. The digital convergence of media provides a starting point for the analysis. This convergence makes technically feasible “interactive product placement” (IPP), the integration of interactively purchasable products in television programs and movies for the purpose of advertising. Such advertising could conceivably outstrip traditional product placement as a source of revenues for the film industry. Moreover, IPP could ...

  20. Relativistic study of the energy-dependent Coulomb potential including Coulomb-like tensor interaction

    CERN Document Server

    Hamzavi, Majid

    2012-01-01

    The exact Dirac equation for the energy-dependent Coulomb (EDC) potential including a Coulomb-like tensor (CLT) potential has been studied in the presence of spin and pseudospin (p-spin) symmetries with arbitrary spin-orbit quantum number The energy eigenvalues and corresponding eigenfunctions are obtained in the framework of asymptotic iteration method (AIM). Some numerical results are obtained in the presence and absence of EDC and CLT potentials.

  1. Factors influencing pollutant-nutrient interactions and their potential implications on human health

    International Nuclear Information System (INIS)

    Considering the continuously increasing development of new chemical substances and their appearance in the environment, little information exists on the relationship between environmental pollution and the nutritional status of humans. The purpose of this report is to provide an overview of factors influencing nutrient-pollutant interactions within the human body. The absorption of essential and toxic elements depends on speciation and bioavailability of the substances, as well as the physiological status of humans, such as their age. The pre-existing trace element status of people can also influence the absorption of elements. For instance, lead and cadmium absorption can be reduced by an adequate iron or calcium status. Some interactions between elements occur predominantly in specific organs, as for example cadmium, which accumulates mainly in kidney and liver and is accompanied by changes in levels of zinc. Pollutant-nutrient interactions can further be influences by socio-cultural aspects, such as processing and preparation of food. Fermentation and germination of maize and white sorghum, for example, can reduce their phytate contents, enhancing iron, zinc and manganese bioavailability. Furthermore, the geographical location can also affect nutrient-pollutant interactions, as it governs food availability and type, and high altitudes can alter the requirements for some nutrients. Thus, many factors influence the interactions between pollutants, nutrients and human health. This extremely complex system needs to be understood in more detail to reduce ill effects on human health and the resulting economic costs. (author)

  2. Understanding the Adsorbate-Substrate and Substrate Mediated Interaction Potentials on Au111

    Science.gov (United States)

    Sykes, Charles; Mantooth, Brent; Han, Patrick; Weiss, Paul

    2004-03-01

    We have studied the ordering and dynamics of CS2 and C6H6 physisorbed on Au111 at 4 K using scanning tunneling microscopy. The weakly bound state of the molecules allows one to probe the weak intermolecular interactions that dominate ordering in such systems. Preferred adsorption of CS2 at specific surface sites is observed and correlated to the positions of standing waves arising from interaction of surface state electrons with surface steps. CS2 molecules have increased interactions with the areas of high electron density on the peaks of standing waves arising from electrons close to the Fermi energy. The importance of this result is discussed in terms of the fundamental surface physics of adsorbate/metal bonding. Using an automated approach to monitor single benzene molecule motion on the same Au surface we are, for the first time, able to quantify substrate-mediated interaction strength using a simple Arrhenius approach. We demonstrate that these weak, attractive, through-substrate forces control the growth of benzene overlayers on Au and we show how benzene self-orders in well defined structures that maximize these interactions.

  3. Chemisorption interaction between solvents and the gallium subgroup metals: a relationship with the ionization potential of the solvent molecules

    International Nuclear Information System (INIS)

    Experimental data characterizing chemisorption metal-solvent interaction on Ga-, (In-Ga)-, (Tl-Ga) - and Hg - electrodes in various solvents have been considered from the viewpoint of quantum-chemical notions of chemical bond formation. It is shown that there is a correlation between parameters characterizing chemisorption metal-solvent interaction on the electrodes and the change in the value of the first adiabatic ionization potential of the solvent molecule, as well as the change in electron energy on the metal Fermi level

  4. Analytic ab initio-based molecular interaction potential for the BrOṡH2O complex

    Science.gov (United States)

    Hoehn, Ross D.; Yeole, Sachin D.; Kais, Sabre; Francisco, Joseph S.

    2016-05-01

    Radical halogen oxide species play important roles within atmospheric processes, specifically those responsible for the removal of O3. To facilitate future investigations on this family of compounds, RCCSD(T)/aug-cc-pVQZ-level electronic structure calculations were employed to generate individual-molecule optimized geometries, as well as to determine the global minimum energy structure for the BrOṡH2O complex. This information facilitated the generation of several one-dimensional potential energy surface (PES) scans for the BrOṡH2O complex. Scans were performed for both the ground state and the first excited state; this inclusion is due to a low-lying first electronic excited-state energy. These rigid-geometry PES scans were used both to generate a novel analytic interaction potential by modifying the existing Thole-type model used for water and to the fitted potential function. This interaction potential features anisotropic atomic polarizabilities facilitating appropriate modeling of the physics regarding the unpaired electron residing within the p-orbitals of the oxygen atom of the bromine oxide radical. The intention of this work is to facilitate future molecular dynamics simulations involving the interaction between the BrO radical and water clusters as a first step in devising possible novel chemistries taking place at the water interface of clouds within the atmosphere.

  5. Potential drug-drug interactions in a Brazilian teaching hospital: age-related differences?

    Directory of Open Access Journals (Sweden)

    Daniela Oliveira Melo

    2016-07-01

    Full Text Available This study proposes to measure frequency and to characterize the profile of potential drug interactions (pDDI in a general medicine ward of a teaching hospital. Data about identification and clinical status of patients were extracted from medical records between March to August 2006. The occurrence of pDDI was analyzed using the database monographs Micromedex® DrugReax® System. From 5,336 prescriptions with two or more drugs, 3,097 (58.0% contained pDDI. The frequency of major and well document pDDI was 26.5%. Among 647 patients, 432 (66.8% were exposed to at least one pDDI and 283 (43.7% to major pDDI. The multivariate analysis identified that factors related to higher rates of major pDDI were the same age (p< 0.0001, length of stay (p< 0.0001, prevalence of hypertension [OR=3.42 (p< 0.0001] and diabetes mellitus [OR=2.1 (p< 0.0001], cardiovascular diseases (p< 0.0001 and the number of prescribed drugs (Spearman’s correlation=0.640622, p< 0.0001. Between major pDDI, the main risk was hemorrhage (50.3%, the most frequent major pDDI involved combination of anticoagulants and antiplatelet drugs. Among moderate pDDI, 3,866 (90.8% involved medicines for the treatment of chronic non-communicable diseases, mainly hypertension. In HU-USP, the profile of pDDI was similar among adults and elderly (the most frequent pDDI and major pDDI were same, the difference was only the frequency in either group. The efforts of the clinical pharmacists should be directed to elderly patients with cardiovascular compromise, mainly in use of anticoagulants and antiplatelet drugs. Furthermore, hospital managers should increase the integration between levels of health care to promote safety patient after discharge.Keywords: Drug interactions. Aged. Internal Medicine. Hospitals, University. RESUMOInterações medicamentosas potenciais em um hospital escolar brasileiro: diferenças relacionadas à idade?O estudo tem por objetivo descrever o perfil de intera

  6. Soliton interaction with small Toeplitz potentials for the Szego equation on the real line

    OpenAIRE

    Pocovnicu, Oana

    2011-01-01

    We consider the cubic Szego equation perturbed by a small Toeplitz potential (natural generalization of a multiplicative potential) and having as initial condition a soliton of the unperturbed equation. We show that the solution preserves the soliton shape for a long time, and we determine the effective ODEs satisfied by the modulation parameters of the soliton.

  7. One spatial dimensional finite volume three-body interaction for a short-range potential

    CERN Document Server

    Guo, Peng

    2016-01-01

    In this work, we use McGuire's model to describe scattering of three spinless identical particles in one spatial dimension, we first present analytic solutions of Faddeev's equation for scattering of three spinless particles in free space. The three particles interaction in finite volume is derived subsequently, and the quantization conditions by matching wave functions in free space and finite volume are presented in terms of two-body scattering phase shifts. The quantization conditions obtained in this work for short range interaction are L\\"uscher's formula like and consistent with Yang's results in \\cite{Yang:1967bm}.

  8. Involvement of platelet-tumor cell interaction in immune evasion. Potential role of podocalyxin-like protein 1

    Directory of Open Access Journals (Sweden)

    SusanaLarrucea

    2014-09-01

    Full Text Available Besides their essential role in hemostasis and thrombosis, platelets are involved in the onset of cancer metastasis by interacting with tumor cells. Platelets release secretory factors that promote tumor growth, angiogenesis, and metastasis. Furthermore, the formation of platelet-tumor cell aggregates in the bloodstream provides cancer cells with an immune escape mechanism by protecting circulating malignant cells from immune-mediated lysis by natural killer (NK cells. Platelet-tumor cell interaction is accomplished by specific adhesion molecules, including integrins, selectins, and their ligands. Podocalyxin-like protein 1 (PCLP1 is a selectin ligand protein which overexpression has been associated with several aggressive cancers. PCLP1 expression enhances cell adherence to platelets in an integrin-dependent process and through the interaction with P-selectin expressed on activated platelets. However, the involvement of PCLP1-induced tumor-platelet interaction in tumor immune evasion still remains unexplored. The identification of selectin ligands involved in the interaction of platelets with tumor cells may provide help for the development of effective therapies to restrain cancer cell dissemination. This article summarizes the current knowledge on molecules that participate in platelet-tumor cell interaction as well as discusses the potential role of PCLP1 as a molecule implicated in tumor immune evasion.

  9. Vapour–liquid equilibria of the two- and three-dimensional monoatomic classical fluids interacting via double Yukawa potential

    Indian Academy of Sciences (India)

    Y Pathania; P K Ahluwalia

    2006-12-01

    We have carried out Monte Carlo simulations in Gibbs ensemble for two-and three-dimensional double Yukawa fluid. We have compared liquid–vapour equilibrium curve with that of Lennard-Jones, when parameters occurring in double Yukawa potential are chosen to fit Lennard-Jones potential. The results are in good agreement. The role of repulsive and attractive contributions for the potential on the liquid–vapour coexistence region as well as on critical temperature and critical density has been studied. The critical temperature is found to be more sensitive than the critical density to the variation in repulsive and attractive parts of the potential. Also, the range of the attractive interaction directly influences range of the liquid–vapour coexistence region. It has been found that smaller the values of the attractive parameter, larger is the coexistence region.

  10. Analysis of Multiple HPV E6 PDZ Interactions Defines Type-Specific PDZ Fingerprints That Predict Oncogenic Potential

    Science.gov (United States)

    Thomas, Miranda; Myers, Michael P.; Guarnaccia, Corrado; Banks, Lawrence

    2016-01-01

    The high-risk Human Papillomavirus (HPV) E6 oncoproteins are characterised by the presence of a class I PDZ-binding motif (PBM) on their extreme carboxy termini. The PBM is present on the E6 proteins derived from all cancer-causing HPV types, but can also be found on some related non-cancer-causing E6 proteins. We have therefore been interested in investigating the potential functional differences between these different E6 PBMs. Using an unbiased proteomic approach in keratinocytes, we have directly compared the interaction profiles of these different PBMs. This has allowed us to identify the potential PDZ target fingerprints of the E6 PBMs from 7 different cancer-causing HPV types, from 3 HPV types with weak cancer association, and from one benign HPV type that possesses an ancestral PBM. We demonstrate a striking increase in the number of potential PDZ targets bound by each E6 PBM as cancer-causing potential increases, and show that the HPV-16 and HPV-18 PBMs have the most flexibility in their PDZ target selection. Furthermore, the specific interaction with hScrib correlates directly with increased oncogenic potential. In contrast, hDlg is bound equally well by all the HPV E6 PBMs analysed, indicating that this is an evolutionarily conserved interaction, and was most likely one of the original E6 PBM target proteins that was important for the occupation of a potential new niche. Finally, we present evidence that the cell junction components ZO-2 and β-2 syntrophin are novel PDZ domain–containing targets of a subset of high-risk HPV types. PMID:27483446

  11. New potential peptide therapeutics perturbing CK1δ/α-tubulin interaction.

    Science.gov (United States)

    Krüger, Marc; Kalbacher, Hubert; Kastritis, Panagiotis L; Bischof, Joachim; Barth, Holger; Henne-Bruns, Doris; Vorgias, Constantinos; Sarno, Stefania; Pinna, Lorenzo A; Knippschild, Uwe

    2016-06-01

    Members of the CK1 family are highly conserved serine/threonine specific kinases being expressed in all eukaryotes. They are involved in many cellular processes and therefore tightly regulated. A central mechanism to modulate CK1 activity is via interaction with cellular proteins. CK1δ interacts with α-/β-tubulin and is involved in the regulation of microtubule dynamics. Therefore, it is important to identify the structural elements responsible for the interaction between these proteins. Using a peptide library covering the human CK1δ amino acid sequence in SPR and ELISA analyses, we identified peptide 39 (P39), encompassing aa361-aa375 of CK1δ, as a prominent binding partner of α-tubulin. P39 decreases α-tubulin phosphorylation by CK1δ and reduces the thermodynamic stability of α-tubulin in fluorescence thermal shift assays. Furthermore, P39 induces an inhibition of mitotic progression and a disruption of cells entering mitosis in CV-1 cells. Taken together our data provide valuable information regarding the interaction of CK1δ and α-tubulin and a novel approach for the development of pharmacological tools to inhibit proliferation of cancer cells. PMID:26996302

  12. Nutrient-pollutant interactions and their potential implications on human health

    International Nuclear Information System (INIS)

    Full text: Little information exists on the relationship between environmental pollution and the nutritional status of humans. The purpose of this report is to provide an overview of factors influencing nutrient-pollutant interactions within the human body. The absorption of essential and toxic elements depends on the speciation and bioavailability of substances, as well as the physiological status of humans, such as their age. The pre-existing trace-element status of people also influences the absorption of elements. Some interactions between elements occur predominantly in specific organs. Furthermore, the interactions will be affected by the environment of people. The geographical location, for example governs food availability and type, and high altitudes can alter the requirements for some nutrients. Socio-cultural aspects, such as the processing and preparation of food can affect the levels and bioavailability of compounds. Thus, many factors influence the interactions between pollution, the nutritional status of people and human health. This extremely complex system needs to be understood in more detail to reduce ill-effects on human health and economic costs. (author)

  13. Identification of potential target levels for Central Baltic Sea fishing mortalities, taking multispecies interactions into account

    DEFF Research Database (Denmark)

    Vinther, Morten; Neuenfeldt, Stefan; Eero, Margit;

    2012-01-01

    The main biological interactions between Baltic cod, herring and sprat have been modelled in a stochastic multispecies (SMS) model. Based on this, a simple approach has been developed to quantify candidates for FMSY proxies (fishing mortality that produces the maximum sustainable yield) in a...

  14. Targeting CD47-SIRPα interactions for potentiating therapeutic antibody-mediated tumor cell destruction by phagocytes

    OpenAIRE

    Zhao, X.W.

    2014-01-01

    The primary aim of the studies described in this thesis was to investigate the role of CD47-SIRPα interactions in therapeutic antibody-dependent tumor cell destruction by human phagocytes and also explore the killing mechanism(s) by which human phagocytes, and in particular human neutrophils, mediate therapeutic antibody-dependent cytotoxicity towards cancer cells.

  15. Effect of attractive interactions on the water-like anomalies of a core-softened model potential

    Energy Technology Data Exchange (ETDEWEB)

    Pant, Shashank [Department of Chemical Sciences, Indian Institute of Science Education and Research-Kolkata, Mohanpur-741252 (India); Gera, Tarun [Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi, 110016 (India); Choudhury, Niharendu, E-mail: nihcho@barc.gov.in, E-mail: niharc2002@yahoo.com [Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai-400 085 (India)

    2013-12-28

    It is now well established that water-like anomalies can be reproduced by a spherically symmetric potential with two length scales, popularly known as core-softened potential. In the present study we aim to investigate the effect of attractive interactions among the particles in a model fluid interacting with core-softened potential on the existence and location of various water-like anomalies in the temperature-pressure plane. We employ extensive molecular dynamic simulations to study anomalous nature of various order parameters and properties under isothermal compression. Order map analyses have also been done for all the potentials. We observe that all the systems with varying depth of attractive wells show structural, dynamic, and thermodynamic anomalies. As many of the previous studies involving model water and a class of core softened potentials have concluded that the structural anomaly region encloses the diffusion anomaly region, which in turn, encloses the density anomaly region, the same pattern has also been observed in the present study for the systems with less depth of attractive well. For the systems with deeper attractive well, we observe that the diffusion anomaly region shifts toward higher densities and is not always enclosed by the structural anomaly region. Also, density anomaly region is not completely enclosed by diffusion anomaly region in this case.

  16. Effect of attractive interactions on the water-like anomalies of a core-softened model potential.

    Science.gov (United States)

    Pant, Shashank; Gera, Tarun; Choudhury, Niharendu

    2013-12-28

    It is now well established that water-like anomalies can be reproduced by a spherically symmetric potential with two length scales, popularly known as core-softened potential. In the present study we aim to investigate the effect of attractive interactions among the particles in a model fluid interacting with core-softened potential on the existence and location of various water-like anomalies in the temperature-pressure plane. We employ extensive molecular dynamic simulations to study anomalous nature of various order parameters and properties under isothermal compression. Order map analyses have also been done for all the potentials. We observe that all the systems with varying depth of attractive wells show structural, dynamic, and thermodynamic anomalies. As many of the previous studies involving model water and a class of core softened potentials have concluded that the structural anomaly region encloses the diffusion anomaly region, which in turn, encloses the density anomaly region, the same pattern has also been observed in the present study for the systems with less depth of attractive well. For the systems with deeper attractive well, we observe that the diffusion anomaly region shifts toward higher densities and is not always enclosed by the structural anomaly region. Also, density anomaly region is not completely enclosed by diffusion anomaly region in this case. PMID:24387380

  17. Effect of attractive interactions on the water-like anomalies of a core-softened model potential

    International Nuclear Information System (INIS)

    It is now well established that water-like anomalies can be reproduced by a spherically symmetric potential with two length scales, popularly known as core-softened potential. In the present study we aim to investigate the effect of attractive interactions among the particles in a model fluid interacting with core-softened potential on the existence and location of various water-like anomalies in the temperature-pressure plane. We employ extensive molecular dynamic simulations to study anomalous nature of various order parameters and properties under isothermal compression. Order map analyses have also been done for all the potentials. We observe that all the systems with varying depth of attractive wells show structural, dynamic, and thermodynamic anomalies. As many of the previous studies involving model water and a class of core softened potentials have concluded that the structural anomaly region encloses the diffusion anomaly region, which in turn, encloses the density anomaly region, the same pattern has also been observed in the present study for the systems with less depth of attractive well. For the systems with deeper attractive well, we observe that the diffusion anomaly region shifts toward higher densities and is not always enclosed by the structural anomaly region. Also, density anomaly region is not completely enclosed by diffusion anomaly region in this case

  18. Multireference configuration interaction potential curve and analytical potential energy function of the ground and low-lying excited states of CdSe

    Institute of Scientific and Technical Information of China (English)

    Gao Feng; Yang Chuan-Lu; Hu Zhen-Yan; Wang Mei-Shan

    2007-01-01

    The potential energy curves (PECs) of the ground state (3Π) and three low-lying excited states (1∑, 3∑,1Π) of CdSe dimer have been studied by emploging quasirelativistic effective core potentials on the basis of the complete active space self-consistent field method followed by multireference configuration interaction calculation. The four PECs are fitted to analytical potential energy functions using the Murrel-Sorbie potential function. Based on the PECs,the vibrational levels of the four states are determined by solving the Schr(o)dinger equation of nuclear motion, and corresponding spectroscopic contants are accurately calculated. The equilibrium positions as well as the spectroscopic constants and the vibrational levels are reported. By our analysis, the 3Π state, of which the dissociation asymptote is Cd(1S) + Se(3p), is identified as a ground state of CdSe dimer, and the corresponding dissociation energy is estimated to be 0.39eV. However, the first excited state is only 1132.49cm-1 above the ground state and the 3∑ state is the highest in the four calculated states.

  19. Interaction of a Two-Level Atom with the Morse Potential in the Framework of Jaynes-Cummings Model

    Science.gov (United States)

    Setare R., M.; Sh., Barzanjeh

    2009-09-01

    A theoretical study of the dynamical behaviors of the interaction between a two-level atom with a Morse potential in the framework of the Jaynes-Cummings model (JCM) is discussed. We show that this system is equivalent to an intensity-dependent coupling between the two-level atom and the non-deformed single-mode radiation field in the presence of an additional nonlinear interaction. We study the dynamical properties of the system such as, atomic population inversion, the probability distribution of cavity-field, the Mandel parameter and atomic dipole squeezing. It is shown how the depth of the Morse potential can be affected by non-classical properties of the system. Moreover, the temporal evolution of the Husimi-distribution function is explored.

  20. A comparison of interatomic potentials for modeling tungsten–hydrogen–helium plasma–surface interactions

    International Nuclear Information System (INIS)

    We compare the hydrogen and helium clustering characteristics of three interatomic potential energy models intended for simulation of plasma-facing materials for fusion applications. Our simulations compare a Finnis–Sinclair potential and two different Tersoff-style bond order potentials created by Juslin et al. (2005) and Li et al. (2011), respectively, with respect to both helium and hydrogen clustering behavior in tungsten. We find significant differences between the Juslin and Li potentials in terms of both hydrogen and helium clustering behavior as well as the spatial distribution of hydrogen below the surface. These simulations are an important test on the road to more accurate models of gas clustering and surface evolution of tungsten divertors in ITER and other plasma devices

  1. A comparison of interatomic potentials for modeling tungsten–hydrogen–helium plasma–surface interactions

    Energy Technology Data Exchange (ETDEWEB)

    Cusentino, Mary Alice, E-mail: mcusenti@utk.edu; Hammond, Karl D.; Sefta, Faiza; Juslin, Niklas; Wirth, Brian D., E-mail: bdwirth@utk.ed

    2015-08-15

    We compare the hydrogen and helium clustering characteristics of three interatomic potential energy models intended for simulation of plasma-facing materials for fusion applications. Our simulations compare a Finnis–Sinclair potential and two different Tersoff-style bond order potentials created by Juslin et al. (2005) and Li et al. (2011), respectively, with respect to both helium and hydrogen clustering behavior in tungsten. We find significant differences between the Juslin and Li potentials in terms of both hydrogen and helium clustering behavior as well as the spatial distribution of hydrogen below the surface. These simulations are an important test on the road to more accurate models of gas clustering and surface evolution of tungsten divertors in ITER and other plasma devices.

  2. Potential Energy Curves and Transport Properties for the Interaction of He with Other Ground-state Atoms

    Science.gov (United States)

    Partridge, Harry; Stallcop, James R.; Levin, Eugene; Arnold, Jim (Technical Monitor)

    2001-01-01

    The interactions of a He atom with a heavier atom are examined for 26 different elements, which are consecutive members selected from three rows (Li - Ne, Na - Ar, and K,Ca, Ga - Kr) and column 12 (Zn,Cd) of the periodic table. Interaction energies are determined wing high-quality ab initio calculations for the states of the molecule that would be formed from each pair of atoms in their ground states. Potential energies are tabulated for a broad range of Interatomic separation distances. The results show, for example, that the energy of an alkali interaction at small separations is nearly the same as that of a rare-gas interaction with the same electron configuration for the dosed shells. Furthermore, the repulsive-range parameter for this region is very short compared to its length for the repulsion dominated by the alkali-valence electron at large separations (beyond about 3-4 a(sub 0)). The potential energies in the region of the van der Waals minimum agree well with the most accurate results available. The ab initio energies are applied to calculate scattering cross sections and obtain the collision integrals that are needed to determine transport properties to second order. The theoretical values of Li-He total scattering cross sections and the rare-gas atom-He transport properties agree well (to within about 1%) with the corresponding measured data. Effective potential energies are constructed from the ab initio energies; the results have been shown to reproduce known transport data and can be readily applied to predict unknown transport properties for like-atom interactions.

  3. The Interaction Potential of an Open Nanotube and its Permeability: Molecular Dynamics Simulation

    Science.gov (United States)

    Bubenchikov, Mikhail A.; Potekaev, Alexander I.; Bubenchikov, Alexey M.; Usenko, Olesya V.; Malozemov, Alexander V.; Tarasov, Egor A.

    2016-02-01

    The integration of the modified LJ-potential allowed revealing the universal effect of the open carbon tube on the molecular objects moving within or proximate to the tube. There has been established that there are modes of the molecule motion without the energy exchange with the atoms of the carbon framing, under which the moving molecules are subjected to the considerable activation in the tube. The potential holes being the sorption zones in fact are localized.

  4. The Interaction Potential of an Open Nanotube and its Permeability: Molecular Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    Bubenchikov Mikhail A

    2016-01-01

    Full Text Available The integration of the modified LJ-potential allowed revealing the universal effect of the open carbon tube on the molecular objects moving within or proximate to the tube. There has been established that there are modes of the molecule motion without the energy exchange with the atoms of the carbon framing, under which the moving molecules are subjected to the considerable activation in the tube. The potential holes being the sorption zones in fact are localized.

  5. The Interaction Potential of an Open Nanotube and its Permeability: Molecular Dynamics Simulation

    OpenAIRE

    Bubenchikov Mikhail A.; Potekaev Alexander I; Bubenchikov Alexey M; Usenko Olesya V; Malozemov Alexander V; Tarasov Egor A

    2016-01-01

    The integration of the modified LJ-potential allowed revealing the universal effect of the open carbon tube on the molecular objects moving within or proximate to the tube. There has been established that there are modes of the molecule motion without the energy exchange with the atoms of the carbon framing, under which the moving molecules are subjected to the considerable activation in the tube. The potential holes being the sorption zones in fact are localized.

  6. Interaction of landscape varibles on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico

    OpenAIRE

    Plasencia–Vázquez, A. H.; Escalona–Segura, G.; Esparza–Olguín, L. G.

    2014-01-01

    The loss, degradation, and fragmentation of forested areas are endangering parrot populations. In this study, we determined the influence of fragmentation in relation to vegetation cover, land use, and spatial configuration of fragments on the potential geographical distribution patterns of parrots in the Yucatan Peninsula, Mexico. We used the potential geographical distribution for eight parrot species, considering the recently published maps obtained with the maximum entropy algorithm, and ...

  7. Fermionic particles with position-dependent mass in the presence of inversely quadratic Yukawa potential and tensor interaction

    Indian Academy of Sciences (India)

    M K Bahar; F Yasuk

    2013-02-01

    Approximate solutions of the Dirac equation with position-dependent mass are presented for the inversely quadratic Yukawa potential and Coulomb-like tensor interaction by using the asymptotic iteration method. The energy eigenvalues and the corresponding normalized eigenfunctions are obtained in the case of position-dependent mass and arbitrary spin-orbit quantum number k state and approximation on the spin-orbit coupling term.

  8. The EC bioethanol blend mandate policy: its effect on ACP sugar trade and potential interaction with EPA policies

    OpenAIRE

    Sukati, M.A.

    2013-01-01

    The study aim was to determine effects of the EC bioethanol blend mandate policy and its potential interaction with the EPA policies on EU/ACP countries. The research analysis focussed on welfare outcomes, changes in trade balance and output of bioethanol crops commodities due to these policies. Emphasis of our analysis was placed on sugar given the economic importance of this commodity to many ACP member states. Absence of an EU bioethanol partial equilbrium model means we had to design one ...

  9. Risk Assessment of Drug Interaction Potential and Concomitant Dosing Pattern on Targeted Toxicities in Pediatric Cancer Patients

    OpenAIRE

    Barrett, Jeffrey S.; Patel, Dimple; Dombrowsky, Erin; Bajaj, Gaurav; Skolnik, Jeffrey M.

    2013-01-01

    This investigation evaluated the impact of potential drug interactions on the incidence of reported toxicities seen with common dosing patterns in children with cancer, with the intent of being able to screen and reduce the incidence of adverse drug reactions (ADRs) in the future. Toxicity reported in pediatric cancer patients treated at the Children’s Hospital of Philadelphia from 2004 to 2010 were abstracted from a cancer tumor registry and merged with drug order profiles from the medical r...

  10. Dynamics of vector solitons in two-component Bose–Einstein condensates with time-dependent interactions and harmonic potential

    International Nuclear Information System (INIS)

    We present two kinds of exact vector-soliton solutions for coupled nonlinear Schroedinger equations with time-varying interactions and time-varying harmonic potential. Using the variational approach, we investigate the dynamics of the vector solitons. It is found that the two bright solitons oscillate about slightly and pass through each other around the equilibration state which means that they are stable under our model. At the same time, we obtain the opposite situation for dark-dark solitons. (general)

  11. One-electron self-interaction and the asymptotics of the Kohn-Sham potential: an impaired relation

    CERN Document Server

    Schmidt, Tobias; Kronik, Leeor; Kümmel, Stephan

    2015-01-01

    One-electron self-interaction and an incorrect asymptotic behavior of the Kohn-Sham exchange-correlation potential are among the most prominent limitations of many present-day density functionals. However, a one-electron self-interaction-free energy does not necessarily lead to the correct long-range potential. This is here shown explicitly for local hybrid functionals. Furthermore, carefully studying the ratio of the von Weizs\\"acker kinetic energy density to the (positive) Kohn-Sham kinetic energy density, $\\tau_\\mathrm{W}/\\tau$, reveals that this ratio, which frequently serves as an iso-orbital indicator and is used to eliminate one-electron self-interaction effects in meta-generalized-gradient approximations and local hybrid functionals, can fail to approach its expected value in the vicinity of orbital nodal planes. This perspective article suggests that the nature and consequences of one-electron self-interaction and some of the strategies for its correction need to be reconsidered.

  12. Lambda alpha, Sigma alpha and Xi alpha potentials derived from the SU6 quark-model baryon-baryon interaction

    CERN Document Server

    Fujiwara, Y; Suzuki, Y

    2006-01-01

    We calculate Lambda alpha, Sigma alpha and Xi alpha potentials from the nuclear-matter G-matrices of the SU6 quark-model baryon-baryon interaction. The alpha-cluster wave function is assumed to be a simple harmonic-oscillator shell-model wave function. A new method is proposed to derive the direct and knock-on terms of the interaction Born kernel from the hyperon-nucleon G-matrices, with explicit treatments of the nonlocality and the center-of-mass motion between the hyperon and alpha. We find that the SU6 quark-model baryon-baryon interactions, FSS and fss2, yield a reasonable bound-state energy for 5 He Lambda, -3.18 -- -3.62 MeV, in spite of the fact that they give relatively large depths for the Lambda single-particle potentials, 46 -- 48 MeV, in symmetric nuclear matter. An equivalent local potential derived from the Wigner transform of the nonlocal Lambda alpha kernel shows a strong energy dependence for the incident Lambda-particle, indicating the importance of the strangeness-exchange process in the o...

  13. Diets of emerald and spottail shiners and potential interactions with other western Lake Erie planktivorous fishes

    Science.gov (United States)

    Hartman, Kyle J.; Vondracek, Bruce; Parrish, Donna L.; Muth, Kenneth M.

    1992-01-01

    Emerald shiner (Notropis atherinoides) and spottail shiner (N. hudsonius) were abundant historically in western Lake Erie. Recent changes in the fish community suggest that shiners may not compete favorably with the invading white perch (Morone americana) or the gizzard shad (Dorosoma cepedianum). We examined the diets of emerald and spottail shiner and compared them to other planktivores in western Lake Erie. Emerald and spottail shiner ate cladocerans such as Daphnia spp.,Leptodora, and Bythotrephes. Biologically significant overlaps (Schoener 1970 index ≥ 0.6) among zooplanktivores occurred from July through September, but most occurred during July. The frequency of significant diet overlaps among planktivores declined since an earlier study in the mid-1970s (Muth and Busch 1989) possibly indicating that competitive interactions have eased since 1975. In addition to competitive interactions, other factors such as increased eutrophication and predator mediated mortality likely played a role in planktivore community changes since the early 1970s.

  14. Statistical Mining of Potential Drug Interaction Adverse Effects in FDA's Spontaneous Reporting System.

    Science.gov (United States)

    Harpaz, Rave; Haerian, Krystl; Chase, Herbert S; Friedman, Carol

    2010-01-01

    Many adverse drug effects (ADEs) can be attributed to drug interactions. Spontaneous reporting systems (SRS) provide a rich opportunity to detect novel post-marketed drug interaction adverse effects (DIAEs), as they include populations not well represented in clinical trials. However, their identification in SRS is nontrivial. Most existing research have addressed the statistical issues used to test or verify DIAEs, but not their identification as part of a systematic large scale database-wide mining process as discussed in this work. This paper examines the application of a highly optimized and tailored implementation of the Apriori algorithm, as well as methods addressing data quality issues, to the identification of DIAEs in FDAs SRS. PMID:21346985

  15. Understanding consumer motivations for interacting in online food communities – potential for innovation

    DEFF Research Database (Denmark)

    Jacobsen, Lina; Sørensen, Bjarne Taulo; Tudoran, Ana Alina;

    innovation task, one may be more important than the other. It is therefore important to understand, how companies can increase user willingness to engage in these different interaction forms. This study investigates the influence of various motivation factors and user interests on intention to provide or...... consume information in online food communities. A survey was conducted among 1009 respondents followed by analysis based on Structural Equation Modelling. Results revealed the effect of motivation factors to be stronger than basic consumer interests indicating that companies can influence the intended...... interaction. More specifically, possibility for self-marketing, improvement of product/skills and expected process enjoyment could be emphasised for supporting information provision. Only possibility for improving product/skills should be emphasised to support information consumption. Product and process...

  16. Klein-Gordon Equation with Casimir Potential for Attosecond Laser Pulse Interaction with Matter

    CERN Document Server

    Kozlovskii, Miroslaw P; Kozlowski, Miroslaw; Marciak-Kozlowska, Janina

    2005-01-01

    In this paper the Klein-Gordon equation (K-GE) is solved for the interaction of attosecond laser pulses with medium in which Casimir force operates. It is shown that for nanoscale structures, NEMS and MEMS, the attosecond laser pulses can be used as the tool for the investigation of the role played by Casimir force on the nanoscale. Key words: Casimir force; NEMS, MEMS, Attosecond laser pulses.

  17. Investigations of the potential schizophrenia susceptibility gene Kinase Interacting with Stathmin (KIS)

    OpenAIRE

    Bristow, Greg; Harrison, Paul J; Eastwood, Sharon L.

    2010-01-01

    Single nucleotide polymorphisms (SNPs) within the gene encoding the serine threonine kinase KIS (Kinase Interacting with Stathmin, also known as UHMK1) have recently been associated with schizophrenia. However, little is known about the neurobiology of KIS or the mechanisms through which disease-associated SNPs may increase susceptibility to schizophrenia. The studies presented in this thesis focus on the distribution of KIS and its mRNA, address the mechanisms through which KIS may confer su...

  18. Two-Particle Cluster Theory for Biaxial Nematic Phase Based on a Recently Proposed Interaction Potential

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-Dong; ZHANG Yan-Jun; SUN Zong-Li

    2006-01-01

    @@ Two-particle cluster theory is applied to study the biaxial nematic phase formed by biaxial molecules interacting with a simplified model proposed by Sonnet et al. [Phys. Rev. E 67 (2003) 061701]. For the temperature dependences of the internal energy per particle and of the order parameters, the two-particle theory yields an improved result compared with mean field theory. Concerning the phase diagram, the two-particle theory gives the numerical result in qualitative agreement with the mean field theory.

  19. Predicting potential responses to future climate in an alpine ungulate : interspecific interactions exceed climate effects.

    OpenAIRE

    Mason, Tom H. E.; Stephens, Philip A.; Apollonio, Marco; Willis, Stephen G.

    2014-01-01

    The altitudinal shifts of many montane populations are lagging behind climate change. Understanding habitual, daily behavioural rhythms, and their climatic and environmental influences, could shed light on the constraints on longterm upslope range-shifts. In addition, behavioural rhythms can be affected by interspecific interactions, which can ameliorate or exacerbate climate-driven effects on ecology. Here, we investigate the relative influences of ambient temperature and an inte...

  20. INTERACTIVE POTENTIAL OF CLARITHROMYCIN IN RATS ADMINISTERED WITH GLICLAZIDE IN NORMAL AND DIABETIC CONDITIONS

    OpenAIRE

    Neelam Raj; Prakash S. B; Vijay Kamat; Shanmukha I; Rajendra SV

    2011-01-01

    To investigate the interaction between clarithromycin and gliclazide, the present study is designed in various animal models. Albino rats and rabbits were selected for the current study. The animals were suitably grouped. In the first part of the experiment, per se effect with clarithromycin was carried out. In the next phase, the animals were treated with gliclazide and hypoglycemic/antidiabetic activity was performed. In the last phase, the animals of the second part were pretreated with cl...

  1. Local Interactions of Higher-Spin Potentials That are Gauge Invariant in Linear Approximation

    CERN Document Server

    Ruehl, Werner

    2009-01-01

    We study connected Wightman functions of $N$ conserved currents, each of which is formed from a scalar field and has even spin $l_{i}$. The UV divergence of this vertex function is regularized by the analytic continuation in the space dimension $D\\longrightarrow D-\\epsilon$. We evaluate the residue of $\\epsilon ^{-1}$ only, which is a local interaction Lagrangian density and gauge invariant in linear

  2. The Potential for Signal Integration and Processing in Interacting Map Kinase Cascades

    OpenAIRE

    John H Schwacke; Voit, Eberhard O.

    2007-01-01

    The cellular response to environmental stimuli requires biochemical information processing through which sensory inputs and cellular status are integrated and translated into appropriate responses by way of interacting networks of enzymes. One such network, the Mitogen Activated Protein (MAP) kinase cascade is a highly conserved signal transduction module that propagates signals from cell surface receptors to various cytosolic and nuclear targets by way of a phosphorylation cascade. We have i...

  3. Seaweed-Coral Interactions: Variance in Seaweed Allelopathy, Coral Susceptibility, and Potential Effects on Coral Resilience

    OpenAIRE

    Bonaldo, Roberta M.; Hay, Mark E.

    2014-01-01

    Tropical reefs are in global decline with seaweeds commonly replacing corals. Negative associations between macroalgae and corals are well documented, but the mechanisms involved, the dynamics of the interactions, and variance in effects of different macroalgal-coral pairings are poorly investigated. We assessed the frequency, magnitude, and dynamics of macroalgal-coral competition involving allelopathic and non-allelopathic macroalgae on three, spatially grouped pairs of no-take Marine Prote...

  4. Static magnetic fields: A summary of biological interactions, potential health effects, and exposure guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1992-05-01

    Interest in the mechanisms of interaction and the biological effects of static magnetic fields has increased significantly during the past two decades as a result of the growing number of applications of these fields in research, industry and medicine. A major stimulus for research on the bioeffects of static magnetic fields has been the effort to develop new technologies for energy production and storage that utilize intense magnetic fields (e.g., thermonuclear fusion reactors and superconducting magnet energy storage devices). Interest in the possible biological interactions and health effects of static magnetic fields has also been increased as a result of recent developments in magnetic levitation as a mode of public transportation. In addition, the rapid emergence of magnetic resonance imaging as a new clinical diagnostic procedure has, in recent years, provided a strong rationale for defining the possible biological effects of magnetic fields with high flux densities. In this review, the principal interaction mechanisms of static magnetic fields will be described, and a summary will be given of the present state of knowledge of the biological, environmental, and human health effects of these fields.

  5. Fungal chitinases: function, regulation, and potential roles in plant/pathogen interactions.

    Science.gov (United States)

    Langner, Thorsten; Göhre, Vera

    2016-05-01

    In the past decades our knowledge about fungal cell wall architecture increased tremendously and led to the identification of many enzymes involved in polysaccharide synthesis and remodeling, which are also of biotechnological interest. Fungal cell walls play an important role in conferring mechanic stability during cell division and polar growth. Additionally, in phytopathogenic fungi the cell wall is the first structure that gets into intimate contact with the host plant. A major constituent of fungal cell walls is chitin, a homopolymer of N-acetylglucosamine units. To ensure plasticity, polymeric chitin needs continuous remodeling which is maintained by chitinolytic enzymes, including lytic polysaccharide monooxygenases N-acetylglucosaminidases, and chitinases. Depending on the species and lifestyle of fungi, there is great variation in the number of encoded chitinases and their function. Chitinases can have housekeeping function in plasticizing the cell wall or can act more specifically during cell separation, nutritional chitin acquisition, or competitive interaction with other fungi. Although chitinase research made huge progress in the last decades, our knowledge about their role in phytopathogenic fungi is still scarce. Recent findings in the dimorphic basidiomycete Ustilago maydis show that chitinases play different physiological functions throughout the life cycle and raise questions about their role during plant-fungus interactions. In this work we summarize these functions, mechanisms of chitinase regulation and their putative role during pathogen/host interactions. PMID:26527115

  6. Diet-gene interactions and PUFA metabolism: a potential contributor to health disparities and human diseases.

    Science.gov (United States)

    Chilton, Floyd H; Murphy, Robert C; Wilson, Bryan A; Sergeant, Susan; Ainsworth, Hannah; Seeds, Michael C; Mathias, Rasika A

    2014-05-01

    The "modern western" diet (MWD) has increased the onset and progression of chronic human diseases as qualitatively and quantitatively maladaptive dietary components give rise to obesity and destructive gene-diet interactions. There has been a three-fold increase in dietary levels of the omega-6 (n-6) 18 carbon (C18), polyunsaturated fatty acid (PUFA) linoleic acid (LA; 18:2n-6), with the addition of cooking oils and processed foods to the MWD. Intense debate has emerged regarding the impact of this increase on human health. Recent studies have uncovered population-related genetic variation in the LCPUFA biosynthetic pathway (especially within the fatty acid desaturase gene (FADS) cluster) that is associated with levels of circulating and tissue PUFAs and several biomarkers and clinical endpoints of cardiovascular disease (CVD). Importantly, populations of African descent have higher frequencies of variants associated with elevated levels of arachidonic acid (ARA), CVD biomarkers and disease endpoints. Additionally, nutrigenomic interactions between dietary n-6 PUFAs and variants in genes that encode for enzymes that mobilize and metabolize ARA to eicosanoids have been identified. These observations raise important questions of whether gene-PUFA interactions are differentially driving the risk of cardiovascular and other diseases in diverse populations, and contributing to health disparities, especially in African American populations. PMID:24853887

  7. Diet-Gene Interactions and PUFA Metabolism: A Potential Contributor to Health Disparities and Human Diseases

    Directory of Open Access Journals (Sweden)

    Floyd H. Chilton

    2014-05-01

    Full Text Available The “modern western” diet (MWD has increased the onset and progression of chronic human diseases as qualitatively and quantitatively maladaptive dietary components give rise to obesity and destructive gene-diet interactions. There has been a three-fold increase in dietary levels of the omega-6 (n-6 18 carbon (C18, polyunsaturated fatty acid (PUFA linoleic acid (LA; 18:2n-6, with the addition of cooking oils and processed foods to the MWD. Intense debate has emerged regarding the impact of this increase on human health. Recent studies have uncovered population-related genetic variation in the LCPUFA biosynthetic pathway (especially within the fatty acid desaturase gene (FADS cluster that is associated with levels of circulating and tissue PUFAs and several biomarkers and clinical endpoints of cardiovascular disease (CVD. Importantly, populations of African descent have higher frequencies of variants associated with elevated levels of arachidonic acid (ARA, CVD biomarkers and disease endpoints. Additionally, nutrigenomic interactions between dietary n-6 PUFAs and variants in genes that encode for enzymes that mobilize and metabolize ARA to eicosanoids have been identified. These observations raise important questions of whether gene-PUFA interactions are differentially driving the risk of cardiovascular and other diseases in diverse populations, and contributing to health disparities, especially in African American populations.

  8. Some fundamental aspects of the optical potential for the interaction of fast neutrons with cobalt

    International Nuclear Information System (INIS)

    Differential elastic- and inelastic-scattering cross sections, measured from ∼1.5 to 10.0 MeV, are interpreted in terms of spherical-optical-statistical (OM) and coupled-channels models. A successful description of the differential elastic scattering below 10 MeV and the total cross section to 20.0 MeV is achieved using the spherical OM with energy-dependent strengths and geometries. These energy dependencies are large below ∼7.0 MeV, but become smaller and similar to those reported for /open quotes/global/close quotes/ potentials at higher energies. This change in the energy dependence of the parameters probably marks the onset of the Fermi surface anomaly ∼19 MeV above the Fermi energy. Inelastic scattering to the levels below 1.8 MeV displays a forward-peaked behavior. This nonstatistical component is interpreted using the weak-coupling model in which the f72 proton hole is coupled to the 2/sup /plus// state in 60Ni. This model provides an explanation of the unusual energy dependence and relatively small radius found for the imaginary OM potential. The coupling also contributes to the large value of this potential. The real spherical OM potential derived from the neutron-scattering results is extrapolated to bound energies by using the dispersion relationship and the method of moments. The resulting real-potential strength and radius peak at ∼-10.0 MeV, whereas the real diffuseness is at a minimum at this energy. The extrapolated potential is ∼8% larger than that implied by reported particle-state energies, and ∼13% smaller than indicated by hole-state energies. 42 refs., 8 figs

  9. Study of the interaction potential between 12 C and 24 Mg: an example of anomalous transparency

    International Nuclear Information System (INIS)

    Complete angular distributions of the 12 C + 24 Mg elastic scattering were measured at ECM = 10.67 and 11.33 MeV, and from ECM = 12.0 to 16.0 MeV, using a 12 C beam produced at Pelletron Accelerator. This energy range is close to the Coulomb barrier of tue system, which is 12.53 MeV. Surprisingly all the angular distributions show strong oscillations even at energies bellow the Coulomb barrier. The angular distributions were fitted by optical model calculations and we determined the shallowest real potential, without continuous ambiguity. The main features of this potential are: very transparent even at the nuclear interior and strong dependence with energy of the real imaginary depths Vo and Wo. At five energies the inelastic scattering data were also analysed and well fitted by coupled-channels calculations. The optical potentials of all channels present the threshold anomaly and are well reproduced by dispersion relation calculations applied to the volume integrals of the optical potentials. (author). 50 refs., 41 figs., 12 tabs

  10. Interaction potential of Trigonella foenum graceum through cytochrome P450 mediated inhibition

    Directory of Open Access Journals (Sweden)

    Sk Milan Ahmmed

    2015-01-01

    Conclusions: From the present study, we may conclude that the TFG or TG has very less potential to inhibit the CYP isozymes (CYP3A4, CYP2D6, so administration of this plant extract or its biomarker TG may be safe.

  11. Chemical Potential Dependence of the Dressed—Quark Propagator from an Effective Quark—Quark Interaction

    Institute of Scientific and Technical Information of China (English)

    ZONGHong-Shi; PINGJia-Lun; 等

    2002-01-01

    We exhibit a method for obtaining the low chemical potential dependence of the dressed quark propagator from the dressed-quark propagator,which provides a means of determining the behavior of the chiral and deconfinement order parameters.A comparison with the results of previous researches is given.

  12. SoundScapes: non-formal learning potentials from interactive VEs

    DEFF Research Database (Denmark)

    Brooks, Tony; Petersson, Eva

    2007-01-01

    Non-formal learning is evident from an inhabited information space that is created from non-invasive multi-dimensional sensor technologies that source human gesture. Libraries of intuitive interfaces empower natural interaction where the gesture is mapped to the multisensory content. Large screen...... and international bodies have consistently recognized SoundScapes which, as a research body of work, is directly responsible for numerous patents. Please note that my full name is Anthony Lewis Brooks. I publish with Anthony Brooks: A. L. Brooks; Tony Brooks.  ...

  13. The interactive potential of post-modern film narrative. Frequency, Order and Simultaneity.

    OpenAIRE

    Carlos Sena Caires

    2009-01-01

    A considerable number of contemporary films are now using narrative models that allow several adaptations on digital and interactive operating systems. This trend is seen in films such as Memento by Christopher Nolan (2000), Irréversible by Gaspar Noé (2002) and Smoking / No Smoking by Alain Resnais (1993), concerning the chronological organization of their narrative parts – here it is a question of order. Or in films such as Elephant by Gus Van Sant (2003), Groundhog Day by Harold Ramis, 199...

  14. Analysis of Potential Drug-Drug Interactions and Its Clinical Manifestation of Pediatric Prescription on 2 Pharmacies in Bandung

    Directory of Open Access Journals (Sweden)

    Melisa I. Barliana

    2013-09-01

    Full Text Available The potential of Drug-Drug Interactions (DDI in prescription have high incidence around the world, including Indonesia. However, scientific evidence regarding DDI in Indonesia is not available. Therefore, in this study we have conducted survey in 2 pharmacies in Bandung against pediatric prescription given by pediatrician. These prescriptions then analyzed the potential for DDI contained in the prescription and clinical manifestation. The analysis showed that in pharmacy A, there are 33 prescriptions (from a total of 155 prescriptions that have potential DDI, or approximately 21.19% (2 prescriptions have the potential DDI major categories, 23 prescriptions categorized as moderate, and 8 prescriptions as minor. In Pharmacy B, there are 6 prescriptions (from a total of 40 prescriptions or 15% of potential DDI (4 prescriptions categorized as moderate and 2 prescriptions as minor. This result showed that potential DDI happened less than 50% in pediatric prescription from both pharmacies. However, this should get attention because DDI should not happen in a prescription considering its clinical manifestations caused by DDI. Moreover, current pharmaceutical care refers to patient oriented than product oriented. In addition, further study for the pediatric prescription on DDI incidence in large scale need to be investigated.

  15. Potential considerations & concerns in the risk characterization for the interaction profiles of metals.

    Science.gov (United States)

    Choudhury, H; Mudipalli, Anu

    2008-10-01

    The contaminants of concern for smelting and mining sites include arsenic (As), cadmium (Cd), lead (Pb) and zinc (Zn). Risk assessments for such sites need to consider whether toxicity values can be developed for this mixture, and if not, whether interactions among the individual components are significant and can be incorporated quantitatively into the assessment. No information is available for the risk characterization of the toxic interactions of AsCdPbZn mixtures. Studies of the AsCdPb and CdPbZn mixtures supported the assumption that a reasonable approximation to the toxicity of a mixture can be achieved by considering the binary submixtures. Data relevant to long-term simultaneous exposure to binary submixtures were not conclusive. For example, data from animal and human studies of Zn and Pb suggested that moderately elevated Zn intakes may slightly inhibit Pb absorption and haematological effects in children who have deficient or marginal Zn intakes, but were not adequate for adjusting absorption parameters in the Integrated Exposure Uptake Biokinetic (IEUBK) model for Pb. Thus the existing database calls for plausible approaches for risk characterization and considerations in the data usage for such characterization. This article is an attempt to identify such data gaps and the scientific considerations for such efforts. PMID:19106441

  16. Wetting transitions on patterned surfaces with diffuse interaction potentials embedded in a Young-Laplace formulation

    Science.gov (United States)

    Pashos, G.; Kokkoris, G.; Papathanasiou, A. G.; Boudouvis, A. G.

    2016-01-01

    The Minimum Energy Paths (MEPs) of wetting transitions on pillared surfaces are computed with the Young-Laplace equation, augmented with a pressure term that accounts for liquid-solid interactions. The interactions are smoothed over a short range from the solid phase, therefore facilitating the numerical solution of problems concerning wetting on complex surface patterns. The patterns may include abrupt geometric features, e.g., arrays of rectangular pillars, where the application of the unmodified Young-Laplace is not practical. The MEPs are obtained by coupling the augmented Young-Laplace with the modified string method from which the energy barriers of wetting transitions are eventually extracted. We demonstrate the method on a wetting transition that is associated with the breakdown of superhydrophobic behavior, i.e., the transition from the Cassie-Baxter state to the Wenzel state, taking place on a superhydrophobic pillared surface. The computed energy barriers quantify the resistance of the system to these transitions and therefore, they can be used to evaluate superhydrophobic performance or provide guidelines for optimal pattern design.

  17. Potential herbs and herbal nutraceuticals: food applications and their interactions with food components.

    Science.gov (United States)

    Hussain, Shaik Abdul; Panjagari, Narender Raju; Singh, R R B; Patil, G R

    2015-01-01

    Since ancient times, herbs have been used as natural remedies for curing many physiological disorders. Traditional medicinal literature appreciated their value as nature's gift to mankind for the healing of illnesses. Some of the herbs have also been used for culinary purposes, and few of them have been used in cheese manufacture both as coagulating agents and flavor ingredients. Scientific investigations regarding biological activity and toxicity of chemical moieties present in many herbs have been carried out over a period of time. Consequently, literature related to the use of herbs or their functional ingredients in foods and their interaction with food constituents has been appearing in recent times. This article presents the information regarding some biologically active constituents occurring in commonly used herbs, viz., alkaloids, anthraquinones, bitters, flavonoids, saponins, tannins, and essential oils, their physiological functionalities, and also the description of few herbs of importance, viz., Asparagus racemosus, Withania somnifera, Bacopa monniera, Pueraria tuberose, Emblica officinalis, Terminalia chebula, Terminalia belerica, Terminalia arjuna, and Aloe vera, in terms of their chemical composition, biological functionality, and toxicity. This article also reviews the use of herbs and their active ingredients in foods and their interactions with different food constituents. PMID:24915396

  18. Interaction of rare gas metastable atoms. [Differential and total cross sections, elastic scattering, ionization, potential scattering, phase shifts, rate constants

    Energy Technology Data Exchange (ETDEWEB)

    Wang, A.Z.F.

    1977-11-01

    The physical and chemical properties of metastable rare gas atoms are discussed and summarized. This is followed by a detailed examination of the various possible pathways whereby the metastable's excess electronic energy can be dissipated. The phenomenon of chemi-ionization is given special emphasis, and a theoretical treatment based on the use of complex (optical) potential is presented. This is followed by a discussion on the unique advantages offered by elastic differential cross section measurements in the apprehension of the fundamental forces governing the ionization process. The methodology generally adopted to extract information about the interaction potential for scattering data is also systematically outlined. Two widely studied chemi-ionization systems are then closely examined in the light of accurate differential cross section measurements obtained in this work. The first system is He(2/sup 3/S) + Ar for which one can obtain an interaction potential which is in good harmony with the experimental results of other investigators. The validity of using the first-order semiclassical approximation for the phase shifts calculation in the presence of significant opacities is also discussed. The second reaction studied is He*+D/sub 2/ for which measurements were made on both spin states of the metastable helium. A self-consistent interaction potential is obtained for the triplet system, and reasons are given for not being able to do likewise for the singlet system. The anomalous hump proposed by a number of laboratories is analyzed. Total elastic and ionization cross sections as well as rate constants are calculated for the triplet case. Good agreement with experimental data is found. Finally, the construction and operation of a high power repetitively pulsed nitrogen laser pumped dye laser system is described in great details. Details for the construction and operation of a flashlamp pumped dye laser are likewise given.

  19. Optical interaction potentials from differential cross section measurements at thermal energies

    International Nuclear Information System (INIS)

    Differential cross sections have been measured for He(21S)+Na at five different kinetic energies between 52 and 207 meV. For the lowest kinetic energy a backward glory is observed. An optical potential is obtained from a simultaneous fit to the data at all energies. A modified Morse potential with a well depth of epsilon=300 meV and a minimum distance of tausub(m)=6.3 au gives the best fit. The well depth is in good agreement with data from Penning electron spectroscopy, but the total ionisation cross section is larger than that determined earlier. The metal beam is generated in a recirculating supersonic oven. (author)

  20. A class of singular logarithmic potentials in a box with different skin thicknesses and wall interactions

    International Nuclear Information System (INIS)

    We obtain an analytic solution for a three-parameter class of logarithmic potentials at zero energy. The potential terms are products of the inverse square and the inverse log to powers 2, 1 and 0. The configuration space is a one-dimensional box. Using point canonical transformation, we simplify the solution by mapping the problem into the oscillator problem. We also obtain an approximate analytic solution for non-zero energy when there is strong attraction to one side of the box. The wavefunction is written in terms of the confluent hypergeometric function. We also present a numerical scheme for calculating the energy spectrum for a general configuration and to any desired accuracy.

  1. Effective medium potentials for molecule-surface interactions: H2 on Cu and Ni surfaces

    DEFF Research Database (Denmark)

    Nørskov, Jens Kehlet

    1989-01-01

    A new approximate method is developed for the calculation of the adiabatic potential energy surface for a molecule outside a metal surface. It is computationally fast enough to be useful in simulations of the dynamics of adsorbing and desorbing molecules. The method is characterized by the fact...... that the functional form of the total energy expression is derived from density functional theory, that each of the terms entering can be given a precise physical interpretation, and that most of the parameters entering can be calculated, within the local density approximation. The method is explicitly...... derived for H2 outside metal surfaces and the applicability is illustrated for H2 adsorbing on various Cu and Ni surfaces. Although very approximate, the calculated potentials seem to include a number of features observed experimentally: Ni is more active in dissociating H2 than Cu, and open surfaces are...

  2. Interactions between mood and the structure of semantic memory: event-related potentials evidence

    OpenAIRE

    Pinheiro, Ana P.; del Re, Elisabetta; Nestor, Paul G.; McCarley, Robert W.; Gonçalves, Óscar F.; Niznikiewicz, Margaret

    2012-01-01

    Recent evidence suggests that affect acts as modulator of cognitive processes and in particular that induced mood has an effect on the way semantic memory is used on-line. We used event-related potentials (ERPs) to examine affective modulation of semantic information processing under three different moods: neutral, positive and negative. Fifteen subjects read 324 pairs of sentences, after mood induction procedure with 30 pictures of neutral, 30 pictures of positive and 30 pictures of neutral ...

  3. How long does a wave packet interact with a potential barrier?

    CERN Document Server

    Begliuomini, A; Begliuomini, Andrea; Bracci, Luciano

    1996-01-01

    We examine the time evolution of a packet approaching a one dimensional potential barrier. The times required for the appearance of a reflected or a transmitted packet are definitely different from the reflection and transmission times presented in the literature for stationary problems. The depletion rate of the packet trapped within the barrier region depends only on the properties of the barrier. We propose new definitions for the dwell, reflection and transmission times suitable for a packet.

  4. A water-like model under confinement for hydrophobic and hydrophilic particle-plate interaction potentials

    OpenAIRE

    Krott, Leandro B.; Barbosa, Marcia C.

    2013-01-01

    Molecular dynamic simulations were employed to study a water-like model confined between hydrophobic and hydrophilic plates. The phase behavior of this system is obtained for different distances between the plates and particle-plate potentials. For both hydrophobic and hydrophilic walls there are the formation of layers. Crystallization occurs at lower temperature at the contact layer than at the middle layer. In addition, the melting temperature decreases as the plates become more hydrophobi...

  5. Determination of substitutional-interstitial interaction from chemical potentials of interstitials in the steel matrix

    Czech Academy of Sciences Publication Activity Database

    Shan, Y. V.; Svoboda, Jiří; Fischer, F. D.; Kozeschnik, E.

    Zurich: Trans Tech Publications, 2014 - (Mishra, B.; Ionescu, M.; Chandra, T.), s. 645-650. ( Advanced Materials Research. 922). ISBN 978-3-03835-074-3. ISSN 1022-6680. [THERMEC 2013 - International Conference on Processing and Manufacturing of Advanced Materials: Processing, Fabrication, Properties, Applications /8/. Las Vegas (US), 02.12.2013-06.12.2013] Institutional support: RVO:68081723 Keywords : interstitial trapping * chemical potential * trapping enthalpy * carbon * nitrogen Subject RIV: BJ - Thermodynamics

  6. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    , and demonstrated in public settings. We then describe INTERACT, a proposed research project that stages the robotic marionettes in a live performance. The interdisciplinary project brings humanities research to bear on scientific and technological inquiry, and culminates in the development a live......This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions...... interaction between a human operator and an artificial actor or agent. We can apply insights from puppetry to develop culturally-aware robots. Here we describe the development of a robotic marionette theatre wherein robotic controllers assume the role of human puppeteers. The system has been built, tested...

  7. TargetNet: a web service for predicting potential drug-target interaction profiling via multi-target SAR models.

    Science.gov (United States)

    Yao, Zhi-Jiang; Dong, Jie; Che, Yu-Jing; Zhu, Min-Feng; Wen, Ming; Wang, Ning-Ning; Wang, Shan; Lu, Ai-Ping; Cao, Dong-Sheng

    2016-05-01

    Drug-target interactions (DTIs) are central to current drug discovery processes and public health fields. Analyzing the DTI profiling of the drugs helps to infer drug indications, adverse drug reactions, drug-drug interactions, and drug mode of actions. Therefore, it is of high importance to reliably and fast predict DTI profiling of the drugs on a genome-scale level. Here, we develop the TargetNet server, which can make real-time DTI predictions based only on molecular structures, following the spirit of multi-target SAR methodology. Naïve Bayes models together with various molecular fingerprints were employed to construct prediction models. Ensemble learning from these fingerprints was also provided to improve the prediction ability. When the user submits a molecule, the server will predict the activity of the user's molecule across 623 human proteins by the established high quality SAR model, thus generating a DTI profiling that can be used as a feature vector of chemicals for wide applications. The 623 SAR models related to 623 human proteins were strictly evaluated and validated by several model validation strategies, resulting in the AUC scores of 75-100 %. We applied the generated DTI profiling to successfully predict potential targets, toxicity classification, drug-drug interactions, and drug mode of action, which sufficiently demonstrated the wide application value of the potential DTI profiling. The TargetNet webserver is designed based on the Django framework in Python, and is freely accessible at http://targetnet.scbdd.com . PMID:27167132

  8. Derivation and Implementation of the Gradient of the R(-7) Dispersion Interaction in the Effective Fragment Potential Method.

    Science.gov (United States)

    Guidez, Emilie B; Xu, Peng; Gordon, Mark S

    2016-02-01

    The dispersion interaction energy may be expressed as a sum over R(-n) terms, with n ≥ 6. Most implementations of the dispersion interaction in model potentials are terminated at n = 6. Those implementations that do include higher order contributions commonly only include even power terms, despite the fact that odd power terms can be important. Because the effective fragment potential (EFP) method contains no empirically fitted parameters, the EFP method provides a useful vehicle for examining the importance of the leading R(-7) odd power term in the dispersion expansion. To fully evaluate the importance of the R(-7) contribution to the dispersion energy, it is important to have analytic energy first derivatives for all terms. In the present work, the gradients of the term E7 ∼ R(-7) are derived analytically, implemented in the GAMESS software package, and evaluated relative to other terms in the dispersion expansion and relative to the total EFP interaction energy. Periodic boundary conditions in the minimum image convention are also implemented. A more accurate dispersion energy contribution can now be obtained during molecular dynamics simulations. PMID:26745447

  9. Role of attractive methane-water interactions in the potential of mean force between methane molecules in water

    CERN Document Server

    Asthagiri, D; Pratt, Lawrence R

    2008-01-01

    On the basis of a gaussian quasi-chemical model of hydration, a model of non van der Waals character, we explore the role of attractive methane-water interactions in the hydration of methane and in the potential of mean force between two methane molecules in water. We find that the hydration of methane is dominated by packing and a mean-field energetic contribution. Contributions beyond the mean-field term are unimportant in the hydration phenomena for a hydrophobic solute such as methane. Attractive solute-water interactions make a net repulsive contribution to these pair potentials of mean force. With no conditioning, the observed distributions of binding energies are super-gaussian and can be effectively modeled by a Gumbel (extreme value) distribution. This further supports the view that the characteristic form of the unconditioned distribution in the high-e tail is due to energetic interactions with a small number of molecules. Generalized extreme value distributions also effectively model the results wi...

  10. Potential drug-drug interactions in pediatric wards of Gondar University Hospital, Ethiopia:A cross sectional study

    Institute of Scientific and Technical Information of China (English)

    Henok Getachew; Mohammed Assen; Feser Dula; Akshaya Srikanth Bhagavathula

    2016-01-01

    Objective: To determine the prevalence, level of severity of potential drug–drug in-teractions (PDDIs) and the associated factors for PDDIs in hospitalized pediatric patients of Gondar University Hospital. Methods: A retrospective cross-sectional study was conducted for a period of 3 months from March to May 2014 in pediatric wards of Gondar University Hospital. Systematic random sampling technique was used to select charts from all pediatric patients' charts with every 7th interval to get sample size of 384. Univariate and multivariate analysis were performed to compute crude odds ratio and adjusted odds ratio respectively. Sta-tistical significance was set at P value Results: A total of 176 (45.8%) patients had at least one PDDI. A total of 393 PDDIs, which were comprised of 283 types of interacting combinations, were identified. Of the total of 393 PDDIs, most were of moderate severity [201 (51%)] followed by minor [152 (39%)] and major severity [40 (10%)]. The most common interacting pairs of major severity were gentamicin + furosemide (6), cotrimoxazole + methotrexate (4) and phenytoin + artemether (4). The occurrence of PDDIs was significantly associated with age and polypharmacy. Conclusions: The study showed that most of the interactions had moderate severity followed by minor severity. Age and polypharmacy were found to show statistically significant association with the occurrence of PDDIs. Due to sensitive nature of pediatrics population, close monitoring is recommended for the detection and management of PDDIs to prevent its negative consequences.

  11. Accuracy of Potential Flow Methods to Solve Real-time Ship-Tug Interaction Effects within Ship Handling Simulators

    Directory of Open Access Journals (Sweden)

    B. Nirman Jayarathne

    2014-12-01

    Full Text Available The hydrodynamic interaction effects between two vessels that are significantly different in size operating in close proximity can adversely affect the safety and handling of these vessels. Many ship handling simulator designers implement Potential Flow (PF solvers to calculate real-time interaction effects. However, these PF solvers struggle to accurately predict the complicated flow regimes that can occur, for example as the flow passes a wet transom hull or one with a drift angle. When it comes to predicting the interaction effects on a tug during a ship assist, it is essential to consider the rapid changes of the tug’s drift angle, as the hull acts against the inflow creating a complicated flow regime. This paper investigates the ability of the commercial PF solver, Futureship®, to predict the accurate interaction effects acting on tugs operating at a drift angle during ship handling operations through a case study. This includes a comparison against Computation Fluid Dynamics (CFD simulations and captive model tests to examine the suitability of the PF method for such duties. Although the PF solver can be tuned to solve streamline bodies, it needs further improvement to deal with hulls at drift angles.

  12. A protocol for a randomized clinical trial of interactive video dance: potential for effects on cognitive function

    Directory of Open Access Journals (Sweden)

    Jovancevic Jelena

    2012-06-01

    Full Text Available Abstract Background Physical exercise has the potential to affect cognitive function, but most evidence to date focuses on cognitive effects of fitness training. Cognitive exercise also may influence cognitive function, but many cognitive training paradigms have failed to provide carry-over to daily cognitive function. Video games provide a broader, more contextual approach to cognitive training that may induce cognitive gains and have carry over to daily function. Most video games do not involve physical exercise, but some novel forms of interactive video games combine physical activity and cognitive challenge. Methods/Design This paper describes a randomized clinical trial in 168 postmenopausal sedentary overweight women that compares an interactive video dance game with brisk walking and delayed entry controls. The primary endpoint is adherence to activity at six months. Additional endpoints include aspects of physical and mental health. We focus this report primarily on the rationale and plans for assessment of multiple cognitive functions. Discussion This randomized clinical trial may provide new information about the cognitive effects of interactive videodance. It is also the first trial to examine physical and cognitive effects in older women. Interactive video games may offer novel strategies to promote physical activity and health across the life span. The study is IRB approved and the number is: PRO08080012 ClinicalTrials.gov Identifier: NCT01443455

  13. Syntrophic interactions improve power production in formic acid fed MFCs operated with set anode potentials or fixed resistances

    KAUST Repository

    Sun, Dan

    2011-10-24

    Formic acid is a highly energetic electron donor but it has previously resulted in low power densities in microbial fuel cells (MFCs). Three different set anode potentials (-0.30, -0.15, and +0.15V; vs. a standard hydrogen electrode, SHE) were used to evaluate syntrophic interactions in bacterial communities for formic acid degradation relative to a non-controlled, high resistance system (1,000Ω external resistance). No current was generated at -0.30V, suggesting a lack of direct formic acid oxidation (standard reduction potential: -0.40V). More positive potentials that allowed for acetic acid utilization all produced current, with the best performance at -0.15V. The anode community in the -0.15V reactor, based on 16S rDNA clone libraries, was 58% Geobacter sulfurreducens and 17% Acetobacterium, with lower proportions of these genera found in the other two MFCs. Acetic acid was detected in all MFCs suggesting that current generation by G. sulfurreducens was dependent on acetic acid production by Acetobacterium. When all MFCs were subsequently operated at an external resistance for maximum power production (100Ω for MFCs originally set at -0.15 and +0.15V; 150Ω for the control), they produced similar power densities and exhibited the same midpoint potential of -0.15V in first derivative cyclic voltammetry scans. All of the mixed communities converged to similar proportions of the two predominant genera (ca. 52% G. sulfurreducens and 22% Acetobacterium). These results show that syntrophic interactions can be enhanced through setting certain anode potentials, and that long-term performance produces stable and convergent communities. © 2011 Wiley Periodicals, Inc.

  14. Interactions

    DEFF Research Database (Denmark)

    The main theme of this anthology is the unique interaction between mathematics, physics and philosophy during the beginning of the 20th century. Seminal theories of modern physics and new fundamental mathematical structures were discovered or formed in this period. Significant physicists such as...

  15. Protein-Ligand Binding Potential of Mean Force Calculations with Hamiltonian Replica Exchange on Alchemical Interaction Grids

    CERN Document Server

    Minh, David D L

    2015-01-01

    A binding potential of mean force (BPMF) is a free energy of noncovalent association in which one binding partner is flexible and the other is rigid. I have developed a method to calculate BPMFs for protein-ligand systems. The method is based on replica exchange sampling from multiple thermodynamic states at different temperatures and protein-ligand interaction strengths. Protein-ligand interactions are represented by interpolating precomputed electrostatic and van der Waals grids. Using a simple estimator for thermodynamic length, thermodynamic states are initialized at approximately equal intervals. The method is demonstrated on the Astex diverse set, a database of 85 protein-ligand complexes relevant to pharmacy or agriculture. Fifteen independent simulations of each complex were started using poses from crystallography, docking, or the lowest-energy pose observed in the other simulations. Benchmark simulations completed within three days on a single processor. Overall, protocols initialized using the ther...

  16. Self-spin-controlled rotation of spatial states of a Dirac electron in a cylindrical potential via spin orbit interaction

    Science.gov (United States)

    Leary, C. C.; Reeb, D.; Raymer, M. G.

    2008-10-01

    Solution of the Dirac equation predicts that when an electron with nonzero orbital angular momentum (OAM) propagates in a cylindrically symmetric potential, its spin and orbital degrees of freedom interact, causing the electron's phase velocity to depend on whether its spin angular momentum (SAM) and OAM vectors are oriented parallel or anti-parallel with respect to each other. This spin-orbit splitting of the electronic dispersion curves can result in a rotation of the electron's spatial state in a manner controlled by the electron's own spin z-component value. These effects persist at non-relativistic velocities. To clarify the physical origin of this effect, we compare solutions of the Dirac equation to perturbative predictions of the Schrödinger-Pauli equation with a spin-orbit term, using the standard Foldy-Wouthuysen Hamiltonian. This clearly shows that the origin of the effect is the familiar relativistic spin-orbit interaction.

  17. The role of internal waves in larval fish interactions with potential predators and prey

    Science.gov (United States)

    Greer, Adam T.; Cowen, Robert K.; Guigand, Cedric M.; Hare, Jonathan A.; Tang, Dorothy

    2014-09-01

    Tidally driven internal wave packets in coastal environments have the potential to influence patchiness of larval fishes, prey, and gelatinous predators. We used the In Situ Ichthyoplankton Imaging System (ISIIS) to synoptically sample larval fishes, copepods, and planktonic predators (ctenophores, hydromedusae, chaetognaths, and polychaetes) across these predictable features in the summer near Stellwagen Bank, Massachusetts, USA. Full water column profiles and fixed depth transects (∼10 m depth) were used to quantify vertical and horizontal components of the fish and invertebrate distributions during stable and vertically mixed conditions associated with tidally generated internal waves. Larval fishes, consisting mostly of Urophycis spp., Merluccius bilinearis, and Labridae, were concentrated near the surface, with larger sizes generally occupying greater depths. During stable water column conditions, copepods formed a near surface thin layer several meters above the chlorophyll-a maximum that was absent when internal waves were propagating. In contrast, ctenophores and other predators were much more abundant at depth, but concentrations near 10 m increased immediately after the internal hydraulic jump mixed the water column. During the propagation of internal waves, the fine-scale abundance of larval fishes was more correlated with the abundance of gelatinous predators and less correlated with copepods compared to the stable conditions. Vertical oscillations caused by the internal hydraulic jump can disperse patches of zooplankton and force surface dwelling larval fishes into deeper water where probability of predator contact is increased, creating conditions potentially less favorable for larval fish growth and survival on short time scales.

  18. Potenciais interações medicamentosas em pacientes com artrite reumatoide Potential drug interactions in patients with rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Fabíola Bagatini

    2011-02-01

    risk of potential undesirable interactions between medications used for managing RA and those used for non-chronic diseases. METHODS: A cohort study was carried out with 103 RA patients registered at the Strategy of Access to Medications from the Brazilian Health Ministry, at the School of Pharmacy of the city of Florianópolis, state of Santa Catarina. Patients were monthly followed up by use of form completion. Drug interactions were identified by use of the Drugdex System - Thomson Micromedex® - Interactions database. RESULTS: Polypharmacy was found in 95.1% of the patients, and 19 potential undesirable interactions were observed between the drugs used by 74 patients (mean of 3.0 ± 1.2 interactions/patient. All potential interactions were related to methotrexate. Omeprazole was the major representative, accounting for 29.3% of the interactions, followed by diclofenac sodium (17.6%, and metamizole sodium (13.2%. CONCLUSION: Considering that this study confirms that polypharmacy is a common therapeutic practice in RA patients, it is worth emphasizing the need for greater surveillance regarding the adverse effects or effectiveness reduction of certain drugs due to drug interaction

  19. Ecosystem Interactions Underlie the Spread of Avian Influenza A Viruses with Pandemic Potential

    Science.gov (United States)

    Bahl, Justin; Pham, Truc T.; Hill, Nichola J.; Hussein, Islam T. M.; Ma, Eric J.; Easterday, Bernard C.; Halpin, Rebecca A.; Stockwell, Timothy B.; Wentworth, David E.; Kayali, Ghazi; Krauss, Scott; Schultz-Cherry, Stacey; Webster, Robert G.; Webby, Richard J.; Swartz, Michael D.; Smith, Gavin J. D.; Runstadler, Jonathan A.

    2016-01-01

    Despite evidence for avian influenza A virus (AIV) transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection. PMID:27166585

  20. Ecosystem Interactions Underlie the Spread of Avian Influenza A Viruses with Pandemic Potential.

    Directory of Open Access Journals (Sweden)

    Justin Bahl

    2016-05-01

    Full Text Available Despite evidence for avian influenza A virus (AIV transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection.

  1. Ecosystem Interactions Underlie the Spread of Avian Influenza A Viruses with Pandemic Potential.

    Science.gov (United States)

    Bahl, Justin; Pham, Truc T; Hill, Nichola J; Hussein, Islam T M; Ma, Eric J; Easterday, Bernard C; Halpin, Rebecca A; Stockwell, Timothy B; Wentworth, David E; Kayali, Ghazi; Krauss, Scott; Schultz-Cherry, Stacey; Webster, Robert G; Webby, Richard J; Swartz, Michael D; Smith, Gavin J D; Runstadler, Jonathan A

    2016-05-01

    Despite evidence for avian influenza A virus (AIV) transmission between wild and domestic ecosystems, the roles of bird migration and poultry trade in the spread of viruses remain enigmatic. In this study, we integrate ecosystem interactions into a phylogeographic model to assess the contribution of wild and domestic hosts to AIV distribution and persistence. Analysis of globally sampled AIV datasets shows frequent two-way transmission between wild and domestic ecosystems. In general, viral flow from domestic to wild bird populations was restricted to within a geographic region. In contrast, spillover from wild to domestic populations occurred both within and between regions. Wild birds mediated long-distance dispersal at intercontinental scales whereas viral spread among poultry populations was a major driver of regional spread. Viral spread between poultry flocks frequently originated from persistent lineages circulating in regions of intensive poultry production. Our analysis of long-term surveillance data demonstrates that meaningful insights can be inferred from integrating ecosystem into phylogeographic reconstructions that may be consequential for pandemic preparedness and livestock protection. PMID:27166585

  2. Trophic mechanisms for exercise-induced stress resilience: Potential role of interactions between BDNF and galanin

    Directory of Open Access Journals (Sweden)

    Philip V Holmes

    2014-07-01

    Full Text Available Current concepts of the neurobiology of stress-related disorders such as anxiety and depression emphasize disruptions in neural plasticity and neurotrophins. The potent trophic actions of exercise therefore represent not only an effective means for prevention and treatment of these disorders, they also afford the opportunity to employ exercise paradigms as a basic research tool to uncover the neurobiological mechanisms underlying these disorders. Novel approaches to studying stress-related disorders focus increasingly on trophic factor signaling in corticolimbic circuits that both mediate and regulate cognitive, behavioral, and physiological responses to deleterious stress. Recent evidence demonstrates that the neural plasticity supported by these trophic mechanisms is vital for establishing and maintaining resilience to stress. Therapeutic interventions that promote these mechanisms, be they pharmacological, behavioral, or environmental, may therefore prevent or reverse stress-related mental illness by enhancing resilience. The present paper will provide an overview of trophic mechanisms responsible for the enhancement of resilience by voluntary exercise with an emphasis on BDNF, galanin, and interactions between these two trophic factors.

  3. Quantitative evaluation of drug-drug interaction potentials by in vivo information- guided prediction approach.

    Science.gov (United States)

    Chen, Feng; Hu, Zhe-Yi; Jia, Wei-Wei; Lu, Jing-Tao; Zhao, Yuan-Sheng

    2014-01-01

    Drug-drug interaction (DDI) is one important topic in drug discovery, drug development and clinical practice. Recently, a novel approach, in vivo information-guided prediction (IVIP), was introduced for predicting the magnitude of pharmacokinetic DDIs which are caused by changes in cytochrome P450 (CYP) activity. This approach utilizes two parameters, i.e. CR (the apparent contribution of the target metabolizing enzyme to the clearance of the substrate drug) and IX (the apparent effect of a perpetrator on the target CYP) to describe the magnitude of DDI between a perpetrator and a victim drug. The essential concept of this method assumes that at a given dose level, the IX for a given perpetrator remains constant whatever the victim drug is. Usually, this IVIP method is only based on information from clinical studies and does not need in vitro information. In this review, basic concept, application and extension, as well as pros and cons of the IVIP method were presented. How to apply this approach was also discussed. Thus far, this method displayed good performance in predicting DDIs associated with CYPs, and can be used to forecast the magnitude of a large number of possible DDIs, of which only a small portion have been investigated in clinical studies. The key concept of this static approach could even be implemented in dynamic modeling to assess risks of DDIs involving drug transporters. PMID:25705907

  4. Unrestricted compact model potentials for ab initio embedded cluster calculations: Magnetic interactions in KNiF3

    Science.gov (United States)

    Mejías, J. A.; Sanz, Javier Fernández

    1995-01-01

    Compact model potentials to introduce the effect of spin-dependent environments in ab initio embedded cluster calculations are reported. The groups forming the environment are described by unrestricted Hartree-Fock wave functions. The method is tested for the magnetic description of KNiF3 by using different model clusters. The cluster calculations are done at the unrestricted Hartree-Fock and unrestricted second-order perturbation levels. The obtained values are in excellent agreement with other more sophisticated ab initio calculations if some Ni-F delocalization is allowed. How the superexchange interaction is accounted for in our method is also discussed.

  5. Dynamics of vector solitons in two-component Bose-Einstein condensates with time-dependent interactions and harmonic potential

    Science.gov (United States)

    Zhou, Zheng; Yu, Hui-You; Yan, Jia-Ren

    2010-01-01

    We present two kinds of exact vector-soliton solutions for coupled nonlinear Schrödinger equations with time-varying interactions and time-varying harmonic potential. Using the variational approach, we investigate the dynamics of the vector solitons. It is found that the two bright solitons oscillate about slightly and pass through each other around the equilibration state which means that they are stable under our model. At the same time, we obtain the opposite situation for dark-dark solitons.

  6. Wave turbulence description of interacting particles: Klein-Gordon model with a Mexican-hat potential

    CERN Document Server

    Gallet, Basile; Dubrulle, Bérengère

    2015-01-01

    In field theory, particles are waves or excitations that propagate on the fundamental state. In experiments or cosmological models one typically wants to compute the out-of-equilibrium evolution of a given initial distribution of such waves. Wave Turbulence deals with out-of-equilibrium ensembles of weakly nonlinear waves, and is therefore well-suited to address this problem. As an example, we consider the complex Klein-Gordon equation with a Mexican-hat potential. This simple equation displays two kinds of excitations around the fundamental state: massive particles and massless Goldstone bosons. The former are waves with a nonzero frequency for vanishing wavenumber, whereas the latter obey an acoustic dispersion relation. Using wave turbulence theory, we derive wave kinetic equations that govern the coupled evolution of the spectra of massive and massless waves. We first consider the thermodynamic solutions to these equations and study the wave condensation transition, which is the classical equivalent of Bo...

  7. Ion focusing and interaction potential for spherical and rodlike obstacles in a supersonic plasma flow: numerical simulations

    International Nuclear Information System (INIS)

    The parameter dependence of the ion focus behind perfectly conducting or alternatively perfectly insulating spherical grains for different electron to ion temperature ratios is studied. For elongated, insulating dust grains we study the potential and plasma density wakes in drifting plasma for rods or plates of different lengths and different inclination angles. These two characteristics (i.e., the rod length and the inclination angle are important for the exact charge distribution on the surface and the wake pattern. For this case we discuss also the interaction potential between two elongated grains in a flowing plasma.Our simulations are carried out in two spatial dimensions by a Particle-in-Cell code, treating ions and electrons as individual particles. These studies can be relevant for finite size dust grains suspended in a plasma sheath or larger objects in space, e.g., meteoroids.

  8. Relativistic symmetries in the Rosen-Morse potential and tensor interaction using the Nikiforov-Uvarov method

    Institute of Scientific and Technical Information of China (English)

    Sameer M Ikhdair; Majid Hamzavi

    2013-01-01

    Approximate analytical bound-state solutions of the Dirac particle in the fields of attractive and repulsive RosenMorse (RM) potentials including the Coulomb-like tensor (CLT) potential are obtained for arbitrary spin-orbit quantum number K.The Pekeris approximation is used to deal with the spin-orbit coupling terms K(K ± 1)r-2.In the presence of exact spin and pseudospin (p-spin) symmetries,the energy eigenvalues and the corresponding normalized two-component wave functions are found by using the parametric generalization of the Nikiforov-Uvarov (NU) method.The numerical results show that the CLT interaction removes degeneracies between the spin and p-spin state doublets.

  9. Relativistic symmetries with the trigonometric P(o)schl-Teller potential plus Coulomb-like tensor interaction

    Institute of Scientific and Technical Information of China (English)

    Babatunde J.Falaye; Sameer M.Ikhdair

    2013-01-01

    The Dirac equation is solved to obtain its approximate bound states for a spin-1/2 particle in the presence of trigonometric P(o)schl-Teller (tPT) potential including a Coulomb-like tensor interaction with arbitrary spin-orbit quantum number κ using an approximation scheme to substitute the centrifugal terms κ(κ ± 1)r-2.In view of spin and pseudo-spin (p-spin) symmetries,the relativistic energy eigenvalues and the corresponding two-component wave functions of a particle moving in the field of attractive and repulsive tPT potentials are obtained using the asymptotic iteration method (AIM).We present numerical results in the absence and presence of tensor coupling A and for various values of spin and p-spin constants and quantum numbers n and κ.The non-relativistic limit is also obtained.

  10. Adiabatic tunneling of Bose—Einstein condensates with modulated atom interaction in a double-well potential

    International Nuclear Information System (INIS)

    We study the adiabatic tunneling of Bose—Einstein condensates in a symmetric double-well potential when the interaction strength between the atoms is modulated linearly or in a cosine periodic form. It is shown that the system evolves along a nonlinear eigenstate path. In the case of linear modulation under the adiabatic approximation conditions, the tunneling probability of the condensate atoms to the other potential well is half. However, when the system is periodically scanned in the adiabatic process, we find an interesting phenomenon. A small change in the cycle period can lead to the condensate atoms returning to the right well or tunneling to the left well. The system comes from a linear eigenstate back to a nonlinear one, which is completely different from the linear eigenstate evolution. We explain the results by using the energy level and the phase diagram. (general)

  11. Relativistic symmetries in the Rosen—Morse potential and tensor interaction using the Nikiforov—Uvarov method

    International Nuclear Information System (INIS)

    Approximate analytical bound-state solutions of the Dirac particle in the fields of attractive and repulsive Rosen—Morse (RM) potentials including the Coulomb-like tensor (CLT) potential are obtained for arbitrary spin-orbit quantum number κ. The Pekeris approximation is used to deal with the spin-orbit coupling terms κ (κ± 1)r−2. In the presence of exact spin and pseudospin (p-spin) symmetries, the energy eigenvalues and the corresponding normalized two-component wave functions are found by using the parametric generalization of the Nikiforov—Uvarov (NU) method. The numerical results show that the CLT interaction removes degeneracies between the spin and p-spin state doublets. (general)

  12. Relativistic symmetries in the Rosen—Morse potential and tensor interaction using the Nikiforov—Uvarov method

    Science.gov (United States)

    Sameer, M. Ikhdair; Majid, Hamzavi

    2013-04-01

    Approximate analytical bound-state solutions of the Dirac particle in the fields of attractive and repulsive Rosen—Morse (RM) potentials including the Coulomb-like tensor (CLT) potential are obtained for arbitrary spin-orbit quantum number κ. The Pekeris approximation is used to deal with the spin-orbit coupling terms κ (κ± 1)r-2. In the presence of exact spin and pseudospin (p-spin) symmetries, the energy eigenvalues and the corresponding normalized two-component wave functions are found by using the parametric generalization of the Nikiforov—Uvarov (NU) method. The numerical results show that the CLT interaction removes degeneracies between the spin and p-spin state doublets.

  13. Seaweed-coral interactions: variance in seaweed allelopathy, coral susceptibility, and potential effects on coral resilience.

    Directory of Open Access Journals (Sweden)

    Roberta M Bonaldo

    Full Text Available Tropical reefs are in global decline with seaweeds commonly replacing corals. Negative associations between macroalgae and corals are well documented, but the mechanisms involved, the dynamics of the interactions, and variance in effects of different macroalgal-coral pairings are poorly investigated. We assessed the frequency, magnitude, and dynamics of macroalgal-coral competition involving allelopathic and non-allelopathic macroalgae on three, spatially grouped pairs of no-take Marine Protected Areas (MPAs and non-MPAs in Fiji. In non-MPAs, biomass of herbivorous fishes was 70-80% lower, macroalgal cover 4-9 fold higher, macroalgal-coral contacts 5-15 fold more frequent and 23-67 fold more extensive (measured as % of colony margin contacted by macroalgae, and coral cover 51-68% lower than in MPAs. Coral contacts with allelopathic macroalgae occurred less frequently than expected by chance across all sites, while contact with non-allelopathic macroalgae tended to occur more frequently than expected. Transplants of allelopathic macroalgae (Chlorodesmis fastigiata and Galaxaura filamentosa against coral edges inflicted damage to Acropora aspera and Pocillopora damicornis more rapidly and extensively than to Porites cylindrica and Porites lobata, which appeared more resistant to these macroalgae. Montipora digitata experienced intermediate damage. Extent of damage from macroalgal contact was independent of coral colony size for each of the 10 macroalgal-coral pairings we established. When natural contacts with Galaxaura filamentosa were removed in the field, recovery was rapid for Porites lobata, but Pocillopora damicornis did not recover and damage continued to expand. As macroalgae increase on overfished tropical reefs, allelopathy could produce feedbacks that suppress coral resilience, prevent coral recovery, and promote the stability of algal beds in habitats previously available to corals.

  14. INTERACTIVE POTENTIAL OF CLARITHROMYCIN IN RATS ADMINISTERED WITH GLICLAZIDE IN NORMAL AND DIABETIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    Neelam Raj

    2011-09-01

    Full Text Available To investigate the interaction between clarithromycin and gliclazide, the present study is designed in various animal models. Albino rats and rabbits were selected for the current study. The animals were suitably grouped. In the first part of the experiment, per se effect with clarithromycin was carried out. In the next phase, the animals were treated with gliclazide and hypoglycemic/antidiabetic activity was performed. In the last phase, the animals of the second part were pretreated with clarithromycin for 7 days and on the 8th day, one hour after clarithromycin administration; the animals were treated with gliclazide. The blood samples were collected from the animals (retro-orbital sinus of rats and marginal ear veins of rabbits up to 24 h before and after clarithromycin administration and blood glucose levels were analyzed by GOD-POD. Onset, peak effect and duration of hypoglycemia/antidiabetic activity were considered as parameters of the study. Clarithromycin increased the peak effect and duration of hypoglycemia induced by gliclazide in all the animal models. These findings suggested that clarithromycin retarded the metabolism of gliclazide. It was reported that clarithromycin is an inhibitor of CYP 3A4 and further gliclazide is metabolized by CYP 2C9 and CYP 3A4. Hence, increased hypoglycemic/antidiabetic activity may be attributed to clarithromycin induced inhibition of CYP enzyme. Therefore, it may be suggested that during concomitant administration of clarithromycin and gliclazide, the dose and frequency of administration of gliclazide has to be readjusted as a precautionary measure so as to avoid the possibility of hypoglycemia.

  15. Smart RISUG: A potential new contraceptive and its magnetic field-mediated sperm interaction

    Directory of Open Access Journals (Sweden)

    Rakhi K Jha

    2009-03-01

    Full Text Available Rakhi K Jha1,2, Pradeep K Jha1,3, Sujoy K Guha11School of Medical Science and Technology, Indian Institute of Technology, Kharagpur, West Bengal, India; 2Toxicology Laboratory, Department of Zoology, ChCS University, Meerut, UP, India; 3Department of Management studies, VIET, UP Tech. Univ., Lucknow, UP, IndiaAbstract: The rationale and technique underlying a novel concept of noninvasive fertility control by a new Cuproferrogel contraceptive drug, iron oxide–copper–styrene maleic anhydride–dimethyl sulphoxide (Fe3O4–Cu–SMA–DMSO composite named ‘Smart RISUG’ (smart reversible inhibition of sperm under guidance in presence of pulsed magnetic field (PMF; 1 mT to 800 mT is explained. It was synthesized by dispersing iron oxide particles and copper particles into SMA-DMSO (male contraceptive RISUG and characterized for particle distribution, particle size measurement and transmittance peaks, etc. Interaction of the RISUG particles as well as Smart RISUG particles with Albino rat sperm cell was studied in presence as well as absence of PMF. To find an explanation to increased reaching of the Smart RISUG drug into sperm under influence of magnetic field, the transport properties were characterized by high resolution transmission electron microscopy and atomic force microscopy. Smart RISUG could be mobilized into sperm cell membrane at the PMF, 760 mT in about 50 seconds. Adoption of novel drug Smart RISUG involving new technique may open the pathway for non surgical control of drug distribution, detection and restoration of the normal fertility after removal of the contraceptive from the male/female reproductive tube in presence of electromagnetic field.Keywords: smart RISUG, pulsed magnetic field, noninvasive fertility control, drug distribution, sperm cell

  16. Systems integration of biodefense omics data for analysis of pathogen-host interactions and identification of potential targets.

    Directory of Open Access Journals (Sweden)

    Peter B McGarvey

    Full Text Available The NIAID (National Institute for Allergy and Infectious Diseases Biodefense Proteomics program aims to identify targets for potential vaccines, therapeutics, and diagnostics for agents of concern in bioterrorism, including bacterial, parasitic, and viral pathogens. The program includes seven Proteomics Research Centers, generating diverse types of pathogen-host data, including mass spectrometry, microarray transcriptional profiles, protein interactions, protein structures and biological reagents. The Biodefense Resource Center (www.proteomicsresource.org has developed a bioinformatics framework, employing a protein-centric approach to integrate and support mining and analysis of the large and heterogeneous data. Underlying this approach is a data warehouse with comprehensive protein + gene identifier and name mappings and annotations extracted from over 100 molecular databases. Value-added annotations are provided for key proteins from experimental findings using controlled vocabulary. The availability of pathogen and host omics data in an integrated framework allows global analysis of the data and comparisons across different experiments and organisms, as illustrated in several case studies presented here. (1 The identification of a hypothetical protein with differential gene and protein expressions in two host systems (mouse macrophage and human HeLa cells infected by different bacterial (Bacillus anthracis and Salmonella typhimurium and viral (orthopox pathogens suggesting that this protein can be prioritized for additional analysis and functional characterization. (2 The analysis of a vaccinia-human protein interaction network supplemented with protein accumulation levels led to the identification of human Keratin, type II cytoskeletal 4 protein as a potential therapeutic target. (3 Comparison of complete genomes from pathogenic variants coupled with experimental information on complete proteomes allowed the identification and

  17. An Event-related Potential Study on the Interaction between Lighting Level and Stimulus Spatial Location

    Science.gov (United States)

    Carretié, Luis; Ruiz-Padial, Elisabeth; Mendoza, María T.

    2015-01-01

    Due to heterogeneous photoreceptor distribution, spatial location of stimulation is crucial to study visual brain activity in different light environments. This unexplored issue was studied through occipital event-related potentials (ERPs) recorded from 40 participants in response to discrete visual stimuli presented at different locations and in two environmental light conditions, low mesopic (L, 0.03 lux) and high mesopic (H, 6.5 lux), characterized by a differential photoreceptor activity balance: rod > cone and rod < cone, respectively. Stimuli, which were exactly the same in L and H, consisted of squares presented at fixation, at the vertical periphery (above or below fixation) or at the horizontal periphery (left or right). Analyses showed that occipital ERPs presented important L vs. H differences in the 100 to 450 ms window, which were significantly modulated by spatial location of stimulation: differences were greater in response to peripheral stimuli than to stimuli presented at fixation. Moreover, in the former case, significance of L vs. H differences was even stronger in response to stimuli presented at the horizontal than at the vertical periphery. These low vs. high mesopic differences may be explained by photoreceptor activation and their retinal distribution, and confirm that ERPs discriminate between rod– and cone-originated visual processing. PMID:26635588

  18. An event-related potential study on the interaction between lighting level and stimulus spatial location

    Directory of Open Access Journals (Sweden)

    Luis eCarretié

    2015-11-01

    Full Text Available Due to heterogeneous photoreceptor distribution, spatial location of stimulation is crucial to study visual brain activity in different light environments. This unexplored issue was studied through occipital event-related potentials (ERPs recorded from 40 participants in response to discrete visual stimuli presented at different locations and in two environmental light conditions, low mesopic (L, 0.03 lux and high mesopic (H, 6.5 lux, characterized by a differential photoreceptor activity balance: rod>cone and rod

  19. Interaction of Ulocladium atrum, a Potential Biological Control Agent, with Botrytis cinerea and Grapevine Plantlets

    Directory of Open Access Journals (Sweden)

    Sébastien Ronseaux

    2013-09-01

    Full Text Available The effectiveness of biological control agent, Ulocladium atrum (isolates U13 and U16 in protecting Vitis vinifera L. cv. Chardonnay against gray mold disease caused by Botrytis cinerea, and simulation of the foliar defense responses was investigated. A degraded mycelium structure during cultural assay on potato dextrose agar revealed that U. atrum isolates U13 and U16 were both antagonistic to B. cinerea, mainly when isolates were inoculated two days before Botrytis. Under in vitro conditions, foliar application of U. atrum protected grapevine leaves against gray mold disease. An increase in chitinase activity was induced by the presence of U. atrum isolates indicating that the biological control agents triggered plant defense mechanisms. Moreover, U13 has the potential to colonize the grapevine plantlets and to improve their growth. The ability of U. atrum isolates to exhibit an antagonistic effect against B. cinerea in addition to their aptitude to induce plant resistance and to promote grapevine growth may explain a part of their biological activity. Hence, this study suggests that U. atrum provides a suitable biocontrol agent against gray mold in grapevines.

  20. National Geothermal Data System: Interactive Assessment of Geothermal Energy Potential in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Lee [Executive Office of the State of Arizona (Arizona Geological Survey); Richard, Stephen [Executive Office of the State of Arizona (Arizona Geological Survey); Clark, Ryan; Patten, Kim; Love, Diane; Coleman, Celia; Chen, Genhan; Matti, Jordan; Pape, Estelle; Musil, Leah

    2012-01-30

    Geothermal-relevant geosciences data from all 50 states (www.stategeothermaldata.org), federal agencies, national labs, and academic centers are being digitized and linked in a distributed online network via the U.S. Department of Energy-funded National Geothermal Data System (NGDS) to foster geothermal energy exploration and development through use of interactive online ‘mashups,’data integration, and applications. Emphasis is first to make as much information as possible accessible online, with a long range goal to make data interoperable through standardized services and interchange formats. An initial set of thirty geoscience data content models is in use or under development to define a standardized interchange format: aqueous chemistry, borehole temperature data, direct use feature, drill stem test, earthquake hypocenter, fault feature, geologic contact feature, geologic unit feature, thermal/hot spring description, metadata, quaternary fault, volcanic vent description, well header feature, borehole lithology log, crustal stress, gravity, heat flow/temperature gradient, permeability, and feature descriptions data like developed geothermal systems, geologic unit geothermal properties, permeability, production data, rock alteration description, rock chemistry, and thermal conductivity. Map services are also being developed for isopach maps, aquifer temperature maps, and several states are working on geothermal resource overview maps. Content models are developed preferentially from existing community use in order to encourage widespread adoption and promulgate minimum metadata quality standards. Geoscience data and maps from other NGDS participating institutions, or “nodes” (USGS, Southern Methodist University, Boise State University Geothermal Data Coalition) are being supplemented with extensive land management and land use resources from the Western Regional Partnership (15 federal agencies and 5 Western states) to provide access to a comprehensive

  1. MRP2 mediated drug-drug interaction: indomethacin increases sulfasalazine absorption in the small intestine, potentially decreasing its colonic targeting.

    Science.gov (United States)

    Dahan, Arik; Amidon, Gordon L

    2010-02-15

    We have recently shown that efflux transport, mediated by multidrug resistance-associated protein 2 (MRP2) and breast cancer resistance protein (BCRP), is responsible for sulfasalazine low-permeability in the small intestine, thereby enabling its colonic targeting and therapeutic action. The purpose of the present study was to evaluate the potential pharmacokinetic interaction between indomethacin and sulfasalazine, in the mechanism of efflux transporter competition. The concentration-dependent effects of indomethacin on sulfasalazine intestinal epithelial transport were investigated across Caco-2 cell monolayers, in both apical to basolateral (AP-BL) and BL-AP directions. The interaction was then investigated in the in situ single-pass rat jejunal perfusion model. Sulfasalazine displayed 30-fold higher BL-AP than AP-BL Caco-2 permeability, indicative of net mucosal secretion. Indomethacin significantly increased AP-BL and decreased BL-AP sulfasalazine Caco-2 transport, in a concentration-dependent manner, with IC(50) values of 75 and 196 microM respectively. In the rat model, higher sulfasalazine concentrations resulted in higher intestinal permeability, consistent with saturation of efflux transporter. Without indomethacin, sulfasalazine demonstrated low rat jejunal permeability (vs. metoprolol). Indomethacin significantly increased sulfasalazine P(eff), effectively shifting it from BCS (biopharmaceutics classification system) Class IV to II. In conclusion, the data indicate that concomitant intake of indomethacin and sulfasalazine may lead to increased absorption of sulfasalazine in the small intestine, thereby reducing its colonic concentration and potentially altering its therapeutic effect. PMID:19944137

  2. Dynamic dependence of the interaction potentials for grazing scattering of fast atoms from metal and insulator surfaces

    International Nuclear Information System (INIS)

    For scattering of fast atoms from metal and insulator surfaces under axial channeling conditions pronounced peaks in the angular distributions of scattered projectiles are interpreted in terms of rainbow scattering. The angular position of such 'rainbow peaks' are closely related to the interaction potential and its corrugation in the topmost surface region. We have scattered N and O atoms, with energies ranging from 10 to 70 keV, from clean and flat Al(0 0 1) and LiF(0 0 1) surfaces along low index axial directions in the surface plane and studied the positions of the rainbow peaks as function of the kinetic energy of the atomic projectiles normal to the surface. For the insulator surface the rainbow angle does not depend on projectile energy for constant normal energy, whereas for the metal surface we find pronounced dynamic effects. We interpret this different behaviour as arising from a projectile energy dependent contribution to the underlying interaction potentials owing to embedding the projectiles into the free electron gas in the selvedge of the surfaces, which is present for the metals but absent for insulators.

  3. Dynamic dependence of the interaction potentials for grazing scattering of fast atoms from metal and insulator surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Schueller, A. [Institut fuer Physik der Humboldt-Universitaet zu Berlin, Newtonstr. 15, D-12489 Berlin-Adlershof (Germany); Winter, H. [Institut fuer Physik der Humboldt-Universitaet zu Berlin, Newtonstr. 15, D-12489 Berlin-Adlershof (Germany)], E-mail: winter@physik.hu-berlin.de

    2009-08-15

    For scattering of fast atoms from metal and insulator surfaces under axial channeling conditions pronounced peaks in the angular distributions of scattered projectiles are interpreted in terms of rainbow scattering. The angular position of such 'rainbow peaks' are closely related to the interaction potential and its corrugation in the topmost surface region. We have scattered N and O atoms, with energies ranging from 10 to 70 keV, from clean and flat Al(0 0 1) and LiF(0 0 1) surfaces along low index axial directions in the surface plane and studied the positions of the rainbow peaks as function of the kinetic energy of the atomic projectiles normal to the surface. For the insulator surface the rainbow angle does not depend on projectile energy for constant normal energy, whereas for the metal surface we find pronounced dynamic effects. We interpret this different behaviour as arising from a projectile energy dependent contribution to the underlying interaction potentials owing to embedding the projectiles into the free electron gas in the selvedge of the surfaces, which is present for the metals but absent for insulators.

  4. Biological aspects of the potential interaction between androgen suppression and radiation therapy

    International Nuclear Information System (INIS)

    It is a basic axiom of radiotherapy that the radiation dose required for tumor eradication increases with increasing tumor volume. These Patterns of Care Studies and prospective studies using rebiopsy have shown that this holds true for prostate cancer as well. Despite our best endeavors with conventional dose, there remains a substantial element of local failure following radiotherapy, and this is T-stage related. Unlikely many other solid tumors, a convenient method of volume reduction exists for prostate carcinoma. Approximately 90% demonstrate shrinkage following androgen suppression, an effect that is more pronounced at the primary site than metastatic sites. Transrectal ultrasound studies have shown a median of 40% prostatic tumor volume reduction after 3-4 months of androgen suppression. With more protracted androgen suppression the shrinkage progresses and a small minority of patients may actually have a complete response determined pathologically. Animal models demonstrate clearly that the TCD50 of androgen dependent tumors may be decreased by prior androgen depression. This effect is most pronounced if radiation is deferred until the time of maximal tumor regression. The advantage is lost if the tumor is allowed to regrow in an androgen independent fashion to its original volume. It is not clear whether this benefit of neoadjuvant androgen suppression results solely from volume shrinkage. The potential for synergy exists as both radiation and androgen suppression have an element of apoptosis as a common pathway of cell death. Although apoptosis is certainly the major cause of cell death from androgen suppression its' contribution to radiation cell kill in prostatic adenocarcinomas is yet to be evaluated. If the two effects are additive and not synergistic, then sequence should be unimportant. Animal models, however, demonstrate that the TCD50 of androgen dependent tumors is not significantly reduced by adjuvant androgen suppression. Human data is still

  5. Alphacoronaviruses in New World Bats: Prevalence, Persistence, Phylogeny, and Potential for Interaction with Humans

    Science.gov (United States)

    Osborne, Christina; Cryan, Paul M.; O'Shea, Thomas J.; Oko, Lauren M.; Ndaluka, Christina; Calisher, Charles H.; Berglund, Andrew D.; Klavetter, Mead L.; Holmes, Kathryn V.; Dominguez, Samuel R.

    2011-01-01

    Bats are reservoirs for many different coronaviruses (CoVs) as well as many other important zoonotic viruses. We sampled feces and/or anal swabs of 1,044 insectivorous bats of 2 families and 17 species from 21 different locations within Colorado from 2007 to 2009. We detected alphacoronavirus RNA in bats of 4 species: big brown bats (Eptesicus fuscus), 10% prevalence; long-legged bats (Myotis volans), 8% prevalence; little brown bats (Myotis lucifugus), 3% prevalence; and western long-eared bats (Myotis evotis), 2% prevalence. Overall, juvenile bats were twice as likely to be positive for CoV RNA as adult bats. At two of the rural sampling sites, CoV RNAs were detected in big brown and long-legged bats during the three sequential summers of this study. CoV RNA was detected in big brown bats in all five of the urban maternity roosts sampled throughout each of the periods tested. Individually tagged big brown bats that were positive for CoV RNA and later sampled again all became CoV RNA negative. Nucleotide sequences in the RdRp gene fell into 3 main clusters, all distinct from those of Old World bats. Similar nucleotide sequences were found in amplicons from gene 1b and the spike gene in both a big-brown and a long-legged bat, indicating that a CoV may be capable of infecting bats of different genera. These data suggest that ongoing evolution of CoVs in bats creates the possibility of a continued threat for emergence into hosts of other species. Alphacoronavirus RNA was detected at a high prevalence in big brown bats in roosts in close proximity to human habitations (10%) and known to have direct contact with people (19%), suggesting that significant potential opportunities exist for cross-species transmission of these viruses. Further CoV surveillance studies in bats throughout the Americas are warranted.

  6. Alphacoronaviruses in New World bats: prevalence, persistence, phylogeny, and potential for interaction with humans.

    Directory of Open Access Journals (Sweden)

    Christina Osborne

    Full Text Available Bats are reservoirs for many different coronaviruses (CoVs as well as many other important zoonotic viruses. We sampled feces and/or anal swabs of 1,044 insectivorous bats of 2 families and 17 species from 21 different locations within Colorado from 2007 to 2009. We detected alphacoronavirus RNA in bats of 4 species: big brown bats (Eptesicus fuscus, 10% prevalence; long-legged bats (Myotis volans, 8% prevalence; little brown bats (Myotis lucifugus, 3% prevalence; and western long-eared bats (Myotis evotis, 2% prevalence. Overall, juvenile bats were twice as likely to be positive for CoV RNA as adult bats. At two of the rural sampling sites, CoV RNAs were detected in big brown and long-legged bats during the three sequential summers of this study. CoV RNA was detected in big brown bats in all five of the urban maternity roosts sampled throughout each of the periods tested. Individually tagged big brown bats that were positive for CoV RNA and later sampled again all became CoV RNA negative. Nucleotide sequences in the RdRp gene fell into 3 main clusters, all distinct from those of Old World bats. Similar nucleotide sequences were found in amplicons from gene 1b and the spike gene in both a big-brown and a long-legged bat, indicating that a CoV may be capable of infecting bats of different genera. These data suggest that ongoing evolution of CoVs in bats creates the possibility of a continued threat for emergence into hosts of other species. Alphacoronavirus RNA was detected at a high prevalence in big brown bats in roosts in close proximity to human habitations (10% and known to have direct contact with people (19%, suggesting that significant potential opportunities exist for cross-species transmission of these viruses. Further CoV surveillance studies in bats throughout the Americas are warranted.

  7. Wnt isoform-specific interactions with coreceptor specify inhibition or potentiation of signaling by LRP6 antibodies.

    Science.gov (United States)

    Gong, Yan; Bourhis, Eric; Chiu, Cecilia; Stawicki, Scott; DeAlmeida, Venita I; Liu, Bob Y; Phamluong, Khanhky; Cao, Tim C; Carano, Richard A D; Ernst, James A; Solloway, Mark; Rubinfeld, Bonnee; Hannoush, Rami N; Wu, Yan; Polakis, Paul; Costa, Mike

    2010-01-01

    β-Catenin-dependent Wnt signaling is initiated as Wnt binds to both the receptor FZD and coreceptor LRP5/6, which then assembles a multimeric complex at the cytoplasmic membrane face to recruit and inactivate the kinase GSK3. The large number and sequence diversity of Wnt isoforms suggest the possibility of domain-specific ligand-coreceptor interactions, and distinct binding sites on LRP6 for Wnt3a and Wnt9b have recently been identified in vitro. Whether mechanistically different interactions between Wnts and coreceptors might mediate signaling remains to be determined. It is also not clear whether coreceptor homodimerization induced extracellularly can activate Wnt signaling, as is the case for receptor tyrosine kinases. We generated monoclonal antibodies against LRP6 with the unexpected ability to inhibit signaling by some Wnt isoforms and potentiate signaling by other isoforms. In cell culture, two antibodies characterized further show reciprocal activities on most Wnts, with one antibody antagonizing and the other potentiating. We demonstrate that these antibodies bind to different regions of LRP6 protein, and inhibition of signaling results from blocking Wnt binding. Antibody-mediated dimerization of LRP6 can potentiate signaling only when a Wnt isoform is also able to bind the complex, presumably recruiting FZD. Endogenous autocrine Wnt signaling in different tumor cell lines can be either antagonized or enhanced by the LRP6 antibodies, indicating expression of different Wnt isoforms. As anticipated from the roles of Wnt signaling in cancer and bone development, antibody activities can also be observed in mice for inhibition of tumor growth and in organ culture for enhancement of bone mineral density. Collectively, our results indicate that separate binding sites for different subsets of Wnt isoforms determine the inhibition or potentiation of signaling conferred by LRP6 antibodies. This complexity of coreceptor-ligand interactions may allow for

  8. Functionalized carbon nanomaterials: exploring the interactions with Caco-2 cells for potential oral drug delivery

    Directory of Open Access Journals (Sweden)

    Coyuco JC

    2011-10-01

    Full Text Available Jurja C Coyuco, Yuanjie Liu, Bee-Jen Tan, Gigi NC ChiuDepartment of Pharmacy, Faculty of Science, National University of Singapore, SingaporeAbstract: Although carbon nanomaterials (CNMs have been increasingly studied for their biomedical applications, there is limited research on these novel materials for oral drug delivery. As such, this study aimed to explore the potential of CNMs in oral drug delivery, and the objectives were to evaluate CNM cytotoxicity and their abilities to modulate paracellular transport and the P-glycoprotein (P-gp efflux pump. Three types of functionalized CNMs were studied, including polyhydroxy small-gap fullerenes (OH-fullerenes, carboxylic acid functionalized single-walled carbon nanotubes (fSWCNT-COOH and poly(ethylene glycol functionalized single-walled carbon nanotubes (fSWCNT-PEG, using the well-established Caco-2 cell monolayer to represent the intestinal epithelium. All three CNMs had minimum cytotoxicity on Caco-2 cells, as demonstrated through lactose dehydrogenase release and 3-(4,5-dimethyliazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assays. Of the three CNMs, fSWCNT-COOH significantly reduced transepithelial electrical resistance and enhanced transport of Lucifer Yellow across the Caco-2 monolayer. Confocal fluorescence microscopy showed that fSWCNT-COOH treated cells had the highest perturbation in the distribution of ZO-1, a protein marker of tight junction, suggesting that fSWCNT-COOH could enhance paracellular permeability via disruption of tight junctions. This modulating effect of fSWCNT-COOH can be reversed over time. Furthermore, cellular accumulation of the P-gp substrate, rhodamine-123, was significantly increased in cells treated with fSWCNT-COOH, suggestive of P-gp inhibition. Of note, fSWCNT-PEG could increase rhodamine-123 accumulation without modifying the tight junction. Collectively, these results suggest that the functionalized CNMs could be useful as modulators for oral drug

  9. In vitro assessment of drug-drug interaction potential of boceprevir associated with drug metabolizing enzymes and transporters.

    Science.gov (United States)

    Chu, Xiaoyan; Cai, Xiaoxin; Cui, Donghui; Tang, Cuyue; Ghosal, Anima; Chan, Grace; Green, Mitchell D; Kuo, Yuhsin; Liang, Yuexia; Maciolek, Cheri M; Palamanda, Jairam; Evers, Raymond; Prueksaritanont, Thomayant

    2013-03-01

    The inhibitory effect of boceprevir (BOC), an inhibitor of hepatitis C virus nonstructural protein 3 protease was evaluated in vitro against a panel of drug-metabolizing enzymes and transporters. BOC, a known substrate for cytochrome P450 (P450) CYP3A and aldo-ketoreductases, was a reversible time-dependent inhibitor (k(inact) = 0.12 minute(-1), K(I) = 6.1 µM) of CYP3A4/5 but not an inhibitor of other major P450s, nor of UDP-glucuronosyltransferases 1A1 and 2B7. BOC showed weak to no inhibition of breast cancer resistance protein (BCRP), P-glycoprotein (Pgp), or multidrug resistance protein 2. It was a moderate inhibitor of organic anion transporting polypeptide (OATP) 1B1 and 1B3, with an IC(50) of 18 and 4.9 µM, respectively. In human hepatocytes, BOC inhibited CYP3A-mediated metabolism of midazolam, OATP1B-mediated hepatic uptake of pitavastatin, and both the uptake and metabolism of atorvastatin. The inhibitory potency of BOC was lower than known inhibitors of CYP3A (ketoconazole), OATP1B (rifampin), or both (telaprevir). BOC was a substrate for Pgp and BCRP but not for OATP1B1, OATP1B3, OATP2B1, organic cation transporter, or sodium/taurocholate cotransporting peptide. Overall, our data suggest that BOC has the potential to cause pharmacokinetic interactions via inhibition of CYP3A and CYP3A/OATP1B interplay, with the interaction magnitude lower than those observed with known potent inhibitors. Conversely, pharmacokinetic interactions of BOC, either as a perpetrator or victim, via other major P450s and transporters tested are less likely to be of clinical significance. The results from clinical drug-drug interaction studies conducted thus far are generally supportive of these conclusions. PMID:23293300

  10. An R package "VariABEL" for genome-wide searching of potentially interacting loci by testing genotypic variance heterogeneity

    Directory of Open Access Journals (Sweden)

    Struchalin Maksim V

    2012-01-01

    Full Text Available Abstract Background Hundreds of new loci have been discovered by genome-wide association studies of human traits. These studies mostly focused on associations between single locus and a trait. Interactions between genes and between genes and environmental factors are of interest as they can improve our understanding of the genetic background underlying complex traits. Genome-wide testing of complex genetic models is a computationally demanding task. Moreover, testing of such models leads to multiple comparison problems that reduce the probability of new findings. Assuming that the genetic model underlying a complex trait can include hundreds of genes and environmental factors, testing of these models in genome-wide association studies represent substantial difficulties. We and Pare with colleagues (2010 developed a method allowing to overcome such difficulties. The method is based on the fact that loci which are involved in interactions can show genotypic variance heterogeneity of a trait. Genome-wide testing of such heterogeneity can be a fast scanning approach which can point to the interacting genetic variants. Results In this work we present a new method, SVLM, allowing for variance heterogeneity analysis of imputed genetic variation. Type I error and power of this test are investigated and contracted with these of the Levene's test. We also present an R package, VariABEL, implementing existing and newly developed tests. Conclusions Variance heterogeneity analysis is a promising method for detection of potentially interacting loci. New method and software package developed in this work will facilitate such analysis in genome-wide context.

  11. Real and imaginary part of the potential between two nuclei and the realistic nucleon-nucleon interaction

    International Nuclear Information System (INIS)

    Starting from a realistic nucleon-nucleon interaction (Reid soft-core) in the model of two infinitely extended confusing nuclear matter complex energy densities are calculated by means of a G matrix. By means of a generalized local-density approximation the results are transferred to finite nuclei. In the framework of the frozen-density approximation in the energy-density formalism a complex potential between two nuclei is calculated. The potential calculated so contains not the contribution of 1-particle-1-hole states to the optical potential. The contribution of these states is therefore calculated in the Feshbach formalism, respectively these states are explicitely regarded in coupled-channel calculations. The model is applied to light (for instance 12C+12C), medium heavy (for instance 48Ca+48Ca), and heavy (for instance 40Ar+208Pb) systems. Potentials for incident energies of 5-84 MeV per projectile nucleon are calculated. By means of these potentials differential cross sections and reaction cross sections are determined and compared with the experimental data. The energy dependence of the reaction cross section is discussed. It is shown that at higher energies (40 MeV/N) the differential cross sections can be quantitatively reproduced. For the reaction cross section in the whole energy range good agreement with the experiment is obtained. Contrarily to current theoretical models it is proved that at low energies the excitation of collective states yields a large contribution to the reaction cross section and therefore must not be neglected. (orig.)

  12. Incidence of potential drug interactions in a transplant centre setting and relevance of electronic alerts for clinical practice support

    Directory of Open Access Journals (Sweden)

    Piera Polidori

    2013-09-01

    Full Text Available Background Adverse drug events may occur as a result of drug–drug interactions (DDIs. Information technology (IT systems can be an important decision-making tool for healthcare workers to identify DDIs.Objective The aim of the study is to analyse drug prescriptions in our main hospital units, in order to measure the incidence and severity of potential DDIs. The utility of clinical decision-support systems (CDSSs and computerised physician order entry (CPOE in term of alerts adherence was also assessed. DDIs were assessed using a Micromedex healthcare series database.Methods The system, adopted by the hospital, generates alerts for prescriptions with negative interactions and thanks to an ’acknowledgement function’ it is possible to verify physician adherence to alerts. This function, although used previously, became mandatory from September 2010. Physician adherence to alerts and mean monthly incidence of potential DDIs in analysed units, before and after the mandatory ‘acknowledgement function’, were calculated.Results The intensive care unit (ICU registered the greatest incidence of potential DDIs (49.0%, followed by the abdominal surgery unit and dialysis (43.4 and 42.0%, respectively. The cardiothoracic surgery unit (41.6%, step-down unit (38.3% and post-anaesthesia care unit (30.0% were comparable. The operating theatre and endoscopy registered the fewest potential DDIs (28.2 and 22.7%, respectively. Adherence to alerts after the ‘acknowledgement function’ increased by 25.0% in the ICU, 54.0% in the cardiothoracic surgery unit, 52.5% in the abdominal surgery unit, 58.0% in the stepdown unit, 67.0% in dialysis, 51.0% in endoscopy and 48.0% in the post-anaesthesia care unit. In the operating theatre, adherence to alerts decreased from 34.0 to 30.0%. The incidence of potential DDIs after mandatory use of the ’acknowledgement function’ decreased slightly in endoscopy (–2.9%, the abdominal surgery unit (–2.7%, dialysis (

  13. Thermal and transport properties of a non-relativistic quantum gas interacting through a delta-shell potential

    CERN Document Server

    Postnikov, Sergey

    2013-01-01

    This work extends the seminal work of Gottfried on the two-body quantum physics of particles interacting through a delta-shell potential to many-body physics by studying a system of non-relativistic particles when the thermal De-Broglie wavelength of a particle is smaller than the range of the potential and the density is such that average distance between particles is smaller than the range. The ability of the delta-shell potential to reproduce some basic properties of the deuteron are examined. Relations for moments of bound states are derived. The virial expansion is used to calculate the first quantum correction to the ideal gas pressure in the form of the second virial coefficient. Additionally, all thermodynamic functions are calculated up to the first order quantum corrections. For small departures from equilibrium, the net flows of mass, energy and momentum, characterized by the coefficients of diffusion, thermal conductivity and shear viscosity, respectively, are calculated. Properties of the gas are...

  14. Exact Solutions of the Mass-Dependent Klein-Gordon Equation with the Vector Quark-Antiquark Interaction and Harmonic Oscillator Potential

    OpenAIRE

    M. K. Bahar; Yasuk, ; F.

    2013-01-01

    Using the asymptotic iteration and wave function ansatz method, we present exact solutions of the Klein-Gordon equation for the quark-antiquark interaction and harmonic oscillator potential in the case of the position-dependent mass.

  15. Strong-field ionization rates of linear polyenes simulated with time-dependent configuration interaction with an absorbing potential

    International Nuclear Information System (INIS)

    The strong field ionization rates for ethylene, trans 1,3-butadiene, and trans,trans 1,3,5-hexatriene have been calculated using time-dependent configuration interaction with single excitations and a complex absorbing potential (TDCIS-CAP). The calculations used the aug-cc-pVTZ basis set with a large set of diffuse functions (3 s, 2 p, 3 d, and 1 f) on each atom. The absorbing boundary was placed 3.5 times the van der Waals radius from each atom. The simulations employed a seven-cycle cosine squared pulse with a wavelength of 800 nm. Ionization rates were calculated for intensities ranging from 0.3 × 1014 W/cm2 to 3.5 × 1014 W/cm2. Ionization rates along the molecular axis increased markedly with increasing conjugation length. By contrast, ionization rates perpendicular to the molecular axis were almost independent of the conjugation length

  16. Brewing and volatiles analysis of three tea beers indicate a potential interaction between tea components and lager yeast.

    Science.gov (United States)

    Rong, Lei; Peng, Li-Juan; Ho, Chi-Tang; Yan, Shou-He; Meurens, Marc; Zhang, Zheng-Zhu; Li, Da-Xiang; Wan, Xiao-Chun; Bao, Guan-Hu; Gao, Xue-Ling; Ling, Tie-Jun

    2016-04-15

    Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC-MS analysis. The PCA of GC-MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC-MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested. PMID:26616936

  17. Inferring coarse-grain histone-DNA interaction potentials from high-resolution structures of the nucleosome

    Science.gov (United States)

    Meyer, Sam; Everaers, Ralf

    2015-02-01

    The histone-DNA interaction in the nucleosome is a fundamental mechanism of genomic compaction and regulation, which remains largely unknown despite increasing structural knowledge of the complex. In this paper, we propose a framework for the extraction of a nanoscale histone-DNA force-field from a collection of high-resolution structures, which may be adapted to a larger class of protein-DNA complexes. We applied the procedure to a large crystallographic database extended by snapshots from molecular dynamics simulations. The comparison of the structural models first shows that, at histone-DNA contact sites, the DNA base-pairs are shifted outwards locally, consistent with locally repulsive forces exerted by the histones. The second step shows that the various force profiles of the structures under analysis derive locally from a unique, sequence-independent, quadratic repulsive force-field, while the sequence preferences are entirely due to internal DNA mechanics. We have thus obtained the first knowledge-derived nanoscale interaction potential for histone-DNA in the nucleosome. The conformations obtained by relaxation of nucleosomal DNA with high-affinity sequences in this potential accurately reproduce the experimental values of binding preferences. Finally we address the more generic binding mechanisms relevant to the 80% genomic sequences incorporated in nucleosomes, by computing the conformation of nucleosomal DNA with sequence-averaged properties. This conformation differs from those found in crystals, and the analysis suggests that repulsive histone forces are related to local stretch tension in nucleosomal DNA, mostly between adjacent contact points. This tension could play a role in the stability of the complex.

  18. Interaction Potential of the Multitargeted Receptor Tyrosine Kinase Inhibitor Dovitinib with Drug Transporters and Drug Metabolising Enzymes Assessed in Vitro

    Directory of Open Access Journals (Sweden)

    Johanna Weiss

    2014-12-01

    Full Text Available Dovitinib (TKI-258 is under development for the treatment of diverse cancer entities. No published information on its pharmacokinetic drug interaction potential is available. Thus, we assessed its interaction with important drug metabolising enzymes and drug transporters and its efficacy in multidrug resistant cells in vitro. P-glycoprotein (P-gp, MDR1, ABCB1 inhibition was evaluated by calcein assay, inhibition of breast cancer resistance protein (BCRP, ABCG2 by pheophorbide A efflux, and inhibition of organic anion transporting polypeptides (OATPs by 8-fluorescein-cAMP uptake. Inhibition of cytochrome P450 3A4, 2C19, and 2D6 was assessed by using commercial kits. Induction of transporters and enzymes was quantified by real-time RT-PCR. Possible aryl hydrocarbon receptor (AhR activating properties were assessed by a reporter gene assay. Substrate characteristics were evaluated by growth inhibition assays in cells over-expressing P-gp or BCRP. Dovitinib weakly inhibited CYP2C19, CYP3A4, P-gp and OATPs. The strongest inhibition was observed for BCRP (IC50 = 10.3 ± 4.5 μM. Among the genes investigated, dovitinib only induced mRNA expression of CYP1A1, CYP1A2, ABCC3 (coding for multidrug resistance-associated protein 3, and ABCG2 and suppressed mRNA expression of some transporters and drug metabolising enzymes. AhR reporter gene assay demonstrated that dovitinib is an activator of this nuclear receptor. Dovitinib retained its efficacy in cell lines over-expressing P-gp or BCRP. Our analysis indicates that dovitinib will most likely retain its efficacy in tumours over-expressing P-gp or BCRP and gives first evidence that dovitinib might act as a perpetrator drug in pharmacokinetic drug–drug interactions.

  19. Kirkwood-Buff Integrals for Aqueous Urea Solutions Based upon the Quantum Chemical Electrostatic Potential and Interaction Energies.

    Science.gov (United States)

    Chiba, Shuntaro; Furuta, Tadaomi; Shimizu, Seishi

    2016-08-11

    Cosolvents, such as urea, affect protein folding and binding, and the solubility of solutes. The modeling of cosolvents has been facilitated significantly by the rigorous Kirkwood-Buff (KB) theory of solutions, which can describe structural thermodynamics over the entire composition range of aqueous cosolvent mixtures based only on the solution density and the KB integrals (KBIs), i.e., the net excess radial distribution functions from the bulk. Using KBIs to describe solution thermodynamics has given rise to a clear guideline that an accurate prediction of KBIs is equivalent to accurate modeling of cosolvents. Taking urea as an example, here we demonstrate that an improvement in the prediction of KBIs comes from an improved reproduction of high-level quantum chemical (QC) electrostatic potential and molecular pairwise interaction energies. This rational approach to the improvement of the KBI prediction stems from a comparison of existing force fields, AMOEBA, and the generalized AMBER force field, as well as the further optimization of the former to enable better agreement with QC interaction energies. Such improvements would pave the way toward a rational and systematic determination of the transferable force field parameters for a number of important small molecule cosolvents. PMID:27434200

  20. Interaction between bradykinin potentiating nonapeptide (BPP9a) and β-cyclodextrin: A structural and thermodynamic study

    International Nuclear Information System (INIS)

    Herein, we demonstrate the physical and chemical characterizations of the supramolecular complex formed between β-cyclodextrin (βCD) and bradykinin potentiating nonapeptide (BPP9a), an endogenous toxin found in Bothrops jararaca. Circular dichroism results indicate a conformational change in the BPP9a secondary structure upon its complexation with βCD. Nuclear magnetic resonance results, mainly from NOESY experiments, and theoretical calculations showed a favorable interaction between the tryptophan residue of BPP9a and the βCD cavity. Thermodynamic inclusion parameters were investigated by isothermal titration calorimetry, demonstrating that βCD/BPP9a complex formation is an exothermic process that results in a reduction in entropy. Additionally, in vitro degradation study of BPP9a against trypsin (37 °C, pH 7.2) showed higher stability of peptide in presence of βCD. This βCD/BPP9a complex, which presents new chemical properties arising from the peptide inclusion process, may be useful as an antihypertensive drug in oral pharmaceutical formulations. Highlights: ► Cd and NMR showed evidences for the existence of more than one structure in solution. ► Complexation with βCD reduces the conformational rigidity of the peptide. ► βCD cavity recognize Trp and/or Pro segments of BPP9a. ► Interactions involving disaggregation of BPP9a assemblies and binding with βCD.

  1. Potential role of lncRNA cyp2c91-protein interactions on diseases of the immune system.

    Science.gov (United States)

    Suravajhala, Prashanth; Kogelman, Lisette J A; Mazzoni, Gianluca; Kadarmideen, Haja N

    2015-01-01

    With unprecedented increase in next generation sequencing technologies, there has been a persistent interest on transcript profiles of long non-coding RNAs (lncRNAs) and protein-coding genes forming an interaction network. Apart from protein-protein interaction (PPI), gene network models such as Weighted Gene Co-expression Network Analysis (WGCNA) are used to functionally annotate lncRNAs in identifying their potential disease associations. To address this, studies have led to characterizing transcript structures and understanding expression profiles mediating regulatory roles. In the current exploratory analysis, we show how a lncRNA - cyp2c91 contributes to the transcriptional regulation localized to cytoplasm thereby making refractory environment for transcription. By applying network methods and pathway analyses on genes related to a disease such as obesity and systemic lupus erythematosus, we show that we can gain deeper insight in biological processes such as the perturbances in immune system, and get a better understanding of the systems biology of diseases. PMID:26284111

  2. Potential role of lncRNA cyp2c91-protein interactions on diseases of the immune system

    Directory of Open Access Journals (Sweden)

    Prashanth eSuravajhala

    2015-07-01

    Full Text Available With unprecedented increase in next generation sequencing (NGS technologies, there has been a persistent interest on transcript profiles of long noncoding RNAs (lncRNAs and protein-coding genes forming an interaction network. Apart from protein-protein interaction (PPI, gene network models such as Weighted Gene Co-expression Network Analysis are used to functionally annotate lncRNAs in identifying their potential disease associations. To address this, studies have led to characterizing transcript structures and understanding expression profiles mediating regulatory roles. In the current exploratory analysis, we show how a lncRNA - cyp2c91 contributes to the transcriptional regulation localized to cytoplasm thereby making refractory environment for transcription. By applying network methods and pathway analyses on genes related to a disease such as obesity and systemic lupus erythematosus, we show that we can gain deeper insight in biological processes such as the perturbances in immune system, and get a better understanding of the systems biology of diseases.

  3. GAMMA RADIATION INTERACTS WITH MELANIN TO ALTER ITS OXIDATION-REDUCTION POTENTIAL AND RESULTS IN ELECTRIC CURRENT PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C.; Ekechukwu, A.; Milliken, C.

    2011-05-17

    The presence of melanin pigments in organisms is implicated in radioprotection and in some cases, enhanced growth in the presence of high levels of ionizing radiation. An understanding of this phenomenon will be useful in the design of radioprotective materials. However, the protective mechanism of microbial melanin in ionizing radiation fields has not yet been elucidated. Here we demonstrate through the electrochemical techniques of chronoamperometry, chronopotentiometry and cyclic voltammetry that microbial melanin is continuously oxidized in the presence of gamma radiation. Our findings establish that ionizing radiation interacts with melanin to alter its oxidation-reduction potential. Sustained oxidation resulted in electric current production and was most pronounced in the presence of a reductant, which extended the redox cycling capacity of melanin. This work is the first to establish that gamma radiation alters the oxidation-reduction behavior of melanin, resulting in electric current production. The significance of the work is that it provides the first step in understanding the initial interactions between melanin and ionizing radiation taking place and offers some insight for production of biomimetic radioprotective materials.

  4. Interaction between bradykinin potentiating nonapeptide (BPP9a) and {beta}-cyclodextrin: A structural and thermodynamic study

    Energy Technology Data Exchange (ETDEWEB)

    Lula, Ivana; De Sousa, Frederico B. [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901, Belo Horizonte, MG (Brazil); Denadai, Angelo M.L. [Centro Federal de Educacao Tecnologica de Minas Gerais, CEFET-MG, Campus VII, 35.183-006, Timoteo, MG (Brazil); Ferreira de Lima, Guilherme; Duarte, Helio Anderson [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901, Belo Horizonte, MG (Brazil); Mares Guia, Thiago R. dos [Departamento de Bioquimica e Imunologia, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); Faljoni-Alario, Adelaide [Departamento de Bioquimica, Instituto de Quimica, Universidade de Sao Paulo, 05508-900, Sao Paulo, SP (Brazil); Santoro, Marcelo M. [Departamento de Bioquimica e Imunologia, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); Camargo, Antonio C.M. de [Center for Applied Toxinology CAT-CEPID, Laboratorio Especial de Toxicologia Aplicada, Instituto Butantan, 05503-900, Sao Paulo, SP (Brazil); Santos, Robson A.S. dos [Departamento de Fisiologia e Biofisica, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); and others

    2012-02-01

    Herein, we demonstrate the physical and chemical characterizations of the supramolecular complex formed between {beta}-cyclodextrin ({beta}CD) and bradykinin potentiating nonapeptide (BPP9a), an endogenous toxin found in Bothrops jararaca. Circular dichroism results indicate a conformational change in the BPP9a secondary structure upon its complexation with {beta}CD. Nuclear magnetic resonance results, mainly from NOESY experiments, and theoretical calculations showed a favorable interaction between the tryptophan residue of BPP9a and the {beta}CD cavity. Thermodynamic inclusion parameters were investigated by isothermal titration calorimetry, demonstrating that {beta}CD/BPP9a complex formation is an exothermic process that results in a reduction in entropy. Additionally, in vitro degradation study of BPP9a against trypsin (37 Degree-Sign C, pH 7.2) showed higher stability of peptide in presence of {beta}CD. This {beta}CD/BPP9a complex, which presents new chemical properties arising from the peptide inclusion process, may be useful as an antihypertensive drug in oral pharmaceutical formulations. Highlights: Black-Right-Pointing-Pointer Cd and NMR showed evidences for the existence of more than one structure in solution. Black-Right-Pointing-Pointer Complexation with {beta}CD reduces the conformational rigidity of the peptide. Black-Right-Pointing-Pointer {beta}CD cavity recognize Trp and/or Pro segments of BPP9a. Black-Right-Pointing-Pointer Interactions involving disaggregation of BPP9a assemblies and binding with {beta}CD.

  5. Chirality of weakly bound complexes: The potential energy surfaces for the hydrogen-peroxide−noble-gas interactions

    Energy Technology Data Exchange (ETDEWEB)

    Roncaratti, L. F., E-mail: lz@fis.unb.br; Leal, L. A.; Silva, G. M. de [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Pirani, F. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Aquilanti, V. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Instituto de Física, Universidade Federal da Bahia, 40210 Salvador (Brazil); Gargano, R. [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Departments of Chemistry and Physics, University of Florida, Quantum Theory Project, Gainesville, Florida 32611 (United States)

    2014-10-07

    We consider the analytical representation of the potential energy surfaces of relevance for the intermolecular dynamics of weakly bound complexes of chiral molecules. In this paper we study the H{sub 2}O{sub 2}−Ng (Ng=He, Ne, Ar, Kr, and Xe) systems providing the radial and the angular dependence of the potential energy surface on the relative position of the Ng atom. We accomplish this by introducing an analytical representation which is able to fit the ab initio energies of these complexes in a wide range of geometries. Our analysis sheds light on the role that the enantiomeric forms and the symmetry of the H{sub 2}O{sub 2} molecule play on the resulting barriers and equilibrium geometries. The proposed theoretical framework is useful to study the dynamics of the H{sub 2}O{sub 2} molecule, or other systems involving O–O and S–S bonds, interacting by non-covalent forces with atoms or molecules and to understand how the relative orientation of the O–H bonds changes along collisional events that may lead to a hydrogen bond formation or even to selectivity in chemical reactions.

  6. A new phenomenological tau-alpha interaction

    CERN Document Server

    Heiberg-Andersen, H; Vaagen, J S

    2003-01-01

    We present a potential model, with distinctive features, reproducing angular distributions and analyzing power data for tau-alpha scattering from 20 to 30 MeV tau energy with regular variation of the parameters. The distinctive features are: (1) a spin-orbit term which incorporates the influence of central depression in the alpha nucleus, and, (2) central terms which are strongly parity dependent. The parity dependence of the real central term is such that the odd-parity component has both a greater rms radius and greater volume integral than the even-parity component. These parity dependence characteristics had been predicted by the inversion of the RGM S-matrix. Our result supports a considerable contribution from three-nucleon exchange processes. The predicted 1/2 sup - level of sup 7 Be is shifted 3 MeV relative to a previous one-level R-matrix formula fit, and depends strongly on the geometry of the spin-orbit potential.

  7. Deduction of the He-Fe interaction potential in eV-range from experimental data by computer simulation in grazing ion-surface scattering: Row-model

    International Nuclear Information System (INIS)

    In glancing-angle scattering of keV-ions from a crystal surface, the ion reflection takes place in the eV-part of the interaction potentials. The elastic interactions are determined by the energy transverse to atomic rows, which can be of the order of 10 eV. A row-model using averaged potentials according to the Lindhard cylindrical potential has been developed using step-by-step integration of Newton's equations of motion. Previously [D. Danailov, K. Gaertner, A. Caro, Nucl. Instr. and Meth. B 153 (1999) 191; presented on COSIRES, Okayama, 1998] we reported that zig-zag trajectories within surface channels and the corresponding multimode azimuthal angular distributions of reflected ions are very sensitive to the interaction potential used in the simulation. Here we simulate the scattering of 15 keV He-atoms from Fe(1 0 0) surfaces at different angles of incidence comparable with previously published experimental results [D. Danailov, T. Igel, R. Pfandzelter, H. Winter, Nucl. Instr. and Meth. B 164-165 (2000) 583]. Our results show that for interaction energies below about 4 eV the well-known 'universal' potential works well. However, for energies between 4 and 13 eV the 'individual' He-Fe potential (D. Danailov, K. Gaertner, A. Caro, Nucl. Instr. and Meth. B 153 (1999) 191; presented on COSIRES, Okayama, 1998) gives a better agreement with the experimental data. For interaction energies above 13 eV both potentials are similar. We have constructed a mixed He-Fe potential, which describes the experimental observations well. The row-model enables us to deduce the He-Fe interaction potential in the eV-range. In addition, a shift in the experimental angular spectra compared with the calculated spectra indicates that the atomistic rows undergo an elastic horizontal bend due to the scattering and an order of magnitude smaller vertical displacement

  8. Wild and domestic pig interactions at the wildlife-livestock interface of Murchison Falls National Park, Uganda, and the potential association with African Swine Fever outbreaks

    Directory of Open Access Journals (Sweden)

    Esther eKukielka

    2016-04-01

    Full Text Available Bushpigs (Potamochoerus larvatus and warthogs (Phacochoerus africanus, which are widely distributed in Eastern Africa, are likely to cohabitate in the same environment with domestic pigs, facilitating the transmission of shared pathogens. However, potential interactions between bushpig, warthog and domestic pig and the resulting potential circulation of infectious diseases have rarely been investigated in Africa to date. In order to understand the dynamics of such interactions and the potential influence of human behavior and husbandry practices on them, individual interviews (n=233 and participatory rural appraisals (n=11 were carried out among Ugandan pig farmers at the edge of Murchison Falls National Park, northern Uganda. In addition, as an example of possible implications of wild and domestic pig interactions, nonlinear multivariate analysis (multiple correspondence analyses was used to investigate the potential association between the aforementioned factors (interactions and human behavior and practices and farmer reported ASF outbreaks. No direct interactions between wild pigs and domestic pig were reported in our study area. However, indirect interactions were described by 83 (35.6 % of the participants and were identified to be more common at water sources during the dry season. Equally, eight (3.4% farmers declared exposing their domestic pig to raw hunting leftovers of wild pigs. The exploratory analysis performed suggested possible associations between the farmer reported ASF outbreaks and indirect interactions, free-range housing systems, dry season, and having a warthog burrow less than 3km from the household. Our study was useful to gather local knowledge and to identify knowledge gaps about potential interactions between wild and domestic pig in this area. This information could be useful to facilitate the design of future observational studies to better understand the potential transmission of pathogens between wild and

  9. On the analysis of protein-protein interactions via knowledge-based potentials for the prediction of protein-protein docking

    DEFF Research Database (Denmark)

    Feliu, Elisenda; Aloy, Patrick; Oliva, Baldo

    2011-01-01

    results were compared with a residue-pair potential scoring function (RPScore) and an atomic-detailed scoring function (Zrank). We have combined knowledge-based potentials to score protein-protein poses of decoys of complexes classified either as transient or as permanent protein-protein interactions......Development of effective methods to screen binary interactions obtained by rigid-body protein-protein docking is key for structure prediction of complexes and for elucidating physicochemical principles of protein-protein binding. We have derived empirical knowledge-based potential functions for...... selecting rigid-body docking poses. These potentials include the energetic component that provides the residues with a particular secondary structure and surface accessibility. These scoring functions have been tested on a state-of-art benchmark dataset and on a decoy dataset of permanent interactions. Our...

  10. Grass carp Ctenopharyngodon idella Fibulin-4 as a potential interacting partner for grass carp reovirus outer capsid proteins.

    Science.gov (United States)

    Yu, Fei; Wang, Hao; Liu, Weisha; Lu, Liqun

    2016-01-01

    Mammalian EGF containing fibulin-like extracellular matrix protein 2 (Fibulin-4/EFEMP2), an extracellular matrix(ECM) protein and a member of the fibulin family, is involved in elastic fiber formation, connective tissue development and some human diseases. In a yeast-two hybrid screening of host proteins interacting with outer capsid protein of grass carp reovirus (GCRV), a grass carp homologue of Fibulin-4 (designated as GcFibulin-4) is suggested to hold the potential to bind VP7, VP56 and VP55, the outer capsid protein encoded by type I, II, III GCRV, respectively. GcFibulin-4 gene of grass carp was cloned and sequenced from the cDNA library constructed for the yeast two-hybrid screening. Full-length cDNA of GcFibulin-4 contains an open reading frame (ORF) of 1323 bp encoding a putative protein of 440 amino acids. Phylogenetic analysis of GcFibulin-4 indicated that it shared a high homology with zebra fish Fibulin-4 protein. Transcriptional distribution analysis of GcFibulin-4 in various tissues of healthy grass carp showed that GcFibulin-4 was highly expressed in muscle, moderately expressed in the intestine and brain, and slightly expressed in other examined tissues; the expression pattern is consistent with tissue tropism of GCRV resulting in hemorrhage symptom in the corresponding tissues. Our results suggested that Fibulin-4 might enable free GCRV particles, the pathogen for grass carp hemorrhagic disease, to target fish tissues more efficiently by interacting with viral outer capsid proteins. PMID:26626583

  11. Further insights in the ability of classical non additive potentials to model actinide ion-water interactions

    International Nuclear Information System (INIS)

    Pursuing our efforts on the development of accurate classical models to simulate radionuclides in complex environments (Real et al., J. Phys. Chem. A 2010, 114, 15913; Trumm et al. J. Chem. Phys. 2012, 136, 044509), this article places a large emphasis on the discussion of the influence of models/parameters uncertainties on the computed structural, dynamical, and temporal properties. Two actinide test cases, trivalent curium and tetravalent thorium, have been studied with three different potential energy functions, which allow us to account for the polarization and charge-transfer effects occurring in hydrated actinide ion systems. The first type of models considers only an additive energy term for modeling ion/water charge-transfer effects, whereas the other two treat cooperative charge-transfer interactions with two different analytical expressions. Model parameters are assigned to reproduce high-level ab initio data concerning only hydrated ion species in gas phase. For the two types of cooperative charge-transfer models, we define two sets of parameters allowing or not to cancel out possible errors inherent to the force field used to model water/water interactions at the ion vicinity. We define thus five different models to characterize the solvation of each ion. For both ions, our cooperative charge-transfer models lead to close results in terms of structure in solution: the coordination number is included within 8 and 9, and the mean ion/water oxygen distances are 2.45 and 2.49 Angstroms, respectively, for Th(IV) and Cm(III). (authors)

  12. Risk assessment of drug interaction potential and concomitant dosing pattern on targeted toxicities in pediatric cancer patients.

    Science.gov (United States)

    Barrett, Jeffrey S; Patel, Dimple; Dombrowsky, Erin; Bajaj, Gaurav; Skolnik, Jeffrey M

    2013-07-01

    This investigation evaluated the impact of potential drug interactions on the incidence of reported toxicities seen with common dosing patterns in children with cancer, with the intent of being able to screen and reduce the incidence of adverse drug reactions (ADRs) in the future. Toxicity reported in pediatric cancer patients treated at the Children's Hospital of Philadelphia from 2004 to 2010 were abstracted from a cancer tumor registry and merged with drug order profiles from the medical record system. Analysis datasets were created in SAS and permutation algorithms were used to identify pairwise drug combinations associated with specific toxicity occurrence. Relative risk of toxicity based on dosing pattern was assessed via comparison to control patients. A total of 326 of 1,713 patients (19%) had reportable toxicities. Neutrophil count decreases and alanine aminotransferase increases represented the highest occurring, corresponding to 28.8% and 31.9% prevalence among patients reporting toxicity, respectively. Of coadministered drug pairs, acetaminophen-diphenhydramine occurred most frequently; however, methotrexate-vincristine was the highest occurring pair linked to a single toxicity (hepatotoxicity). Toxicity was highly associated with the diagnoses of leukemia (52.1%) or neuroblastoma (28.5%). Comparison of the dosing interval (≤30 versus >30 min) suggested that risk of toxicity can be associated with the timing of coadministration, with ≤30 min increasing the risk of hepatotoxicity with fentanyl-midazolam and methotrexate-midazolam combinations. Knowledge of drug interactions in children with cancer may help reduce the incidence of ADRs by providing pharmacotherapy options that may reduce the likelihood of toxicity. PMID:23595361

  13. Is pomegranate juice a potential perpetrator of clinical drug-drug interactions? Review of the in vitro, preclinical and clinical evidence.

    Science.gov (United States)

    Srinivas, Nuggehally R

    2013-12-01

    The area of fruit juice-drug interaction has received wide attention with numerous scientific and clinical investigations performed and reported for scores of drugs metabolized by CYP3A4/CYP2C9. While grapefruit juice has been extensively studied with respect to its drug-drug interaction potential, numerous other fruit juices such as cranberry juice, orange juice, grape juice, pineapple juice and pomegranate juice have also been investigated for its potential to show drug-drug interaction of any clinical relevance. This review focuses on establishing any relevance for clinical drug-drug interaction potential with pomegranate juice, which has been shown to produce therapeutic benefits over a wide range of disease areas. The review collates and evaluates relevant published in vitro, preclinical and clinical evidence of the potential of pomegranate juice to be a perpetrator in drug-drug interactions mediated by CYP3A4 and CYP2C9. In vitro and animal pharmacokinetic data support the possibility of CYP3A4/CYP2C9 inhibition by pomegranate juice; however, the human relevance for drug-drug interaction was not established based on the limited case studies. PMID:23673492

  14. CADRE-SS, an in Silico Tool for Predicting Skin Sensitization Potential Based on Modeling of Molecular Interactions.

    Science.gov (United States)

    Kostal, Jakub; Voutchkova-Kostal, Adelina

    2016-01-19

    Using computer models to accurately predict toxicity outcomes is considered to be a major challenge. However, state-of-the-art computational chemistry techniques can now be incorporated in predictive models, supported by advances in mechanistic toxicology and the exponential growth of computing resources witnessed over the past decade. The CADRE (Computer-Aided Discovery and REdesign) platform relies on quantum-mechanical modeling of molecular interactions that represent key biochemical triggers in toxicity pathways. Here, we present an external validation exercise for CADRE-SS, a variant developed to predict the skin sensitization potential of commercial chemicals. CADRE-SS is a hybrid model that evaluates skin permeability using Monte Carlo simulations, assigns reactive centers in a molecule and possible biotransformations via expert rules, and determines reactivity with skin proteins via quantum-mechanical modeling. The results were promising with an overall very good concordance of 93% between experimental and predicted values. Comparison to performance metrics yielded by other tools available for this endpoint suggests that CADRE-SS offers distinct advantages for first-round screenings of chemicals and could be used as an in silico alternative to animal tests where permissible by legislative programs. PMID:26650775

  15. Chemical potential for the interacting classical gas and the ideal quantum gas obeying a generalized exclusion principle

    International Nuclear Information System (INIS)

    In this work, we address the concept of the chemical potential μ in classical and quantum gases towards the calculation of the equation of state μ = μ(n, T) where n is the particle density and T the absolute temperature using the methods of equilibrium statistical mechanics. Two cases seldom discussed in elementary textbooks are presented with detailed calculations. The first one refers to the explicit calculation of μ for the interacting classical gas exemplified by van der Waals gas. For this purpose, we used the method described by van Kampen (1961 Physica 27 783). The second one refers to the calculation of μ for ideal quantum gases that obey a generalized Pauli's exclusion principle that leads to statistics that go beyond the Bose-Einstein and Fermi-Dirac cases. The audience targeted in this work corresponds mainly to advanced undergraduates and graduate students in the physical-chemical sciences but it is not restricted to them. In regard of this, we have put a special emphasis on showing some additional details of calculations that usually do not appear explicitly in textbooks. (paper)

  16. Effects on the Non-Relativistic Dynamics of a Charged Particle Interacting with a Chern-Simons Potential

    CERN Document Server

    Caruso, F; Martins, J; Oguri, V

    2012-01-01

    The hydrogen atom in two dimensions, described by a Schr\\"odinger equation with a Chern-Simons potential, is numerically solved. Both its wave functions and eigenvalues were determined for small values of the principal quantum number $n$ The only possible states correspond to $l=0$ . How the result depends on the topological mass of the photon is also discussed. In the case $n=1$, the energy of the fundamental state corresponding to different choice for the photon mass scale are found to be comprehended in the interval $-3,5 \\times 10^{-3} eV \\leq E \\leq -9,0 \\times 10^{-2} eV$, corresponding to a mean radius of the electron in the range $ (5.637 \\pm 0.005) \\times 10^{-8} \\leq \\leq (48.87 \\pm 0.03) \\times 10^{-8} cm$. In any case, the planar atom is found to be very weekly bounded showing some features similar to the Rydberg atoms in three dimensions with a Coulombian interaction.

  17. Adiabatic and sudden interaction potentials in the fusion-fission of heavy ion collisions: Asymmetric target-projectile combinations

    International Nuclear Information System (INIS)

    It is now well known that many reactions giving measurable fusion cross-sections also show a fission of the compound system formed, similar to the low energy fission of the known fissioning nuclei. Recently, both the fusion excitation functions and the mass equilibration in the fragmentation of the composite system were measured for a large number of systems with 94208Pb on different targets of 26Mg, 48Ca, 50Ti, 52Cr, 58Fe and 64Ni. From a theoretical point of view, it is relevant to ask the question: how do the colliding nuclei fuse and then why does the compound system formed fission instead of going to the ground state to give a stable system. In this Letter, we attempt to show that the fusion of asymmetric colliding nuclei is due to the overcoming of the interaction barriers in adiabatic potentials and the fission of the compound system should perhaps occur as a sudden process, like the one in the spontaneous fission phenomenon. We have made our calculations for the compound systems with 102<=Z<=110 and for the asymmetric target-projectile combinations of the experiments of Ref. 1, using the fragmentation theory whose basis is the asymmetric two-centre shell model

  18. Strong-field ionization rates of linear polyenes simulated with time-dependent configuration interaction with an absorbing potential

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Pascal; Schlegel, H. Bernhard [Department of Chemistry, Wayne State University, Detroit, Michigan 48202-3489 (United States)

    2014-11-07

    The strong field ionization rates for ethylene, trans 1,3-butadiene, and trans,trans 1,3,5-hexatriene have been calculated using time-dependent configuration interaction with single excitations and a complex absorbing potential (TDCIS-CAP). The calculations used the aug-cc-pVTZ basis set with a large set of diffuse functions (3 s, 2 p, 3 d, and 1 f) on each atom. The absorbing boundary was placed 3.5 times the van der Waals radius from each atom. The simulations employed a seven-cycle cosine squared pulse with a wavelength of 800 nm. Ionization rates were calculated for intensities ranging from 0.3 × 10{sup 14} W/cm{sup 2} to 3.5 × 10{sup 14} W/cm{sup 2}. Ionization rates along the molecular axis increased markedly with increasing conjugation length. By contrast, ionization rates perpendicular to the molecular axis were almost independent of the conjugation length.

  19. The Co-Metabolism within the Gut-Brain Metabolic Interaction: Potential Targets for Drug Treatment and Design.

    Science.gov (United States)

    Obrenovich, Mark; Flückiger, Rudolf; Sykes, Lorraine; Donskey, Curtis

    2016-01-01

    We know that within the complex mammalian gut is any number of metabolic biomes. The gut has been sometimes called the "second brain" within the "gut-brain axis". A more informative term would be the gut-brain metabolic interactome, which is coined here to underscore the relationship between the digestive system and cognitive function or dysfunction as the case may be. Co-metabolism between the host and the intestinal microbiota is essential for life's processes. How diet, lifestyle, antibiotics and other factors shape the gut microbiome constitutes a rapidly growing area of research. Conversely, the gut microbiome also affects mammalian systems. Metabolites of the gut-brain axis are potential targets for treatment and drug design since the interaction or biochemical interplay results in net metabolite production or end-products with either positive or negative effects on human health. This review explores the gut-brain metabolic interactome, with particular emphasis on drug design and treatment strategies and how commensal bacteria or their disruption lead to dysbiosis and the effect this has on neurochemistry. Increasing data indicate that the intestinal microbiome can affect neurobiology, from mental and even behavioral health to memory, depression, mood, anxiety, obesity, cravings and even the creation and maintenance of the blood brain barrier. PMID:26831263

  20. Tweaking Dendrimers and Dendritic Nanoparticles for Controlled Nano-bio Interactions: Potential Nanocarriers for Improved Cancer Targeting

    Science.gov (United States)

    Bugno, Jason; Hsu, Hao-Jui; Hong, Seungpyo

    2016-01-01

    Nanoparticles have shown great promise in the treatment of cancer, with a demonstrated potential in targeted drug delivery. Among a myriad of nanocarriers that have been recently developed, dendrimers have attracted a great deal of scientific interests due to their unique chemical and structural properties that allow for precise engineering of their characteristics. Despite this, the clinical translation of dendrimers has been hindered due to their drawbacks, such as scale-up issues, rapid systemic elimination, inefficient tumor accumulation, and limited drug loading. In order to overcome these limitations, a series of reengineered dendrimers have been recently introduced using various approaches, including: i) modifications of structure and surfaces; ii) integration with linear polymers; and iii) hybridization with other types of nanocarriers. Chemical modifications and surface engineering have tailored dendrimers to improve their pharmacokinetics and tissue permeation. Copolymerization of dendritic polymers with linear polymers has resulted in various amphiphilic copolymers with self-assembly capabilities and improved drug loading efficiencies. Hybridization with other nanocarriers integrates advantageous characteristics of both systems, which includes prolonged plasma circulation times and enhanced tumor targeting. This review provides a comprehensive summary of the newly emerging drug delivery systems that involve reengineering of dendrimers in an effort to precisely control their nano-bio interactions, mitigating their inherent weaknesses. PMID:26453160

  1. Strong-field ionization rates of linear polyenes simulated with time-dependent configuration interaction with an absorbing potential.

    Science.gov (United States)

    Krause, Pascal; Schlegel, H Bernhard

    2014-11-01

    The strong field ionization rates for ethylene, trans 1,3-butadiene, and trans,trans 1,3,5-hexatriene have been calculated using time-dependent configuration interaction with single excitations and a complex absorbing potential (TDCIS-CAP). The calculations used the aug-cc-pVTZ basis set with a large set of diffuse functions (3 s, 2 p, 3 d, and 1 f) on each atom. The absorbing boundary was placed 3.5 times the van der Waals radius from each atom. The simulations employed a seven-cycle cosine squared pulse with a wavelength of 800 nm. Ionization rates were calculated for intensities ranging from 0.3 × 10(14) W/cm(2) to 3.5 × 10(14) W/cm(2). Ionization rates along the molecular axis increased markedly with increasing conjugation length. By contrast, ionization rates perpendicular to the molecular axis were almost independent of the conjugation length. PMID:25381499

  2. The importance of ‘double embeddedness’: The potential of migrants in international interactions and in the creation of national images

    OpenAIRE

    Pantović Branislav; Bašić Ivana

    2015-01-01

    This paper closely examines the influence of trans-migrants on the formation and development of interactions between the country of origin and the adopted country, based on the previous ethnoantropological, politicological, sociological and communicological researches. The potential of migrant activities is studied in interactions between countries, societies and cultures, as well as in the formation of national and country images. The dual identity and dua...

  3. Characterization of the In Vitro Kinetic Interaction of Chlorpyrifos-Oxon with Rat Salivary Cholinesterase: A Potential Biomonitoring Matrix

    Energy Technology Data Exchange (ETDEWEB)

    Kousba, Ahmed A.(BATTELLE (PACIFIC NW LAB)); Poet, Torka S.(BATTELLE (PACIFIC NW LAB)); Timchalk, Charles (Pacific Northwest National Laboratory)

    2003-02-12

    Chlorpyrifos (CPF) is a commonly used organophosphate insecticide (OP). The primary mechanism of action for CPF involves the inhibition of acetylcholinesterase (AChE) by the active metabolite, CPF-oxon, with subsequent accumulation of acetylcholine (ACh) resulting in a wide range of neutotoxicity. CPF-oxon, can likewise inhibit other non-target cholinesterases (ChE) such as butyrylcholinesterase (BuChE), which represents a detoxification mechanism and a potential biomarker of exposure/response. Biological monitoring for OPs has focused on measuring parent chemical or metabolite in blood and urine or blood ChE inhibition. Salivary biomonitoring has recently been explored as a practical method for examination of chemical exposure; however, there are a limited number of studies exploring its use for OPs. To evaluate the use of salivary ChE as a biological monitor for OP exposure, the current study characterized salivary ChE activity in Sprague-Dawley rats through its comparison with brain and plasma ChE using BW284C51 and iso-OMPA as selective inhibitors of AChE and BuChE, respectively. The study also estimated the kinetic constants describing BuChE interaction with CPF-oxon. A modified Ellman assay in conjunction with pharmacodynamic (PD) modeling was used to characterize the in vitro titration of diluted rat salivary ChE enzyme with CPF-oxon. The results indicated that, more than 95% of rat salivary ChE activity was associated with BuChE activity, total BuChE active site concentration was 0.0012 0.00013 nmol/ml saliva, reactivation rate constant (Kr) was 0.068 0.008 h-1 and inhibitory (Ki) rate constant of 8.825 and 9.80 nM-1h-1 determined experimentally and using model optimization respectively. These study results would be helpful for further evaluating the potential utility of salivary ChE as a practical tool for biological monitor of OP exposures.

  4. Interaction between groundwater and trees in an arid site: Potential impacts of climate variation and groundwater abstraction on trees

    Science.gov (United States)

    Yin, Lihe; Zhou, Yangxiao; Huang, Jinting; Wenninger, Jochen; Zhang, Eryong; Hou, Guangcai; Dong, Jiaqiu

    2015-09-01

    The understanding of the interaction between groundwater and trees is vital for sustainable groundwater use and maintenance of a healthy ecosystem in arid regions. The short- and long-term groundwater contribution to tree water use was investigated using the HYDRUS-1D model and stable isotopes. For the short-term simulation, the ratio between the actual transpiration (Ta) and potential transpiration (Tp) approached almost ∼1.0 due to the constant groundwater uptake. The results from the short-term simulation indicated that the groundwater contribution to tree water use ranged between 53% and 56% in the dry season (May-June) and 16-19% in the wet period (August-September). Isotopic analysis indicated that groundwater contributed to 45% of plant water use in the dry season, decreasing to 4-12% during the wet period. Because of canopy interception and transpiration, groundwater recharge only occurred after heavy rainfall and accounted for 3-8% of the total heavy rainfall. For the long-term simulation, Ta/Tp ranged between 0.91 and 1.00 except in 2007 (0.78), when the water table declined because of groundwater abstraction. In the scenario simulation for deep water table conditions caused by anthropogenic activities, Ta/Tp ranged between 0.09 and 0.40 (mean = 0.22) that is significantly lower than the values in the natural conditions. In conclusion, vegetation restoration in arid zones should be cautious as over-planting of trees will decrease the groundwater recharge and potentially cause a rapid drop in water table levels, which in turn may result in the death of planted trees. Trees adapt to arid regions by adopting root patterns that allow soil water uptake by shallow roots and groundwater use by deep roots, thus climatic variation itself may not bring severe negative impact on trees. However, anthropogenic activities, such as groundwater abstraction, will result in significant water table decline that will reduce actual transpiration of trees significantly

  5. Gene Prospector: An evidence gateway for evaluating potential susceptibility genes and interacting risk factors for human diseases

    Directory of Open Access Journals (Sweden)

    Khoury Muin J

    2008-12-01

    Full Text Available Abstract Background Millions of single nucleotide polymorphisms have been identified as a result of the human genome project and the rapid advance of high throughput genotyping technology. Genetic association studies, such as recent genome-wide association studies (GWAS, have provided a springboard for exploring the contribution of inherited genetic variation and gene/environment interactions in relation to disease. Given the capacity of such studies to produce a plethora of information that may then be described in a number of publications, selecting possible disease susceptibility genes and identifying related modifiable risk factors is a major challenge. A Web-based application for finding evidence of such relationships is key to the development of follow-up studies and evidence for translational research. We developed a Web-based application that selects and prioritizes potential disease-related genes by using a highly curated and updated literature database of genetic association studies. The application, called Gene Prospector, also provides a comprehensive set of links to additional data sources. Results We compared Gene Prospector results for the query "Parkinson" with a list of 13 leading candidate genes (Top Results from a curated, specialty database for genetic associations with Parkinson disease (PDGene. Nine of the thirteen leading candidate genes from PDGene were in the top 10th percentile of the ranked list from Gene Prospector. In fact, Gene Prospector included more published genetic association studies for the 13 leading candidate genes than PDGene did. Conclusion Gene Prospector provides an online gateway for searching for evidence about human genes in relation to diseases, other phenotypes, and risk factors, and provides links to published literature and other online data sources. Gene Prospector can be accessed via http://www.hugenavigator.net/HuGENavigator/geneProspectorStartPage.do.

  6. The glutamate-glutamine(GABA cycle: importance of late postnatal development and potential reciprocal interactions between biosynthesis and degradation

    Directory of Open Access Journals (Sweden)

    Leif eHertz

    2013-05-01

    Full Text Available The gold standard for studies of glutamate-glutamine(GABA cycling and its connections to brain biosynthesis from glucose of glutamate and GABA and their subsequent metabolism are the elegant in vivo studies by 13C magnetic resonance spectroscopy (NMR, showing the large fluxes in the cycle. However, simpler experiments in intact brain tissue (e.g. immunohistochemistry, brain slices, cultured brain cells and mitochondria have also made important contributions to the understanding of details, mechanisms and functional consequences of glutamate/GABA biosynthesis and degradation. The purpose of this review is to attempt to integrate evidence from different sources regarding i the enzyme(s responsible for the initial conversion of -ketoglutarate to glutamate; ii the possibility that especially glutamate oxidation is essentially confined to astrocytes; and iii the ontogenetically very late onset and maturation of glutamine-glutamate(GABA cycle function. Pathway models based on the functional importance of aspartate for glutamate synthesis suggest the possibility of interacting pathways for biosynthesis and degradation of glutamate and GABA and the use of transamination as the default mechanism for initiation of glutamate oxidation. The late development and maturation are related to the late cortical gliogenesis and convert brain cortical function from being purely neuronal to becoming neuronal-astrocytic. This conversion is associated with huge increases in energy demand and production, and the character of potentially incurred gains of function are discussed. These may include alterations in learning mechanisms, in mice indicated by lack of pairing of odor learning with aversive stimuli in newborn animals but the development of such an association 10-12 days later. The possibility is suggested that analogous maturational changes may contribute to differences in the way learning is accomplished in the newborn human brain and during later development.

  7. Dynamical instability of a Bose-Einstein condensate with higher-order interactions in an optical potential through a variational approach.

    Science.gov (United States)

    Wamba, E; Sabari, S; Porsezian, K; Mohamadou, A; Kofané, T C

    2014-05-01

    We investigate the dynamical instability of Bose-Einstein condensates (BECs) with higher-order interactions immersed in an optical lattice with weak driving harmonic potential. For this, we compute both analytically and numerically a modified Gross-Pitaevskii equation with higher-order nonlinearity and external potentials generated by magnetic and optical fields. Using the time-dependent variational approach, we derive the ordinary differential equations for the time evolution of the amplitude and phase of modulational perturbation. Through an effective potential, we obtain the modulational instability condition of BECs and discuss the effect of the higher-order interaction in the dynamics of the condensates in presence of optical potential. We perform direct numerical simulations to support our analytical results, and good agreement is found. PMID:25353871

  8. Potential drug interactions and duplicate prescriptions among ambulatory cancer patients: a prevalence study using an advanced screening method

    OpenAIRE

    Schuitenmaker Martin S; Boom Frits A; Swart Eleonora L; van Leeuwen Roelof WF; Hugtenburg Jacqueline G

    2010-01-01

    Abstract Background The pharmacotherapeutic treatment of patients with cancer is generally associated with multiple side-effects. Drug interactions and duplicate prescriptions between anti-cancer drugs or interactions with medication to treat comorbidity can reinforce or intensify side-effects. The aim of the present study is to gain more insight into the prevalence of drug interactions and duplicate prescriptions among patients being treated in the outpatient day care departments for oncolog...

  9. Two-dimensional array of particles originating from dipole-dipole interaction as evidenced by potential curve measurements at vertical oil/water interfaces

    OpenAIRE

    Sakka, Tetsuo; Kozawa, Daichi; Tsuchiya, Kiyoto; Sugiman, Nao; Øye, Gisle; Fukami, Kazuhiro; Nishi, Naoya; Ogata, Yukio H.

    2014-01-01

    We propose a new method to evaluate the interaction potential energy between the particles adsorbed at an oil/water interface as a function of interparticle distance. The method is based on the measurement of the interparticle distance at a vertical oil/water interface, at which the gravitational force is naturally applied to compress the particle monolayer in the in-plane direction. We verified the method by examining whether we obtained the same potential curve upon varying the gravitationa...

  10. Modulational and oscillatory instabilities of Bose–Einstein condensates with two- and three-body interactions trapped in an optical lattice potential

    International Nuclear Information System (INIS)

    We explain how the modulational and oscillatory instabilities can be generated in Bose–Einstein condensates (BECs) with two- and three-body interactions trapped in a periodic optical lattice with driving harmonic potential. We solve a cubic–quintic Gross–Pitaevskii (GP) equation with external trapping potentials by using both analytical and numerical methods. Using the time-dependent variational approach, we derive and analyze the variational equations for the time evolution of the amplitude and phase of modulational perturbation, and effective potential of the system. Through the effective potential, we obtain the modulational instability condition of the BECs with two- and three-body interactions and shown the effects of the optical potential on the dynamics of the system. We perform direct numerical simulations to support our analytical results, and good agreement is observed. - Highlights: • A cubic–quintic Gross–Pitaevskii equation with optical lattice (OL) and harmonic potentials is used. • We find the stability domain and time-dependent criteria for modulational instability. • Matter waves are generated through the modulational and oscillatory instabilities for four different possible cases. • Tuning the strength of OL shrinks and grows the bandwidth of unstable wave numbers. • In condensates with two- and three-body interactions, oscillatory instability can be realized

  11. Modulational and oscillatory instabilities of Bose–Einstein condensates with two- and three-body interactions trapped in an optical lattice potential

    Energy Technology Data Exchange (ETDEWEB)

    Sabari, S. [Department of Physics, Pondicherry University, Puducherry-605014 (India); Porsezian, K., E-mail: ponzsol@yahoo.com [Department of Physics, Pondicherry University, Puducherry-605014 (India); Murali, R. [Photonics, Nuclear and Medical Physics Division, School of Advanced Sciences, VIT University, Vellore-632 014, Tamilnadu (India)

    2015-02-06

    We explain how the modulational and oscillatory instabilities can be generated in Bose–Einstein condensates (BECs) with two- and three-body interactions trapped in a periodic optical lattice with driving harmonic potential. We solve a cubic–quintic Gross–Pitaevskii (GP) equation with external trapping potentials by using both analytical and numerical methods. Using the time-dependent variational approach, we derive and analyze the variational equations for the time evolution of the amplitude and phase of modulational perturbation, and effective potential of the system. Through the effective potential, we obtain the modulational instability condition of the BECs with two- and three-body interactions and shown the effects of the optical potential on the dynamics of the system. We perform direct numerical simulations to support our analytical results, and good agreement is observed. - Highlights: • A cubic–quintic Gross–Pitaevskii equation with optical lattice (OL) and harmonic potentials is used. • We find the stability domain and time-dependent criteria for modulational instability. • Matter waves are generated through the modulational and oscillatory instabilities for four different possible cases. • Tuning the strength of OL shrinks and grows the bandwidth of unstable wave numbers. • In condensates with two- and three-body interactions, oscillatory instability can be realized.

  12. A method for creating interactive content for the iPod, and its potential use as a learning tool: Technical Advances

    Directory of Open Access Journals (Sweden)

    Palmer Edward J

    2007-09-01

    Full Text Available Abstract Background Podcasting is currently a popular means of delivery of information with a large number of podcasts specifically tailored for educational purposes. It can be argued that the passive nature of this teaching methodology limits the educational benefit that can be derived from podcasts. This paper describes the development and construction of interactive material for the iPod, and a survey of student attitudes towards this type of learning material. Methods The development of interactive material for an iPod is described in detail. This material was developed and demonstrated to 50 medical students. These students completed a paper-based survey on the potential uses of this technology, before and after a 20 minute presentation in class of an interactive case-study on an iPod. Results A technical description of how to develop interactive content for the iPod was created. The results of the student survey indicate a favourable shift in student attitudes after viewing the interactive case. Despite only 15% of the students owning an iPod, 57% of the students were positive about having access to interactive iPod content and 59% believed they would use it whilst travelling. The percentage of students who felt podcasting was a useful means of learning increased from 9% to 41%. Conclusion The development of interactive content for the iPod is feasible. There are indications that students view interactive iPod cases as having value as an additional learning resource.

  13. Exact equivalence between one-dimensional Bose gases interacting via hard-sphere and zero-range potentials

    DEFF Research Database (Denmark)

    Valiente, Manuel

    2012-01-01

    We prove the equivalence between the hard-sphere Bose gas and a system with momentum-dependent zero-range interactions in one spatial dimension, which we call extended hard-sphere Bose gas. The two-body interaction in the latter model has the advantage of being a regular pseudopotential. The most...

  14. Effects of a dimple potential on the ground-state properties of a quasi-one-dimensional Bose–Einstein condensate with two- and three-body interactions

    International Nuclear Information System (INIS)

    The ground state of a quasi-one-dimensional interacting Bose gas confined by a harmonic plus Gaussian dimple potential is studied within the variational approach and also Gross–Pitaevskii mean-field approximation. The effect of the superimposed dimple trap on the order parameter, the chemical and effective potentials of the system is analyzed for repulsive and attractive two- as well as three-body interactions between the particles. The results obtained from both methods show that the characteristics of the trap such as the width and depth of the dimple affect the corresponding ground state properties of the system in a qualitatively similar way to the repulsive and attractive interatomic interactions, respectively. - Highlights: • We study the effects of a dimple potential on a quasi-1D Bose-Einstein condensate. • We used variational and Gross-Pitaevskii mean-field approaches. • The width of the dimple affects the system similarly to repulsive interaction. • The depth of the dimple affects the system similarly to attractive interaction

  15. Effects of a dimple potential on the ground-state properties of a quasi-one-dimensional Bose–Einstein condensate with two- and three-body interactions

    Energy Technology Data Exchange (ETDEWEB)

    Karabulut, Elife Ö.

    2015-04-01

    The ground state of a quasi-one-dimensional interacting Bose gas confined by a harmonic plus Gaussian dimple potential is studied within the variational approach and also Gross–Pitaevskii mean-field approximation. The effect of the superimposed dimple trap on the order parameter, the chemical and effective potentials of the system is analyzed for repulsive and attractive two- as well as three-body interactions between the particles. The results obtained from both methods show that the characteristics of the trap such as the width and depth of the dimple affect the corresponding ground state properties of the system in a qualitatively similar way to the repulsive and attractive interatomic interactions, respectively. - Highlights: • We study the effects of a dimple potential on a quasi-1D Bose-Einstein condensate. • We used variational and Gross-Pitaevskii mean-field approaches. • The width of the dimple affects the system similarly to repulsive interaction. • The depth of the dimple affects the system similarly to attractive interaction.

  16. Two-dimensional array of particles originating from dipole-dipole interaction as evidenced by potential curve measurements at vertical oil/water interfaces.

    Science.gov (United States)

    Sakka, Tetsuo; Kozawa, Daichi; Tsuchiya, Kiyoto; Sugiman, Nao; Øye, Gisle; Fukami, Kazuhiro; Nishi, Naoya; Ogata, Yukio H

    2014-08-28

    We propose a new method to evaluate the interaction potential energy between the particles adsorbed at an oil/water interface as a function of interparticle distance. The method is based on the measurement of the interparticle distance at a vertical oil/water interface, at which the gravitational force is naturally applied to compress the particle monolayer in the in-plane direction. We verified the method by examining whether we obtained the same potential curve upon varying the gravitational acceleration by tilting the interface. The present method is applicable in the force range from ∼0.1 to ∼100 pN, determined by the effective weight of the particles at the interface. The method gives a rather simple procedure to estimate a long range interaction among the particles adsorbed at oil/water interfaces. We applied this method to polystyrene particles at the decane/aqueous surfactant solution interface, and obtained the interparticle potential curves. All the potential curves obtained by the present method indicated that the interparticle repulsion is due to the electrical dipole-dipole interaction based on the negative charge of the particles. The mechanism of the dipole-dipole interaction is further discussed on the basis of the effects of surfactants. PMID:25005863

  17. Exact Solutions of the Mass-Dependent Klein-Gordon Equation with the Vector Quark-Antiquark Interaction and Harmonic Oscillator Potential

    Directory of Open Access Journals (Sweden)

    M. K. Bahar

    2013-01-01

    Full Text Available Using the asymptotic iteration and wave function ansatz method, we present exact solutions of the Klein-Gordon equation for the quark-antiquark interaction and harmonic oscillator potential in the case of the position-dependent mass.

  18. Study of potential drug-drug interactions between benzodiazepines and four commonly used antiepileptic drugs in mice

    Directory of Open Access Journals (Sweden)

    Kartik N. Shah

    2014-10-01

    Conclusion: Clonazepam potentiates the action of all the four anti-epileptics while diazepam potentiates only phenytoin and CBZ against MES seizures. Clonazepam but not diazepam potentiates the action of sodium valproate against PTZ seizures. [Int J Basic Clin Pharmacol 2014; 3(5.000: 830-835

  19. Basis sets for the evaluation of van der Waals complex interaction energies: Ne-N2 intermolecular potential and microwave spectrum.

    Science.gov (United States)

    Baranowska-Łączkowska, Angelika; Fernández, Berta

    2014-01-30

    In order to obtain efficient basis sets for the evaluation of van der Waals complex intermolecular potentials, we carry out systematic basis set studies. For this, interaction energies at representative geometries on the potential energy surfaces are evaluated using the CCSD(T) correlation method and large polarized LPol-n and augmented polarization-consistent aug-pc-2 basis sets extended with different sets of midbond functions. On the basis of the root mean square errors calculated with respect to the values for the most accurate potentials available, basis sets are selected for fitting the corresponding interaction energies and getting analytical potentials. In this work, we study the Ne-N2 van der Waals complex and after the above procedure, the aug-pc-2-3321 and the LPol-ds-33221 basis set results are fitted. The obtained potentials are characterized by T-shaped global minima at distances between the Ne atom and the N2 center of mass of 3.39 Å, with interaction energies of -49.36 cm(-1) for the aug-pc-2-3321 surface and -50.28 cm(-1) for the LPol-ds-33221 surface. Both sets of results are in excellent agreement with the reference surface. To check the potentials further microwave transition frequencies are calculated that agree well with the experimental and the aV5Z-33221 values. The success of this study suggests that it is feasible to carry out similar accurate calculations of interaction energies and ro-vibrational spectra at reduced cost for larger complexes than has been possible hitherto. PMID:24375320

  20. General hydrophobic interaction potential for surfactant/lipid bilayers from direct force measurements between light-modulated bilayers

    OpenAIRE

    Donaldson, Stephen H., Jr.; Lee, C. Ted; Chmelka, Bradley F.; Israelachvili, Jacob N.

    2011-01-01

    We establish and quantify correlations among the molecular structures, interaction forces, and physical processes associated with light-responsive self-assembled surfactant monolayers or bilayers at interfaces. Using the surface forces apparatus (SFA), the interaction forces between adsorbed monolayers and bilayers of an azobenzene-functionalized surfactant can be drastically and controllably altered by light-induced conversion of trans and cis molecular conformations. These reversible confor...

  1. A Multiple Interaction Analysis Reveals ADRB3 as a Potential Candidate for Gallbladder Cancer Predisposition via a Complex Interaction with Other Candidate Gene Variations

    Directory of Open Access Journals (Sweden)

    Rajani Rai

    2015-11-01

    Full Text Available Gallbladder cancer is the most common and a highly aggressive biliary tract malignancy with a dismal outcome. The pathogenesis of the disease is multifactorial, comprising the combined effect of multiple genetic variations of mild consequence along with numerous dietary and environmental risk factors. Previously, we demonstrated the association of several candidate gene variations with GBC risk. In this study, we aimed to identify the combination of gene variants and their possible interactions contributing towards genetic susceptibility of GBC. Here, we performed Multifactor-Dimensionality Reduction (MDR and Classification and Regression Tree Analysis (CRT to investigate the gene–gene interactions and the combined effect of 14 SNPs in nine genes (DR4 (rs20576, rs6557634; FAS (rs2234767; FASL (rs763110; DCC (rs2229080, rs4078288, rs7504990, rs714; PSCA (rs2294008, rs2978974; ADRA2A (rs1801253; ADRB1 (rs1800544; ADRB3 (rs4994; CYP17 (rs2486758 involved in various signaling pathways. Genotyping was accomplished by PCR-RFLP or Taqman allelic discrimination assays. SPSS software version 16.0 and MDR software version 2.0 were used for all the statistical analysis. Single locus investigation demonstrated significant association of DR4 (rs20576, rs6557634, DCC (rs714, rs2229080, rs4078288 and ADRB3 (rs4994 polymorphisms with GBC risk. MDR analysis revealed ADRB3 (rs4994 to be crucial candidate in GBC susceptibility that may act either alone (p < 0.0001, CVC = 10/10 or in combination with DCC (rs714 and rs2229080, p < 0.0001, CVC = 9/10. Our CRT results are in agreement with the above findings. Further, in-silico results of studied SNPs advocated their role in splicing, transcriptional and/or protein coding regulation. Overall, our result suggested complex interactions amongst the studied SNPs and ADRB3 rs4994 as candidate influencing GBC susceptibility.

  2. A Multiple Interaction Analysis Reveals ADRB3 as a Potential Candidate for Gallbladder Cancer Predisposition via a Complex Interaction with Other Candidate Gene Variations.

    Science.gov (United States)

    Rai, Rajani; Kim, Jong Joo; Misra, Sanjeev; Kumar, Ashok; Mittal, Balraj

    2015-01-01

    Gallbladder cancer is the most common and a highly aggressive biliary tract malignancy with a dismal outcome. The pathogenesis of the disease is multifactorial, comprising the combined effect of multiple genetic variations of mild consequence along with numerous dietary and environmental risk factors. Previously, we demonstrated the association of several candidate gene variations with GBC risk. In this study, we aimed to identify the combination of gene variants and their possible interactions contributing towards genetic susceptibility of GBC. Here, we performed Multifactor-Dimensionality Reduction (MDR) and Classification and Regression Tree Analysis (CRT) to investigate the gene-gene interactions and the combined effect of 14 SNPs in nine genes (DR4 (rs20576, rs6557634); FAS (rs2234767); FASL (rs763110); DCC (rs2229080, rs4078288, rs7504990, rs714); PSCA (rs2294008, rs2978974); ADRA2A (rs1801253); ADRB1 (rs1800544); ADRB3 (rs4994); CYP17 (rs2486758)) involved in various signaling pathways. Genotyping was accomplished by PCR-RFLP or Taqman allelic discrimination assays. SPSS software version 16.0 and MDR software version 2.0 were used for all the statistical analysis. Single locus investigation demonstrated significant association of DR4 (rs20576, rs6557634), DCC (rs714, rs2229080, rs4078288) and ADRB3 (rs4994) polymorphisms with GBC risk. MDR analysis revealed ADRB3 (rs4994) to be crucial candidate in GBC susceptibility that may act either alone (p ADRB3 rs4994 as candidate influencing GBC susceptibility. PMID:26602921

  3. Identification of New Potential Interaction Partners for Human Cytoplasmic Copper Chaperone Atox1: Roles in Gene Regulation?

    Directory of Open Access Journals (Sweden)

    Helena Öhrvik

    2015-07-01

    Full Text Available The human copper (Cu chaperone Atox1 delivers Cu to P1B type ATPases in the Golgi network, for incorporation into essential Cu-dependent enzymes. Atox1 homologs are found in most organisms; it is a 68-residue ferredoxin-fold protein that binds Cu in a conserved surface-exposed Cys-X-X-Cys (CXXC motif. In addition to its well-documented cytoplasmic chaperone function, in 2008 Atox1 was suggested to have functionality in the nucleus. To identify new interactions partners of Atox1, we performed a yeast two-hybrid screen with a large human placenta library of cDNA fragments using Atox1 as bait. Among 98 million fragments investigated, 25 proteins were found to be confident interaction partners. Nine of these were uncharacterized proteins, and the remaining 16 proteins were analyzed by bioinformatics with respect to cell localization, tissue distribution, function, sequence motifs, three-dimensional structures and interaction networks. Several of the hits were eukaryotic-specific proteins interacting with DNA or RNA implying that Atox1 may act as a modulator of gene regulation. Notably, because many of the identified proteins contain CXXC motifs, similarly to the Cu transport reactions, interactions between these and Atox1 may be mediated by Cu.

  4. Physiological effects of climate warming on flowering plants and insect pollinators and potential consequences for their interactions

    Directory of Open Access Journals (Sweden)

    Victoria L. SCAVEN, Nicole E. RAFFERTY

    2013-06-01

    Full Text Available Growing concern about the influence of climate change on flowering plants, pollinators, and the mutualistic interactions between them has led to a recent surge in research. Much of this research has addressed the consequences of warming for phenological and distributional shifts. In contrast, relatively little is known about the physiological responses of plants and insect pollinators to climate warming and, in particular, how these responses might affect plant-pollinator interactions. Here, we summarize the direct physiological effects of temperature on flowering plants and pollinating insects to highlight ways in which plant and pollinator responses could affect floral resources for pollinators, and pollination success for plants, respectively. We also consider the overall effects of these responses on plant-pollinator interaction networks. Plant responses to warming, which include altered flower, nectar, and pollen production, could modify floral resource availability and reproductive output of pollinating insects. Similarly, pollinator responses, such as altered foraging activity, body size, and life span, could affect patterns of pollen flow and pollination success of flowering plants. As a result, network structure could be altered as interactions are gained and lost, weakened and strengthened, even without the gain or loss of species or temporal overlap. Future research that addresses not only how plant and pollinator physiology are affected by warming but also how responses scale up to affect interactions and networks should allow us to better understand and predict the effects of climate change on this important ecosystem service [Current Zoolo­gy 59 (3: 418–426, 2013].

  5. A molecular beam scattering investigation of methanol-noble gas complexes: Characterization of the isotropic potential and insights into the nature of the interaction

    Science.gov (United States)

    Cappelletti, D.; Candori, P.; Falcinelli, S.; Albertí, M.; Pirani, F.

    2012-08-01

    Integral cross section experiments involving rotationally hot CH3OH projectiles and noble gas (Ng = Ne, Ar, Kr and Xe) targets are reported for the first time. Measured data have been exploited to characterize the phenomenological radial interaction in the CH3OH-Ng weakly bound complexes. Potential energy surfaces for all the systems have been formulated on the basis of a pairwise additive multicenter model. The comparison of model predictions with the most relevant experimental findings suggests that in CH3OH-Ng complexes, at variance with the behavior of the analogous complexes involving water or ammonia, the interaction is mainly due to van der Waals and induction components.

  6. New Theoretical Insight into the Interactions and Properties of Formic Acid: Development of a Quantum-Based Pair Potential for Formic Acid.

    Energy Technology Data Exchange (ETDEWEB)

    Roszak, S; Gee, R; Balasubramanian, K; Fried, L

    2005-08-08

    We performed ab initio quantum chemical studies for the development of intra and intermolecular interaction potentials for formic acid for use in molecular dynamics simulations of formic acid molecular crystal. The formic acid structures considered in the ab initio studies include both the cis and trans monomers which are the conformers that have been postulated as part of chains constituting liquid and crystal phases under extreme conditions. Although the cis to trans transformation is not energetically favored, the trans isomer was found as a component of stable gas-phase species. Our decomposition scheme for the interaction energy indicates that the hydrogen bonded complexes are dominated by the Hartree-Fock forces while parallel clusters are stabilized by the electron correlation energy. The calculated three-body and higher interactions are found to be negligible, thus rationalizing the development of an atom-atom pair potential for formic acid based on high-level ab initio calculations of small formic acid clusters. Here we present an atom-atom pair potential that includes both intra- and inter-molecular degrees of freedom for formic acid. The newly developed pair potential is used to examine formic acid in the condensed phase via molecular dynamics simulations. The isothermal compression under hydrostatic pressure obtained from molecular dynamics simulations is in good agreement with experiment. Further, the calculated equilibrium melting temperature is found to be in good agreement with experiment.

  7. New theoretical insight into the interactions and properties of formic acid: development of a quantum-based pair potential for formic acid.

    Science.gov (United States)

    Roszak, Szczepan; Gee, Richard H; Balasubramanian, Krishnan; Fried, Laurence E

    2005-10-01

    We performed ab initio quantum-chemical studies for the development of intra- and intermolecular interaction potentials for formic acid for use in molecular-dynamics simulations of formic acid molecular crystal. The formic acid structures considered in the ab initio studies include both the cis and trans monomers which are the conformers that have been postulated as part of chains constituting liquid and crystal phases under extreme conditions. Although the cis to trans transformation is not energetically favored, the trans isomer was found as a component of stable gas-phase species. Our decomposition scheme for the interaction energy indicates that the hydrogen-bonded complexes are dominated by the Hartree-Fock forces while parallel clusters are stabilized by the electron correlation energy. The calculated three-body and higher interactions are found to be negligible, thus rationalizing the development of an atom-atom pair potential for formic acid based on high-level ab initio calculations of small formic acid clusters. Here we present an atom-atom pair potential that includes both intra- and inter molecular degrees of freedom for formic acid. The newly developed pair potential is used to examine formic acid in the condensed phase via molecular-dynamics simulations. The isothermal compression under hydrostatic pressure obtained from molecular-dynamics simulations is in good agreement with experiment. Further, the calculated equilibrium melting temperature is found to be in good agreement with experiment. PMID:16238411

  8. Oscillatory interaction between dorsal root excitability and dorsal root potentials in the spinal cord of the turtle

    DEFF Research Database (Denmark)

    Delgado-Lezama, R; Perrier, J F; Hounsgaard, J

    1999-01-01

    The response to dorsal root stimulation, at one to two times threshold, was investigated in the isolated cervical enlargement of the turtle spinal cord. At frequencies near 10 Hz the synaptic response in motoneurons and the cord dorsum potential, after an initial lag time, oscillated in amplitude...... with a period of more than 1 s. The mono- and polysynaptyic postsynaptic response in motoneurons, the pre- and postsynaptic component of the cord dorsum potential and the dorsal root potential oscillated in synchrony. These oscillations were only observed with stimulus frequencies in the range 9-11 Hz....... The oscillating response could only be evoked from stimulus sites to which dorsal root potentials were conducted from the spinal cord (2-3 mm). At more distant stimulus sites cyclic variations in amplitude of the cord dorsum potential and the synaptic response in motoneurons were not observed. During...

  9. Multiple-scattering effects in proton- and alpha-nucleus reactions with Glauber theory

    International Nuclear Information System (INIS)

    We study the total reaction and elastic differential cross sections for proton-nucleus and 4He-nucleus reactions in the framework of the Glauber theory which describes multiplescattering processes. The input wave functions are obtained using the Skyrme-Hartree-Fock method and prepared for a wide range of mass numbers, O, Ca, Ni, Sn, and Pb isotopes. The theory reproduces experimental data very well. An effect of the multiple scattering is discussed by comparing with a standard optical-limit approximation. We see that the multiple-scattering effects play a crucial role, especially in enhancing the elastic differential cross sections at large scattering angles

  10. The fusion dynamics for a positive Q-value system: $^{27}$Al+$^{45}$Sc using SEDF and role of spin-orbit interaction potential

    CERN Document Server

    Verma, Dalip Singh

    2016-01-01

    The fusion dynamics for a positive Q-value systems: $^{27}$Al+$^{45}$Sc, at near and deep sub-barrier energies has been investigated using the proximity potentials of Skyrme energy density formalism in semi classical extended Thomas Fermi approach for arbitrarily chosen Skyrme forces: SLy4, SIV, SGII and Proximity77 of Blocki and co-workers. The calculated fusion excitation functions for the proximity potentials obtained for Skyrme forces mentioned above and for the Proximity77 have been compared with experimental data. The proximity potential for Skyrme force SIV is found to be the best and is used in the calculations of the quantities like logarithmic derivative, barriers distributions and $S$-factor. Further, the role of spin-orbit interaction potential in the fusion dynamics of this system has been investigated.

  11. Collecting high-order interactions in an effective pairwise intermolecular potential using the hydrated ion concept: The hydration of Cf{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Galbis, Elsa; Pappalardo, Rafael R.; Marcos, Enrique Sánchez, E-mail: sanchez@us.es [Departmento de Química Física, Universidad de Sevilla, 41012 Seville (Spain); Hernández-Cobos, Jorge [Instituto de Ciencias Físicas, UNAM, Apartado Postal 48-3, 62251 Cuernavaca (Mexico)

    2014-06-07

    This work proposes a new methodology to build interaction potentials between a highly charged metal cation and water molecules. These potentials, which can be used in classical computer simulations, have been fitted to reproduce quantum mechanical interaction energies (MP2 and BP86) for a wide range of [M(H{sub 2}O){sub n}]{sup m+}(H{sub 2}O){sub ℓ} clusters (n going from 6 to 10 and ℓ from 0 to 18). A flexible and polarizable water shell model (Mobile Charge Density of Harmonic Oscillator) has been coupled to the cation-water potential. The simultaneous consideration of poly-hydrated clusters and the polarizability of the interacting particles allows the inclusion of the most important many-body effects in the new polarizable potential. Applications have been centered on the californium, Cf(III) the heaviest actinoid experimentally studied in solution. Two different strategies to select a set of about 2000 structures which are used for the potential building were checked. Monte Carlo simulations of Cf(III)+500 H{sub 2}O for three of the intermolecular potentials predict an aquaion structure with coordination number close to 8 and average R{sub Cf−−O} in the range 2.43–2.48 Å, whereas the fourth one is closer to 9 with R{sub Cf−−O} = 2.54 Å. Simulated EXAFS spectra derived from the structural Monte Carlo distribution compares fairly well with the available experimental spectrum for the simulations bearing 8 water molecules. An angular distribution similar to that of a square antiprism is found for the octa-coordination.

  12. Ab initio interaction potentials and scattering lengths for ultracold mixtures of metastable helium and alkali-metal atoms

    Science.gov (United States)

    Kedziera, Dariusz; Mentel, Łukasz; Żuchowski, Piotr S.; Knoop, Steven

    2015-06-01

    We have obtained accurate ab initio +4Σ quartet potentials for the diatomic metastable triplet helium+alkali-metal (Li, Na, K, Rb) systems, using all-electron restricted open-shell coupled cluster singles and doubles with noniterative triples corrections CCSD(T) calculations and accurate calculations of the long-range C6 coefficients. These potentials provide accurate ab initio quartet scattering lengths, which for these many-electron systems is possible, because of the small reduced masses and shallow potentials that result in a small amount of bound states. Our results are relevant for ultracold metastable triplet helium+alkali-metal mixture experiments.

  13. College Chemistry Students' Understanding of Potential Energy in the Context of Atomic-Molecular Interactions

    Science.gov (United States)

    Becker, Nicole M.; Cooper, Melanie M.

    2014-01-01

    Understanding the energy changes that occur as atoms and molecules interact forms the foundation for understanding the macroscopic energy changes that accompany chemical processes. In order to identify ways to scaffold students' understanding of the connections between atomic-molecular and macroscopic energy perspectives, we conducted a…

  14. Potential for alcohol and drug interactions in older adults: evidence from the Irish longitudinal study on ageing.

    LENUS (Irish Health Repository)

    Cousins, Gráinne

    2014-08-01

    Older adults are susceptible to adverse effects from the concomitant use of prescription medications and alcohol. This study estimates the prevalence of exposure to alcohol interactive (AI) medications and concomitant alcohol use by therapeutic class in a large, nationally representative sample of older adults.

  15. Physiological effects of climate warming on flowering plants and insect pollinators and potential consequences for their interactions

    Institute of Scientific and Technical Information of China (English)

    Victoria L.SCAVEN; Nicole E.RAFFERTY

    2013-01-01

    Growing concern about the influence of climate change on flowering plants,pollinators,and the mutualistic interactions between them has led to a recent surge in research.Much of this research has addressed the consequences of warming for phenological and distributional shifts.In contrast,relatively little is known about the physiological responses of plants and insect pollinators to climate warming and,in particular,how these responses might affect plant-pollinator interactions.Here,we summabrize the direct physiological effects of temperature on flowering plants and pollinating insects to highlight ways in which plant and pollinator responses could affect floral resources for pollinators,and pollination success for plants,respectively.We also consider the overall effects of these responses on plant-pollinator interaction networks.Plant responses to warming,which include altered flower,nectar,and pollen production,could modify floral resource availability and reproductive output of pollinating insects.Similarly,pollinator responses,such as altered foraging activity,body size,and life span,could affect patterns of pollen flow and pollination success of flowering plants.As a result,network structure could be altered as interactions are gained and lost,weakened and strengthened,even without the gain or loss of species or temporal overlap.Future research that addresses not only how plant and pollinator physiology are affected by warming but also how responses scale up to affect interactions and networks should allow us to better understand and predict the effects of climate change on this important ecosystem service.

  16. Ab initio calculation of the interaction potentials of helium, neon, and methane as well as theoretical studies on their thermophysical properties and those of water vapor

    International Nuclear Information System (INIS)

    Thermophysical properties of the pure gases helium, neon, methane and water vapor were calculated for low densities over wide temperature ranges. Statistical thermodynamics was used for the determination of the pressure virial coefficients. The kinetic theory of gases was utilized for the calculation of the transport and relaxation properties. So far kinetic theory was limited to linear molecules and has now been extended to molecules of arbitrary geometry to enable calculations on methane and water vapor. The interaction potentials, which are needed for all computations, were determined for helium, neon and methane from the supermolecular approach using quantum chemical ab initio methods. For water the interaction potentials were taken from the literature. The calculated values of the thermophysical properties for the four gases show very good agreement with the best experimental data. At very low and very high temperatures the theoretical values are more accurate than experimental data. (orig.)

  17. A Stochastic System with Infinite Interacting Components to Model the Time Evolution of the Membrane Potentials of a Population of Neurons

    Science.gov (United States)

    Yaginuma, K.

    2016-05-01

    We consider a new class of interacting particle systems with a countable number of interacting components. The system represents the time evolution of the membrane potentials of an infinite set of interacting neurons. We prove the existence and uniqueness of the process, using a perfect simulation procedure. We show that this algorithm is successful, that is, we show that the number of steps of the algorithm is almost surely finite. We also construct a perfect simulation procedure for the coupling of a process with a finite number of neurons and the process with an infinite number of neurons. As a consequence, we obtain an upper bound for the error that we make when sampling from a finite set of neurons instead of the infinite set of neurons.

  18. Study of the nucleus-nucleus interaction potential via 16O elastic scattering at 94 MeV/u

    International Nuclear Information System (INIS)

    The elastic scattering angular distributions of 16O at 94 MeV/u on 12C, 28Si, 40Ca, 90Zr, 208Pb targets have been measured. They have been analyzed in the framework of the optical model with Woods-Saxon potentials and in the framework of the folding model. Concerning the heaviest system 16O + 208Pb, these analyses show that the real potential is well-defined only in the vicinity of the strong absorption radius, whereas for the lighter systems, it is defined in a relatively wide region (2-3 fm), which corresponds to a strong overlap of the two nuclei, especially for the systems 16O + 28Si and 16O + 12C. This difference, between the 16O + 208Pb system and the other systems originates in the appearance of the far-side contribution which manifests itself in the angular distributions by the so-called Fraunhoefer oscillations. The imaginary part of the potential is determined only in the vicinity of the strong absorption radius. The large reduction of the strong absorption radius for all the studied systems as the energy increases shows that the nuclear surface transparency is strongly enhanced at intermediate energies. The calculations performed with folding potentials allowed a study of the nuclear potential strength, in a less ambiguous way than with phenomenological potentials. In the regions where they are well-defined, the real and imaginary potentials decrease regularly when the energy goes from 10 to 100 MeV/u. This decrease disagrees with the results of microscopic calculations which predict an increase or a saturation of the nuclear potential in this energy range

  19. Quarkonia potential

    OpenAIRE

    Durnev, M. A.

    2008-01-01

    Using the quark-antiquark interactions obtained in the framework of the bootstrap method we construct a potential model, investigate the possibility of describing of heavy quarkonia and calculate the bottomonium spectrum. The potential of the interaction was obtained as a nonrelativistic limit of the relativistic quark-antiquark amplitudes Q{\\bar Q} -> Q\\bar Q.

  20. Difference between potentials of zero charge in the absence of the metal-solvent chemisorption interaction of mercury and metals of the gallium subgroup

    International Nuclear Information System (INIS)

    The modern solution of the Volt problem is introduced. The difference values of the zero-charge potentials between Hg- and Ga-(In-Ga)- and (Tl-Ga)-electrodes in six solvents in the absence of the metal-solvent chemisorption interaction of mercury and the gallium subgroup metals are calculated. The errors of the calculated values and the possibility of their minimization are evaluated. It is shown, that the values obtained are determined by the metal nature alone

  1. Evacetrapib: in vitro and clinical disposition, metabolism, excretion, and assessment of drug interaction potential with strong CYP3A and CYP2C8 inhibitors

    OpenAIRE

    Cannady, Ellen A.; Wang, Ming-Dauh; Friedrich, Stuart; Rehmel, Jessica L F; Yi, Ping; Small, David S; ZHANG Wei; Suico, Jeffrey G.

    2015-01-01

    Evacetrapib is an investigational cholesteryl ester transfer protein inhibitor (CETPi) for reduction of risk of major adverse cardiovascular events in patients with high-risk vascular disease. Understanding evacetrapib disposition, metabolism, and the potential for drug–drug interactions (DDI) may help guide prescribing recommendations. In vitro, evacetrapib metabolism was investigated with a panel of human recombinant cytochromes P450 (CYP). The disposition, metabolism, and excretion of evac...

  2. An investigation of the potential of interactive simulations for developing system thinking skills in elementary school: a case study with fifth- and sixth- graders

    OpenAIRE

    Evagorou, Maria; Korfiatis, Kostas; Nicolaou, Christiana; Constantinou, Costas

    2009-01-01

    Abstract The purpose of this study was to investigate the impact of a simulation-based learning environment on elementary school students? (11- to 12- year old) development of system thinking skills. The learning environment included interactive simulations using the Stagecast Creator software to simulate the ecosystem of a marsh. Simulations are an important tool in any effort to develop system thinking, because they have the potential to highlight the dynamic nature of systems. B...

  3. Endogenous 17β-estradiol is required for activity-dependent long-term potentiation in the striatum: interaction with the dopaminergic system

    OpenAIRE

    Tozzi, Alessandro; de Iure, Antonio; Tantucci, Michela; Durante, Valentina; Quiroga-Varela, Ana; Giampà, Carmela; Di Mauro, Michela; Mazzocchetti, Petra; Costa, Cinzia; Di Filippo, Massimiliano; Grassi, Silvarosa; Pettorossi, Vito Enrico; Calabresi, Paolo

    2015-01-01

    17β-estradiol (E2), a neurosteroid synthesized by P450-aromatase (ARO), modulates various brain functions. We characterized the role of the locally synthesized E2 on striatal long-term synaptic plasticity and explored possible interactions between E2 receptors (ERs) and dopamine (DA) receptors in the dorsal striatum of adult male rats. Inhibition of E2 synthesis or antagonism of ERs prevented the induction of long-term potentiation (LTP) in both medium spiny neurons (MSNs) and cholinergic int...

  4. Endogenous 17ß-estradiol is required for activity-dependent long-term potentiation in the striatum: interaction with the dopaminergic system

    OpenAIRE

    Alessandro eTozzi; Antonio ede Iure; Michela eTantucci; Valentina eDurante; Ana eQuiroga-Varela; Carmela eGiampà; Michela eDi Mauro; Petra eMazzocchetti; Cinzia eCosta; Massimiliano eDi Filippo; Silvarosa eGrassi; Vito Enrico Pettorossi; Paolo eCalabresi

    2015-01-01

    17β-estradiol (E2), a neurosteroid synthesized by P450-aromatase (ARO), modulates various brain functions. We characterized the role of the locally synthesized E2 on striatal long-term synaptic plasticity and explored possible interactions between E2 receptors (ERs) and dopamine (DA) receptors in the dorsal striatum of adult male rats. Inhibition of E2 synthesis or antagonism of ERs prevented the induction of long-term potentiation (LTP) in both medium spiny neurons (MSNs) and cholinergic int...

  5. ARTE: French-German Experiments in Crossing the Borders. 'One Media – Three Screens' Convergence and Interactivity at its Full Potential?

    OpenAIRE

    Wiehl, Anna

    2014-01-01

    abstractThis contribution aims at discussing policies of convergence as well as at questioning whether the current strategies really exploit the options of digital media to its full potential – especially with regard to transmedia-storytelling, interactivity, participation and networking. By the paradigm of the 'European Culture Channel' ARTE, we draw a sketch of the portfolio of existing and emerging new formats and user practices. In the second part, we examine one specific genre from this ...

  6. Spectra of barium, radium, and element 120; application of the combined correlation potential, singles-doubles, and configuration interaction ab initio method

    CERN Document Server

    Ginges, J S M

    2015-01-01

    We apply a version of the recently developed approach combining the correlation potential, linearized singles-doubles coupled-cluster, and the configuration interaction methods to the spectra of the heavy alkaline earths barium, radium, and element 120. Quantum electrodynamics radiative corrections are included. We have found unprecedented agreement between ab initio theory and experiment for the spectra of barium and radium, and we make accurate predictions for missing and unreliable data for all three atoms.

  7. Spectra of barium, radium, and element 120; application of the combined correlation potential, singles-doubles, and configuration interaction ab initio method

    OpenAIRE

    Ginges, J. S. M.; Dzuba, V. A.

    2015-01-01

    We apply a version of the recently developed approach combining the correlation potential, linearized singles-doubles coupled-cluster, and the configuration interaction methods to the spectra of the heavy alkaline earths barium, radium, and element 120. Quantum electrodynamics radiative corrections are included. We have found unprecedented agreement between ab initio theory and experiment for the spectra of barium and radium, and we make accurate predictions for missing and unreliable data fo...

  8. Internal Josephson-like tunnelling in two-component Bose-Einstein condensates affected by sign of the atomic interaction and external trapping potential

    Institute of Scientific and Technical Information of China (English)

    Xiong Bo; Liu Xun-Xu

    2007-01-01

    This paper studies the Josephson-like tunnelling in two-component Bose-Einstein condensates coupled with microwave field, which is in respond to various attractive and repulsive atomic interaction under the various aspect ratio of trapping potential. It is very interesting to find that the dynamic of Josephson-like tunnelling can be controlled from fast damped oscillations to nondamped oscillation, and relative number of atoms changes from asymmetric occupation to symmetric occupation correspondingly.

  9. Extent of poly-pharmacy, occurrence and associated factors of drug-drug interaction and potential adverse drug reactions in Gondar Teaching Referral Hospital, North West Ethiopia

    OpenAIRE

    Endalkachew Admassie; Tesfahun Melese; Woldeselassie Mequanent; Wubshet Hailu; B Akshaya Srikanth

    2013-01-01

    The aim of this study was to assess the extent of poly-pharmacy, occurrence, and associated factors for the occurrence of drug–drug interaction (DDI) and potential adverse drug reaction (ADR) in Gondar University Teaching Referral Hospital. Institutional-based retrospective cross-sectional study. This study was conducted on prescriptions of both in and out-patients for a period of 3 months at Gondar University Hospital. Both bivariate analysis and multivariate logistic regression were used to...

  10. An exchange-Coulomb model potential energy surface for the Ne-CO interaction. II. Molecular beam scattering and bulk gas phenomena in Ne-CO mixtures.

    Science.gov (United States)

    Dham, Ashok K; McBane, George C; McCourt, Frederick R W; Meath, William J

    2010-01-14

    Four potential energy surfaces are of current interest for the Ne-CO interaction. Two are high-level fully ab initio surfaces obtained a decade ago using symmetry-adapted perturbation theory and supermolecule coupled-cluster methods. The other two are very recent exchange-Coulomb (XC) model potential energy surfaces constructed by using ab initio Heitler-London interaction energies and literature long range dispersion and induction energies, followed by the determination of a small number of adjustable parameters to reproduce a selected subset of pure rotational transition frequencies for the (20)Ne-(12)C(16)O van der Waals cluster. Testing of the four potential energy surfaces against a wide range of available experimental microwave, millimeter-wave, and mid-infrared Ne-CO transition frequencies indicated that the XC potential energy surfaces gave results that were generally far superior to the earlier fully ab initio surfaces. In this paper, two XC model surfaces and the two fully ab initio surfaces are tested for their abilities to reproduce experiment for a wide range of nonspectroscopic Ne-CO gas mixture properties. The properties considered here are relative integral cross sections and the angle dependence of rotational state-to-state differential cross sections, rotational relaxation rate constants for CO(v=2) in Ne-CO mixtures at T=296 K, pressure broadening of two pure rotational lines and of the rovibrational lines in the CO fundamental and first overtone transitions at 300 K, and the temperature and, where appropriate, mole fraction dependencies of the interaction second virial coefficient, the binary diffusion coefficient, the interaction viscosity, the mixture shear viscosity and thermal conductivity coefficients, and the thermal diffusion factor. The XC model potential energy surfaces give results that lie within or very nearly within the experimental uncertainties for all properties considered, while the coupled-cluster ab initio surface gives

  11. New bases for the evaluation of interaction energies: An ab initio study of the CO-Ne van der Waals complex intermolecular potential and ro-vibrational spectrum

    International Nuclear Information System (INIS)

    Graphical abstract: CO-Ne IPES. Highlights: → From the LPol, MLPol, and aug-pc-2 bases we obtained new bases for the evaluation of CO-Ne interaction energies. → We checked the bases on the evaluation of the rovibrational spectrum. → The results were satisfactory, being the new bases more efficient than those previously available. - Abstract: Recently we have derived new efficient basis sets for the evaluation of interaction energies in the X-Y (X, Y = He, Ne, Ar) van der Waals complexes. Here we extend the study to the CO-Ne complex. For this, we start with a systematic basis set study, where the LPol, MLPol and Jensen's aug-pc-2 basis sets are considered as starting point (for the Ne atom LPol bases are developed). As reference we take interaction energy results obtained with Dunning's augmented correlation consistent polarized valence basis sets. In all cases we test extensions with different sets of midbond functions. With the selected bases we evaluate CCSD(T) interaction potentials, and to check the potentials further, we obtain the ro-vibrational spectrum of the complex. The results are compared to the available experimental data.

  12. Potential role of chitinases and chitin-binding proteins in host-microbial interactions during the development of intestinal inflammation

    OpenAIRE

    Tran, Hoa T.; Barnich, Nicolas; Mizoguchi, Emiko

    2011-01-01

    The small and large intestines contain an abundance of luminal antigens derived from food products and enteric microorganisms. The function of intestinal epithelial cells is tightly regulated by several factors produced by enteric bacteria and the epithelial cells themselves. Epithelial cells actively participate in regulating the homeostasis of intestine, and failure of this function leads to abnormal and host-microbial interactions resulting in the development of intestinal inflammation. Ma...

  13. Older Age and Steroid Use Are Associated with Increasing Polypharmacy and Potential Medication Interactions Among Patients with Inflammatory Bowel Disease

    OpenAIRE

    Parian, Alyssa; Ha, Christina Y.

    2015-01-01

    Background: Comorbidity and polypharmacy, more prevalent among older persons, may impact the treatment of patients with inflammatory bowel disease (IBD). The aims of this study were to assess the frequency of polypharmacy and medication interactions within a cohort of older patients with IBD and describe IBD treatment patterns. Methods: Cohort study of 190 patients with IBD 65 years or older followed at a tertiary IBD referral center from 2006 to 2012. Data collected included demographics, IB...

  14. The Isolation of DNA by Polycharged Magnetic Particles: An Analysis of the Interaction by Zeta Potential and Particle Size

    OpenAIRE

    Yazan Haddad; Kledi Xhaxhiu; Pavel Kopel; David Hynek; Ondrej Zitka; Vojtech Adam

    2016-01-01

    Magnetic isolation of biological targets is in major demand in the biotechnology industry today. This study considers the interaction of four surface-modified magnetic micro- and nanoparticles with selected DNA fragments. Different surface modifications of nanomaghemite precursors were investigated: MAN37 (silica-coated), MAN127 (polyvinylpyrrolidone-coated), MAN158 (phosphate-coated), and MAN164 (tripolyphosphate-coated). All particles were positive polycharged agglomerated monodispersed sys...

  15. Constraining early and interacting dark energy with gravitational wave standard sirens: the potential of the eLISA mission

    CERN Document Server

    Caprini, Chiara

    2016-01-01

    We perform a forecast analysis of the capability of the eLISA space-based interferometer to constrain models of early and interacting dark energy using gravitational wave standard sirens. We employ simulated catalogues of standard sirens given by merging massive black hole binaries visible by eLISA, with an electromagnetic counterpart detectable by future telescopes. We consider three-arms mission designs with arm length of 1, 2 and 5 million km, 5 years of mission duration and the best-level low frequency noise as recently tested by the LISA Pathfinder. Standard sirens with eLISA give access to an intermediate range of redshift $1\\lesssim z \\lesssim 8$, and can therefore provide competitive constraints on models where the onset of the deviation from $\\Lambda$CDM (i.e.~the epoch when early dark energy starts to be non-negligible, or when the interaction with dark matter begins) occurs relatively late, at $z\\lesssim 6$. If instead early or interacting dark energy is relevant already in the pre-recombination er...

  16. Potential Effects of Climate Change on Ecological Interaction Outcomes Between Two Disease-Vector Mosquitoes: A Mesocosm Experimental Study.

    Science.gov (United States)

    Leonel, B F; Koroiva, R; Hamada, N; Ferreira-Keppler, R L; Roque, F O

    2015-09-01

    The objective of this study was to experimentally assess the effects of different climate change scenarios on the outcomes of interactions between Aedes aegypti (L.) and Culex quinquefasciatus (Say) (Diptera: Culicidae) larvae. The experimental design maintained a constant density of specimens while the proportion of the species in different experimental climate change scenarios varied. Our results indicate that survival of the two species was not affected, but larval development and pupation times decreased under elevated atmospheric CO(2) concentration and high air temperature. In climate change scenarios with both species together, the survival of Ae. aegypti increased and its larval development time decreased with increasing density of Cx. quinquefasciatus. This may be attributed to the effects of intraspecific competition being more significant than interspecific competition in Ae. aegypti. Our study also reveals that climatic changes may affect the patterns of interactions between Cx. quinquefasciatus and Ae. aegypti. Alterations in climatic conditions changed the response of context-dependent competition, indicating the importance of studies on how ecological interactions will be affected by projected future climatic change. PMID:26336208

  17. Global potential energy surface for the O2 + N2 interaction. Applications to the collisional, spectroscopic, and thermodynamic properties of the complex

    CERN Document Server

    Bartolomei, Massimiliano; Hernádez, Marta I; Campos-Martínez, José; Moszyński, Robert

    2014-01-01

    A detailed characterization of the interaction between the most abundant molecules in air is important for the understanding of a variety of phenomena in atmospherical science. A completely {\\em ab initio} global potential energy surface (PES) for the O$_2(^3\\Sigma^-_g)$ + N$_2(^1\\Sigma^+_g)$ interaction is reported for the first time. It has been obtained with the symmetry-adapted perturbation theory utilizing a density functional description of monomers [SAPT(DFT)] extended to treat the interaction involving high-spin open-shell complexes. The computed interaction energies of the complex are in a good agreement with those obtained by using the spin-restricted coupled cluster methodology with singles, doubles and noniterative triple excitations [RCCSD(T)]. A spherical harmonics expansion containing a large number of terms due to the anisotropy of the interaction has been built from the {\\em ab initio} data. The radial coefficients of the expansion are matched in the long range with the analytical functions b...

  18. Image potential in the interaction of fast ions with carbon nanotubes: A comparison between the one- and two-fluid hydrodynamic models

    Energy Technology Data Exchange (ETDEWEB)

    Karbunar, L., E-mail: ziloot@verat.net [School of Electrical Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11120 Belgrade (Serbia); Borka, D., E-mail: dusborka@vin.bg.ac.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Radović, I., E-mail: iradovic@vin.bg.ac.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Mišković, Z.L., E-mail: zmiskovi@uwaterloo.ca [Department of Applied Mathematics, and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2015-09-01

    Highlights: • We study the interaction of protons with carbon nanotubes under channeling conditions. • We use the linearized, 2D, one-fluid and two-fluid hydrodynamic models. • The image potential for a proton moving parallel to the nanotube axis is calculated. • Results for the image potential are compared for different types of nanotubes. • We also compute the angular and spatial distributions of channeled protons. - Abstract: We study the interaction of charged particles with four different types of single-walled carbon nanotubes (SWNTs) under channeling conditions by means of the linearized, two dimensional, one-fluid and two-fluid hydrodynamic models. The models are used to calculate the image potential for protons moving parallel to the axis of the SWNTs at the speeds up to 10 a.u. Numerical results are obtained to show the influence of the damping factor, the nanotube radius, and the particle position on the image potential inside the nanotube. We also compute the spatial and angular distributions of protons and compare them for the two models.

  19. Bound state solutions of the Dirac equation with the Deng—Fan potential including a Coulomb tensor interaction

    International Nuclear Information System (INIS)

    Approximate analytical solutions of the Dirac equation in the case of pseudospin and spin symmetry limits are investigated under the Deng—Fan potential by applying the asymptotic iteration method for the arbitrary quantum numbers n and κ. Some of the numerical results are also represented in both pseudospin symmetry and spin symmetry limits

  20. Influence of positive bias potential in plasma surface interactions and its application for simulation of radiolytic corrosion

    International Nuclear Information System (INIS)

    A simulation and acceleration test apparatus with helicon plasma for the radiolytic corrosion were arranged to investigate the corrosion phenomena of the metal surface under the heavy irradiation environment. The oxidation of 304 stainless steel by contact with the oxygen plasma was investigated. It was confirmed that the plasma oxidation phenomenon is enhanced by biasing the positive potential. (author)

  1. Particle resonance in the (1+1)-dimensional Dirac equation with kink-like vector potential and delta interaction

    CERN Document Server

    Eshghi, M; Ikhdair, Sameer M

    2015-01-01

    The relativistic problem of spin- fermions subject to vector hyperbolic (kink-like) potential tanh (kx) is investigated by using the parametric Nikiforov-Uvarov method. The energy eigenvalue equation and the corresponding normalized wave functions are obtained in terms of the Jacobi polynomials for x>0 and x<0 cases.

  2. Web Based Interactive Software in International Business: The Case of the Global Market Potential System Online (GMPSO[C])

    Science.gov (United States)

    Janavaras, Basil J.; Gomes, Emanuel; Young, Richard

    2008-01-01

    This paper seeks to confirm whether students using the Global Market Potential System Online (GMPSO) web based software, (http://globalmarketpotential.com), for their class project enhanced their knowledge and understanding of international business. The challenge most business instructors and practitioners face is to determine how to bring the…

  3. Potential interactions among disease, pesticides, water quality and adjacent land cover in amphibian habitats in the United States.

    Science.gov (United States)

    Battaglin, W A; Smalling, K L; Anderson, C; Calhoun, D; Chestnut, T; Muths, E

    2016-10-01

    To investigate interactions among disease, pesticides, water quality, and adjacent land cover, we collected samples of water, sediment, and frog tissue from 21 sites in 7 States in the United States (US) representing a variety of amphibian habitats. All samples were analyzed for >90 pesticides and pesticide degradates, and water and frogs were screened for the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) using molecular methods. Pesticides and pesticide degradates were detected frequently in frog breeding habitats (water and sediment) as well as in frog tissue. Fungicides occurred more frequently in water, sediment, and tissue than was expected based upon their limited use relative to herbicides or insecticides. Pesticide occurrence in water or sediment was not a strong predictor of occurrence in tissue, but pesticide concentrations in tissue were correlated positively to agricultural and urban land, and negatively to forested land in 2-km buffers around the sites. Bd was detected in water at 45% of sites, and on 34% of swabbed frogs. Bd detections in water were not associated with differences in land use around sites, but sites with detections had colder water. Frogs that tested positive for Bd were associated with sites that had higher total fungicide concentrations in water and sediment, but lower insecticide concentrations in sediments relative to frogs that were Bd negative. Bd concentrations on frog swabs were positively correlated to dissolved organic carbon, and total nitrogen and phosphorus, and negatively correlated to pH and water temperature. Data were collected from a range of locations and amphibian habitats and represent some of the first field-collected information aimed at understanding the interactions between pesticides, land use, and amphibian disease. These interactions are of particular interest to conservation efforts as many amphibians live in altered habitats and may depend on wetlands embedded in these landscapes to survive

  4. Quantum dynamical simulation of the scattering of Ar from a frozen LiF(100) surface based on a first principles interaction potential

    International Nuclear Information System (INIS)

    In-plane two and three dimensional diffraction patterns are computed for the vertical scattering of an Ar atom from a frozen LiF(100) surface. Suitable collimation of the incoming wavepacket serves to reveal the quantum mechanical diffraction. The interaction potential is based on a fit to an ab initio potential calculated using density functional theory with dispersion corrections. Due to the potential coupling found between the two horizontal surface directions, there are noticeable differences between the quantum angular distributions computed for two and three dimensional scattering. The quantum results are compared to analogous classical Wigner computations on the same surface and with the same conditions. The classical dynamics largely provides the envelope for the quantum diffractive scattering. The classical results also show that the corrugation along the [110] direction of the surface is smaller than along the [100] direction, in qualitative agreement with experimental observations of unimodal and bimodal scattering for the [110] and [100] directions, respectively

  5. Quantum dynamical simulation of the scattering of Ar from a frozen LiF(100) surface based on a first principles interaction potential

    Energy Technology Data Exchange (ETDEWEB)

    Azuri, Asaf; Pollak, Eli, E-mail: eli.pollak@weizmann.ac.il [Chemical Physics Department, Weizmann Institute of Science, 76100 Rehovoth (Israel)

    2015-07-07

    In-plane two and three dimensional diffraction patterns are computed for the vertical scattering of an Ar atom from a frozen LiF(100) surface. Suitable collimation of the incoming wavepacket serves to reveal the quantum mechanical diffraction. The interaction potential is based on a fit to an ab initio potential calculated using density functional theory with dispersion corrections. Due to the potential coupling found between the two horizontal surface directions, there are noticeable differences between the quantum angular distributions computed for two and three dimensional scattering. The quantum results are compared to analogous classical Wigner computations on the same surface and with the same conditions. The classical dynamics largely provides the envelope for the quantum diffractive scattering. The classical results also show that the corrugation along the [110] direction of the surface is smaller than along the [100] direction, in qualitative agreement with experimental observations of unimodal and bimodal scattering for the [110] and [100] directions, respectively.

  6. New method of evaluation for interatomic interaction potential in LEIS with large-angle scattering using the two-atom scattering model

    Science.gov (United States)

    Takeuchi, Wataru; Matsuda, Naoki

    2008-03-01

    The interaction potential between an incident ion and a target atom in impact-collision ion scattering spectroscopy (ICISS), which is a specialization of low energy ion scattering (LEIS) and its variants, i.e. ICISS with detection of neutrals (NICISS), coaxial ICISS (CAICISS) and impact-collision atom scattering spectroscopy with detection of neutrals (NICASS), has been evaluated by the new method using the dependence of the total scattering angle on the impact parameter for the first collision in the numerical calculations based on the two-atom scattering model (TWASM). From the comparison of determined values of scaling factor for the Firsov screening length by three-dimensional computer simulations with calculated ones by TWASM, it became obviously that the interatomic potentials for the various combinations of an incident ion and a target atom in LEIS are suitably given by the Moliere potential with the reduced Firsov screening length employing the scaling factor obtained in TWASM calculations.

  7. van der Waals interactions and dipole polarizabilities of lanthanides: Tm(2F)-He and Yb(1S)-He potentials

    Science.gov (United States)

    Buchachenko, Alexei A.; Szczȩśniak, Małgorzata M.; Chałasiński, Grzegorz

    2006-03-01

    Anisotropic dipole polarizabilities of Tm(F2),Tm+2(F2), and Yb(S1) are calculated using the finite-field multireference averaged quadratic coupled cluster (MR-AQCC) (Tm and Tm+2) and RCCSD(T) (Yb) methods with small-core relativistic pseudopotentials ECP28MWB combined with the augmented ANO basis sets. The lanthanide atoms are strongly polarizable with the scalar part originating from the 6s electrons and the tensorial part from the open 4f shells. The adiabatic interaction potentials Σ+2,Π2,Δ2, and Φ2 of Tm(F2)-He and Tm+2(F2)-He were examined by the multireference approaches, multireference configuration interaction and MR-AQCC, using the basis sets designed in the polarizability calculations. A closed-shell lanthanide system Yb(S1)-He was included for comparison. The Tm-He Σ+2,Π2,Δ2, and Φ2 interaction potentials are very shallow and nearly degenerate (within 0.01cm-1), with the well depths in the range of 2.35-2.36cm-1 at R =6.17Å. The basis-set saturated well depths are expected to be larger by ca. 25%, as estimated using the bond-function augmented basis set. The interactions of lanthanide atoms with He are one order of magnitude less anisotropic than those involving first-row transition metal atoms. The suppression of anisotropy is chiefly attributed to the screening effected by the 6s shell. When these electrons are removed as in the di-cation complex Tm+2(F2)-He, the potentials deepen to a thousand wave number range and their anisotropy is enhanced 500-fold.

  8. Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions

    Science.gov (United States)

    Wang, Yimin; Bowman, Joel M.; Kamarchik, Eugene

    2016-03-01

    We report full-dimensional, ab initio-based potentials and dipole moment surfaces for NaCl, NaF, Na+H2O, F-H2O, and Cl-H2O. The NaCl and NaF potentials are diabatic ones that dissociate to ions. These are obtained using spline fits to CCSD(T)/aug-cc-pV5Z energies. In addition, non-linear least square fits using the Born-Mayer-Huggins potential are presented, providing accurate parameters based strictly on the current ab initio energies. The long-range behavior of the NaCl and NaF potentials is shown to go, as expected, accurately to the point-charge Coulomb interaction. The three ion-H2O potentials are permutationally invariant fits to roughly 20 000 coupled cluster CCSD(T) energies (awCVTZ basis for Na+ and aVTZ basis for Cl- and F-), over a large range of distances and H2O intramolecular configurations. These potentials are switched accurately in the long range to the analytical ion-dipole interactions, to improve computational efficiency. Dipole moment surfaces are fits to MP2 data; for the ion-ion cases, these are well described in the intermediate- and long-range by the simple point-charge expression. The performance of these new fits is examined by direct comparison to additional ab initio energies and dipole moments along various cuts. Equilibrium structures, harmonic frequencies, and electronic dissociation energies are also reported and compared to direct ab initio results. These indicate the high fidelity of the new PESs.

  9. Prediction of dynamic Rankine Cycle waste heat recovery performance and fuel saving potential in passenger car applications considering interactions with vehicles’ energy management

    International Nuclear Information System (INIS)

    Highlights: • Method for evaluating fuel saving potential of vehicle waste heat recovery systems. • Analysis of interactions between waste heat recovery system and vehicle. • Evaluation of fuel saving potential in dynamic motorway driving scenario. • Parameter study for increasing fuel saving potential of integrated system. - Abstract: Waste heat recovery (WHR) by means of a Rankine Cycle is a promising approach for achieving reductions in fuel consumption and, as a result, exhaust emissions of passenger car engines. To find the best compromise between complexity and fuel saving potential, methods for predicting the WHR performance for different system configurations and stationary as well as dynamic driving scenarios are needed. Since WHR systems are usually not included in today’s car concepts, they are mostly designed as add-on systems. As a result their integration may lead to negative interactions due to increased vehicle weight, engine backpressure and cooling demand. These effects have to be considered when evaluating the fuel saving potential. A new approach for predicting WHR performance and fuel saving potential was developed and is presented in this paper. It is based on simple dynamic models of a system for recovering exhaust gas waste heat and its interfaces with the vehicle: the exhaust system for heat input, the on-board electric system for power delivery and the engine cooling system for heat rejection. The models are validated with test bench measurements of the cycle components. A study of fuel saving potential in an exemplary dynamic motorway driving scenario shows the effect of vehicle integration: while the WHR system could improve fuel economy by 3.4%, restrictions in power output due to the architecture of the on-board electric system, package considerations, increased weight, cooling demand and exhaust gas backpressure lead to a reduction of fuel saving potential by 60% to 1.3%. A parameter study reveals that, in addition to weight

  10. Linear quadratic game and non-cooperative predictive methods for potential application to modelling driver-AFS interactive steering control

    Science.gov (United States)

    Na, Xiaoxiang; Cole, David J.

    2013-02-01

    This paper is concerned with the modelling of strategic interactions between the human driver and the vehicle active front steering (AFS) controller in a path-following task where the two controllers hold different target paths. The work is aimed at extending the use of mathematical models in representing driver steering behaviour in complicated driving situations. Two game theoretic approaches, namely linear quadratic game and non-cooperative model predictive control (non-cooperative MPC), are used for developing the driver-AFS interactive steering control model. For each approach, the open-loop Nash steering control solution is derived; the influences of the path-following weights, preview and control horizons, driver time delay and arm neuromuscular system (NMS) dynamics are investigated, and the CPU time consumed is recorded. It is found that the two approaches give identical time histories as well as control gains, while the non-cooperative MPC method uses much less CPU time. Specifically, it is observed that the introduction of weight on the integral of vehicle lateral displacement error helps to eliminate the steady-state path-following error; the increase in preview horizon and NMS natural frequency and the decline in time delay and NMS damping ratio improve the path-following accuracy.

  11. Review of potential interactions between stocked rainbow trout and listed Snake River sockeye salmon in Pettit Lake Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Teuscher, D.

    1996-05-01

    The objective of this study was to determine if hatchery rainbow trout compete with or prey on juvenile Snake River sockeye salmon Oncorhynchus nerka in Pettit Lake, Idaho. In 1995, a total of 8,570 age-0 sockeye and 4,000 hatchery rainbow trout were released in Pettit Lake. After releasing the fish, gillnets were set in the pelagic and littoral zones to collected diet and spatial distribution data. Interactions were assessed monthly from June 1995 through March 1996. Competition for food was discounted based on extremely low diet overlap results observed throughout the sample period. Conversely, predation interactions were more significant. A total of 119 rainbow trout stomachs were analyzed, two contained O. nerka. The predation was limited to one sample period, but when extrapolated to the whole rainbow trout populations results in significant losses. Total consumption of O. nerka by rainbow trout ranged from an estimated 10 to 23% of initial stocking numbers. Predation results contradict earlier findings that stocked rainbow trout do not prey on wild kokanee or sockeye in the Sawtooth Lakes. The contradiction may be explained by a combination of poorly adapted hatchery sockeye and a littoral release site that forced spatial overlap that was not occurring in the wild populations. Releasing sockeye in the pelagic zone may have reduced or eliminated predation losses to rainbow trout.

  12. Physicochemical properties of liposomes as potential anticancer drugs carriers. Interaction of etoposide and cytarabine with the membrane: Spectroscopic studies

    Science.gov (United States)

    Pentak, Danuta

    2014-03-01

    The interactions between etoposide, cytarabine and 1,2-dihexadecanoyl-sn-glycerol-3-phosphocholine bilayers were studied using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR). These techniques have proven to be a very powerful tool in studying the structure and dynamics of phospholipid bilayers. In particular, DSC can provide information on the phase transition temperature and cooperativity of the lipid molecules in the absence and presence of the drug. Vibrational spectroscopy is well suited to the study of drug-lipid interactions, since it allows for an investigation of the conformation of phospholipid molecules at different levels in lipid bilayers and follows structural changes that occur during the gel to liquid-crystalline phase transition. NMR supported the determination of the main phase transition temperatures (TC) of 1,2-dihexadecanoyl-sn-glycerol-3-phosphocholine (DPPC). The main phase transition temperature (TC) determined by 1H NMR is comparable with values obtained by DSC for all studied liposomes. The location of cytarabine and etoposide in liposomes was also determined by NMR. Atomic force microscopy (AFM) images, acquired immediately after sample deposition on a mica surface, revealed the spherical shape of lipid vesicles.

  13. Review of potential interactions between stocked rainbow trout and listed Snake River sockeye salmon in Pettit Lake Idaho

    International Nuclear Information System (INIS)

    The objective of this study was to determine if hatchery rainbow trout compete with or prey on juvenile Snake River sockeye salmon Oncorhynchus nerka in Pettit Lake, Idaho. In 1995, a total of 8,570 age-0 sockeye and 4,000 hatchery rainbow trout were released in Pettit Lake. After releasing the fish, gillnets were set in the pelagic and littoral zones to collected diet and spatial distribution data. Interactions were assessed monthly from June 1995 through March 1996. Competition for food was discounted based on extremely low diet overlap results observed throughout the sample period. Conversely, predation interactions were more significant. A total of 119 rainbow trout stomachs were analyzed, two contained O. nerka. The predation was limited to one sample period, but when extrapolated to the whole rainbow trout populations results in significant losses. Total consumption of O. nerka by rainbow trout ranged from an estimated 10 to 23% of initial stocking numbers. Predation results contradict earlier findings that stocked rainbow trout do not prey on wild kokanee or sockeye in the Sawtooth Lakes. The contradiction may be explained by a combination of poorly adapted hatchery sockeye and a littoral release site that forced spatial overlap that was not occurring in the wild populations. Releasing sockeye in the pelagic zone may have reduced or eliminated predation losses to rainbow trout

  14. Determination of a correction factor for the interaction potential of He + ions backscattered from a Cu(1 0 0) surface

    Science.gov (United States)

    Draxler, M.; Walker, M.; McConville, C. F.

    2006-08-01

    We have used coaxial impact collision ion scattering spectroscopy (CAICISS) data collected from 3 keV He+ ions backscattered from a Cu(1 0 0) surface in different azimuthal orientations to investigate the influence of the screening length on CAICISS polar angle scans. We have compared the experimental data to computer simulations generated with the FAN code and found that for our experimental conditions an exceptionally low value of 0.53 was required for the correction factor to the Firsov screening length used with the Thomas-Fermi-Moliere potential. In addition we found that the Ziegler-Biersack-Littmark potential is not applicable, resulting in incorrect peak positions in the CAICISS polar angle plots.

  15. Mannose-specific interactions of Lactobacillus plantarum in the intestine : bacterial genes, molecular host responses and potential probiotic effects

    OpenAIRE

    Pretzer, G.

    2008-01-01

    One potential mechanism by which probiotic microorganisms may exert beneficial health effects to the host is the inhibition of intestinal infections by competitive exclusion of pathogenic bacteria. This concept may also be applicable for mannose-specific adhesion to the epithelial surface, which has been demonstrated for several pathogens as well as for the probiotic Lactobacillus plantarum. In this thesis, a complementary approach was performed to focus on mannose-specific host-microbe inter...

  16. Iron overload causes osteoporosis in thalassemia major patients through interaction with transient receptor potential vanilloid type 1 (TRPV1) channels

    OpenAIRE

    Rossi, Francesca; Perrotta, Silverio; Bellini, Giulia; Luongo, Livio; Tortora, Chiara; Siniscalco, Dario; Francese, Matteo; Torella, Marco; Nobili, Bruno; Di Marzo, Vincenzo; Maione, Sabatino

    2014-01-01

    The pathogenesis of bone resorption in β-thalassemia major is multifactorial and our understanding of the underlying molecular and cellular mechanisms remains incomplete. Considering the emerging importance of the endocannabinoid/endovanilloid system in bone metabolism, it may be instructive to examine a potential role for this system in the development of osteoporosis in patients with β-thalassemia major and its relationship with iron overload and iron chelation therapy. This study demonstra...

  17. It's a dark, dark world: background evolution of interacting phiCDM models beyond simple exponential potentials

    Science.gov (United States)

    Singh, Suprit; Singh, Parminder

    2016-05-01

    We study the background cosmological dynamics with a three component source content: a radiation fluid, a barotropic fluid to mimic the matter sector and a single scalar field which can act as dark energy giving rise to the late-time accelerated phase. Using the well-known dimensionless variables, we cast the dynamical equations into an autonomous system of ordinary differential equations (ASODE), which are studied by computing the fixed points and the conditions for their stability. The matter fluid and the scalar field are taken to be uncoupled at first and later, we consider a coupling between the two of the form Q = √(2/3)κβρṁphi where ρm is the barotropic fluid density. The key point of our analysis is that for the closure of ASODE, we only demand that the jerk, Γ = V V''/V'2 is a function of acceleration, z = -MpV'/V, that is, Γ = 1+f(z). In this way, we are able to accommodate a large class of potentials that goes beyond the simple exponential potentials. The analysis is completely generic and independent of the form of the potential for the scalar field. As an illustration and confirmation of the analysis, we consider f(z) of the forms μ/z2, μ/z, (μ-z)/z2 and (μ-z) to numerically compute the evolution of cosmological parameters with and without coupling. Implications of the approach and the results are discussed.

  18. In Vitro Interaction of 5-Hydroxytrptamine with Cytosolic Molybdenum Hydroxylases as a Potential Inhibitor for Initial Rates Activities

    Directory of Open Access Journals (Sweden)

    Abdullah M. Al-Mohizea

    2010-01-01

    Full Text Available Problem statement: The role of 5-HT has been investigated in many behavioral activities. Thus, studies using raphe lesion showed that 5-HT is involved in sleep, general activity levels, habituation, aggression, pain sensitivity and morphine analgesia, avoidance behavior, self-stimulation and water consumption. Approach: The metabolic interaction between serotonin (5- hydroxytrptamine and indole-3-aldehyde and xanthine via aldehyde oxidase (EC 1.2.3.1 and xanthine oxidase (EC 1.1.3.22, respectively, were studied in liver tissue homogenate of Dunkin-Hartley guinea pigs by following the decrease in substrate concentration using spectrophotometer. Homogenates of liver were incubated with indole-3-aldehyde in the presence and absence of serotonin or (chlorpromazine and allopurinol a potent and selective inhibitors for aldehyde oxidase and xanthine oxidase, respectively. Oxidation of indole-3-aldehyde to indole-3-acetic acid was reduced up to 63.2% in the presence of serotonin (100 µM, while oxidation of xanthine to uric acid was reduced up to 51.6% under the same conditions. Results: In comparison, incubation of the substrates with their specific inhibitors (100 µM of chlorpromazine and 100 µM allopurinol give almost complete inhibition. These results demonstrate that in the guinea pig liver a metabolic interaction between serotonin and indole-3-aldehyde or xanthine via molybdenum hydroxylases system may take place in liver, which is the main tissue for xenobiotics detoxification. Conclusion: The overall conclusion from this research is that serotonin could be a protector for neurons and other tissue from the insult of oxidation of aldehydes and xanthines by molybdenum hydroxylases.

  19. Are ineffective defence reactions potential target for induced resistance during the compatible wheat-powdery mildew interaction?

    Science.gov (United States)

    Tayeh, Ch; Randoux, B; Tisserant, B; Khong, G; Jacques, Ph; Reignault, Ph

    2015-11-01

    Powdery mildew caused by Blumeria graminis f.sp. tritici, an obligate aerial biotrophic fungus, would be one of the most damaging wheat (Triticum aestivum) diseases without the extensive use of conventional fungicides. In our study, the expression levels of some basal defence-related genes were investigated during a compatible interaction in order to evaluate wheat reactions to infection, along with the different stages of the infectious process in planta. As fungal conidia initiated their germination and developed appressorial germ tube (AGT), early defence reactions involved the expression of a lipoxygenase (LOX)- and an oxalate oxidase (OXO)-encoding genes, followed by activations of corresponding LOX (EC 1.13.11.12) and OXO (EC 1.2.3.4) activities, respectively. When penetration of AGT took place, up-regulation of chitinases (CHI) and PR1-encoding genes expression occurred along with an increase of CHI (EC 3.2.1.14) activity. Meanwhile, expression of a phenylalanine ammonia-lyase-encoding gene also took place. Up-regulation of a phospholipase C- and lipid transfer proteins-encoding genes expression occurred during the latest stages of infection. Neither the phi glutathione S-transferase (GST)-encoding gene expression nor the GST (EC 2.5.1.13) activity was modified upon wheat infection by powdery mildew. Whether these defence reactions during such a compatible interaction are markers of immunity or susceptibility, and whether they have the ability to contribute to protection upon modulation of their timing and their intensity by resistance inducers are discussed. PMID:26218548

  20. Pharmacophore mapping based inhibitor selection and molecular interaction studies for identification of potential drugs on calcium activated potassium channel blockers, tamulotoxin

    Directory of Open Access Journals (Sweden)

    R Barani Kumar

    2013-01-01

    Full Text Available Background: Tamulotoxin (TmTx from Buthus tamulus was found to be a highly venomous toxin which accelerates the neurotransmitter release that directly affects the cardiovascular tissues and the respiratory system leading to death. TmTx from red Indian scorpion is a crucial inhibitor for Ca 2+ activated K + channel in humans. Objective: The study is aimed at the identification of potential inhibitors of TmTx through pharmacophore based inhibitor screening and understanding the molecular level interactions. Materials and Method: The potential inhibitors for TmTx were identified using pharmacophore model based descriptor information present in existing drugs with the analysis of pharmacokinetic properties. The compounds with good ADMET (Absorption, Distribution, Metabolism, Excretion and Toxicity descriptors were subjected to molecular interaction studies. The stability of bound toxin-inhibitor complex was studied using molecular dynamics simulation over a period of one nanosecond. Results: From a dataset of 3406 compounds, few compounds were selected as potential inhibitors based on the generated best pharmacophore models, pharmacokinetic analysis, molecular docking and molecular dynamics studies. Conclusion: In conclusion, two compounds containing better inhibition properties against TmTx are suggested to be better lead molecules for drug development in future and this study will help us to explore more inhibitors from natural origin against tamulotoxin.

  1. Characterization of Long-Lasting Oatp Inhibition by Typical Inhibitor Cyclosporine A and In Vitro-In Vivo Discrepancy in Its Drug Interaction Potential in Rats.

    Science.gov (United States)

    Taguchi, Takayuki; Masuo, Yusuke; Kogi, Tatsuya; Nakamichi, Noritaka; Kato, Yukio

    2016-07-01

    Quantitative assessment of potential drug-drug interactions (DDIs) is one of the major focuses in drug development. The aim of the present study was to quantitatively evaluate in vitro-in vivo discrepancy of DDI potential for prototypical organic anion transporting polypeptide (Oatp) inhibitor cyclosporine A (CsA) using rats. Plasma concentration of pravastatin, prototypical Oatp substrate, after oral administration was increased by CsA intravenously administered at 1 d before the pravastatin administration. The ratio of the area under the curve of pravastatin to the control was much higher than the R-values calculated using the plasma unbound concentrations of CsA and the inhibition constant (Ki) assessed in isolated hepatocytes, indicating in vitro-in vivo discrepancy. This interaction with pravastatin persisted for 3 d after CsA administration, demonstrating long-lasting inhibition in vivo. The Ki value for unbound CsA in the presence of serum was comparable with that in its absence. M1, the major metabolite of CsA inhibited pravastatin uptake at much higher concentration compared with its plasma unbound concentration. Thus, the DDI potential of CsA-mediated hepatic Oatp inhibition cannot be extrapolated from in vitro data, and this could be due to the long-lasting Oatp inhibition by CsA, but not the effect of plasma protein or metabolites. PMID:27290622

  2. Interaction between ropinirole hydrochloride and aspirin with human serum albumin as binary and ternary systems by multi-spectroscopic, molecular modeling and zeta potential

    Energy Technology Data Exchange (ETDEWEB)

    Mahaki, Hanie, E-mail: hanieh.mahaki@gmail.com [Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Memarpoor-Yazdi, Mina; Chamani, Jamshidkhan [Department of Biology, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Reza Saberi, Mohammad [Medical Chemistry Department, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of)

    2013-02-15

    The aim of the present study was to describe the competition of ropinirole hydrochloride (RP) and aspirin (ASA) in binding to human serum albumin (HSA) in physiological buffer (pH=7.4) using multi-spectroscopic, molecular modeling and zeta-potential measurements. Fluorescence analysis was used to define the binding and quenching properties of drug-HSA complexes in binary and ternary systems. Fluorescence spectroscopy showed that in the presence of RP, the binding constant of HSA-ASA was increased. Static quenching was confirmed to result in the fluorescence quenching and FRET. The effect of drugs on the conformation of HSA was analyzed using synchronous fluorescence spectroscopy, three-dimensional fluorescence spectra and circular dichroism (CD). The RLS method determined the critical aggregation concentration of drugs on HSA in binary and ternary systems that confirmed the zeta potential results. Structural modeling showed that the affinity of each of the drugs to HSA in binary and ternary systems confirms the spectroscopic results. - Highlights: Black-Right-Pointing-Pointer We studied the interaction of ropinirole hydrochloride and aspirin with HSA. Black-Right-Pointing-Pointer Molecular modeling and zeta-potential used to describe competitive interaction. Black-Right-Pointing-Pointer We determined the critical induced aggregation concentration of both drugs on HSA. Black-Right-Pointing-Pointer The binding mechanism of drugs as separate and simultaneous to HSA has been compared. Black-Right-Pointing-Pointer The binding site of both drugs as simultaneous effects on HSA has been determined.

  3. Comment on 'Non-relativistic treatment of diatomic molecules interacting with generalized Kratzer potential in hyperspherical coordinates'

    International Nuclear Information System (INIS)

    We argue that the textbook method for solving eigenvalue equations is simpler, more elegant and efficient than the asymptotic iteration method applied in Durmus (2011 J. Phys. A: Math. Theor.44 155205). We show that the Kratzer potential is not a realistic model for the vibration-rotation spectra of diatomic molecules because it predicts the position of the absorption infrared bands too far from the experimental ones (at least for the HCl and H2 molecules chosen as illustrative examples in that paper). (comment)

  4. Modeling of the potential coiled-coil structure of snapin protein and its interaction with SNARE complex

    OpenAIRE

    Gowthaman, Ragul; Silvester, A Johnwin; Saranya, K.; Kanya, KS Rathna; Archana, NR

    2006-01-01

    Autism is a developmental disability causing learning and memory disorder. The heart of the search for a cure for this syndrome is the need to understand dendrite branch patterning, a process crucial for proper synaptic transmission. Due to the association of snapin with the SNARE complex and its role in synaptic transmission it is reported as a potential drug target for autism therapies. We wish to impart the noesis of the 3D structure of the snapin protein, and in this chase we predict the ...

  5. A Density Functional Approach to Polarizable Models: A Kim-Gordon-Response Density Interaction Potential for Molecular Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Tabacchi, G; Hutter, J; Mundy, C

    2005-04-07

    A combined linear response--frozen electron density model has been implemented in a molecular dynamics scheme derived from an extended Lagrangian formalism. This approach is based on a partition of the electronic charge distribution into a frozen region described by Kim-Gordon theory, and a response contribution determined by the instaneous ionic configuration of the system. The method is free from empirical pair-potentials and the parameterization protocol involves only calculations on properly chosen subsystems. They apply this method to a series of alkali halides in different physical phases and are able to reproduce experimental structural and thermodynamic properties with an accuracy comparable to Kohn-Sham density functional calculations.

  6. Modified transverse phonon-helicon interaction in colloids laden semiconductor plasmas due to Bohm potential and Fermi degenerate pressure

    International Nuclear Information System (INIS)

    A detailed study of the quantum modification of acousto-helicon wave spectra due to Bohm potential and Fermi degenerate pressure in colloids laden semiconductor plasma has been presented. We have used quantum hydrodynamic model of plasmas to arrive at most general dispersion relation in presence of magnetic field. This dispersion relation has been analyzed in three different velocity regimes and the expressions for gain constants have been obtained. From the present study it has been concluded that the quantum effect and the magnetic field significantly modify the wave characteristics particularly in high doping regime in semiconductor plasma medium in presence of colloids in it

  7. Self-spin-controlled rotation of spatial states of a Dirac electron in a cylindrical potential via spin-orbit interaction

    Energy Technology Data Exchange (ETDEWEB)

    Leary, C C; Reeb, D; Raymer, M G [Oregon Center for Optics and Department of Physics, 1274 University of Oregon, Eugene, OR 97403-1274 (United States)], E-mail: cleary@uoregon.edu

    2008-10-15

    Solution of the Dirac equation predicts that when an electron with nonzero orbital angular momentum (OAM) propagates in a cylindrically symmetric potential, its spin and orbital degrees of freedom interact, causing the electron's phase velocity to depend on whether its spin angular momentum (SAM) and OAM vectors are oriented parallel or anti-parallel with respect to each other. This spin-orbit splitting of the electronic dispersion curves can result in a rotation of the electron's spatial state in a manner controlled by the electron's own spin z-component value. These effects persist at non-relativistic velocities. To clarify the physical origin of this effect, we compare solutions of the Dirac equation to perturbative predictions of the Schroedinger-Pauli equation with a spin-orbit term, using the standard Foldy-Wouthuysen Hamiltonian. This clearly shows that the origin of the effect is the familiar relativistic spin-orbit interaction.

  8. Self-spin-controlled rotation of spatial states of a Dirac electron in a cylindrical potential via spin-orbit interaction

    International Nuclear Information System (INIS)

    Solution of the Dirac equation predicts that when an electron with nonzero orbital angular momentum (OAM) propagates in a cylindrically symmetric potential, its spin and orbital degrees of freedom interact, causing the electron's phase velocity to depend on whether its spin angular momentum (SAM) and OAM vectors are oriented parallel or anti-parallel with respect to each other. This spin-orbit splitting of the electronic dispersion curves can result in a rotation of the electron's spatial state in a manner controlled by the electron's own spin z-component value. These effects persist at non-relativistic velocities. To clarify the physical origin of this effect, we compare solutions of the Dirac equation to perturbative predictions of the Schroedinger-Pauli equation with a spin-orbit term, using the standard Foldy-Wouthuysen Hamiltonian. This clearly shows that the origin of the effect is the familiar relativistic spin-orbit interaction.

  9. The interaction of HAb18G/CD147 with integrin α6β1 and its implications for the invasion potential of human hepatoma cells

    Directory of Open Access Journals (Sweden)

    Tang Juan

    2009-09-01

    Full Text Available Abstract Background HAb18G/CD147 plays pivotal roles in invasion by hepatoma cells, but the underlying mechanism remains unclear. Our previous study demonstrated that overexpression of HAb18G/CD147 promotes invasion by interacting with integrin α3β1. However, it has never been investigated whether α3β1 is solely responsible for this process or if other integrin family members also interact with HAb18G/CD147 in human hepatoma cells. Methods Human SMMC-7721 and FHCC98 cells were cultured and transfected with siRNA fragments against HAb18G/CD147. The expression levels of HAb18G/CD147 and integrin α6β1 were determined by immunofluorescent double-staining and confocal imaging analysis. Co-immunoprecipitation and Western blot analyses were performed to examine the native conformations of HAb18G/CD147 and integrin α6β1. Invasion potential was evaluated with an invasion assay and gelatin zymography. Results We found that integrin α6β1 co-localizes and interacts with HAb18G/CD147 in human hepatoma cells. The enhancing effects of HAb18G/CD147 on invasion capacity and secretion of matrix metalloproteinases (MMPs were partially blocked by integrin α6β1 antibodies (P 2+ mobilization, significantly reduced cell invasion potential and secretion of MMPs in human hepatoma cells (P Conclusion These results suggest that α6β1 interacts with HAb18G/CD147 to mediate tumor invasion and metastatic processes through the PI3K pathway.

  10. ARG1 (altered response to gravity) encodes a DnaJ-like protein that potentially interacts with the cytoskeleton

    Science.gov (United States)

    Sedbrook, J. C.; Chen, R.; Masson, P. H.

    1999-01-01

    Gravitropism allows plant organs to direct their growth at a specific angle from the gravity vector, promoting upward growth for shoots and downward growth for roots. Little is known about the mechanisms underlying gravitropic signal transduction. We found that mutations in the ARG1 locus of Arabidopsis thaliana alter root and hypocotyl gravitropism without affecting phototropism, root growth responses to phytohormones or inhibitors of auxin transport, or starch accumulation. The positional cloning of ARG1 revealed a DnaJ-like protein containing a coiled-coil region homologous to coiled coils found in cytoskeleton-interacting proteins. These data suggest that ARG1 participates in a gravity-signaling process involving the cytoskeleton. A combination of Northern blot studies and analysis of ARG1-GUS fusion-reporter expression in transgenic plants demonstrated that ARG1 is expressed in all organs. Ubiquitous ARG1 expression in Arabidopsis and the identification of an ortholog in Caenorhabditis elegans suggest that ARG1 is involved in other essential processes.

  11. Analysis of paralytic shellfish toxins, potential chemical threat agents, in food using hydrophilic interaction liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Jansson, Daniel; Åstot, Crister

    2015-10-23

    A novel method for determining paralytic shellfish toxin (PST) profiles in food was developed using a combination of silica and strong cation exchange (SCX) solid phase extraction (SPE) coupled to hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). Besides the risk for natural contamination of seafood and drinking water, PSTs also pose potent threats through intentional contamination of food, due to their high toxicity and the wide distributions of toxin-producing algae. The new preparation method aim to maintain the samples' original toxin profiles by avoiding conditions known to induce interconversion or degradation of the PSTs. The method was evaluated for PST extraction from water, milk, orange juice, apple purée, baby food, and blue mussels (Mytilus edulis). The extracts were found to produce reproducible retention times in HILIC-MS/MS analysis. When an authentic toxic mussel sample was analyzed using the novel method, saxitoxin and gonyautoxin-3 were identified, in agreement with data acquired using the Lawrence pre-column oxidation high-performance liquid chromatography-fluorescence detection (HPLC-FLD) method. Overall recoveries of the PSTs from tested foods by the novel method ranged from 36% to 111%. PMID:26404910

  12. Synthesis and bioactive evaluations of novel benzotriazole compounds as potential antimicrobial agents and the interaction with calf thymus DNA

    Indian Academy of Sciences (India)

    Yu Ren; Hui Zhen Zhang; Shao Lin Zhang; Yun Lei Luo; Ling Zhang; Cheng He Zhou; Rong Xia Geng

    2015-12-01

    A novel series of benzotriazole derivatives were synthesized and characterized by NMR, IR and MS spectra. The bioactive assay manifested that most of the new compounds exhibited moderate to good antibacterial and antifungal activities against the tested strains in comparison to reference drugs chloromycin, norfloxacin and fluconazole. Especially, 2,4-dichlorophenyl substituted benzotriazole derivative 6f displayed good antibacterial activity against MRSA with MIC value of 4 g/mL, which was 2-fold more potent than Chloromycin, and it also displayed 3-fold stronger antifungal activity (MIC = 4 g/mL) than fluconazole (MIC = 16 g/mL) against Beer yeast. The preliminary interactive investigations of compound 6f with calf thymus DNA revealed that compound 6f could effectively intercalate into DNA to form compound 6f–DNA complex which might block DNA replication to exert antimicrobial activities. Molecular docking experiments suggested that compound 6f projected into base-pairs of DNA hexamer duplex forming two hydrogen bonds with guanine of DNA. The theoretical calculations were in accordance with the experimental results.

  13. Inferring coarse-grain histone-DNA interaction potentials from high-resolution structures of the nucleosome

    CERN Document Server

    Meyer, Sam

    2014-01-01

    The histone-DNA interaction in the nucleosome is a fundamental mechanism of genomic compaction and regulation, which remains largely unkown despite a growing structural knowledge of the complex. Here, we propose a framework for the extraction of a nanoscale histone-DNA force-field from a collection of high-resolution structures, which may be adapted to a larger class of protein-DNA complexes. We apply the procedure on a large crystallographic database extended by snapshots from molecular dynamics simulations. The comparison of the structural models first shows that, at the sites of histone-DNA contact, the DNA base-pairs are locally shifted outwards, consistent with locally repulsive forces exerted by the histones. In a second step, we show that the various force profiles of the analyzed structures derive locally from a unique, sequence-independent, quadratic repulsive force field, while the sequence preferences are entirely due to the internal DNA mechanics. We thus obtain the first knowledge-derived nanosca...

  14. Screening and Biological Effects of Marine Pyrroloiminoquinone Alkaloids: Potential Inhibitors of the HIF-1α/p300 Interaction.

    Science.gov (United States)

    Goey, Andrew K L; Chau, Cindy H; Sissung, Tristan M; Cook, Kristina M; Venzon, David J; Castro, Amaya; Ransom, Tanya R; Henrich, Curtis J; McKee, Tawnya C; McMahon, James B; Grkovic, Tanja; Cadelis, Melissa M; Copp, Brent R; Gustafson, Kirk R; Figg, William D

    2016-05-27

    Inhibition of the hypoxia-inducible factor 1α (HIF-1α) pathway by disrupting its association with the transcriptional coactivator p300 inhibits angiogenesis and tumor development. Development of HIF-1α/p300 inhibitors has been hampered by preclinical toxicity; therefore, we aimed to identify novel HIF-1α/p300 inhibitors. Using a cell-free assay designed to test compounds that block HIF-1α/p300 binding, 170 298 crude natural product extracts and prefractionated samples were screened, identifying 25 active extracts. One of these extracts, originating from the marine sponge Latrunculia sp., afforded six pyrroloiminoquinone alkaloids that were identified as positive hits (IC50 values: 1-35 μM). Luciferase assays confirmed inhibition of HIF-1α transcriptional activity by discorhabdin B (1) and its dimer (2), 3-dihydrodiscorhabdin C (3), makaluvamine F (5), discorhabdin H (8), discorhabdin L (9), and discorhabdin W (11) in HCT 116 colon cancer cells (0.1-10 μM, p cells (0.1-10 μM, p cell death) under hypoxic conditions. At the downstream HIF-1α target level, compound 8 (0.5 μM) significantly decreased VEGF secretion in LNCaP cells (p cells no activity was shown in the luciferase or cytotoxicity assays. Pyrroloiminoquinone alkaloids are a novel class of HIF-1α inhibitors, which interrupt the protein-protein interaction between HIF-1α and p300 and consequently reduce HIF-related transcription. PMID:27140429

  15. CYP3A-mediated drug-drug interaction potential and excretion of brentuximab vedotin, an antibody-drug conjugate, in patients with CD30-positive hematologic malignancies

    OpenAIRE

    Han, Tae H.; Gopal, Ajay K.; Ramchandren, Radhakrishnan; Goy, Andre; Chen, Robert; Matous, Jeffrey V.; Cooper, Maureen; Grove, Laurie E.; Alley, Stephen C.; Lynch, Carmel M.; O’Connor, Owen A.

    2013-01-01

    Brentuximab vedotin is an antibody-drug conjugate (ADC) that selectively delivers monomethyl auristatin E (MMAE) into CD30-expressing cells. This study evaluated the CYP3A-mediated drug-drug interaction potential of brentuximab vedotin and the excretion of MMAE. Two 21-day cycles of brentuximab vedotin (1.2 or 1.8 mg/kg intravenously) were administered to 56 patients with CD30-positive hematologic malignancies. Each patient also received either a sensitive CYP3A substrate (midazolam), an effe...

  16. Potential for Drug-Drug Interactions between Antiretrovirals and HCV Direct Acting Antivirals in a Large Cohort of HIV/HCV Coinfected Patients

    OpenAIRE

    Poizot-Martin, Isabelle; Naqvi, Alissa; Obry-Roguet, Véronique; Valantin, Marc-Antoine; Cuzin, Lise; Billaud, Eric; Cheret, Antoine; Rey, David; Jacomet, Christine; Duvivier, Claudine; Pugliese, Pascal; Pradat, Pierre; Cotte, Laurent

    2015-01-01

    Objectives Development of direct acting antivirals (DAA) offers new benefits for patients with chronic hepatitis C. The combination of these drugs with antiretroviral treatment (cART) is a real challenge in HIV/HCV coinfected patients. The aim of this study was to describe potential drug-drug interactions between DAAs and antiretroviral drugs in a cohort of HIV/HCV coinfected patients. Methods Cross-sectional study of all HIV/HCV coinfected patients attending at least one visit in 2012 in the...

  17. Interaction potentials and energy transfer cross sections for collisions of metastable helium and neon I: He (23S) + Ne

    International Nuclear Information System (INIS)

    Differential cross sections have been measured for He(23S) + Ne at kinetic energies between 28 and 370 meV. For energies above 90 meV the elastic cross sections show Stueckelberg oscillations from curve crossings, which lead to the energy exchange process: He(23S) + Ne → He(11S) + Ne(2p54s,3d,4p). Differential cross sections for this inelastic process could be measured above 200 meV. A fit to the data gives the potentials for He(23S) + Ne and, less accurately, for He + Nesup(*). These results offer a simple explanation, why the exothermic pumping process of the infrared lines of the HeNe laser has a threshold of about 80 meV and a small cross section. (orig.)

  18. A stable and adaptive semi-Lagrangian potential model for unsteady and nonlinear ship-wave interactions

    CERN Document Server

    Mola, Andrea; DeSimone, Antonio

    2012-01-01

    We present an innovative numerical discretization of the equations of inviscid potential flow for the simulation of three dimensional unsteady and nonlinear water waves generated by a ship hull advancing in water. The equations of motion are written in a semi-Lagrangian framework, and the resulting integro-differential equations are discretized in space via an adaptive iso-parametric collocation Boundary Element Method, and in time via adaptive implicit Backward Differentiation Formulas (BDF) with variable step and variable order. When the velocity of the advancing ship hull is non-negligible, the semi-Lagrangian formulation (also known as Arbitrary Lagrangian Eulerian formulation, or ALE) of the free surface equations contains dominant transport terms which are stabilized with a Streamwise Upwind Petrov-Galerkin (SUPG) method. The SUPG stabilization allows automatic and robust adaptation of the spatial discretization with unstructured quadrilateral grids. Preliminary results are presented where we compare ou...

  19. Modeling of human prokineticin receptors: interactions with novel small-molecule binders and potential off-target drugs.

    Directory of Open Access Journals (Sweden)

    Anat Levit

    Full Text Available BACKGROUND AND MOTIVATION: The Prokineticin receptor (PKR 1 and 2 subtypes are novel members of family A GPCRs, which exhibit an unusually high degree of sequence similarity. Prokineticins (PKs, their cognate ligands, are small secreted proteins of ∼80 amino acids; however, non-peptidic low-molecular weight antagonists have also been identified. PKs and their receptors play important roles under various physiological conditions such as maintaining circadian rhythm and pain perception, as well as regulating angiogenesis and modulating immunity. Identifying binding sites for known antagonists and for additional potential binders will facilitate studying and regulating these novel receptors. Blocking PKRs may serve as a therapeutic tool for various diseases, including acute pain, inflammation and cancer. METHODS AND RESULTS: Ligand-based pharmacophore models were derived from known antagonists, and virtual screening performed on the DrugBank dataset identified potential human PKR (hPKR ligands with novel scaffolds. Interestingly, these included several HIV protease inhibitors for which endothelial cell dysfunction is a documented side effect. Our results suggest that the side effects might be due to inhibition of the PKR signaling pathway. Docking of known binders to a 3D homology model of hPKR1 is in agreement with the well-established canonical TM-bundle binding site of family A GPCRs. Furthermore, the docking results highlight residues that may form specific contacts with the ligands. These contacts provide structural explanation for the importance of several chemical features that were obtained from the structure-activity analysis of known binders. With the exception of a single loop residue that might be perused in the future for obtaining subtype-specific regulation, the results suggest an identical TM-bundle binding site for hPKR1 and hPKR2. In addition, analysis of the intracellular regions highlights variable regions that may provide

  20. Granule and Symmetrical Double Potential Barrier Interaction Tunneling Phenomenon%粒子与对称双势垒相互作用的隧穿现象

    Institute of Scientific and Technical Information of China (English)

    任青; 杨文平

    2009-01-01

    在非相对论条件下,计算了粒子与对称双势垒相互作用的反射系数和透射系数,并与一维对称方势垒的相位和隧穿时间相比较,通过计算和比较,对隧穿现象有了更深地理解.%This article, under the non-theory of relativity condition, has calculated the granule and the symmetrical double potential barrier interaction reflection coefficient and the transmission coefficient, and compares with the univariate symmetrical square potential harrier's phase and tunneling time, through the computation and the comparison, had a deeper understanding to the tunneling phenomenon.