WorldWideScience

Sample records for condensed matter volume

  1. Condensed Matter Theories - Volume 22

    Science.gov (United States)

    Reinholz, Heidi; Röpke, Gerd; de Llano, Manuel

    2007-09-01

    pke -- pt. H. Biophysics. Condensed matter physics of biomolecule systems in a differential geometric framework / H. Bohr, J.I. Ipsen and S. Markvorsen. The brain's view of the natural world in motion: computing structure from function using directional Fourier transformations / B.K. Dellen, J.W. Clark and R. Wessel -- pt. I. Quantum information. Control and error prevention in condensed matter quantum computing devices / M.S. Byrd and L.A. Wu. Maxent approaches to qubits / C.M. Sarris, A.N. Proto and F B. Malik -- pt. J. New formalisms. Thermal coherent states, a broader class of mixed coherent states, and generalized thermo-field dynamics / R.F. Bishop and A. Vourdas. Ergodic condition and magnetic models / M. Howard Lee. From thermodynamics to Maxent / A. Plastino and E. M.F. Curado. Recent progress in the density-matrix renormalization group / U. Schollwöck.

  2. Condensed matter physics

    CERN Document Server

    Isihara, A

    2007-01-01

    More than a graduate text and advanced research guide on condensed matter physics, this volume is useful to plasma physicists and polymer chemists, and their students. It emphasizes applications of statistical mechanics to a variety of systems in condensed matter physics rather than theoretical derivations of the principles of statistical mechanics and techniques. Isihara addresses a dozen different subjects in separate chapters, each designed to be directly accessible and used independently of previous chapters. Topics include simple liquids, electron systems and correlations, two-dimensional

  3. Paul Scherrer Institute Scientific Report 1998. Volume III: Condensed Matter Research with Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, Juerg; Castellazzi, Denise; Bucher-Zimmermann, Claudia [eds.

    1999-09-01

    As a consequence of a major reorganisation at PSI, a new department has been formed with the groups focussing on research of condensed matter. The activities of the Laboratory of Neutron Scattering (jointly operated with the Swiss Federal Institute of Technology, ETH Zuerich), the Condensed Matter Theory Group, and the Group for Low Temperature Facilities, are described in this annual report figs., tabs., refs.

  4. Physics of condensed matter

    CERN Document Server

    Misra, Prasanta K

    2012-01-01

    Physics of Condensed Matter is designed for a two-semester graduate course on condensed matter physics for students in physics and materials science. While the book offers fundamental ideas and topic areas of condensed matter physics, it also includes many recent topics of interest on which graduate students may choose to do further research. The text can also be used as a one-semester course for advanced undergraduate majors in physics, materials science, solid state chemistry, and electrical engineering, because it offers a breadth of topics applicable to these majors. The book be

  5. Condensed Matter Physics

    Science.gov (United States)

    Marder, Michael P.

    2000-01-01

    A modern, unified treatment of condensed matter physics This new work presents for the first time in decades a sweeping review of the whole field of condensed matter physics. It consolidates new and classic topics from disparate sources, teaching "not only about the effective masses of electrons in semiconductor crystals and band theory, but also about quasicrystals, dynamics of phase separation, why rubber is more floppy than steel, electron interference in nanometer-sized channels, and the quantum Hall effect." Six major areas are covered---atomic structure, electronic structure, mechanical properties, electron transport, optical properties, and magnetism. But rather than defining the field in terms of particular materials, the author focuses on the way condensed matter physicists approach physical problems, combining phenomenology and microscopic arguments with information from experiments. For graduate students and professionals, researchers and engineers, applied mathematicians and materials scientists, Condensed Matter Physics provides: * An exciting collection of new topics from the past two decades. * A thorough treatment of classic topics, including band theory, transport theory, and semiconductor physics. * Over 300 figures, incorporating many images from experiments. * Frequent comparison of theory and experiment, both when they agree and when problems are still unsolved. * More than 50 tables of data and a detailed index. * Ample end-of-chapter problems, including computational exercises. * Over 1000 references, both recent and historically significant.

  6. Soft condensed matter

    NARCIS (Netherlands)

    Frenkel, D.

    2002-01-01

    These lectures illustrate some of the concepts of soft-condensed matter physics, taking examples from colloid physics. Many of the theoretical concepts will be illustrated with the results of computer simulations. After a brief introduction describing interactions between colloids, the paper focuses

  7. Asymmetric condensed dark matter

    Science.gov (United States)

    Aguirre, Anthony; Diez-Tejedor, Alberto

    2016-04-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.

  8. Asymmetric condensed dark matter

    CERN Document Server

    Aguirre, Anthony

    2015-01-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate can be very light, $10^{-22}\\,{\\rm eV} \\lesssim m \\lesssim 10^2\\,{\\rm eV}$; the lower limit arises from constraints on small-scale structure formation, while the upper bound ensures that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of deco...

  9. Condensed matter physics

    CERN Document Server

    Marder, Michael P

    2010-01-01

    This Second Edition presents an updated review of the whole field of condensed matter physics. It consolidates new and classic topics from disparate sources, teaching not only about the effective masses of electrons in semiconductor crystals and band theory, but also about quasicrystals, dynamics of phase separation, why rubber is more floppy than steel, granular materials, quantum dots, Berry phases, the quantum Hall effect, and Luttinger liquids.

  10. Paul Scherrer Institute Scientific Report 2000. Volume III: Condensed Matter Research with Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, Juerg; Castellazzi, Denise; Shea-Braun, Margit [eds.

    2001-07-01

    This year started with a highlight for the Swiss Spallation Neutron Source SINQ located at PSI: The thermal neutron flux exceeded the value of 10{sup 14} n cm{sup -2} s{sup 1} which may be considered as the critical limit for an advanced medium-flux neutron source. The excellent performance attracted a large number of external users to participate at the neutron scattering programme. The major part of this annual report gives an overview on the scientific activities of the staff members of the Laboratory of Neutron Scattering (jointly operated with the Swiss Federal Institute of Technology, ETH Zurich). The research topics covered diverse areas such as strongly correlated electron systems including high-temperature superconductors, low-dimensional and quantum magnetism, materials research on soft and hard matter including multilayers. Progress in 2000 in these topical areas as well as the activities of the Condensed Matter Theory Group, and the Group for Low Temperature Facilities, is described in this report. A list of scientific publications in 2000 is also provided.

  11. Paul Scherrer Institute Scientific Report 1999. Volume III: Condensed Matter Research with Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, Juerg; Castellazzi, Denise; Shea-Braun, Margit [eds.

    2000-07-01

    This year was a period of consolidation of the operation at the spallation source of PSI and its scientific exploitation at an increasing number of instruments. The major part of this annual report gives an overview of the research activities in the Laboratory of Neutron Scattering (jointly operated with the Swiss Federal Institute of Technology, ETH Zurich) of our department, mainly emphasizing highly correlated electron systems and the investigation of magnetism. The activities on multilayers and surfaces, a basic research object by itself, is however also to a large extent motivated by the development of optical components for neutron- and X-ray instrumentation. While most of the solid-state work has been done with neutrons, some contributions deal with other probes, like muons and synchrotron light, exploiting the unique possibilities at PSI, to take advantage of the complementary nature of the different probes. Progress in 1999 in these topical areas as well as the activities of the Condensed Matter Theory Group, and the Group for Low Temperature Facilities, is described in this report. A list of scientific publications in 1999 is also provided.

  12. Condensed Matter Nuclear Science

    Science.gov (United States)

    Biberian, Jean-Paul

    2006-02-01

    1. General. A tribute to gene Mallove - the "Genie" reactor / K. Wallace and R. Stringham. An update of LENR for ICCF-11 (short course, 10/31/04) / E. Storms. New physical effects in metal deuterides / P. L. Hagelstein ... [et al.]. Reproducibility, controllability, and optimization of LENR experiments / D. J. Nagel -- 2. Experiments. Electrochemistry. Evidence of electromagnetic radiation from Ni-H systems / S. Focardi ... [et al.]. Superwave reality / I. Dardik. Excess heat in electrolysis experiments at energetics technologies / I. Dardik ... [et al.]. "Excess heat" during electrolysis in platinum/K[symbol]CO[symbol]/nickel light water system / J. Tian ... [et al.]. Innovative procedure for the, in situ, measurement of the resistive thermal coefficient of H(D)/Pd during electrolysis; cross-comparison of new elements detected in the Th-Hg-Pd-D(H) electrolytic cells / F. Celani ... [et al.]. Emergence of a high-temperature superconductivity in hydrogen cycled Pd compounds as an evidence for superstoihiometric H/D sites / A. Lipson ... [et al.]. Plasma electrolysis. Calorimetry of energy-efficient glow discharge - apparatus design and calibration / T. B. Benson and T. O. Passell. Generation of heat and products during plasma electrolysis / T. Mizuno ... [et al.]. Glow discharge. Excess heat production in Pd/D during periodic pulse discharge current in various conditions / A. B. Karabut. Beam experiments. Accelerator experiments and theoretical models for the electron screening effect in metallic environments / A. Huke, K. Czerski, and P. Heide. Evidence for a target-material dependence of the neutron-proton branching ratio in d+d reactions for deuteron energies below 20keV / A. Huke ... [et al.]. Experiments on condensed matter nuclear events in Kobe University / T. Minari ... [et al.]. Electron screening constraints for the cold fusion / K. Czerski, P. Heide, and A. Huke. Cavitation. Low mass 1.6 MHz sonofusion reactor / R. Stringham. Particle detection. Research

  13. Nuclear fusion inside condense matters

    Institute of Scientific and Technical Information of China (English)

    HE Jing-tang

    2007-01-01

    This article describes in detail the nuclear fusion inside condense matters--the Fleischmann-Pons effect, the reproducibility of cold fusions, self-consistentcy of cold fusions and the possible applications.

  14. Proceedings of the 1984 workshop on high-energy excitations in condensed matter. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Silver, R.N. (comp.)

    1984-12-01

    This volume covers electronic excitations, momentum distributions, high energy photons, and a wrap-up session. Abstracts of individual items from the conference were prepared separately for the data base. (GHT)

  15. Condensed Matter Physics - Biology Resonance

    Science.gov (United States)

    Baskaran, G.

    The field of condensed matter physics had its genesis this century and it has had a remarkable evolution. A closer look at its growth reveals a hidden aim in the collective consciousness of the field - a part of the development this century is a kind of warm up exercise to understand the nature of living condensed matter, namely the field of biology, by a growing new breed of scientists in the coming century. Through some examples the vitality of this interaction will be pointed out.

  16. Fundamentals of condensed matter physics

    CERN Document Server

    Cohen, Marvin L

    2016-01-01

    Based on an established course and covering the fundamentals, central areas, and contemporary topics of this diverse field, Fundamentals of Condensed Matter Physics is a much-needed textbook for graduate students. The book begins with an introduction to the modern conceptual models of a solid from the points of view of interacting atoms and elementary excitations. It then provides students with a thorough grounding in electronic structure as a starting point to understand many properties of condensed matter systems - electronic, structural, vibrational, thermal, optical, transport, magnetic and superconductivity - and methods to calculate them. Taking readers through the concepts and techniques, the text gives both theoretically and experimentally inclined students the knowledge needed for research and teaching careers in this field. It features 200 illustrations, 40 worked examples and 150 homework problems for students to test their understanding. Solutions to the problems for instructors are available at w...

  17. Advances in condensed matter optics

    CERN Document Server

    Chen, Liangyao; Jiang, Xunya; Jin, Kuijuan; Liu, Hui; Zhao, Haibin

    2015-01-01

    This book describes some of the more recent progresses and developmentsin the study of condensed matter optics in both theoretic and experimental fields.It will help readers, especially graduate students and scientists who are studying and working in the nano-photonic field, to understand more deeply the characteristics of light waves propagated in nano-structure-based materials with potential applications in the future.

  18. Condensed matter analogues of cosmology

    Science.gov (United States)

    Kibble, Tom; Srivastava, Ajit

    2013-10-01

    It is always exciting when developments in one branch of physics turn out to have relevance in a quite different branch. It would be hard to find two branches farther apart in terms of energy scales than early-universe cosmology and low-temperature condensed matter physics. Nevertheless ideas about the formation of topological defects during rapid phase transitions that originated in the context of the very early universe have proved remarkably fruitful when applied to a variety of condensed matter systems. The mathematical frameworks for describing these systems can be very similar. This interconnection has led to a deeper understanding of the phenomena in condensed matter systems utilizing ideas from cosmology. At the same time, one can view these condensed matter analogues as providing, at least in a limited sense, experimental access to the phenomena of the early universe for which no direct probe is possible. As this special issue well illustrates, this remains a dynamic and exciting field. The basic idea is that when a system goes through a rapid symmetry-breaking phase transition from a symmetric phase into one with spontaneously broken symmetry, the order parameter may make different choices in different regions, creating domains that when they meet can trap defects. The scale of those domains, and hence the density of defects, is constrained by the rate at which the system goes through the transition and the speed with which order parameter information propagates. This is what has come to be known as the Kibble-Zurek mechanism. The resultant scaling laws have now been tested in a considerable variety of different systems. The earliest experiments illustrating the analogy between cosmology and condensed matter were in liquid crystals, in particular on the isotropic-to-nematic transition, primarily because it is very easy to induce the phase transition (typically at room temperature) and to image precisely what is going on. This field remains one of the

  19. Lorentz violation and Condensed Matter Physics

    CERN Document Server

    Ajaib, Muhammad Adeel

    2014-01-01

    We present heuristic arguments that hint to a possible connection of Lorentz violation with observed phenomenon in condensed matter physics. Various references from condensed matter literature are cited where operators in the Standard Model Extension (SME) appear to be enhanced. Based on this we propose that, in the non-relativistic limit, Lorentz violation in the context of the SME exhibits itself in various condensed matter systems.

  20. Condensed matter applied atomic collision physics, v.4

    CERN Document Server

    Datz, Sheldon

    1983-01-01

    Applied Atomic Collision Physics, Volume 4: Condensed Matter deals with the fundamental knowledge of collision processes in condensed media.The book focuses on the range of applications of atomic collisions in condensed matter, extending from effects on biological systems to the characterization and modification of solids. This volume begins with the description of some aspects of the physics involved in the production of ion beams. The radiation effects in biological and chemical systems, ion scattering and atomic diffraction, x-ray fluorescence analysis, and photoelectron and Auger spectrosc

  1. Dissipative phenomena in condensed matter some applications

    CERN Document Server

    Dattagupta, Sushanta

    2004-01-01

    From the field of nonequilibrium statistical physics, this graduate- and research-level volume treats the modeling and characterization of dissipative phenomena. A variety of examples from diverse disciplines like condensed matter physics, materials science, metallurgy, chemical physics etc. are discussed. Dattagupta employs the broad framework of stochastic processes and master equation techniques to obtain models for a wide range of experimentally relevant phenomena such as classical and quantum Brownian motion, spin dynamics, kinetics of phase ordering, relaxation in glasses, dissipative tunneling. It provides a pedagogical exposition of current research material and will be useful to experimentalists, computational physicists and theorists.

  2. Muonic Chemistry in Condensed Matter

    CERN Multimedia

    2002-01-01

    When polarized muons (@m|+) stop in condensed matter, muonic atoms are formed in the final part of their range, and direct measurements of the @m|+-spin polarization are possible via the asymmetric decay into positrons. The hyperfine interaction determines the characteristic precession frequencies of the @m|+ spin in muonium, @w(Mu). Such frequencies can be altered by the interactions of the muonium's electron spin with the surrounding medium. The measurement of @w(Mu) in a condensed system is known often to provide unique information regarding the system. \\\\ \\\\ In particular, the use of muonium atoms as a light isotope of the simple reactive radical H|0 allows the investigation of fast reactions of radicals over a typical time scale 10|-|9~@$<$~t~@$<$~10|-|5~sec, which is determined by the instrumental resolution at one end and by the @m|+ lifetime at the other. \\\\ \\\\ In biological macromolecules transient radicals, such as the constituents of DNA itself, exist on a time scale of sub-microseconds, acco...

  3. Holographic Duality in Condensed Matter Physics

    Science.gov (United States)

    Zaanen, Jan; Liu, Yan; Sun, Ya-Wen; Schalm, Koenraad

    2015-11-01

    Preface; 1. Introduction; 2. Condensed matter: the charted territory; 3. Condensed matter: the challenges; 4. Large N field theories for holography and condensed matter; 5. The AdS/CFT correspondence as computational device: the dictionary; 6. Finite temperature magic: black holes and holographic thermodynamics; 7. Holographic hydrodynamics; 8. Finite density: the Reissner-Nordström black hole and strange metals; 9. Holographic photoemission and the RN metal: the fermions as probes; 10. Holographic superconductivity; 11. Holographic Fermi liquids; 12. Breaking translational invariance; 13. AdS/CMT from the top down; 14. Outlook: holography and quantum matter; References; Index.

  4. Statistical physics and condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This document is divided into 4 sections: 1) General aspects of statistical physics. The themes include: possible geometrical structures of thermodynamics, the thermodynamical foundation of quantum measurement, transport phenomena (kinetic theory, hydrodynamics and turbulence) and out of equilibrium systems (stochastic dynamics and turbulence). The techniques involved here are typical of applied analysis: stability criteria, mode decomposition, shocks and stochastic equations. 2) Disordered, glassy and granular systems: statics and dynamics. The complexity of the systems can be studied through the structure of their phase space. The geometry of this phase space is studied in several works: the overlap distribution can now be computed with a very high precision; the boundary energy between low lying states does not behave like in ordinary systems; and the Edward's hypothesis of equi-probability of low lying metastable states is invalidated. The phenomenon of aging, characteristic of glassy dynamics, is studied in several models. Dynamics of biological systems or of fracture is shown to bear some resemblance with that of disordered systems. 3) Quantum systems. The themes include: mesoscopic superconductors, supersymmetric approach to strongly correlated electrons, quantum criticality and heavy fermion compounds, optical sum rule violation in the cuprates, heat capacity of lattice spin models from high-temperature series expansion, Lieb-Schultz-Mattis theorem in dimension larger than one, quantum Hall effect, Bose-Einstein condensation and multiple-spin exchange model on the triangular lattice. 4) Soft condensed matter and biological systems. Path integral representations are invaluable to describe polymers, proteins and self-avoiding membranes. Using these methods, problems as diverse as the titration of a weak poly-acid by a strong base, the denaturation transition of DNA or bridge-hopping in conducting polymers have been addressed. The problems of RNA folding

  5. Stellar matter with pseudoscalar condensates

    Energy Technology Data Exchange (ETDEWEB)

    Andrianov, A.A. [Saint-Petersburg State University, St. Petersburg (Russian Federation); Universitat de Barcelona, Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos (ICCUB), Barcelona, Catalonia (Spain); Andrianov, V.A.; Kolevatov, S.S. [Saint-Petersburg State University, St. Petersburg (Russian Federation); Espriu, D. [Universitat de Barcelona, Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos (ICCUB), Barcelona, Catalonia (Spain)

    2016-03-15

    In this work we consider how the appearance of gradients of pseudoscalar condensates in dense systems may possibly influence the transport properties of photons in such a medium as well as other thermodynamic characteristics. We adopt the hypothesis that in regions where the pseudoscalar density gradient is large the properties of photons and fermions are governed by the usual lagrangian extended with a Chern-Simons interaction for photons and a constant axial field for fermions. We find that these new pieces in the lagrangian produce non-trivial reflection coefficients both for photons and fermions when entering or leaving a region where the pseudoscalar has a non-zero gradient. A varying pseudoscalar density may also lead to instability of some fermion and boson modes and modify some properties of the Fermi sea. We speculate that some of these modifications could influence the cooling rate of stellar matter (for instance in compact stars) and have other observable consequences. While quantitative results may depend on the precise astrophysical details most of the consequences are quite universal and consideration should be given to this possibility. (orig.)

  6. Primes, Geometry and Condensed Matter

    Directory of Open Access Journals (Sweden)

    Al Rabeh R. H.

    2009-07-01

    Full Text Available Fascination with primes dates back to the Greeks and before. Primes are named by some "the elementary particles of arithmetic" as every nonprime integer is made of a unique set of primes. In this article we point to new connections between primes, geometry and physics which show that primes could be called "the elementary particles of physics" too. This study considers the problem of closely packing similar circles/spheres in 2D/3D space. This is in effect a discretization process of space and the allowable number in a pack is found to lead to some unexpected cases of prime configurations which is independent of the size of the constituents. We next suggest that a non-prime can be considered geometrically as a symmetric collection that is separable (factorable into similar parts- six is two threes or three twos for example. A collection that has no such symmetry is a prime. As a result, a physical prime aggregate is more difficult to split symmetrically resulting in an inherent stability. This "number/physical" stability idea applies to bigger collections made from smaller (prime units leading to larger stable prime structures in a limitless scaling up process. The distribution of primes among numbers can be understood better using the packing ideas described here and we further suggest that differing numbers (and values of distinct prime factors making a nonprime collection is an important factor in determining the probability and method of possible and subsequent disintegration. Disintegration is bound by energy conservation and is closely related to symmetry by Noether theorems. Thinking of condensed matter as the packing of identical elements, we examine plots of the masses of chemical elements of the periodic table, and also those of the elementary particles of physics, and show that prime packing rules seem to play a role in the make up of matter. The plots show convincingly that the growth of prime numbers and that of the masses of

  7. Primes, Geometry and Condensed Matter

    Directory of Open Access Journals (Sweden)

    Al Rabeh R. H.

    2009-07-01

    Full Text Available Fascination with primes dates back to the Greeks and before. Primes are named by some “the elementary particles of arithmetic” as every nonprime integer is made of a unique set of primes. In this article we point to new connections between primes, geometry and physics which show that primes could be called “the elementary particles of physics” too. This study considers the problem of closely packing similar circles / spheres in 2D / 3D space. This is in effect a discretization process of space and the allowable num- ber in a pack is found to lead to some unexpected cases of prime configurations which is independent of the size of the constituents. We next suggest that a non-prime can be considered geometrically as a symmetric collection that is separable (factorable into similar parts- six is two threes or three twos for example. A collection that has no such symmetry is a prime. As a result, a physical prime aggregate is more difficult to split symmetrically resulting in an inherent stability. This “number / physical” stability idea applies to bigger collections made from smaller (prime units leading to larger sta- ble prime structures in a limitless scaling up process. The distribution of primes among numbers can be understood better using the packing ideas described here and we further suggest that differing numbers (and values of distinct prime factors making a nonprime collection is an important factor in determining the probability and method of possible and subsequent disintegration. Disintegration is bound by energy conservation and is closely related to symmetry by Noether theorems. Thinking of condensed matter as the packing of identical elements, we examine plots of the masses of chemical elements of the periodic table, and also those of the elementary particles of physics, and show that prime packing rules seem to play a role in the make up of matter. The plots show con- vincingly that the growth of prime numbers and that

  8. Arnold Sommerfeld and Condensed Matter Physics

    Science.gov (United States)

    Joas, Christian; Eckert, Michael

    2017-03-01

    Arnold Sommerfeld (1868-1951), one of the founders of modern theoretical physics and a pioneer of quantum theory, was no condensed matter physicist. He nevertheless played a crucial role for the history of the field. Besides his important contributions to the study of condensed matter systems, among which his seminal electron gas theory of metallic conduction probably stands out, he influenced the field through his very approach to science, through his way of “doing” physics. Sommerfeld's specific style permeated not only his research but also his teaching and his promoting of physics. This has had a lasting influence on the practices of physicists to this day, and not only, but importantly, on those of condensed matter physicists. This article aims to provide a concise account of Sommerfeld's influence on the study of condensed matter systems, with regard to both his research and his practice.

  9. Essay: fifty years of condensed matter physics.

    Science.gov (United States)

    Cohen, Marvin L

    2008-12-19

    Since the birth of Physical Review Letters fifty years ago, condensed matter physics has seen considerable growth, and both the journal and the field have flourished during this period. In this essay, I begin with some general comments about condensed matter physics and then give some personal views on the conceptual development of the field and list some highlights. The focus is mostly on theoretical developments.

  10. Excitation energy transfer processes in condensed matter theory and applications

    CERN Document Server

    Singh, Jai

    1994-01-01

    Applying a unified quantum approach, contributors offer fresh insights into the theoretical developments in the excitation energy transfer processes in condensed matter This comprehensive volume examines Frenkel and Wannier excitonic processes; rates of excitonic processes; theory of laser sputter and polymer ablation; and polarons, excitonic polarons and self-trapping

  11. Spatially inhomogeneous condensate in asymmetric nuclear matter

    NARCIS (Netherlands)

    Sedrakian, A

    2001-01-01

    We study the isospin singlet pairing in asymmetric nuclear matter with nonzero total momentum of the condensate Cooper pairs. The quasiparticle excitation spectrum is fourfold split compared to the usual BCS spectrum of the symmetric, homogeneous matter. A twofold splitting of the spectrum into sepa

  12. The NSF Condensed Matter Physics Program

    Science.gov (United States)

    Sokol, Paul

    The Condensed Matter Physics (CMP) program in the NSF Division of Materials Research (DMR) supports experimental, as well as combined experiment and theory projects investigating the fundamental physics behind phenomena exhibited by condensed matter systems. CMP is the largest Individual Investigator Award program in DMR and supports a broad portfolio of research spanning both hard and soft condensed matter. Representative research areas include: 1) phenomena at the nano- to macro-scale including: transport, magnetic, and optical phenomena; classical and quantum phase transitions; localization; electronic, magnetic, and lattice structure or excitations; superconductivity; topological insulators; and nonlinear dynamics. 2) low-temperature physics: quantum fluids and solids; 1D & 2D electron systems. 3) soft condensed matter: partially ordered fluids, granular and colloid physics, liquid crystals, and 4) understanding the fundamental physics of new states of matter as well as the physical behavior of condensed matter under extreme conditions e.g., low temperatures, high pressures, and high magnetic fields. In this talk I will review the current CMP portfolio and discuss future funding trends for the program. I will also describe recent activities in the program aimed at addressing the challenges facing current and future principal investigators.

  13. Field theories of condensed matter physics

    CERN Document Server

    Fradkin, Eduardo

    2013-01-01

    Presenting the physics of the most challenging problems in condensed matter using the conceptual framework of quantum field theory, this book is of great interest to physicists in condensed matter and high energy and string theorists, as well as mathematicians. Revised and updated, this second edition features new chapters on the renormalization group, the Luttinger liquid, gauge theory, topological fluids, topological insulators and quantum entanglement. The book begins with the basic concepts and tools, developing them gradually to bring readers to the issues currently faced at the frontiers of research, such as topological phases of matter, quantum and classical critical phenomena, quantum Hall effects and superconductors. Other topics covered include one-dimensional strongly correlated systems, quantum ordered and disordered phases, topological structures in condensed matter and in field theory and fractional statistics.

  14. Computer Simulation Studies in Condensed-Matter Physics XVII

    Science.gov (United States)

    Landau, D. P.; Lewis, S. P.; Schüttler, H.-B.

    This status report features the most recent developments in the field, spanning a wide range of topical areas in the computer simulation of condensed matter/materials physics. Both established and new topics are included, ranging from the statistical mechanics of classical magnetic spin models to electronic structure calculations, quantum simulations, and simulations of soft condensed matter. The book presents new physical results as well as novel methods of simulation and data analysis. Highlights of this volume include various aspects of non-equilibrium statistical mechanics, studies of properties of real materials using both classical model simulations and electronic structure calculations, and the use of computer simulations in teaching.

  15. Fundamentals of neutron scattering by condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    Scherm, R. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1996-12-31

    The purpose of this introductory lecture is to give the basic facts about the scattering of neutrons by condensed matter. This lecture is restricted to nuclear scattering, whereas magnetic scattering will be dealt with in an other course. Most of the formalism, however, can also be easily extended to magnetic scattering. (author) 17 figs., 3 tabs., 10 refs.

  16. Springer Handbook of Condensed Matter and Materials Data

    CERN Document Server

    Martienssen, Werner

    2005-01-01

    Condensed Matter and Materials Science are two of the most active fields of applied physics, with a stream of discoveries in areas from superconductivity and magnetism to the optical, electronic and mechanical properties of materials. While a huge amount of data has been compiled and spread over numerous reference works, no single volume compiles the most used information. Springer Handbook of Condensed Matter and Materials Data provides a concise compilation of data and functional relationships from the fields of solid-state physics and materials in this 1200-page volume. The data, encapsulated in over 750 tables and 1025 illustrations, have been selected and extracted primarily from the extensive high-quality data collection Landolt-Börnstein and also from other systematic data sources and recent publications of physical and technical property data. Many chapters are authored by Landolt-Börnstein editors, including the editors of this Springer Handbook. Key Topics Fundamental Constants The International S...

  17. 10th International Workshop on Condensed Matter Theories

    CERN Document Server

    Kalia, Rajiv; Bishop, R

    1987-01-01

    The second volume of Condensed Matter Theories contains the proceedings of the 10th International Workshop held at Argonne National Laboratory, Argonne, IL, U.S.A. during the week of July 21, 1986. The workshop was attended by high-energy, nuclear and condensed-matter physicists as well as materials scientists. This diverse blend of participants was in keeping with the flavor of the previous workshops. This annual series of international workshops was"started in 1977 in Sao Paulo, Brazil. Subsequent'workshops were held in Trieste (Italy), Buenos Aires (Argentina), Caracas (Venezuela), Altenberg (West Germany), Granada (Spain), and San Francisco (U.S.A.). What began as a meeting of the physicists from the Western Hemisphere has expanded in the last three years into an international conference of scientists with diverse interests and backgrounds. This diversity has promoted a healthy exchange of ideas from different branches of physics and also fruitful interactions among the participants. The present volume is...

  18. Electrostrong Nuclear Disintegration in Condensed Matter

    CERN Document Server

    Swain, J; Widom, A

    2013-01-01

    Photo- and electro-disintegration techniques have been traditionally used for studying giant dipole resonances and through them nuclear structure. Over a long period, detailed theoretical models for the giant dipole resonances were proposed and low energy electron accelerators were constructed to perform experiments to test their veracity. More recently, through laser and "smart" material devices, electrons have been accelerated in condensed matter systems up to several tens of MeV. We discuss here the possibility of inducing electro-disintegration of nuclei through such devices. It involves a synthesis of electromagnetic and strong forces in condensed matter via giant dipole resonances to give an effective "electro-strong interaction" - a large coupling of electromagnetic and strong interactions in the tens of MeV range.

  19. Exact Mappings in Condensed Matter Physics

    OpenAIRE

    Lee, Ching Hua

    2016-01-01

    Condensed matter systems are complex yet simple. Amidst their complexity, one often find order specified by not more than a few parameters. Key to such a reductionistic description is an appropriate choice of basis, two of which I shall describe in this thesis. The first, an exact mapping known as the Wannier State Representation (WSR), provides an exact Hilbert space correspondence between two intensely-studied topological systems, the Fractional Quantum Hall (FQH) and Fractional Chern Insul...

  20. Majorana fermions in condensed-matter physics

    Science.gov (United States)

    Leggett, A. J.

    2016-06-01

    It is an honor and a pleasure to have been invited to give a talk in this conference celebrating the memory of the late Professor Abdus Salam. To my regret, I did not know Professor Salam personally, but I am very aware of his work and of his impact on my area of specialization, condensed matter physics, both intellectually through his ideas on spontaneously broken symmetry and more practically through his foundation of the ICTP. Since I assume that most of this audience are not specialized in condensed-matter physics, I thought I would talk about one topic which to some extent bridges this field and the particle-physics interests of Salam, namely Majorana fermions (M.F.s). However, as we shall see, the parallels which are often drawn in the current literature may be a bit too simplistic. I will devote most of this talk to a stripped-down exposition of the current orthodoxy concerning M.F.s. in condensed-matter physics and their possible applications to topological quantum computing (TQC), and then at the end briefly indicate why I believe this orthodoxy may be seriously misleading.

  1. Condensation of galactic cold dark matter

    Science.gov (United States)

    Visinelli, Luca

    2016-07-01

    We consider the steady-state regime describing the density profile of a dark matter halo, if dark matter is treated as a Bose-Einstein condensate. We first solve the fluid equation for ``canonical'' cold dark matter, obtaining a class of density profiles which includes the Navarro-Frenk-White profile, and which diverge at the halo core. We then solve numerically the equation obtained when an additional ``quantum pressure'' term is included in the computation of the density profile. The solution to this latter case is finite at the halo core, possibly avoiding the ``cuspy halo problem'' present in some cold dark matter theories. Within the model proposed, we predict the mass of the cold dark matter particle to be of the order of Mχ c2 ≈ 10-24 eV, which is of the same order of magnitude as that predicted in ultra-light scalar cold dark matter models. Finally, we derive the differential equation describing perturbations in the density and the pressure of the dark matter fluid.

  2. Solitonic axion condensates modeling dark matter halos

    Energy Technology Data Exchange (ETDEWEB)

    Castañeda Valle, David, E-mail: casvada@gmail.com; Mielke, Eckehard W., E-mail: ekke@xanum.uam.mx

    2013-09-15

    Instead of fluid type dark matter (DM), axion-like scalar fields with a periodic self-interaction or some truncations of it are analyzed as a model of galaxy halos. It is probed if such cold Bose–Einstein type condensates could provide a viable soliton type interpretation of the DM ‘bullets’ observed by means of gravitational lensing in merging galaxy clusters. We study solitary waves for two self-interacting potentials in the relativistic Klein–Gordon equation, mainly in lower dimensions, and visualize the approximately shape-invariant collisions of two ‘lump’ type solitons. -- Highlights: •An axion model of dark matter is considered. •Collision of axion type solitons are studied in a two dimensional toy model. •Relations to dark matter collisions in galaxy clusters are proposed.

  3. Holographic duality in condensed matter physics

    CERN Document Server

    Zaanen, Jan; Sun, Ya-Wen; Schalm, Koenraad

    2015-01-01

    A pioneering treatise presenting how the new mathematical techniques of holographic duality unify seemingly unrelated fields of physics. This innovative development morphs quantum field theory, general relativity and the renormalisation group into a single computational framework and this book is the first to bring together a wide range of research in this rapidly developing field. Set within the context of condensed matter physics and using boxes highlighting the specific techniques required, it examines the holographic description of thermal properties of matter, Fermi liquids and superconductors, and hitherto unknown forms of macroscopically entangled quantum matter in terms of general relativity, stars and black holes. Showing that holographic duality can succeed where classic mathematical approaches fail, this text provides a thorough overview of this major breakthrough at the heart of modern physics. The inclusion of extensive introductory material using non-technical language and online Mathematica not...

  4. Computational Theory of Warm Condensed Matter

    Energy Technology Data Exchange (ETDEWEB)

    Barbee, T W; Surh, M P; Benedict, L X

    2001-02-25

    We have developed an improved computational theory of condensed matter in the regime where T {le} T{sub Fermi}. Previous methods of calculating the equation of state (EOS) relied on interpolation between low-temperature (solid) and high-temperature (plasma) limits, or employed severe approximations. Recent theoretical and experimental developments have highlighted the need for accurate EOS and opacity data in the intermediate temperature range and offer the opportunity to test theoretical models. We describe our results for EOS and optical properties for temperatures up to 10{sup 6} K, and describe directions for future work.

  5. Diffusion in condensed matter methods, materials, models

    CERN Document Server

    Kärger, Jörg

    2005-01-01

    Diffusion as the process of particle transport due to stochastic movement is a phenomenon of crucial relevance for a large variety of processes and materials. This comprehensive, handbook- style survey of diffusion in condensed matter gives detailed insight into diffusion as the process of particle transport due to stochastic movement. Leading experts in the field describe in 23 chapters the different aspects of diffusion, covering microscopic and macroscopic experimental techniques and exemplary results for various classes of solids, liquids and interfaces as well as several theoretical concepts and models. Students and scientists in physics, chemistry, materials science, and biology will benefit from this detailed compilation.

  6. Hidden Scale Invariance in Condensed Matter

    DEFF Research Database (Denmark)

    Dyre, J. C.

    2014-01-01

    . This means that the phase diagram becomes effectively one-dimensional with regard to several physical properties. Liquids and solids with isomorphs include most or all van der Waals bonded systems and metals, as well as weakly ionic or dipolar systems. On the other hand, systems with directional bonding...... (hydrogen bonds or covalent bonds) or strong Coulomb forces generally do not exhibit hidden scale invariance. The article reviews the theory behind this picture of condensed matter and the evidence for it coming from computer simulations and experiments...

  7. Strange Baryonic Matter and Kaon Condensation

    Science.gov (United States)

    Gazda, D.; Friedman, E.; Gal, A.; Mareš, J.

    In this contribution we address the question whether kaon condensation could occur in strongly interacting self-bound strange hadronic matter. In our comprehensive dynamical relativistic mean-field (RMF) calculations of nuclear and hypernuclear systems containing several antikaons we found saturation of bar K separation energy as well as the associated nuclear and bar K density distributions upon increasing the number of bar K mesons. The saturation pattern was found to be a universal feature of these multi-strangeness configurations. Since in all cases the bar K separation energy does not exceed 200 MeV, we conclude that bar K mesons do not provide the physical "strangeness" degrees of freedom for self-bound strange hadronic matter.

  8. Chiral magnetic effect in condensed matter systems

    Science.gov (United States)

    Li, Qiang; Kharzeev, Dmitri E.

    2016-12-01

    The chiral magnetic effect (CME) is the generation of electrical current induced by chirality imbalance in the presence of magnetic field. It is a macroscopic manifestation of the quantum chiral anomaly [S. L. Adler. Axial-vector vertex in spinor electrodynamics. Physical Review, 177, 2426 (1969), J. S. Bell and R. Jackiw. A PCAC puzzle: π 0 γγin the σ-model. Il Nuovo Cimento A, 60, 47-61 (1969)] in systems possessing charged chiral fermions. In quark-gluon plasma containing nearly massless quarks, the chirality imbalance is sourced by the topological transitions. In condensed matter systems, the chiral quasiparticles emerge in gapless semiconductors with two energy bands having pointlike degeneracies opening the path to the study of chiral anomaly [H. B. Nielsen and M. Ninomiya. The Adler-Bell-Jackiw anomaly and Weyl fermions in a crystal. Physics Letters B, 130, 389-396 (1983)]. Recently, these novel materials - so-called Dirac and Weyl semimetals have been discovered experimentally, are suitable for the investigation of the CME in condensed matter experiments. Here we report on the first experimental observation of the CME in a 3D Dirac semimetal ZrTe5 [Q. Li, D. E. Kharzeev, C. Zhang, Y. Huang, I. Pletikosić, A. V. Fedorov, R. D. Zhong, J. A. Schneeloch, G. D. Gu, and T. Valla. Chiral magnetic effect in ZrTe5. Nature Physics (2016) doi:10.1038/nphys3648].

  9. Equation of state of warm condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    Barbee, T.W., III; Young, D.A.; Rogers, F.J.

    1998-03-01

    Recent advances in computational condensed matter theory have yielded accurate calculations of properties of materials. These calculations have, for the most part, focused on the low temperature (T=0) limit. An accurate determination of the equation of state (EOS) at finite temperature also requires knowledge of the behavior of the electron and ion thermal pressure as a function of T. Current approaches often interpolate between calculated T=0 results and approximations valid in the high T limit. Plasma physics-based approaches are accurate in the high temperature limit, but lose accuracy below T{approximately}T{sub Fermi}. We seek to ``connect up`` these two regimes by using ab initio finite temperature methods (including linear-response[1] based phonon calculations) to derive an equation of state of condensed matter for T{<=}T{sub Fermi}. We will present theoretical results for the principal Hugoniot of shocked materials, including carbon and aluminum, up to pressures P>100 GPa and temperatures T>10{sup 4}K, and compare our results with available experimental data.

  10. Gravity, holography and applications to condensed matter

    CERN Document Server

    Baggioli, Matteo

    2016-01-01

    Momentum relaxation is an ever-present and unavoidable ingredient of any realistic condensed matter system. In real-world materials the presence of a lattice, impurities or disorder forces momentum to dissipate and leads to relevant physical effects such as the finiteness of the DC transport properties, i.e. conductivities. The main purpose of this thesis is the introduction of momentum dissipation and its consequent effects into the framework of AdS/CMT, namely the applications of the gauge-gravity duality to condensed matter. A convenient and effective way of breaking the translational symmetry associated to such a conservation law is provided by massive gravity (MG) bulk theories. We consider generic massive gravity models embedded into asymptotically Anti de Sitter spacetime and we analyze them using holographic techniques. We study in detail their consistency and stability. We then focus our attention on the transport properties of the CFT duals. A big part of our work is devoted to the analysis of the e...

  11. Nanophenomena at surfaces fundamentals of exotic condensed matter phenomena

    CERN Document Server

    Michailov, Michail

    2011-01-01

    This book presents the state of the art in nanoscale surface physics. It outlines contemporary trends in the field covering a wide range of topical areas: atomic structure of surfaces and interfaces, molecular films and polymer adsorption, biologically inspired nanophysics, surface design and pattern formation, and computer modeling of interfacial phenomena. Bridging 'classical' and 'nano' concepts, the present volume brings attention to the physical background of exotic condensed-matter properties. The book is devoted to Iwan Stranski and Rostislaw Kaischew, remarkable scientists, who played

  12. 11th International Workshop on Condensed Matter Theories

    CERN Document Server

    Bishop, R; Manninen, Matti; Condensed Matter Theories : Volume 3

    1988-01-01

    This book is the third volume in an approximately annual series which comprises the proceedings of the International Workshops on Condensed Matter Theories. The first of these meetings took place in 1977 in Sao Paulo, Brazil, and successive workshops have been held in Trieste, Italy (1978), Buenos Aires, Argentina (1979), Caracas, Venezuela (1980), Mexico City, Mexico (1981), St. Louis, USA (1982), Altenberg, Federal Republic of Germany (1983), Granada, Spain (1984), San Francisco, USA (1985), and Argonne, USA (1986). The present volume contains the proceedings of the Eleventh Workshop which took place in Qulu, Finland during the period 27 July - 1 August, 1987. The original motivation and the historical evolution of the series of Workshops have been amply described in the preface to the first volume in the present series. An important objective throughout has been to work against the ever-present trend for physics to fragment into increasingly narrow fields of specialisation, between which communication is d...

  13. PAC Spectrometer for Condensed Matter Investigation

    CERN Document Server

    Brudanin, V B; Kochetov, O I; Korolev, N A; Milanov, M; Ostrovsky, I V; Pavlov, V N; Salamatin, A V; Timkin, V V; Velichkov, A I; Fomicheva, L N; Tsvyaschenko, A V; Akselrod, Z Z

    2005-01-01

    A four-detector spectrometer of perturbed angular $\\gamma \\gamma $ correlations is developed for investigation of hyperfine interactions in condensed matter. It allows measurements with practically any types of detectors. A unique circuit design involving a specially developed Master PAC unit combined with a computer allows a substantially higher efficiency, reduced setup time and simpler operation in comparison with traditional PAC spectrometers. A cryostat and a high-temperature oven allow measurements in the temperature range from 120 to 1300 K. An encased electromagnet makes it possible to generate a magnetic field up to 2 T on a sample. The measurement system includes a press with a specially designed high-pressure chamber allowing on-line PAC measurements in samples under pressure up to 60 GPa.

  14. Statistical mechanics and applications in condensed matter

    CERN Document Server

    Di Castro, Carlo

    2015-01-01

    This innovative and modular textbook combines classical topics in thermodynamics, statistical mechanics and many-body theory with the latest developments in condensed matter physics research. Written by internationally renowned experts and logically structured to cater for undergraduate and postgraduate students and researchers, it covers the underlying theoretical principles and includes numerous problems and worked examples to put this knowledge into practice. Three main streams provide a framework for the book; beginning with thermodynamics and classical statistical mechanics, including mean field approximation, fluctuations and the renormalization group approach to critical phenomena. The authors then examine quantum statistical mechanics, covering key topics such as normal Fermi and Luttinger liquids, superfluidity and superconductivity. Finally, they explore classical and quantum kinetics, Anderson localization and quantum interference, and disordered Fermi liquids. Unique in providing a bridge between ...

  15. The Solar Photosphere: Evidence for Condensed Matter

    Directory of Open Access Journals (Sweden)

    Robitaille P. M.

    2006-04-01

    Full Text Available The stellar equations of state treat the Sun much like an ideal gas, wherein the photosphere is viewed as a sparse gaseous plasma. The temperatures inferred in the solar interior give some credence to these models, especially since it is counterintuitive that an object with internal temperatures in excess of 1 MK could be existing in the liquid state. Nonetheless, extreme temperatures, by themselves, are insufficient evidence for the states of matter. The presence of magnetic fields and gravity also impact the expected phase. In the end, it is the physical expression of a state that is required in establishing the proper phase of an object. The photosphere does not lend itself easily to treatment as a gaseous plasma. The physical evidence can be more simply reconciled with a solar body and a photosphere in the condensed state. A discussion of each physical feature follows: (1 the thermal spectrum, (2 limb darkening, (3 solar collapse, (4 the solar density, (5 seismic activity, (6 mass displacement, (7 the chromosphere and critical opalescence, (8 shape, (9 surface activity, (10 photospheric/coronal flows, (11 photospheric imaging, (12 the solar dynamo, and (13 the presence of Sun spots. The explanation of these findings by the gaseous models often requires an improbable combination of events, such as found in the stellar opacity problem. In sharp contrast, each can be explained with simplicity by the condensed state. This work is an invitation to reconsider the phase of the Sun.

  16. Quantum entanglement in condensed matter systems

    Energy Technology Data Exchange (ETDEWEB)

    Laflorencie, Nicolas, E-mail: laflo@irsamc.ups-tlse.fr

    2016-08-03

    This review focuses on the field of quantum entanglement applied to condensed matter physics systems with strong correlations, a domain which has rapidly grown over the last decade. By tracing out part of the degrees of freedom of correlated quantum systems, useful and non-trivial information can be obtained through the study of the reduced density matrix, whose eigenvalue spectrum (the entanglement spectrum) and the associated Rényi entropies are now well recognized to contain key features. In particular, the celebrated area law for the entanglement entropy of ground-states will be discussed from the perspective of its subleading corrections which encode universal details of various quantum states of matter, e.g. symmetry breaking states or topological order. Going beyond entropies, the study of the low-lying part of the entanglement spectrum also allows to diagnose topological properties or give a direct access to the excitation spectrum of the edges, and may also raise significant questions about the underlying entanglement Hamiltonian. All these powerful tools can be further applied to shed some light on disordered quantum systems where impurity/disorder can conspire with quantum fluctuations to induce non-trivial effects. Disordered quantum spin systems, the Kondo effect, or the many-body localization problem, which have all been successfully (re)visited through the prism of quantum entanglement, will be discussed in detail. Finally, the issue of experimental access to entanglement measurement will be addressed, together with its most recent developments.

  17. Quantum entanglement in condensed matter systems

    Science.gov (United States)

    Laflorencie, Nicolas

    2016-08-01

    This review focuses on the field of quantum entanglement applied to condensed matter physics systems with strong correlations, a domain which has rapidly grown over the last decade. By tracing out part of the degrees of freedom of correlated quantum systems, useful and non-trivial information can be obtained through the study of the reduced density matrix, whose eigenvalue spectrum (the entanglement spectrum) and the associated Rényi entropies are now well recognized to contain key features. In particular, the celebrated area law for the entanglement entropy of ground-states will be discussed from the perspective of its subleading corrections which encode universal details of various quantum states of matter, e.g. symmetry breaking states or topological order. Going beyond entropies, the study of the low-lying part of the entanglement spectrum also allows to diagnose topological properties or give a direct access to the excitation spectrum of the edges, and may also raise significant questions about the underlying entanglement Hamiltonian. All these powerful tools can be further applied to shed some light on disordered quantum systems where impurity/disorder can conspire with quantum fluctuations to induce non-trivial effects. Disordered quantum spin systems, the Kondo effect, or the many-body localization problem, which have all been successfully (re)visited through the prism of quantum entanglement, will be discussed in detail. Finally, the issue of experimental access to entanglement measurement will be addressed, together with its most recent developments.

  18. Power spectrum for the Bose-Einstein condensate dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Velten, Hermano, E-mail: velten@physik.uni-bielefeld.de [Departamento de Fisica, UFES, Vitoria, 29075-910 Espirito Santo (Brazil); Fakultaet fuer Physik, Universitaet Bielefeld, Postfach 100131, 33501 Bielefeld (Germany); Wamba, Etienne [Laboratory of Mechanics, Department of Physics, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde (Cameroon)

    2012-03-13

    We assume that dark matter is composed of scalar particles that form a Bose-Einstein condensate (BEC) at some point during the cosmic evolution. Afterwards, cold dark matter is in the form of a condensate and behaves slightly different from the standard dark matter component. We study the large scale perturbative dynamics of the BEC dark matter in a model where this component coexists with baryonic matter and cosmological constant. The perturbative dynamics is studied using neo-Newtonian cosmology (where the pressure is dynamically relevant for the homogeneous and isotropic background) which is assumed to be correct for small values of the sound speed. We show that BEC dark matter effects can be seen in the matter power spectrum if the mass of the condensate particle lies in the range 15 MeV

  19. Power spectrum for the Bose-Einstein condensate dark matter

    CERN Document Server

    Velten, Hermano

    2011-01-01

    We assume that dark matter is composed of scalar particles that form a Bose-Einstein condensate (BEC) at some point during the cosmic evolution. Afterwards, cold dark matter is in the form of a condensate and behaves slightly different from the standard dark matter component. We study the large scale perturbative dynamics of the BEC dark matter in a model where this component coexists with baryonic matter and cosmological constant. The perturbative dynamics is studied using neo- Newtonian cosmology (where the pressure is dynamically relevant for the homogeneous and isotropic background) which is assumed to be correct for small values of the sound speed. We show that BEC dark matter effects can be seen in the matter power spectrum if the mass of the condensate particle lies in the range 15meV < m < 700meV leading to a small, but perceptible, excess of power at large scales.

  20. International Workshop on Current Problems in Condensed Matter

    CERN Document Server

    Current Problems in Condensed Matter

    1998-01-01

    This volume contains the papers presented at the International Workshop on the Cur­ rent Problems in Condensed Matter: Theory and Experiment, held at Cocoyoc, More­ los, Mexico, during January 5-9, 1997. The participants had come from Argentina, Austria, Chile, England, France, Germany, Italy, Japan, Mexico, Switzerland, and the USA. The presentations at the Workshop provided state-of-art reviews of many of the most important problems, currently under study, in condensed matter. Equally important to all the participants in the workshop was the fact that we had come to honor a friend, Karl Heinz Bennemann, on his sixty-fifth birthday. This Festschrift is just a small measure of recognition of the intellectualleadership of Professor Bennemann in the field and equally important, as a sincere tribute to his qualities as an exceptional friend, college and mentor. Those who have had the privilege to work closely with Karl have been deeply touched by Karl's inquisitive scientific mind as well as by bis k...

  1. International Symposium on Dynamics of Ordering Processes in Condensed Matter

    CERN Document Server

    Furukawa, H

    1988-01-01

    The International Symposium on Dynamics of Ordering Processes in Condensed Matter was held at the Kansai Seminar House, Kyoto, for four days, from 27 to 30 August 1987, under the auspices of the Physical Soci­ ety of Japan. The symposium was financially supported by the four orga­ nizations and 45 companies listed on other pages in this volume. We are very grateful to all of them and particularly to the greatest sponsor, the Commemorative Association for the Japan World Exposition 1970. A total Df 22 invited lectures and 48 poster presentations were given and 110 participants attended from seven nations. An objective of the Symposium was to review and extend our present understanding of the dynamics of ordering processes in condensed matters, (for example, alloys, polymers and fluids), that are brought to an un­ stable state by sudden change of such external parameters as temperature and pressure. A second objective, no less important, was to identify new fields of science that might be investigated by sim...

  2. Dark matter as a condensate: Deduction of microscopic properties

    CERN Document Server

    Gutierrez, Sergio; Camacho, Abel

    2016-01-01

    In the present work we model dark matter as a Bose-Einstein condensate and the main goal is the deduction of the microscopic properties, namely, mass, number of particles, and scattering length, related to the particles comprised in the corresponding condensate. This task is done introducing in the corresponding model the effects of the thermal cloud of the system. Three physical conditions are imposed, i.e., mechanical equilibrium of the condensate, explanation of the rotation curves of stars belonging to dwarf galaxies, and, finally, the deflection of light due to the presence of dark matter. These three aforementioned expressions allow us to cast the features of the particles in terms of detectable astrophysical variables. Finally, the model is contrasted against observational data and in this manner we obtain values for the involved microscopic parameters of the condensate. The deduced results are compared with previous results in which dark matter has not been considered a condensate. The main conclusion...

  3. The diffusive instability of kaon condensate in neutron star matter

    CERN Document Server

    Kubis, S

    2004-01-01

    The beta equilibrated dense matter with kaon condensate is analyzed with respect to extended stability conditions including charge fluctuations. This kind of the diffusive instability, appeared to be common property in the kaon condensation case. Results for three different nuclear models are presented.

  4. Resource Letter HCMP-1: History of Condensed Matter Physics

    Science.gov (United States)

    Martin, Joseph D.

    2017-02-01

    This Resource Letter provides a guide to the literature on the history of condensed matter physics, including discussions of the development of the field and strategies for approaching its complicated historical trajectory. Following the presentation of general resources, journal articles and books are cited for the following topics: conceptual development; institutional and community structure; social, cultural, and political history; and connections between condensed matter physics and technology.

  5. Connections between quantum chromodynamics and condensed matter physics

    Indian Academy of Sciences (India)

    Shailesh Chandrasekharan

    2003-11-01

    Features of QCD can be seen qualitatively in certain condensed matter systems. Recently some of the analyses that originated in condensed matter physics have found applications in QCD. Using examples we discuss some of the connections between the two fields and show how progress can be made by exploiting this connection. Some of the challenges that remain in the two fields are quite similar. We argue that recent algorithmic developments call for optimism in both fields.

  6. Shattered glass seeking the densest matter: the color glass condensate

    CERN Multimedia

    Appell, D

    2004-01-01

    "Physicists investigating heavy-particle collisions believe they are on the track of a universal form of matter, one common to very high energy particles ranging from protons to heavy nuclei such as uranium. Some think that this matter, called a color glass condensate, may explain new nuclear properties and the process of particle formation during collisions. Experimentalists have recently reported intriguing data that suggest a color glass condensate has actually formed in past work" (1 page)

  7. Seventeenth Workshop on Computer Simulation Studies in Condensed-Matter Physics

    CERN Document Server

    Landau, David P; Schütler, Heinz-Bernd; Computer Simulation Studies in Condensed-Matter Physics XVI

    2006-01-01

    This status report features the most recent developments in the field, spanning a wide range of topical areas in the computer simulation of condensed matter/materials physics. Both established and new topics are included, ranging from the statistical mechanics of classical magnetic spin models to electronic structure calculations, quantum simulations, and simulations of soft condensed matter. The book presents new physical results as well as novel methods of simulation and data analysis. Highlights of this volume include various aspects of non-equilibrium statistical mechanics, studies of properties of real materials using both classical model simulations and electronic structure calculations, and the use of computer simulations in teaching.

  8. Eighteenth Workshop on Recent Developments in Computer Simulation Studies in Condensed Matter Physics

    CERN Document Server

    Landau, David P; Schüttler, Heinz-Bernd; Computer Simulation Studies in Condensed-Matter Physics XVIII

    2006-01-01

    This volume represents a "status report" emanating from presentations made during the 18th Annual Workshop on Computer Simulations Studies in Condensed Matter Physics at the Center for Simulational Physics at the University of Georgia in March 2005. It provides a broad overview of the most recent advances in the field, spanning the range from statistical physics to soft condensed matter and biological systems. Results on nanostructures and materials are included as are several descriptions of advances in quantum simulations and quantum computing as well as.methodological advances.

  9. FOREWORD: International Scientific Seminars on "Fundamental and Applied Problems of Photonics and Condensed Matter Physics"

    Science.gov (United States)

    Yurchenko, Stanislav; Ryzhii, Viktor

    2015-01-01

    International Scientific Seminars ''Fundamental and Applied Problems of Photonics and Condensed Matter Physics'' were held in Bauman Moscow State Technical University (BMSTU) in May - June 2014. The idea of the Seminars was to organize a series of meetings between young scientists and discuss actual problems and the latest results in Photonics and Condensed Matter Physics. There were eight Sessions: Modern Problems of Condensed Matter Physics; Laser Physics; Spectroscopy of Condensed Matter; Terahertz Optical Technology; Optical Signals Processing; Physics of Optical Strong Correlated Systems; Complex Dusty Plasma Physics; Biomediacal Applications of Photonics. Seminars were organized by the young group of scientists and students from Research and Educational Center ''Photonics and Infrared Technology'' at BMSTU. It brought a significant contribution to the development of youth science in the field of Physics and Photonics in Russia. More than 100 young scientists and students participated in the Seminars in spring - summer 2014. The International Scientific Seminars were supported by the Russian Foundation for Basic Research (grant # 14-08-06030-g). This volume contains proceedings of the International Scientific Seminars ''Fundamental and Applied Problems of Photonics and Condensed Matter Physics''. Stanislav Yurchenko and Viktor Ryzhii Bauman Moscow State Technical University

  10. Gauge and Matter Condensates in Realistic String Models

    CERN Document Server

    Kalara, S; Pages, D N

    1992-01-01

    We examine the inter-relationship of the superpotential containing hidden and observable matter fields and the ensuing condensates in free fermionic string models. These gauge and matter condensates of the strongly interacting hidden gauge groups play a crucial role in the determination of the physical parameters of the observable sector. Supplementing the above information with the requirement of modular invariance, we find that a generic model with only trilinear superpotential allows for a degenerate (and sometimes pathological) set of vacua. This degeneracy may be lifted by higher order terms in the superpotential. We also point out some other subtle points that may arise in calculations of this nature. We exemplify our observations by computing explicitly the modular invariant gaugino and matter condensates in the flipped $SU(5)$ string model with hidden gauge group $SO(10)\\times SU(4)$.

  11. Coherence vs. decoherence in (some) problems of condensed matter physics

    Indian Academy of Sciences (India)

    Sushanta Dattagupta

    2002-08-01

    We present an `overview’ of coherence-to-decoherence transition in certain selected problems of condensed matter physics. Our treatment is based on a subsystem-plus-environment approach. All the examples chosen in this paper have one thing in common – the environmental degrees of freedom are taken to be bosonic and their spectral density of excitations is assumed to be `ohmic’. The examples are drawn from a variety of phenomena in condensed matter physics involving, for instance, quantum diffusion of hydrogen in metals, Landau diamagnetism and -axis transport in high c superconductors.

  12. Diagrammatics lectures on selected problems in condensed matter theory

    CERN Document Server

    Sadovskii, Michael V

    2006-01-01

    The introduction of quantum field theory methods has led to a kind of "revolution" in condensed matter theory. This resulted in the increased importance of Feynman diagrams or diagram technique. It has now become imperative for professionals in condensed matter theory to have a thorough knowledge of this method.There are many good books that cover the general aspects of diagrammatic methods. At the same time, there has been a rising need for books that describe calculations and methodical "know how" of specific problems for beginners in graduate and postgraduate courses. This unique collection

  13. Kaon condensation and multi-strange matter

    Science.gov (United States)

    Gazda, D.; Friedman, E.; Gal, A.; Mareš, J.

    2010-04-01

    We report on dynamical calculations of multi- K¯ hypernuclei, which were performed by adding K¯ mesons to particle-stable configurations of nucleons, Λ and Ξ hyperons. The K¯ separation energy as well as the baryonic densities saturate with the number of antikaons. We demonstrate that the saturation is a robust feature of multi- K¯ hypernuclei. Because the K¯ separation energy B does not exceed 200 MeV, we conclude that kaon condensation is unlikely to occur in finite strong-interaction self-bound {N,Λ,Ξ} strange hadronic systems.

  14. The Rethermalizing Bose-Einstein Condensate of Dark Matter Axions

    CERN Document Server

    Banik, Nilanjan; Sikivie, Pierre; Todarello, Elisa Maria

    2015-01-01

    The axions produced during the QCD phase transition by vacuum realignment, string decay and domain wall decay thermalize as a result of their gravitational self-interactions when the photon temperature is approximately 500 eV. They then form a Bose-Einstein condensate (BEC). Because the axion BEC rethermalizes on time scales shorter than the age of the universe, it has properties that distinguish it from other forms of cold dark matter. The observational evidence for caustic rings of dark matter in galactic halos is explained if the dark matter is axions, at least in part, but not if the dark matter is entirely WIMPs or sterile neutrinos.

  15. Particle Physics and Condensed Matter: The Saga Continues

    CERN Document Server

    Wilczek, Frank

    2016-01-01

    Ideas from quantum field theory and topology have proved remarkably fertile in suggesting new phenomena in the quantum physics of condensed matter. Here I'll supply some broad, unifying context, both conceptual and historical, for the abundance of results reported at the Nobel Symposium on "New Forms of Matter, Topological Insulators and Superconductors". Since they distill some most basic ideas in their simplest forms, these concluding remarks might also serve, for non-specialists, as an introduction.

  16. Surface Tension between Kaon Condensate and Normal Nuclear Matter Phase

    OpenAIRE

    Christiansen, Michael B.; Glendenning, Norman K.; Schaffner-Bielich, Jurgen

    2000-01-01

    We calculate for the first time the surface tension and curvature coefficient of a first order phase transition between two possible phases of cold nuclear matter, a normal nuclear matter phase in equilibrium with a kaon condensed phase, at densities a few times the saturation density. We find the surface tension is proportional to the difference in energy density between the two phases squared. Furthermore, we show the consequences for the geometrical structures of the mixed phase region in ...

  17. SHM of Galaxies Embedded within Condensed Neutrino Matter

    CERN Document Server

    Morley, Peter D

    2014-01-01

    We re-examine the question of condensed neutrino objects (de- generate neutrino matter) based on new calculations. The potential show-stopper issue of free-streaming light neutrinos inhibiting galaxy formation is addressed. We compute the period associated with sim- ple harmonic motion (SHM) of galaxies embedded within condensed neutrino objects. For observational consequences, we examine the ro- tational velocities of embedded galaxies using Hickson 88A (N6978) as the prototype. Finally, we point out that degenerate neutrino objects repel each other in overlap and we compute directly the repulsive force between two interesting and relevant con?gurations. An outstanding issue is whether the accompanying tidal forces generated by condensed neutrino matter on embedded galaxies give rise to galactic bulges and halos.

  18. (K)0 Condensation in Hyperonic Neutron Star Matter

    Institute of Scientific and Technical Information of China (English)

    DING Wen-Bo; LIU Guang-Zhou; ZHU Ming-Feng; YU Zi; ZHAO En-Guang

    2008-01-01

    In the framework of the relativistic mean field theory,we investigate (K)0 condensation along with Kˉcondensation occur well in the core of the maximum mass stars for relatively shallow optical potentials of (K) in the range of-100 MeV~-160 MeV.With the increasing optical potential of (K),the critical densities of (K) decrease and the species of baryons appearing in neutron stars become fewer.The main role of (K)0 condensation is to make the abundances of particles become identical leading to isospin saturated symmetric matter including antikaons,state,which leads to a large reduction in the maximum masses of neutron stars.In the core of massive neutron stars,neutron star matter including rich particle species,such as antikaons,nucleons and hyperons,may exist.

  19. Soft condensed matter: Polymers, complex fluids, and biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, D.

    1995-10-01

    Historians often characterize epochs through their dominant materials, clay, bronze, iron, and steel. From this perspective, the modern era is certainly the age of plastics. The progression from hard to soft materials suggests that the emerging era will be the age of {open_quotes}soft condensed matter.{close_quotes}

  20. The 18th Annual Condensed Matter Physics Meeting

    Science.gov (United States)

    Chaplin, Don; Hutchinson, Wayne; Yazidjoglou, Nick; Stewart, Glen

    The Handbook contains abstracts of oral and poster presentations covering various aspects of condensed matter physics such as magnetism, superconductivity, semiconductor materials and their properties, as well as the use of nuclear techniques in studies of these materials. 162 contributions have been considered to be in the INIS subject scope and were indexed separately.

  1. Condensates and correlations in nuclear matter

    Directory of Open Access Journals (Sweden)

    Röpke G.

    2010-10-01

    Full Text Available Nuclei in dense matter are influenced by the medium. Solving an A-particle Schroedinger equation including the effects of self-energy and Pauli blocking, a quasiparticle description is introduced. Deriving thermodynamic properties, this approach contains the NSE at low densities as well as mean-field approaches at high densities. Consequences for the symmetry energy, the phase transition, the determination of thermodynamic parameters from cluster yields and astrophysical applications are discussed.

  2. 13th International Workshop on Condensed Matter Theories

    CERN Document Server

    1990-01-01

    This volume gathers the invited talks of the XIII International Work­ shop on Condensed Matter Theories which took place in Campos do Jordao near Sao Paulo, Brazil, August 6-12, 1989. It contains contributions in a wide variety of fields including neutral quantum and classical fluids, electronic systems, composite materials, plasmas, atoms, molecules and nuclei, and as this year's workshop reflected the natural preoccupation in materials science with its spectacular prospect for mankind, room tempera­ ture super-conductivity. All topics are treated from a common viewpoint: that of many-body physics, whether theoretical or simu1ational. Since the very first workshop, held at the prestigious Instituto de Fisica Teorica in Sao Paulo, and organized by the same organizer of the 1989 workshop, Professor Valdir Casaca Aguilera-Navarro, the meeting has taken place annually six times in Latin America, four in Europe and three in the United States. Its principal objective has been to innitiate and nurture collaborati...

  3. Holographic geometries for condensed matter applications

    CERN Document Server

    Keranen, V

    2013-01-01

    Holographic modeling of strongly correlated many-body systems motivates the study of novel spacetime geometries where the scaling behavior of quantum critical systems is encoded into spacetime symmetries. Einstein-Dilaton-Maxwell theory has planar black brane solutions that exhibit Lifshitz scaling and in some cases hyperscaling violation. Entanglement entropy and Wilson loops in the dual field theory are studied by inserting simple geometric probes involving minimal surfaces into the black brane geometry. Coupling to background matter fields leads to interesting low-energy behavior in holographic models, such as U(1) symmetry breaking and emergent Lifshitz scaling.

  4. Bose-Einstein condensation of dark matter axions.

    Science.gov (United States)

    Sikivie, P; Yang, Q

    2009-09-11

    We show that cold dark matter axions thermalize and form a Bose-Einstein condensate (BEC). We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the nonlinear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles.

  5. Particle physics and condensed matter: the saga continues

    Science.gov (United States)

    Wilczek, Frank

    2016-12-01

    Ideas from quantum field theory and topology have proved remarkably fertile in suggesting new phenomena in the quantum physics of condensed matter. Here I will supply some broad, unifying context, both conceptual and historical, for the abundance of results reported at the Nobel Symposium on ‘New Forms of Matter, Topological Insulators and Superconductors’. Since they distill some most basic ideas in their simplest forms, these concluding remarks might also serve, for non-specialists, as an introduction. Invited presentation of concluding remarks at Nobel Symposium 156 on New Forms of Matter, Topological Insulators and Superconductors, 13-15 June 2014, Högberga Gård, Stockholm.

  6. Dwarf spheroidal galaxies and Bose-Einstein condensate dark matter

    CERN Document Server

    Diez-Tejedor, Alberto; Profumo, Stefano

    2014-01-01

    We constrain the parameters of a self-interacting massive dark matter scalar particle in a condensate using the kinematics of the eight brightest dwarf spheroidal satellites of the Milky Way. For the case of an attractive self-interaction the condensate develops a mass density profile with a characteristic scale radius that is closely related to the fundamental parameters of the theory. We find that the velocity dispersion of dwarf spheroidal galaxies suggests a scale radius of the order of 1 kpc, in tension with previous results found using the rotational curve of low-surface-brightness and dwarf galaxies. We discuss the implications of our findings for the particle dark matter model and argue that a single classical coherent state cannot play, in general, a relevant role for the description of dark matter in galaxies.

  7. Experimental and Computational Techniques in Soft Condensed Matter Physics

    Science.gov (United States)

    Olafsen, Jeffrey

    2010-09-01

    1. Microscopy of soft materials Eric R. Weeks; 2. Computational methods to study jammed Systems Carl F. Schrek and Corey S. O'Hern; 3. Soft random solids: particulate gels, compressed emulsions and hybrid materials Anthony D. Dinsmore; 4. Langmuir monolayers Michael Dennin; 5. Computer modeling of granular rheology Leonardo E. Silbert; 6. Rheological and microrheological measurements of soft condensed matter John R. de Bruyn and Felix K. Oppong; 7. Particle-based measurement techniques for soft matter Nicholas T. Ouellette; 8. Cellular automata models of granular flow G. William Baxter; 9. Photoelastic materials Brian Utter; 10. Image acquisition and analysis in soft condensed matter Jeffrey S. Olafsen; 11. Structure and patterns in bacterial colonies Nicholas C. Darnton.

  8. Order and chaos in soft condensed matter

    Indian Academy of Sciences (India)

    A K Sood; Rajesh Ganapathy

    2006-07-01

    Soft matter, like colloidal suspensions and surfactant gels, exhibit strong response to modest external perturbations. This paper reviews our recent experiments on the nonlinear flow behaviour of surfactant worm-like micellar gels. A rich dynamic behaviour exhibiting regular, quasi-periodic, intermittency and chaos is observed. In particular, we have shown experimentally that the route to chaos is via Type-II intermittency in shear thinning worm-like micellar solution of cetyltrimethylammonium tosylate where the strength of flow-concentration coupling is tuned by the addition of sodium chloride. A Poincaré first return map of the time series and the probability distribution of laminar length between burst events show that our data are consistent with Type-II intermittency. The existence of a `Butterfly' intensity pattern in small angle light scattering (SALS) measurements performed simultaneously with the rheological measurements confirms the coupling of flow to concentration fluctuations in the system under study. The scattered depolarised intensity in SALS, sensitive to orientational order fluctuations, shows the same time-dependence (like intermittency) as that of shear stress.

  9. Dark matter and dark energy induced by condensates

    CERN Document Server

    Capolupo, Antonio

    2016-01-01

    It is shown that the vacuum condensate induced by many phenomena behaves as a perfect fluid which, under particular conditions, has zero or negative pressure. In particular, the condensates of thermal states, of fields in curved space and of mixed particles have been analyzed. It is shown that the thermal states with the cosmic microwave radiation temperature, the Unruh and the Hawking radiations give negligible contributions to the critical energy density of the universe, while the thermal vacuum of the intercluster medium could contribute to the dark matter, together with the vacuum energy of fields in curved space-time and of mixed neutrinos. Moreover, a component of the dark energy can be represented by the vacuum of axion-like particles mixed with photons and superpartners of neutrinos. The formal analogy among the systems characterized by the condensates can open new scenarios in the possibility to detect the dark components of the universe in table top experiments.

  10. Dark Matter and Dark Energy Induced by Condensates

    Directory of Open Access Journals (Sweden)

    Antonio Capolupo

    2016-01-01

    Full Text Available It is shown that the vacuum condensate induced by many phenomena behaves as a perfect fluid which, under particular conditions, has zero or negative pressure. In particular, the condensates of thermal states of fields in curved space and of mixed particles have been analyzed. It is shown that the thermal states with the cosmic microwave radiation temperature and the Unruh and the Hawking radiations give negligible contributions to the critical energy density of the universe, while the thermal vacuum of the intercluster medium could contribute to the dark matter, together with the vacuum energy of fields in curved space-time and of mixed neutrinos. Moreover, a component of the dark energy can be represented by the vacuum of axion-like particles mixed with photons and superpartners of neutrinos. The formal analogy among the systems characterized by the condensates can open new scenarios in the possibility of detecting the dark components of the universe in table top experiments.

  11. Applications of lattice QCD techniques for condensed matter systems

    Science.gov (United States)

    Buividovich, P. V.; Ulybyshev, M. V.

    2016-08-01

    We review the application of lattice QCD techniques, most notably the Hybrid Monte Carlo (HMC) simulations, to first-principle study of tight-binding models of crystalline solids with strong inter-electron interactions. After providing a basic introduction into the HMC algorithm as applied to condensed matter systems, we review HMC simulations of graphene, which in the recent years have helped to understand the semimetal behavior of clean suspended graphene at the quantitative level. We also briefly summarize other novel physical results obtained in these simulations. Then we comment on the applicability of hybrid Monte Carlo to topological insulators and Dirac and Weyl semimetals and highlight some of the relevant open physical problems. Finally, we also touch upon the lattice strong-coupling expansion technique as applied to condensed matter systems.

  12. A Scientific Cloud Computing Platform for Condensed Matter Physics

    Science.gov (United States)

    Jorissen, K.; Johnson, W.; Vila, F. D.; Rehr, J. J.

    2013-03-01

    Scientific Cloud Computing (SCC) makes possible calculations with high performance computational tools, without the need to purchase or maintain sophisticated hardware and software. We have recently developed an interface dubbed SC2IT that controls on-demand virtual Linux clusters within the Amazon EC2 cloud platform. Using this interface we have developed a more advanced, user-friendly SCC Platform configured especially for condensed matter calculations. This platform contains a GUI, based on a new Java version of SC2IT, that permits calculations of various materials properties. The cloud platform includes Virtual Machines preconfigured for parallel calculations and several precompiled and optimized materials science codes for electronic structure and x-ray and electron spectroscopy. Consequently this SCC makes state-of-the-art condensed matter calculations easy to access for general users. Proof-of-principle performance benchmarks show excellent parallelization and communication performance. Supported by NSF grant OCI-1048052

  13. Aperiodic structures in condensed matter fundamentals and applications

    CERN Document Server

    Macia Barber, Enrique

    2008-01-01

    One of the Top Selling Physics Books according to YBP Library ServicesOrder can be found in all the structures unfolding around us at different scales, including in the arrangements of matter and in energy flow patterns. Aperiodic Structures in Condensed Matter: Fundamentals and Applications focuses on a special kind of order referred to as aperiodic order.The book covers several topics dealing with the role of aperiodic order in numerous domains of the physical sciences and technology. It first presents the most characteristic features of various aperiodic systems. The author then describes t

  14. PREFACE: Symmetry and Structural Properties of Condensed Matter

    Science.gov (United States)

    Lulek, Tadeusz; Wal, Andrzej; Lulek, Barbara

    2008-03-01

    This volume comprises the proceedings of the Ninth Summer School on Theoretical Physics under the leading title `Symmetry and Structural Properties of Condensed Matter' (SSPCM 2007). The school, organised by Rzeszów University of Technology, Poland, together with AGH University of Science and Technology, Cracow, Poland, in 5-12 September 2007 in Myczkowce. The meeting aimed to continue the series of biannual SSPCM schools (since 1990), and focused on the promotion of some advanced mathematical methods within the physics of condensed matter, with an emphasis on quantum information aspects. The main topics of the SSPCM07 school were the following: Quantum information and computing Finite dimensional Hilbert spaces Generating functions and exactly soluble models The Proceedings are divided into three parts accordingly. These topics can be seen as a natural continuation of the previous SSPCM05 school, aimed at studying interrelations between solid state physics and quantum informatics, as well as an extension of earlier SSPCM meetings, devoted to mathematical tools of condensed matter theory. The school gathered together more than 60 participants from 11 countries and 7 scientific centres in Poland. Some of them were there for the first time, and some had attended nearly all previous meetings. We had advanced researchers as well as their young collaborators and students. Acknowledgements The Organizing Committee wishes to express our gratitude to all participants for several their activities at the school and for creating so friendly and inspiring an atmosphere that one can talk about the term: `SSPCM society'. Special thanks are due to all lecturers, for preparing and presenting their talks, and for several valuable discussions. We also give thanks to all those who prepared manuscripts, giving us thus an opportunity to share their ideas, to all referees who improved significantly the quality of this volume, to all members of our International Advisory Committee, and

  15. Quark and gluon condensates in nuclear matter with Brown- Rho scaling

    Institute of Scientific and Technical Information of China (English)

    郭华; 杨树; 刘玉鑫

    2001-01-01

    Quark and gluon condensates in nuclear matter are investigated in a density-dependent relativistic mean-field theory. The in-medium quark condensate decreases rapidly as the density of nu-clear matter increases, if the Brown-Rho scaling is included. The decrease in the in-medium quark condensate with the nuclear matter density is consistent with the result predicted by the partial chiral symmetry restoration. The gluon condensate and the influence of the strange quark contents on the gluon condensate in nuclear matter are discussed.

  16. Shock wave compression of condensed matter a primer

    CERN Document Server

    Forbes, Jerry W

    2012-01-01

    This book introduces the core concepts of the shock wave physics of condensed matter, taking a continuum mechanics approach to examine liquids and isotropic solids. The text primarily focuses on one-dimensional uniaxial compression in order to show the key features of condensed matter’s response to shock wave loading. The first four chapters are specifically designed to quickly familiarize physical scientists and engineers with how shock waves interact with other shock waves or material boundaries, as well as to allow readers to better understand shock wave literature, use basic data analysis techniques, and design simple 1-D shock wave experiments. This is achieved by first presenting the steady one-dimensional strain conservation laws using shock wave impedance matching, which insures conservation of mass, momentum and energy. Here, the initial emphasis is on the meaning of shock wave and mass velocities in a laboratory coordinate system. An overview of basic experimental techniques for measuring pressure...

  17. Enhanced tubes for steam condensers. Volume 1, Summary of condensation and fouling; Volume 2, Detailed study of steam condensation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, R.L.; Chamra, L.; Jaber, H.

    1992-02-01

    Electric utility steam condensers typically use plain tubes made of titanium, stainless steel, or copper alloys. Approximately two-thirds of the total thermal resistance is on the water side of the plain tube. This program seeks to conceive and develop a tube geometry that has special enhancement geometries on the tube (water) side and the steam (shell) side. This ``enhanced`` tube geometry, will provide increased heat transfer coefficients. The enhanced tubes will allow the steam to condense at a lower temperature. The reduced condensing temperature will reduce the turbine heat rate, and increase the plant peak load capability. Water side fouling and fouling control is a very important consideration affecting the choice of the tube side enhancement. Hence, we have consciously considered fouling potential in our selection of the tube side surface geometry. Using appropriate correlations and theoretical models, we have designed condensation and water side surface geometries that will provide high performance and be cleanable using sponge ball cleaning. Commercial tube manufacturers have made the required tube geometries for test purposes. The heat transfer test program includes measurement of the condensation and water side heat transfer coefficients. Fouling tests are being run to measure the waterside fouling resistance, and to the test the ability of the sponge ball cleaning system to clean the tubes.

  18. Dark Matter Halos as Bose-Einstein Condensates

    CERN Document Server

    Mielke, E W; Schunck, F E; Mielke, Eckehard W.; Fuchs, Burkhard; Schunck, Franz E.

    2006-01-01

    Galactic dark matter is modelled by a scalar field in order to effectively modify Kepler's law without changing standard Newtonian gravity. In particular, a solvable toy model with a self-interaction U(Phi) borrowed from non-topological solitons produces already qualitatively correct rotation curves and scaling relations. Although relativistic effects in the halo are very small, we indicate corrections arising from the general relativistic formulation. Thereby, we can also probe the weak gravitational lensing of our soliton type halo. For cold scalar fields, it corresponds to a gravitationally confined Boson-Einstein condensate, but of galactic dimensions.

  19. Non-Commutative Mechanics in Mathematical & in Condensed Matter Physics

    Directory of Open Access Journals (Sweden)

    Peter A. Horváthy

    2006-12-01

    Full Text Available Non-commutative structures were introduced, independently and around the same time, in mathematical and in condensed matter physics (see Table 1. Souriau's construction applied to the two-parameter central extension of the planar Galilei group leads to the ''exotic'' particle, which has non-commuting position coordinates. A Berry-phase argument applied to the Bloch electron yields in turn a semiclassical model that has been used to explain the anomalous/spin/optical Hall effects. The non-commutative parameter is momentum-dependent in this case, and can take the form of a monopole in momentum space.

  20. Lectures on holographic methods for condensed matter physics

    CERN Document Server

    Hartnoll, Sean A

    2009-01-01

    These notes are loosely based on lectures given and to be given at the CERN Winter School on Supergravity, Strings and Gauge theories, February 2009 and at the IPM String School in Tehran, April 2009, respectively. I have focused on a few concrete topics and also on addressing questions that have arisen repeatedly. Background condensed matter physics material is included as motivation and easy reference for the high energy physics community. The discussion of holographic techniques progresses from equilibrium, to transport and to superconductivity.

  1. Applied mathematics and condensed matter; Mathematiques appliquees et matiere condensee

    Energy Technology Data Exchange (ETDEWEB)

    Bouche, D.; Jollet, F. [CEA Bruyeres-le-Chatel, 91 (France)

    2011-01-15

    Applied mathematics have always been a key tool in computing the structure of condensed matter. In this paper, we present the most widely used methods, and show the importance of mathematics in their genesis and evolution. After a brief survey of quantum Monte Carlo methods, which try to compute the N electrons wave function, the paper describes the theoretical foundations of N independent particle approximations. We mainly focus on density functional theory (DFT). This theory associated with advanced numerical methods, and high performance computing, has produced significant achievements in the field. This paper presents the foundations of the theory, as well as different numerical methods used to solve DFT equations. (authors)

  2. Weak Nonlinear Matter Waves in a Trapped Spin-1 Condensates

    Institute of Scientific and Technical Information of China (English)

    CAI Hong-Qiang; YANG Shu-Rong; XUE Ju-Kui

    2011-01-01

    The dynamics of the weak nonlinear matter solitary waves in a spin-1 condensates with harmonic external potential are investigated analytically by a perturbation method. It is shown that, in the small amplitude limit, the dynamics of the solitary waves are governed by a variable-coefficient Korteweg-de Vries (KdV) equation. The reduction to the (KdV) equation may be useful to understand the dynamics of nonlinear matter waves in spinor BEGs. The analytical expressions for the evolution of soliton show that the small-amplitude vector solitons of the mixed types perform harmonic oscillations in the presence of the trap. Furthermore, the emitted radiation profiles and the soliton oscillation freauencv are also obtained.

  3. Conventional and Unconventional Pairing and Condensates in Dilute Nuclear Matter

    CERN Document Server

    Clark, John W; Stein, Martin; Huang, Xu-Guang; Khodel, Victor A; Shaginyan, Vasily R; Zverev, Mikhail V

    2016-01-01

    This contribution will survey recent progress toward an understanding of diverse pairing phenomena in dilute nuclear matter at small and moderate isospin asymmetry, with results of potential relevance to supernova envelopes and proto-neutron stars. Application of {\\it ab initio} many-body techniques has revealed a rich array of temperature-density phase diagrams, indexed by isospin asymmetry, which feature both conventional and unconventional superfluid phases. At low density there exist a homogeneous translationally invariant BCS phase, a homogeneous LOFF phase violating translational invariance, and an inhomogeneous translationally invariant phase-separated BCS phase. The transition from the BCS to the BEC phases is characterized in terms of the evolution, from weak to strong coupling, of the pairing gap, condensate wave function, and quasiparticle occupation numbers and spectra. Additionally, a schematic formal analysis of pairing in neutron matter at low to moderate densities is presented that establishes...

  4. Use of ultracold neutrons for condensed-matter studies

    Energy Technology Data Exchange (ETDEWEB)

    Michaudon, A.

    1997-05-01

    Ultracold neutrons have such low velocities that they are reflected by most materials at all incident angles and can be stored in material bottles for long periods of time during which their intrinsic properties can be studied in great detail. These features have been mainly used for fundamental-physics studies including the detection of a possible neutron electric dipole moment and the precise determination of neutron-decay properties. Ultracold neutrons can also play a role in condensed-matter studies with the help of high-resolution spectrometers that use gravity as a strongly dispersive medium for low-velocity neutrons. Such studies have so far been limited by the low intensity of existing ultracold-neutron sources but could be reconsidered with more intense sources, which are now envisaged. This report provides a broad survey of the properties of ultracold neutrons (including their reflectivity by different types of samples), of ultracold-neutron spectrometers that are compared with other high-resolution instruments, of results obtained in the field of condensed matter with these instruments, and of neutron microscopes. All these subjects are illustrated by numerous examples.

  5. Condensed Matter Physics in Colombia is in its forties

    Science.gov (United States)

    Camacho, Angela

    2015-03-01

    Physics in Colombia started to develop in the 70's as a research part of basic sciences with the acquisition, at that time, of large research equipments such as x-rays and EPR. Experimental work was soon supplemented by theoretical investigations, which led to the formation of research groups in condensed matter. In the early 80's existed such groups in five universities. In this report we present, after a short history of the main steps that guided the initial research subjects, the major areas already developed and the minor research groups that are in the stage of consolidation. Currently this type of work is done at least in 20 universities. We also show the actual numbers of researchers, publications, PhD students and laboratories discriminated in gender to complete an overview of Condensed Matter Physics in Colombia. Finally, we present a short review of the main theoretical issues that have been worked in the last decade focusing on low dimensional systems, their structural and optical properties

  6. Fröhlich Condensate: Emergence of Synergetic Dissipative Structures in Information Processing Biological and Condensed Matter Systems

    Directory of Open Access Journals (Sweden)

    Roberto Luzzi

    2012-10-01

    Full Text Available We consider the case of a peculiar complex behavior in open boson systems sufficiently away from equilibrium, having relevance in the functioning of information-processing biological and condensed matter systems. This is the so-called Fröhlich–Bose–Einstein condensation, a self-organizing-synergetic dissipative structure, a phenomenon apparently working in biological processes and present in several cases of systems of boson-like quasi-particles in condensed inorganic matter. Emphasis is centered on the quantum-mechanical-statistical irreversible thermodynamics of these open systems, and the informational characteristics of the phenomena.

  7. Phi meson spectral moments and QCD condensates in nuclear matter

    Science.gov (United States)

    Gubler, Philipp; Weise, Wolfram

    2016-10-01

    A detailed analysis of the lowest two moments of the ϕ meson spectral function in vacuum and nuclear matter is performed. The consistency is examined between the constraints derived from finite energy QCD sum rules and the spectra computed within an improved vector dominance model, incorporating the coupling of kaonic degrees of freedom with the bare ϕ meson. In the vacuum, recent accurate measurements of the e+e- →K+K- cross section allow us to determine the spectral function with high precision. In nuclear matter, the modification of the spectral function can be described by the interactions of the kaons from ϕ → K K ‾ with the surrounding nuclear medium. This leads primarily to a strong broadening and an asymmetric deformation of the ϕ meson peak structure. We confirm that, both in vacuum and nuclear matter, the zeroth and first moments of the corresponding spectral functions satisfy the requirements of the finite energy sum rules to a remarkable degree of accuracy. Limits on the strangeness sigma term of the nucleon are examined in this context. Applying our results to the second moment of the spectrum, we furthermore discuss constraints on four-quark condensates and the validity of the commonly used ground state saturation approximation.

  8. Geometric nonlinearities in field theory, condensed matter and analytical mechanics

    Directory of Open Access Journals (Sweden)

    J.J. Sławianowski

    2010-01-01

    Full Text Available There are two very important subjects in physics: Symmetry of dynamical models and nonlinearity. All really fundamental models are invariant under some particular symmetry groups. There is also no true physics, no our Universe and life at all, without nonlinearity. Particularly interesting are essential, non-perturbative nonlinearities which are not described by correction terms imposed on some well-defined linear background. Our idea in this paper is that there exists some mysterious, still incomprehensible link between essential, physically relevant nonlinearity and dynamical symmetry, first of all, of large symmetry groups. In some sense the problem is known even in soliton theory, where the essential nonlinearity is often accompanied by the infinite system of integrals of motion, thus, by infinite-dimensional symmetry groups. Here we discuss some more familiar problems from the realm of field theory, condensed matter physics, and analytical mechanics, where the link between essential nonlinearity and high symmetry is obvious, although not fully understandable.

  9. The Sun is Condensed Matter and has a Real Surface

    Science.gov (United States)

    Robitaille, Pierre-Marie

    2014-03-01

    The idea that the Sun was a gaseous in nature was born from 1858-65. At that time, a group of men, including Herbert Spencer, Father Angelo Secchi, Warren de la Rue, Balfour Stewart, and Benjamin Loewy, advanced that the Sun was a ball of gas. In 1865, Hervé Faye was the first to argue that the solar surface was merely an illusion. Dismissing all signs to the contrary, solar physics has promoted this idea to the present day, as manifested by the Standard Solar Model. In this work, overwhelming observational evidence will be presented that the Sun does indeed possess a distinct surface (see P.M. Robitaille, Forty Lines of Evidence for Condensed Matter -- The Sun on Trial: Liquid Metallic Hydrogen as a Solar Building Block, Progress in Physics, 2013, v. 4, 90-143). Our telescopes and satellites are sampling real structures on the surface of the Sun.

  10. Integrating Condensed Matter Physics into a Liberal Arts Physics Curriculum

    Science.gov (United States)

    Collett, Jeffrey

    2008-03-01

    The emergence of nanoscale science into the popular consciousness presents an opportunity to attract and retain future condensed matter scientists. We inject nanoscale physics into recruiting activities and into the introductory and the core portions of the curriculum. Laboratory involvement and research opportunity play important roles in maintaining student engagement. We use inexpensive scanning tunneling (STM) and atomic force (AFM) microscopes to introduce students to nanoscale structure early in their college careers. Although the physics of tip-surface interactions is sophisticated, the resulting images can be interpreted intuitively. We use the STM in introductory modern physics to explore quantum tunneling and the properties of electrons at surfaces. An interdisciplinary course in nanoscience and nanotechnology course team-taught with chemists looks at nanoscale phenomena in physics, chemistry, and biology. Core quantum and statistical physics courses look at effects of quantum mechanics and quantum statistics in degenerate systems. An upper level solid-state physics course takes up traditional condensed matter topics from a structural perspective by beginning with a study of both elastic and inelastic scattering of x-rays from crystalline solids and liquid crystals. Students encounter reciprocal space concepts through the analysis of laboratory scattering data and by the development of the scattering theory. The course then examines the importance of scattering processes in band structure and in electrical and thermal conduction. A segment of the course is devoted to surface physics and nanostructures where we explore the effects of restricting particles to two-dimensional surfaces, one-dimensional wires, and zero-dimensional quantum dots.

  11. Front Matter: Volume 1 (Proceedings of CBU

    Directory of Open Access Journals (Sweden)

    Petr Hájek

    2013-06-01

    Full Text Available This PDF file contains the front matter associated with CBU Proceedings Volume 1 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

  12. Front Matter: Volume 3 (Proceedings of CBU

    Directory of Open Access Journals (Sweden)

    Petr Hájek

    2015-09-01

    Full Text Available This PDF file contains the front matter associated with CBU Proceedings Volume 1 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

  13. Genesis of electroweak and dark matter scales from a bilinear scalar condensate

    CERN Document Server

    Kubo, Jisuke

    2015-01-01

    The condensation of scalar bilinear in a classically scale invariant strongly interacting hidden sector is used to generate electroweak scale, where the excitation of the condensate is identified as dark matter. We formulate an effective theory for the condensation of scalar bilinear and find in the self-consistent mean field approximation that the dark matter mass is of $O(1)$ TeV with the spin-independent elastic cross section off the nucleon slightly below the LUX upper bound.

  14. Gravitational, lensing, and stability properties of Bose-Einstein condensate dark matter halos

    CERN Document Server

    Harko, Tiberiu

    2015-01-01

    The possibility that dark matter, whose existence is inferred from the study of the galactic rotation curves and from the mass deficit in galaxy clusters, can be in a form of a Bose-Einstein condensate has recently been extensively investigated. In the present work, we consider a detailed analysis of the astrophysical properties of the Bose-Einstein condensate dark matter halos that could provide clear observational signatures and help discriminate between different dark matter models. In the Bose-Einstein condensation model dark matter can be described as a non-relativistic, gravitationally confined Newtonian gas, whose density and pressure are related by a polytropic equation of state with index $n=1$. The mass and the gravitational properties of the condensate halos are obtained in a systematic form, including the mean logarithmic slopes of the density and of the tangential velocity. Furthermore, the lensing properties of the condensate dark matter are also investigated in detail. In particular, a general ...

  15. Dark matter as the Bose-Einstein condensation in loop quantum cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Atazadeh, K.; Mousavi, M. [Azarbaijan Shahid Madani University, Department of Physics, Tabriz (Iran, Islamic Republic of); Darabi, F. [Azarbaijan Shahid Madani University, Department of Physics, Tabriz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of)

    2016-06-15

    We consider the FLRW universe in a loop quantum cosmological model filled with radiation, baryonic matter (with negligible pressure), dark energy, and dark matter. The dark matter sector is supposed to be of Bose-Einstein condensate type. The Bose-Einstein condensation process in a cosmological context by supposing it as an approximate first-order phase transition, has already been studied in the literature. Here, we study the evolution of the physical quantities related to the early universe description such as the energy density, temperature, and scale factor of the universe, before, during, and after the condensation process. We also consider in detail the evolution era of the universe in a mixed normal-condensate dark matter phase. The behavior and time evolution of the condensate dark matter fraction is also analyzed. (orig.)

  16. Physical activity, fitness, and gray matter volume.

    Science.gov (United States)

    Erickson, Kirk I; Leckie, Regina L; Weinstein, Andrea M

    2014-09-01

    In this review, we explore the association among physical activity, cardiorespiratory fitness, and exercise on gray matter volume in older adults. We conclude that higher cardiorespiratory fitness levels are routinely associated with greater gray matter volume in the prefrontal cortex and hippocampus and less consistently in other regions. We also conclude that physical activity is associated with greater gray matter volume in the same regions that are associated with cardiorespiratory fitness including the prefrontal cortex and hippocampus. Some heterogeneity in the literature may be explained by effect moderation by age, stress, or other factors. Finally, we report promising results from randomized exercise interventions that suggest that the volume of the hippocampus and prefrontal cortex remain pliable and responsive to moderate intensity exercise for 6 months-1 year. Physical activity appears to be a propitious method for influencing gray matter volume in late adulthood, but additional well-controlled studies are necessary to inform public policies about the potential protective or therapeutic effects of exercise on brain volume. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Volume Integral Theorem for Exotic Matter

    OpenAIRE

    Nandi, Kamal Kanti; Zhang, Yuan-Zhong; Kumar, K. B. Vijaya

    2004-01-01

    We answer an important question in general relativity about the volume integral theorem for exotic matter by suggesting an exact integral quantifier for matter violating Averaged Null Energy Condition (ANEC). It is checked against some well known static, spherically symmetric traversable wormhole solutions of general relativity with a sign reversed kinetic term minimally coupled scalar field. The improved quantifier is consistent with the principle that traversable wormholes can be supported ...

  18. Excluded-Volume Approximation for Supernova Matter

    CERN Document Server

    Yudin, A V

    2014-01-01

    A general scheme of the excluded-volume approximation as applied to multicomponent systems with an arbitrary degree of degeneracy has been developed. This scheme also admits an allowance for additional interactions between the components of a system. A specific form of the excluded-volume approximation for investigating supernova matter at subnuclear densities has been found from comparison with the hard-sphere model. The possibility of describing the phase transition to uniform nuclear matter in terms of the formalism under consideration is discussed.

  19. FOREWORD: 18th International School on Condensed Matter Physics

    Science.gov (United States)

    Dimova-Malinovska, Doriana; Genova, Julia; Nesheva, Diana; Petrov, Alexander G.; Primatarowa, Marina T.

    2014-12-01

    We are delighted to present the Proceedings of the 18th International School on Condensed Matter Physics: Challenges of Nanoscale Science: Theory, Materials, Applications, organized by the Institute of Solid State Physics of the Bulgarian Academy of Sciences and chaired by Professor Alexander G Petrov. On this occasion the School was held in memory of Professor Nikolay Kirov (1943-2013), former Director of the Institute and Chairman between 1991 and 1998. The 18ISCMP was one of several events dedicated to the 145th anniversary of the Bulgarian Academy of Sciences in 2014, and was held in the welcoming Black Sea resort of St. Constantine and Helena near Varna, at the Hotel and Congress Centre Frederic Joliot-Curie. Participants from 16 countries delivered 32 invited lectures, and 71 contributed posters were presented over three lively and well-attended evening sessions. Manuscripts submitted to the Proceedings were refereed in accordance with the guidelines of the Journal of Physics: Conference Series, and we believe the papers published herein testify to the high technical quality and diversity of contributions. A satellite meeting, Transition Metal Oxide Thin Films - Functional Layers in Smart Windows and Water Splitting Devices: Technology and Optoelectronic Properties was held in parallel with the School (http://www.inera.org, 3-6 Sept 2014). This activity, which took place under the FP7-funded project INERA, offered opportunities for crossdisciplinary discussions and exchange of ideas between both sets of participants. As always, a major factor in the success of the 18ISCMP was the social programme, headed by the organized events (Welcome and Farewell Parties) and enhanced in no small measure by a variety of pleasant local restaurants, bars and beaches. We are most grateful to staff of the Journal of Physics: Conference Series for their continued support for the School, this being the third occasion on which the Proceedings have been published under its

  20. Dark matter as a Bose-Einstein Condensate: the relativistic non-minimally coupled case

    Energy Technology Data Exchange (ETDEWEB)

    Bettoni, Dario; Colombo, Mattia; Liberati, Stefano, E-mail: bettoni@sissa.it, E-mail: mattia.colombo@studenti.unitn.it, E-mail: liberati@sissa.it [SISSA, Via Bonomea 265, Trieste, 34136 (Italy)

    2014-02-01

    Bose-Einstein Condensates have been recently proposed as dark matter candidates. In order to characterize the phenomenology associated to such models, we extend previous investigations by studying the general case of a relativistic BEC on a curved background including a non-minimal coupling to curvature. In particular, we discuss the possibility of a two phase cosmological evolution: a cold dark matter-like phase at the large scales/early times and a condensed phase inside dark matter halos. During the first phase dark matter is described by a minimally coupled weakly self-interacting scalar field, while in the second one dark matter condensates and, we shall argue, develops as a consequence the non-minimal coupling. Finally, we discuss how such non-minimal coupling could provide a new mechanism to address cold dark matter paradigm issues at galactic scales.

  1. Neutron reflection from condensed matter, the Goos-Haenchen effect and coherence

    Energy Technology Data Exchange (ETDEWEB)

    Ignatovich, V.K

    2004-02-23

    The Goos-Haenchen (GH) effect for neutron reflection from condensed matter is considered. An experiment to quantify the effect is proposed. The relation of GH shift to the neutron coherence length is considered.

  2. On abelianizations of the ABJM model and applications to condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    Murugan, Jeff, E-mail: jeff@nassp.uct.ac.za [The Laboratory for Quantum Gravity and Strings, Department of Mathematics and Applied Mathematics, University of Cape Town (South Africa); Nastase, Horatiu, E-mail: nastase@ift.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sao Paulo, SP (Brazil). Instituto de Fisica Teorica

    2015-08-15

    In applications of AdS/CFT to condensed matter systems in 2+1 dimensions, the ABJM model is often used; however, the condensed matter models are usually abelian and contain charged fields. We show that a naive reduction of the ABJM model to N = 1 does not have the desired features, but we can find an abelian reduction that has most features, and we can also add fundamental fields to the ABJM model to obtain other models with similar properties. (author)

  3. Dark matter and dark energy induced by condensates

    OpenAIRE

    Antonio Capolupo

    2016-01-01

    It is shown that the vacuum condensate induced by many phenomena behaves as a perfect fluid which, under particular conditions, has zero or negative pressure. In particular, the condensates of thermal states of fields in curved space and of mixed particles have been analyzed. It is shown that the thermal states with the cosmic microwave radiation temperature and the Unruh and the Hawking radiations give negligible contributions to the critical energy density of the universe, while the thermal...

  4. Condensed-matter physics: Quantum mechanics in a spin

    Science.gov (United States)

    Balents, Leon

    2016-12-01

    Quantum spin liquids are exotic states of matter first predicted more than 40 years ago. An inorganic material has properties consistent with these predictions, revealing details about the nature of quantum matter. See Letter p.559

  5. Why Matter Occupies so Large a Volume?

    Science.gov (United States)

    E. B., Manoukian

    2013-12-01

    The paper represents a rigorous treatment of the underlying quantum theory, not just in words but providing the underlying technical details, as to why matter occupies so large a volume and its intimate connection with the Pauli exclusion principle, as more and more matter is put together, as well as of the contraction or shrinkage of “bosonic matter”, upon collapse, for which the Pauli exclusion is abolished. From the derived explicit bounds of integrals of powers of the particle number densities, explicit bounds on probabilities of the occurrences of the events just described are extracted. These probabilities lead one to infer the change of the “size” or extension of such matter, upon expansion or contraction, respectively, as their content is increased.

  6. Fundamentals of Condensed Matter Physics Marvin L. Cohen and Steven G. Louie

    Energy Technology Data Exchange (ETDEWEB)

    Devanathan, Ram

    2017-06-01

    This graduate level textbook on Condensed Matter Physics is written lucidly by two leading luminaries in this field. The volume draws its material from the graduate course in condensed matter physics that has been offered by the authors for several decades at the University of California, Berkeley. Cohen and Louie have done an admirable job of guiding the reader gradually from elementary concepts to advanced topics. The book is divided into four main parts that have four chapters each. Chapter 1 presents models of solids in terms of interacting atoms, which is appropriate for the ground state, and excitations to describe collective effects. Chapter 2 deals with the properties of electrons in crystalline materials. The authors introduce the Born-Oppenheimer approximation and then proceed to the periodic potential approximation. Chapter 3 discusses energy bands in materials and covers concepts from the free electron model to the tight binding model and periodic boundary conditions. Chapter 4 starts with fixed atomic cores and introduces lattice vibrations, phonons, and the concept of density of states. By the end of this part, the student should have a basic understanding of electrons and phonons in materials. Part II presents electron dynamics and the response of materials to external probes. Chapter 5 covers the effective Hamiltonian approximation and the motion of the electron under a perturbation, such as an external field. The discussion moves to many-electron interactions and the exchange-correlation energy in Chapter 6, the widely-used Density Functional Theory (DFT) in chapter 7, and the dielectric response function in Chapter 8. The next two parts of the book cover advanced topics. Part III begins with a discussion of the response of materials to photons in Chapter 9. Chapter 10 goes into the details of electron-phonon interactions in different materials and introduces the polaron. Chapter 11 presents electron dynamics in a magnetic field and Chapter 12

  7. Understanding soft condensed matter via modeling and computation

    CERN Document Server

    Shi, An-Chang

    2011-01-01

    All living organisms consist of soft matter. For this reason alone, it is important to be able to understand and predict the structural and dynamical properties of soft materials such as polymers, surfactants, colloids, granular matter and liquids crystals. To achieve a better understanding of soft matter, three different approaches have to be integrated: experiment, theory and simulation. This book focuses on the third approach - but always in the context of the other two.

  8. Spin-polarized versus chiral condensate in quark matter at finite temperature and density

    DEFF Research Database (Denmark)

    Matsuoka, Hiroaki; Tsue, Yasuhiko; da Providencia, Joao

    2016-01-01

    It is shown that the spin-polarized condensate appears in quark matter at high baryon density and low temperature due to the tensor-type four-point interaction in the Nambu-Jona-Lasiniotype model as a low-energy effective theory of quantum chromodynamics. It is indicated within this low-energy ef......It is shown that the spin-polarized condensate appears in quark matter at high baryon density and low temperature due to the tensor-type four-point interaction in the Nambu-Jona-Lasiniotype model as a low-energy effective theory of quantum chromodynamics. It is indicated within this low......-energy effective model that the chiral symmetry is broken again by the spin-polarized condensate on increasing the quark number density, while chiral symmetry restoration occurs, in which the chiral condensate disappears at a certain density....

  9. Emergence, causation and storytelling: condensed matter physics and the limitations of the human mind

    CERN Document Server

    Blundell, S J

    2016-01-01

    The physics of matter in the condensed state is concerned with problems in which the number of constituent particles is vastly greater than can be easily comprehended. The inherent physical limitations of the human mind are fundamental and restrict the way in which we can interact with and learn about the universe. This presents challenges for developing scientific explanations that are met by emergent narratives, concepts and arguments that have a non-trivial relationship to the underlying microphysics. By examining examples within condensed matter physics, and also from cellular automata, I show how such emergent narratives efficiently describe elements of reality.

  10. Fermion condensate generates a new state of matter by making flat bands

    Science.gov (United States)

    Shaginyan, V. R.; Popov, K. G.; Khodel, V. A.

    2014-09-01

    This short review paper is devoted to 90th anniversary of S.T. Belyaev birthday. Belyaev's ideas associated with the condensate state in Bose interacting systems have stimulated intensive studies of the possible manifestation of such a condensation in Fermi systems. In many Fermi systems and compounds at zero temperature a phase transition happens that leads to a quite specific state called fermion condensation. As a signal of such a fermion condensation quantum phase transition (FCQPT) serves unlimited increase of the effective mass of quasiparticles that determines the excitation spectrum and creates flat bands. We show that the class of Fermi liquids with the fermion condensate forms a new state of matter. We discuss the phase diagrams and the physical properties of systems located near that phase transition. A common and essential feature of such systems is quasiparticles different from those suggested by L.D. Landau by crucial dependence of their effective mass on temperature, external magnetic field, pressure, etc. It is demonstrated that a huge amount of experimental data collected on different compounds suggest that they, starting from some temperature and down, form the new state of matter, and are governed by the fermion condensation. Our discussion shows that the theory of fermion condensation develops completely good description of the NFL behavior of strongly correlated Fermi systems. Moreover, the fermion condensation can be considered as the universal reason for the NFL behavior observed in various HF metals, liquids, compounds with quantum spin liquids, and quasicrystals. We show that these systems exhibit universal scaling behavior of their thermodynamic properties. Therefore, the quantum critical physics of different strongly correlated compounds is universal, and emerges regardless of the underlying microscopic details of the compounds. This uniform behavior, governed by the universal quantum critical physics, allows us to view it as the main

  11. BES-HEP Connections: Common Problems in Condensed Matter and High Energy Physics, Round Table Discussion

    Energy Technology Data Exchange (ETDEWEB)

    Fradkin, Eduardo [Univ. of Illinois, Urbana, IL (United States); Maldacena, Juan [Inst. for Advanced Study, Princeton, NJ (United States); Chatterjee, Lali [Dept. of Energy (DOE), Washington DC (United States). Office of Science. Office of High Energy Physics; Davenport, James W [Dept. of Energy (DOE), Washington DC (United States). Office of Science. Office of Basic Energy Sciences

    2015-02-02

    On February 2, 2015 the Offices of High Energy Physics (HEP) and Basic Energy Sciences (BES) convened a Round Table discussion among a group of physicists on ‘Common Problems in Condensed Matter and High Energy Physics’. This was motivated by the realization that both fields deal with quantum many body problems, share many of the same challenges, use quantum field theoretical approaches and have productively interacted in the past. The meeting brought together physicists with intersecting interests to explore recent developments and identify possible areas of collaboration.... Several topics were identified as offering great opportunity for discovery and advancement in both condensed matter physics and particle physics research. These included topological phases of matter, the use of entanglement as a tool to study nontrivial quantum systems in condensed matter and gravity, the gauge-gravity duality, non-Fermi liquids, the interplay of transport and anomalies, and strongly interacting disordered systems. Many of the condensed matter problems are realizable in laboratory experiments, where new methods beyond the usual quasi-particle approximation are needed to explain the observed exotic and anomalous results. Tools and techniques such as lattice gauge theories, numerical simulations of many-body systems, and tensor networks are seen as valuable to both communities and will likely benefit from collaborative development.

  12. Quark and gluon condensates in nuclear matter with Brown- Rho scaling

    Institute of Scientific and Technical Information of China (English)

    GUO; Hua(

    2001-01-01

    [1]Brown, G. E., Rho, M., Scaling effective Lagrangian in a dense medium, Phys. Rev. Lett., 1991, 66: 2720-2723.[2]Delfino, A., Dey, J., Dey, M. et al., Decoupling of quark condensate from the effective nucleon at high density and tem-perature, Phys. Lett. B, 1995, 363: 17-23.[3]Guo, H., In-medium QMC model parameters and quark condensate in nuclear matter, J. Physics (London) G, 1999, 25: 1701-1711.[4]Li, G. Q., Ko, C. M., Quark condensate in nuclear matter, Phys. Lett. B, 1994, 338: 118-122.[5]Mitsumori, T., Noda, N., Kouno, H. et al., Quark condensate in nuclear matter based on nuclear Schwinger-Dyson for-mulism, Phys. Rev. C, 1997, 55: 1577-1579.[6]Malheiro, M., Dey, M., Delfino, A. et al., Connection between the nuclear matter mean-field equation of state and the quark and gluon condensates at high density, Phys. Rev. C, 1997, 55: 521-524.[7]Li, L., Shen, H., Ning, P. Z., Quark condensate in dense and hot baryonic matter, in Proceedings of CCAST-World Labo-ratory Workshop (CCAST-WL, Beijing), 1996, 77-98.[8]Haddad, S., Weigel, M. K., Finite nuclear systems in a relativistic extended Thomas-Fermi approach with density-dependent coupling parameters, Phys. Rev. C, 1993, 48: 2740-2745.[9]Brockman, R., Machleidt, R., Relativistic nuclear structure. I. Nuclear Matter, Phys. Rev. C, 1990, 42: 1965-1980.[10]Haddad, S., Weigel, M. K., Thermostatic properties and Coulomb instability of highly excited nuclei, Phys. Rev. C, 1994, 49: 3228-3233.[11]Fuchs, C., Lenske, H., Wolter, H., Density dependent hadron field theory, Phys. Rev. C, 1995, 52: 3043-3060.[12]Ineichen, F., Weigel, M. K., Eiff, D., Nuclear structure calculation in the density-dependent relativistic Hartree theory, Phys. Rev. C, 1996, 53: 2158-2162.[13]Guo, H., Liu, B., Toro, D. M., Phase transition in warm nuclear matter, Phys. Rev. C, 2000, 62: 1-8.[14]Cohen, T. D., Furnstahl, R. J., Griegel, D. K., Quark and gluon condensates in nuclear matter, Phys

  13. ICTP Spring College in Condensed Matter on Superconductivity

    CERN Document Server

    Lu, Y

    1995-01-01

    This volume contains the lecture notes of the ""Spring College on Superconductivity"" held from 27 April to 19 June 1992 at ICTP. The distinguished faculty of lecturers has provided a wide coverage of topics on the fascinating subject of superconductivity, ranging from basic physics to the latest developments. The comprehensive reviews included in this volume will prove invaluable for research workers and graduate students in the field.

  14. Wave packet dynamics of the matter wave field of a Bose-Einstein condensate

    CERN Document Server

    Sudheesh, C; Lakshmibala, S

    2004-01-01

    We show in the framework of a tractable model that revivals and fractional revivals of wave packets afford clear signatures of the extent of departure from coherence and from Poisson statistics of the matter wave field in a Bose-Einstein condensate, or of a suitably chosen initial state of the radiation field propagating in a Kerr-like medium.

  15. Condensed matter physics of biomolecule systems in a differential geometric framework

    DEFF Research Database (Denmark)

    Bohr, Henrik; Ipsen, J. H.; Markvorsen, Steen

    2007-01-01

    In this contribution biomolecular systems are analyzed in a framework of differential geometry in order to derive important condensed matter physics information. In the first section lipid bi-layer membranes are examined with respect to statistical properties and topology, e.g. a relation between...

  16. Condensed matter physics of biomolecule systems in a differential geometric framework

    DEFF Research Database (Denmark)

    Bohr, H.; Ipsen, John Hjort; Markvorsen, S

    2007-01-01

    In this contribution biomolecular systems are analyzed in a framework of differential geometry in order to derive important condensed matter physics information. In the first section lipid bi-layer membranes axe examined with respect to statistical properties and topology, e.g. a relation between...

  17. Effect of light assisted collisions on matter wave coherence in superradiant Bose-Einstein condensates

    DEFF Research Database (Denmark)

    Kampel, Nir Shlomo; Griesmaier, Axel Rudolf; Steenstrup, Mads Peter Hornbak;

    2012-01-01

    We investigate experimentally the effects of light assisted collisions on the coherence between momentum states in Bose-Einstein condensates. The onset of superradiant Rayleigh scattering serves as a sensitive monitor for matter-wave coherence. A subtle interplay of binary and collective effects...

  18. Topological phases in condensed matter systems: A study of symmetries, quasiparticles and phase transitions

    NARCIS (Netherlands)

    Haaker, S.M.

    2014-01-01

    The research described in this thesis focuses on topological phases in condensed matter systems. It can be roughly divided into two parts. In the first part noninteracting systems are studied. The symmetry algebra of a charged spin-1/2 particle coupled to a non-Abelian magnetic field is determined,

  19. Condensed matter physics of biomolecule systems in a differential geometric framework

    DEFF Research Database (Denmark)

    Bohr, Henrik; Ipsen, J. H.; Markvorsen, Steen

    2007-01-01

    In this contribution biomolecular systems are analyzed in a framework of differential geometry in order to derive important condensed matter physics information. In the first section lipid bi-layer membranes are examined with respect to statistical properties and topology, e.g. a relation between...

  20. Parametric amplification of matter waves in dipolar spinor Bose-Einstein condensates

    DEFF Research Database (Denmark)

    Deuretzbacher, F.; Gebreyesus, G.; Topic, O.;

    2010-01-01

    Spin-changing collisions may lead under proper conditions to the parametric amplification of matter waves in spinor Bose-Einstein condensates. Magnetic dipole-dipole interactions, although typically very weak in alkali-metal atoms, are shown to play a very relevant role in the amplification process...

  1. PREFACE: 10th Summer School on Theoretical Physics 'Symmetry and Structural Properties of Condensed Matter'

    Science.gov (United States)

    Lulek, Tadeusz; Wal, Andrzej; Lulek, Barbara

    2010-03-01

    This volume contains the Proceedings of the Tenth Summer School on Theoretical Physics under the banner title 'Symmetry and Structural Properties of Condensed Matter' (SSPCM 2009). The School was organized by Rzeszow University of Technology, Poland, in cooperation with AGH University of Science and Technology, Cracow, Poland, and took place on 2-9 September 2009 in Myczkowce, Poland. With this meeting we have reached the round number ten of the series of biannual SSPCM schools, which started in 1990 and were focused on some advanced mathematical methods of condensed matter physics. The first five meetings were held in Zajaczkowo near Poznan, under the auspices of The Institute of Physics of Adam Mickiewicz University, and the last five in Myczkowce near Rzeszów, in the south-eastern part of Poland. Within these two decades several young workers who started at kindergarten lectures at SSPCM, have now reached their PhD degrees, professorships and authority. Proceedings of the first seven SSPCM meetings were published as separate volumes by World Scientific, and the last two as volumes 30 and 104 of Journal of Physics: Conference Series. The present meeting is also the third of the last schools which put the emphasis on quantum informatics. The main topics of our jubilee SSPCM'09 are the following: Information processing, entanglement, and tensor calculus, Integrable models and unitary symmetry, Finite systems and nanophysics. The Proceedings are divided into three parts accordingly. The school gathered together 55 participants from seven countries and several scientific centers in Poland, accommodating again advanced research with young collaborators and students. Acknowledgements The Organizing Committee would like to express its gratitude to all participants for their many activities during the School and for creating a friendly and inspiring atmosphere within our SSPCM society. Special thanks are due to all lecturers for preparing and presenting their talks and

  2. Material science and Condensed matter Physics. 8th International Conference. Abstracts.

    Science.gov (United States)

    Kulyuk, L. L.; Paladi, Florentin; Canter, Valeriu; Nikorich, Valentina; Filippova, Irina

    2016-08-01

    The book includes the abstracts of the communications presented at the 8th International Conference on Materials Science and Condensed Matter Physics (MSCMP 2016), a traditional biennial meeting organized by the Institute of Applied Physics of the Academy of Sciences of Moldova (IAP).A total of 346 abstracts has been included in the book. The Conference programm included plenary lectures, topical keynote lectures, contributed oral and poster presentations distributed into 7 sections: * Condensed Matter Theory; * Advanced Bulk Materials; * Design and Structural Characterization of Materials; * Solid State Nanophysics and Nanotechnology; * Energy Conversion and Storage. Solid State Devices; * Surface Engineering and Applied Electrochemistry; * Digital and Optical holography: Materials and Methods. The abstracts are arranged according to the sections mentioned above. The Abstracts book includes a table of matters at the beginning of the book and an index of authors at the finish of the book.

  3. Graphene a new paradigm in condensed matter and device physics

    CERN Document Server

    Wolf, E L

    2014-01-01

    The book is an introduction to the science and possible applications of Graphene, the first one-atom-thick crystalline form of matter. Discovered in 2004 by now Nobelists Geim and Novoselov, the single layer of graphite, a hexagonal network of carbon atoms, has astonishing electrical and mechanical properties. It supports the highest electrical current density of any material, far exceeding metals copper and silver. Its absolute minimum thickness, 0.34 nanometers, provides an inherent advantage in possible forms of digital electronics past the era of Moore's Law. The book describes the unusual physics of the material, that it offers linear rather than parabolic energy bands. The Dirac-like electron energy bands lead to high constant carrier speed, similar to light photons. The lattice symmetry further implies a two-component wave-function, which has a practical effect of cancelling direct backscattering of carriers. The resulting high carrier mobility allows observation of the Quantum Hall Effect at room temp...

  4. Dark Energy and Dark Matter from the same Vacuum Condensate

    Science.gov (United States)

    Sarfatti, Jack

    2003-04-01

    The micro-quantum Dirac negative energy electron Fermi sphere with Planck scale cutoff is unstable to the formation of off-mass-shell Cooper pairs of virtual electrons and positrons from their static Coulomb attraction. The resulting virtual BEC complex macro-quantum coherent local order parameter (0|e+e-|0) gives rise to both spin 2 gravity guv and spin 0 quintessence / from the Goldstone and Higgs oscillations respectively, Susskind's "world hologram" conjecture replaces the Planck scale Lp with Lp^2/3L^1/3 at scale L. Hagen Kleinert's strain tensor for the "world crystal" is Einstein's geometrodynamic field: guv = nuv + Lp^4/3L^2/3Du,Dvarg(0|e+e-|0)/2 nuv = Minkowski metric, = anti-commutator Du = ,u + TaAu^a is the spin 1 gauge covariant derivative for Lie group P with Lie algebra [Ta,Tb] = Cab^cTc / = Lp-4/3L-2/3[1 - Lp^2L|(0|e+e-|0)|^2] When L = size of visible universe 10^28 cm, Lp^2/3L^1/3 1 fermi / > 0 is anti-gravitating zero point vacuum dark energy, i.e. Kip Thorne's "exotic matter" for traversable wormhole time machines. / < 0 is gravitating zero point vacuum dark matter The non-perturbative BCS energy gap equation for a basic vacuum polarization closed loop with one virtual photon Feynman diagram is: z^2 = ge^-(1/gz) z = (Lp/L)^1/3 and the dimensionless coupling vertex is g^1/2 http://stardrive.org/Jack/nambu.pdf http://stardrive.org/Jack/Lambda1.pdf

  5. Simple-Minded Models of Condensed Matter Systems.

    Science.gov (United States)

    Lammert, Paul Edward

    Chapter 0 presents a survey of recent work on the role of topological defects in classical equilibrium phase transitions. A wide variety of systems and models are covered. The range includes XY models in two and three dimensions, defect theories of two and three dimensional melting of solids and smectic-A liquid crystals, and systems with nonabelian global symmetries, specifically three-dimensional Heisenberg models and IR P^{(n -1)}(generalized nematic) models in two and three dimensions. An attempt is made to bring some clarity to the conceptual problems and to draw attention to the common themes. The general review is followed by detailed study of the effects of topological defects in a specific system, namely nematic media. Chapters 1 and 2 present analysis of a new model of the isotropic-nematic transition in which disclination lines--the characteristic topological defects of nematics--figure prominently. This nematic model incorporates the nematic inversion symmetry as a gauge symmetry. In Chapter 1, Monte Carlo and analytical results on this model are presented. It is found that the first-order isotropic-nematic transition is weakened by increasing defect suppression. Sufficiently great suppression causes that transition to split into two continuous ones, which correspond to unbinding and condensation of dislocation loops, respectively. The intermediate phase possesses a subtle sort of topological ordering. Observable consequences of the new scenario are calculated in detail in Chapter 2. Specifically these are the critical behavior associated with the two continuous transitions. Specific heat, light scattering, magnetic susceptibility and Frank elastic constants are treated. The remaining chapters are devoted to the phenomenon of superconductivity in doped C_{60 }. A selective overview of the physics and a bit of the chemistry of these materials is found in Chapter 3. The focus is on superconducting phenomenology and the attempts which have been made to

  6. Evolution and thermalization of dark matter axions in the condensed regime

    CERN Document Server

    Saikawa, Ken'ichi

    2012-01-01

    We discuss the possibility that dark matter axions form a Bose-Einstein condensate (BEC) due to the gravitational self-interactions. The formation of BEC occurs in the condensed regime, where the transition rate between different momentum states is large compared to the energy exchanged in the transition. The time evolution of the quantum state occupation number of axions in the condensed regime is derived based on the in-in formalism. We recover the expression for the thermalization rate due to self-interaction of the axion field, which was obtained in the other literature. It is also found that the leading order contributions for interactions between axions and other species vanish, which implies that the axion BEC does not give any significant modifications on standard cosmological parameters.

  7. Gauge/gravity duality applied to condensed matter systems

    Energy Technology Data Exchange (ETDEWEB)

    Ammon, Martin Matthias

    2010-07-07

    developed. Finally a second model for the field theory at the quantum-critical point, a Chern-Simons matter theory in (2+1) dimensions is studied more precisely. On the gravitational side thereby higher-dimensional membranes and other non-perturbative objects, so-called KK-monopoles are embedded in M-theory respectively its type IIA limit.

  8. Why more is different philosophical issues in condensed matter physics and complex systems

    CERN Document Server

    Morrison, Margaret

    2015-01-01

    The physics of condensed matter, in contrast to quantum physics or cosmology, is not traditionally associated with deep philosophical questions. However, as science - largely thanks to more powerful computers - becomes capable of analysing and modelling ever more complex many-body systems, basic questions of philosophical relevance arise. Questions about the emergence of structure, the nature of cooperative behaviour, the implications of the second law,  the quantum-classical transition and many other issues. This book is a collection of essays by leading physicists and philosophers. Each investigates one or more of these issues, making use of examples from modern condensed matter research.  Physicists and philosophers alike will find surprising and stimulating ideas in these pages.

  9. In-Medium K+ and K- Production and K- Condensation in Supernova Matter

    Institute of Scientific and Technical Information of China (English)

    GUO Hua; ZHOU Ran; LIU Yu-Xin; LIU Bo; LI Xi-Guo

    2004-01-01

    @@ In-medium effects and neutrino trapping on K+ and K- production and K- condensation in supernova matter are investigated in a chiral hadronic model. Our results show that neutrino trapping shifts the critical density for K- condensation to higher density, the Q values for K+ and K- production are not sensitive to neutrino trapping, in-medium effects decrease the Q values for NN → NNK+ K- and ∧N → NNK- and increase those for NN → N∧K+, K-p →∧π0 and K-n →∧π- as the density of supernova matter increases. Moreover,it is shown that neutrino trapping decreases the maximum masses of protoneutron stars compared with the neutrino-free case.

  10. The beginnings of theoretical condensed matter physics in Rome: a personal remembrance

    Science.gov (United States)

    Di Castro, Carlo; Bonolis, Luisa

    2014-02-01

    This oral history interview provides a personal view on how theoretical condensed matter physics developed in Rome starting in the sixties of the last century. It then follows along the lines of research pursued by the interviewee up to the date of the interview, in March 2006. The topics considered range from the phenomenology of superfluid helium and superconductors, critical phenomena and renormalisation group approach, quantum fluids to strongly correlated electron systems and high temperature superconductors. Within these topics, fundamental problems of condensed matter physics are touched upon, such as the microscopic derivation of scaling, the metal-insulator transition and the interaction effects on disordered electron systems beyond the Anderson localisation, and the existence of heterogeneous states in cuprates. The English text presented here and revised by the authors is based on the original oral history interview recorded in Italian at Carlo Di Castro's office, Physics Department of Sapienza University, Rome, Italy, March 2006.

  11. Zoology of condensed matter: Framids, ordinary stuff, extra-ordinary stuff

    CERN Document Server

    Nicolis, Alberto; Piazza, Federico; Rattazzi, Riccardo

    2015-01-01

    We classify condensed matter systems in terms of the spacetime symmetries they spontaneously break. In particular, we characterize condensed matter itself as any state in a Poincar\\'e-invariant theory that spontaneously breaks Lorentz boosts while preserving at large distances some form of spatial translations, time-translations, and possibly spatial rotations. Surprisingly, the simplest, most minimal system achieving this symmetry breaking pattern---the "framid"---does not seem to be realized in Nature. Instead, Nature usually adopts a more cumbersome strategy: that of introducing internal translational symmetries---and possibly rotational ones---and of spontaneously breaking them along with their space-time counterparts, while preserving unbroken diagonal subgroups. This symmetry breaking pattern describes the infrared dynamics of ordinary solids, fluids, superfluids, and---if they exist---supersolids. A third, "extra-ordinary", possibility involves replacing these internal symmetries with other symmetries ...

  12. Temporal condensed matter physics in gas-filled photonic crystal fibers

    CERN Document Server

    Saleh, Mohammed F; Tran, Truong X; Marini, Andrea; Belli, Federico; Abdolvand, Amir; Biancalana, Fabio

    2014-01-01

    Raman effect in gases can generate an extremely long-living wave of coherence that can lead to the establishment of an almost perfect periodic variation of the medium refractive index. We show theoretically and numerically that the equations, regulate the pulse propagation in hollow-core photonic crystal fibers filled by Raman-active gas, are exactly identical to a classical problem in quantum condensed matter physics -- but with the role of space and time reversed -- namely an electron in a periodic potential subject to a constant electric field. We are therefore able to infer the existence of Wannier-Stark ladders, Bloch oscillations, and Zener tunneling, phenomena that are normally associated with condensed matter physics only, now realized with purely optical means in the temporal domain.

  13. Topics and methods in condensed matter theory from basic quantum mechanics to the frontiers of research

    CERN Document Server

    Cini, M

    2007-01-01

    This book provides material for courses in theoretical physics for undergraduate and graduate students specializing in condensed matter, including experimentalists who want a thorough theoretical background; the advanced part should be of interest to research workers too. A good first course in quantum mechanics is assumed. Here a variety of many-body phenomena in condensed matter are discussed, with special attention paid to the understanding of strong correlation effects. This requires a variety of theoretical tools (diagram expansions, groups, recursion methods and more). The text, which arose naturally from teaching, is eminently readable and the mathematical treatments are explained in enough detail to be followed easily. Proofs of all the relevant theorems are provided, but the main emphasis is always on the physical meaning or applicability of the results. Many examples are provided for illustration and also serve as worked problems.

  14. Modern trends in the development of position sensitive neutron detectors for condensed matter research

    Indian Academy of Sciences (India)

    A V Belushkin

    2008-10-01

    Different types of neutron scattering experiment for the study of condensed matter properties pose specific and often contradictory requirements for detector characteristics. There is no single type of detector which satisfies all the criteria. Therefore, compromise is inevitable and some of the characteristics are trade off in favour of others. Present report gives an overview of detector systems presently operating at the leading neutron scattering facilities as well as some development work around the globe.

  15. Consequences of a condensed matter realization of Lorentz violating QED in Weyl semi-metals

    CERN Document Server

    Grushin, Adolfo G

    2012-01-01

    In Lorentz violating quantum electrodynamics (QED) it is known that a radiatively induced Chern-Simons term appears in the effective action for the gauge field, which is finite but undetermined. This ambiguity is shown to be absent in a condensed matter realization of such a theory in Weyl semi-metals due to the existence of a full microscopic model from which this effective theory emerges. Physically observable consequences such as birefringence are also discussed in this scenario.

  16. Condensed matter research using the UCSB FEL. [Univ. of California, Santa Barbara Free Electron Laser project

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The University of California, Santa Barbara (UCSB) Free Electron Laser (FEL) project was initiated in 1981 to test the idea of using an electrostatic accelerator in a recirculating beam mode to produce high-power, continuously tunable, coherent far infrared radiation. The development and application of this device to condensed matter research are briefly recounted. Emphasis was on semiconductor research and two-photon experiments. (RWR)

  17. Condensed matter research using the UCSB FEL. Final technical report, May 1, 1984--January 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-09-01

    The University of California, Santa Barbara (UCSB) Free Electron Laser (FEL) project was initiated in 1981 to test the idea of using an electrostatic accelerator in a recirculating beam mode to produce high-power, continuously tunable, coherent far infrared radiation. The development and application of this device to condensed matter research are briefly recounted. Emphasis was on semiconductor research and two-photon experiments. (RWR)

  18. RH Sneutrino Condensate CDM and the Baryon-to-Dark Matter Ratio

    CERN Document Server

    McDonald, John

    2007-01-01

    The similarity of the observed mass densities of baryons and cold dark matter may be a sign they have a related origin. The baryon-to-dark matter ratio can be understood in the MSSM with right-handed (RH) neutrinos if CDM is due to a d = 4 flat direction condensate of very weakly coupled RH sneutrino LSPs and the baryon asymmetry is generated by Affleck-Dine leptogenesis along a d = 4 (H_{u}L)^2 flat direction. Observable signatures of the model include CDM and baryon isocurvature perturbations and distinctive long-lived NLSP phenomenology.

  19. Dynamics of Bose-Einstein Condensates: Exact Representation and Topological Classification of Coherent Matter Waves

    Directory of Open Access Journals (Sweden)

    Leilei Jia

    2014-01-01

    Full Text Available By using the bifurcation theory of dynamical systems, we present the exact representation and topological classification of coherent matter waves in Bose-Einstein condensates (BECs, such as solitary waves and modulate amplitude waves (MAWs. The existence and multiplicity of such waves are determined by the parameter regions selected. The results show that the characteristic of coherent matter waves can be determined by the “angular momentum” in attractive BECs while for repulsive BECs; the waves of the coherent form are all MAWs. All exact explicit parametric representations of the above waves are exhibited and numerical simulations support the result.

  20. Quantum simulations with photons and polaritons merging quantum optics with condensed matter physics

    CERN Document Server

    2017-01-01

    This book reviews progress towards quantum simulators based on photonic and hybrid light-matter systems, covering theoretical proposals and recent experimental work. Quantum simulators are specially designed quantum computers. Their main aim is to simulate and understand complex and inaccessible quantum many-body phenomena found or predicted in condensed matter physics, materials science and exotic quantum field theories. Applications will include the engineering of smart materials, robust optical or electronic circuits, deciphering quantum chemistry and even the design of drugs. Technological developments in the fields of interfacing light and matter, especially in many-body quantum optics, have motivated recent proposals for quantum simulators based on strongly correlated photons and polaritons generated in hybrid light-matter systems. The latter have complementary strengths to cold atom and ion based simulators and they can probe for example out of equilibrium phenomena in a natural driven-dissipative sett...

  1. Invited Article: High-pressure techniques for condensed matter physics at low temperature

    Science.gov (United States)

    Feng, Yejun; Jaramillo, R.; Wang, Jiyang; Ren, Yang; Rosenbaum, T. F.

    2010-04-01

    Condensed matter experiments at high pressure accentuate the need for accurate pressure scales over a broad range of temperatures, as well as placing a premium on a homogeneous pressure environment. However, challenges remain in diamond anvil cell technology, including both the quality of various pressure transmitting media and the accuracy of secondary pressure scales at low temperature. We directly calibrate the ruby fluorescence R1 line shift with pressure at T=4.5 K using high-resolution x-ray powder diffraction measurements of the silver lattice constant and its known equation of state up to P=16 GPa. Our results reveal a ruby pressure scale at low temperatures that differs by 6% from the best available ruby scale at room T. We also use ruby fluorescence to characterize the pressure inhomogeneity and anisotropy in two representative and commonly used pressure media, helium and methanol:ethanol 4:1, under the same preparation conditions for pressures up to 20 GPa at T=5 K. Contrary to the accepted wisdom, both media show equal levels of pressure inhomogeneity measured over the same area, with a consistent ΔP /P per unit area of ±1.8%/(104 μm2) from 0 to 20 GPa. The helium medium shows an essentially constant deviatoric stress of 0.021±0.011 GPa up to 16 GPa, while the methanol:ethanol mixture shows a similar level of anisotropy up to 10 GPa, above which the anisotropy increases. The quality of both pressure media is further examined under the more stringent requirements of single crystal x-ray diffraction at cryogenic temperature. For such experiments we conclude that the ratio of sample-to-pressure chamber volume is a critical parameter in maintaining sample quality at high pressure, and may affect the choice of pressure medium.

  2. Invited article: High-pressure techniques for condensed matter physics at low temperature.

    Science.gov (United States)

    Feng, Yejun; Jaramillo, R; Wang, Jiyang; Ren, Yang; Rosenbaum, T F

    2010-04-01

    Condensed matter experiments at high pressure accentuate the need for accurate pressure scales over a broad range of temperatures, as well as placing a premium on a homogeneous pressure environment. However, challenges remain in diamond anvil cell technology, including both the quality of various pressure transmitting media and the accuracy of secondary pressure scales at low temperature. We directly calibrate the ruby fluorescence R1 line shift with pressure at T=4.5 K using high-resolution x-ray powder diffraction measurements of the silver lattice constant and its known equation of state up to P=16 GPa. Our results reveal a ruby pressure scale at low temperatures that differs by 6% from the best available ruby scale at room T. We also use ruby fluorescence to characterize the pressure inhomogeneity and anisotropy in two representative and commonly used pressure media, helium and methanol:ethanol 4:1, under the same preparation conditions for pressures up to 20 GPa at T=5 K. Contrary to the accepted wisdom, both media show equal levels of pressure inhomogeneity measured over the same area, with a consistent DeltaP/P per unit area of +/-1.8 %/(10(4) microm(2)) from 0 to 20 GPa. The helium medium shows an essentially constant deviatoric stress of 0.021+/-0.011 GPa up to 16 GPa, while the methanol:ethanol mixture shows a similar level of anisotropy up to 10 GPa, above which the anisotropy increases. The quality of both pressure media is further examined under the more stringent requirements of single crystal x-ray diffraction at cryogenic temperature. For such experiments we conclude that the ratio of sample-to-pressure chamber volume is a critical parameter in maintaining sample quality at high pressure, and may affect the choice of pressure medium.

  3. Invited article : High pressure standards for condensed matter physics at low temperature.

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Y.; Jaramillo, R.; Wang, J.; Ren, Y.; Rosenbaum, T. F.; Univ. of Chicago

    2010-04-01

    Condensed matter experiments at high pressure accentuate the need for accurate pressure scales over a broad range of temperatures, as well as placing a premium on a homogeneous pressure environment. However, challenges remain in diamond anvil cell technology, including both the quality of various pressure transmitting media and the accuracy of secondary pressure scales at low temperature. We directly calibrate the ruby fluorescence R1 line shift with pressure at T = 4.5 K using high-resolution x-ray powder diffraction measurements of the silver lattice constant and its known equation of state up to P = 16 GPa. Our results reveal a ruby pressure scale at low temperatures that differs by 6% from the best available ruby scale at room T. We also use ruby fluorescence to characterize the pressure inhomogeneity and anisotropy in two representative and commonly used pressure media, helium and methanol:ethanol 4:1, under the same preparation conditions for pressures up to 20 GPa at T = 5 K. Contrary to the accepted wisdom, both media show equal levels of pressure inhomogeneity measured over the same area, with a consistent {Delta}P/P per unit area of {+-}1.8?%/(10{sup 4}{mu}m{sup 2}) from 0 to 20 GPa. The helium medium shows an essentially constant deviatoric stress of 0.021{+-}/{+-}0.011 GPa up to 16 GPa, while the methanol:ethanol mixture shows a similar level of anisotropy up to 10 GPa, above which the anisotropy increases. The quality of both pressure media is further examined under the more stringent requirements of single crystal x-ray diffraction at cryogenic temperature. For such experiments we conclude that the ratio of sample-to-pressure chamber volume is a critical parameter in maintaining sample quality at high pressure, and may affect the choice of pressure medium.

  4. An introduction to gauge-gravity duality and its application in condensed matter

    Science.gov (United States)

    Green, A. G.

    2013-02-01

    The past few years have witnessed a remarkable crossover of string theoretical ideas from the abstract world of geometrical forms to the concrete experimental realm of condensed matter physics. The basis for this - variously known as holography, the AdS/CFT correspondence or gauge-gravity duality - comes from notions right at the cutting edge of string theory. Nevertheless, the insights afforded can often be expressed in ways very familiar to condensed matter physicists. ? The aim of this short, introductory review is to survey the ideas underpinning this crossover, in a way that - as far as possible - strips them of sophisticated mathematical formalism, whilst at the same time retaining their fundamental essence. I will sketch the areas in which progress has been made to date and highlight where the challenges and open questions lie. Finally, I will attempt to give a perspective upon these ideas. What contribution can we realistically expect from this approach and how might it be accommodated into the canon of condensed matter theory? Inevitably, any attempt to do this in such a rapidly evolving field will be superseded by events. Nevertheless, I hope that this will provide a useful way to think about gauge-gravity duality and the uncharted directions in which it might take us.

  5. PREFACE: 17th International School on Condensed Matter Physics (ISCMP): Open Problems in Condensed Matter Physics, Biomedical Physics and their Applications

    Science.gov (United States)

    Dimova-Malinovska, Doriana; Nesheva, Diana; Pecheva, Emilia; Petrov, Alexander G.; Primatarowa, Marina T.

    2012-12-01

    We are pleased to introduce the Proceedings of the 17th International School on Condensed Matter Physics: Open Problems in Condensed Matter Physics, Biomedical Physics and their Applications, organized by the Institute of Solid State Physics of the Bulgarian Academy of Sciences. The Chairman of the School was Professor Alexander G Petrov. Like prior events, the School took place in the beautiful Black Sea resort of Saints Constantine and Helena near Varna, going back to the refurbished facilities of the Panorama hotel. Participants from 17 different countries delivered 31 invited lecturers and 78 posters, contributing through three sessions of poster presentations. Papers submitted to the Proceedings were refereed according to the high standards of the Journal of Physics: Conference Series and the accepted papers illustrate the diversity and the high level of the contributions. Not least significant factor for the success of the 17 ISCMP was the social program, both the organized events (Welcome and Farewell Parties) and the variety of pleasant local restaurants and beaches. Visits to the Archaeological Museum (rich in valuable gold treasures of the ancient Thracian culture) and to the famous rock monastery Aladja were organized for the participants from the Varna Municipality. These Proceedings are published for the second time by the Journal of Physics: Conference Series. We are grateful to the Journal's staff for supporting this idea. The Committee decided that the next event will take place again in Saints Constantine and Helena, 1-5 September 2014. It will be entitled: Challenges of the Nanoscale Science: Theory, Materials and Applications. Doriana Dimova-Malinovska, Diana Nesheva, Emilia Pecheva, Alexander G Petrov and Marina T Primatarowa Editors

  6. Particulate matter in exhaled breath condensate: A promising indicator of environmental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Teresa, E-mail: murmur@itn.pt [ITN, E.N. 10, 2685-953 Sacavem (Portugal); CFN-UL, Prof. Gama Pinto, 2, 1649-003 Lisboa (Portugal); Alexandra Barreiros, M. [LNEG, Estrada Paco do Lumiar, 22, 1649-038 Lisboa (Portugal); Alves, Luis C. [ITN, E.N. 10, 2685-953 Sacavem (Portugal); CFN-UL, Prof. Gama Pinto, 2, 1649-003 Lisboa (Portugal); Felix, Pedro M.; Franco, Cristiana; Sousa, Joana; Almeida, S.M. [ITN, E.N. 10, 2685-953 Sacavem (Portugal)

    2011-10-15

    Assessing the retention of aerosol particles in the human lung, one of the most important pathways of absorption, is a demanding issue. At present, there is no direct biomarker of exposure for the respiratory system. The collection of exhaled breath condensate (EBC) constitutes a new non-invasive method for sampling from the lung. However, the heterogeneity of the sample due to particulate matter suspended in the condensed phase may influence the quality of analytical results in occupational assessments. The main objective of the study was to confirm the presence of particulate matter in the condensate, to investigate how large the particles in suspension could be and to determine their elemental contents relative to those of EBC matrix. This paper reports on preliminary nuclear microprobe data of particulate matter in EBC. The sizes and the elemental contents of particles suspended in EBC of workers of a lead processing industry and in EBC of non-exposed individuals were inspected. Results demonstrated that EBC of workers contain large aerosol particles, isolated and in agglomerates, contrasting with non-exposed individuals. The particles contained high concentrations of Cl, Ca, Zn and Pb that are elements associated to the production process. These elements were also present in the EBC matrix although in much lower levels, suggesting that a fraction of the inhaled particulate matter was solubilised or their size-ranges were below the nuclear microprobe resolution. Therefore, the morphological characterization of individual particles achieved with nuclear microprobe techniques helped describing EBC constituents in detail, to comprehend their origin and enabled to delineate methodological procedures that can be recommended in occupational assessments. These aspects are critical to the validation of EBC as a biomarker of exposure to metals for the respiratory system.

  7. Dynamics of bisolitonic matter waves in a Bose-Einstein condensate subjected to an atomic beam splitter and gravity

    CERN Document Server

    Dikande, Alain Moise; Ebobenow, Joseph

    2010-01-01

    A theoretical scheme for an experimental implementation involving bisolitonic matter waves from an attractive Bose-Einstein condensate, is considered within the framework of a non-perturbative approach to the associate Gross-Pitaevskii equation. The model consists of a single condensate subjected to an expulsive harmonic potential creating a double-condensate structure, and a gravitational potential that induces atomic exchanges between the two overlapping post condensates. Using a non-isospectral scattering transform method, exact expressions for the bright-matter-wave bisolitons are found in terms of double-lump envelopes with the co-propagating pulses displaying more or less pronounced differences in their widths and tails depending on the mass of atoms composing the condensate.

  8. Fourth American Physical Society Topical Conference on Shock Waves in Condensed Matter

    CERN Document Server

    Shock Waves in Condensed Matter

    1986-01-01

    The Fourth American Physical Society Topical Conference on Shock Waves in Condensed Matter was held in Spokane, Washington, July 22-25, 1985. Two hundred and fifty scientists and engineers representing thirteen countries registered at the conference. The countries represented included the United States of America, Australia, Canada, The People's Repub­ lic of China, France, India, Israel, Japan, Republic of China (Taiwan), United Kingdom, U. S. S. R, Switzerland and West Germany. One hundred and sixty-two technical papers, cov­ ering recent developments in shock wave and high pressure physics, were presented. All of the abstracts have been published in the September 1985 issue of the Bulletin of the American Physical Society. The topical conferences, held every two years since 1979, have become the principal forum for shock wave studies in condensed materials. Both formal and informal technical discussions regarding recent developments conveyed a sense of excitement. Consistent with the past conferences, th...

  9. Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 1999

    DEFF Research Database (Denmark)

    2000-01-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1999 are presented in this progress report. Theresearch in physics is concentrated on neutron...... and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small...

  10. Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 2000

    DEFF Research Database (Denmark)

    2001-01-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 2000 are presented in this progress report. Theresearch in physics is concentrated on neutron...... and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures.The research in chemistry includes chemical synthesis and physico-chemical investigation of small...

  11. Physics in the Andean Countries: A Perspective from Condensed Matter, Novel Materials and Nanotechnology

    Science.gov (United States)

    Prieto, P.

    2009-05-01

    We will discuss the current state of R&D in the fields of condensed matter, novel materials, and nanotechnology in the Andean nations. We will initially consider Latin America and the Caribbean (LAC) to then visualize individual developments, as well as those for the region as a whole in these fields of knowledge in each of the nations constituting the Andean Region (Bolivia, Ecuador, Chile, Venezuela, Peru, and Colombia). Based on Science & Technology watch exercises in the countries involved, along with the Iberian American and Inter-American Science & Technology Network of Indicators (Red de indicadores de Ciencia y Tecnolog'ia (RICYT) iberoamericana e interamericana)1, we will reveal statistical data that will shed light on the development in the fields mentioned. As will be noted, total R&D investment in Latin American and Caribbean countries remained constant since 1997. In spite of having reached a general increase in publications without international collaboration in LAC nations, the countries with greatest research productivity in Latin America (Argentina, Mexico, Brazil, and Chile) have strengthened their international collaboration with the United States, France, Germany, and Italy through close links associated with the formation processes of their researchers. Academic and research integration is evaluated through joint authorship of scientific articles, evidencing close collaboration in fields of research. This principle has been used in the creation of cooperation networks among participating nations. As far as networks of research on condensed matter, novel materials, and nanotechnology, the Andean nations have not consolidated a regional network allowing permanent and effective cooperation in research and technological development; as would be expected, given their idiomatic and cultural similarities, their historical background, and geographical proximity, which have been integrating factors in other research areas or socio-economic aspects. This

  12. Finding new signature effects on galactic dynamics to constrain Bose-Einstein-condensed cold dark matter

    CERN Document Server

    Rindler-Daller, Tanja

    2012-01-01

    If cosmological cold dark matter (CDM) consists of light enough bosonic particles that their phase-space density exceeds unity, they will comprise a Bose-Einstein condensate (BEC). The nature of this BEC-CDM as a quantum fluid may then distinguish it dynamically from the standard form of CDM involving a collisionless gas of non-relativistic particles that interact purely gravitationally. We summarize some of the dynamical properties of BEC-CDM that may lead to observable signatures in galactic halos and present some of the bounds on particle mass and self-interaction coupling strength that result from a comparison with observed galaxies.

  13. Phase Diagram of the Gross-Neveu Model: Exact Results and Condensed Matter Precursors

    CERN Document Server

    Schnetz, O; Urlichs, K; Schnetz, Oliver; Thies, Michael; Urlichs, Konrad

    2004-01-01

    Recently the revised phase diagram of the (large N) Gross-Neveu model in 1+1 dimensions with discrete chiral symmetry has been determined numerically. It features three phases, a massless and a massive Fermi gas and a kink-antikink crystal. Here we investigate the phase diagram by analytical means, mapping the Dirac-Hartree-Fock equation onto the non-relativistic Schroedinger equation with the (single gap) Lame potential. It is pointed out that mathematically identical phase diagrams appeared in the condensed matter literature some time ago in the context of the Peierls-Froehlich model and ferromagnetic superconductors.

  14. High-performance computational condensed-matter physics in the cloud

    Science.gov (United States)

    Rehr, J. J.; Svec, L.; Gardner, J. P.; Prange, M. P.

    2009-03-01

    We demonstrate the feasibility of high performance scientific computation in condensed-matter physics using cloud computers as an alternative to traditional computational tools. The availability of these large, virtualized pools of compute resources raises the possibility of a new compute paradigm for scientific research with many advantages. For research groups, cloud computing provides convenient access to reliable, high performance clusters and storage, without the need to purchase and maintain sophisticated hardware. For developers, virtualization allows scientific codes to be pre-installed on machine images, facilitating control over the computational environment. Detailed tests are presented for the parallelized versions of the electronic structure code SIESTA ootnotetextJ. Soler et al., J. Phys.: Condens. Matter 14, 2745 (2002). and for the x-ray spectroscopy code FEFF ootnotetextA. Ankudinov et al., Phys. Rev. B 65, 104107 (2002). including CPU, network, and I/O performance, using the the Amazon EC2 Elastic Cloud.

  15. Condensation for non-relativistic matter in Hořava–Lifshitz gravity

    Directory of Open Access Journals (Sweden)

    Jiliang Jing

    2015-10-01

    Full Text Available We study condensation for non-relativistic matter in a Hořava–Lifshitz black hole without the condition of the detailed balance. We show that, for the fixed non-relativistic parameter α2 (or the detailed balance parameter ϵ, it is easier for the scalar hair to form as the parameter ϵ (or α2 becomes larger, but the condensation is not affected by the non-relativistic parameter β2. We also find that the ratio of the gap frequency in conductivity to the critical temperature decreases with the increase of ϵ and α2, but increases with the increase of β2. The ratio can reduce to the Horowitz–Roberts relation ωg/Tc≈8 obtained in the Einstein gravity and Cai's result ωg/Tc≈13 found in a Hořava–Lifshitz gravity with the condition of the detailed balance for the relativistic matter. Especially, we note that the ratio can arrive at the value of the BCS theory ωg/Tc≈3.5 by taking proper values of the parameters.

  16. The History of the APS Shock Compression of Condensed Matter Topical Group

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, J W

    2001-05-02

    In order to provide broader scientific recognition and to advance the science of shock compressed condensed matter, a group of American Physical Society (APS) members worked within the Society to make this field an active part of the APS. Individual papers were presented at APS meetings starting in the 1940's and shock wave sessions were organized starting with the 1967 Pasadena meeting. Shock wave topical conferences began in 1979 in Pullman, WA. Signatures were obtained on a petition in 1984 from a balanced cross-section of the shock wave community to form an APS Topical Group (TG). The APS Council officially accepted the formation of the Shock Compression of Condensed Matter (SCCM) TG at its October 1984 meeting. This action firmly aligned the shock wave field with a major physical science organization. Most early topical conferences were sanctioned by the APS while those held after 1992 were official APS meetings. The topical group organizes a shock wave topical conference in odd numbered years while participating in shock wave/high pressure sessions at APS general meetings in even numbered years.

  17. History of the APS Topical Group on Shock Compression of Condensed Matter

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, J W

    2001-10-19

    In order to provide broader scientific recognition and to advance the science of shock compressed condensed matter, a group of American Physical Society (APS) members worked within the Society to make this field an active part of the APS. Individual papers were presented at APS meetings starting in the 1940's and shock wave sessions were organized starting with the 1967 Pasadena meeting. Shock wave topical conferences began in 1979 in Pullman, WA. Signatures were obtained on a petition in 1984 from a balanced cross-section of the shock wave community to form an APS Topical Group (TG). The APS Council officially accepted the formation of the Shock Compression of Condensed Matter (SCCM) TG at its October 1984 meeting. This action firmly aligned the shock wave field with a major physical science organization. Most early topical conferences were sanctioned by the APS while those held after 1992 were official APS meetings. The topical group organizes a shock wave topical conference in odd numbered years while participating in shock wavehigh pressure sessions at APS general meetings in even numbered years.

  18. A Duality Web in 2+1 Dimensions and Condensed Matter Physics

    CERN Document Server

    Seiberg, Nathan; Wang, Chong; Witten, Edward

    2016-01-01

    Building on earlier work in the high energy and condensed matter communities, we present a web of dualities in $2+1$ dimensions that generalize the known particle/vortex duality. Some of the dualities relate theories of fermions to theories of bosons. Others relate different theories of fermions. For example, the long distance behavior of the $2+1$-dimensional analog of QED with a single Dirac fermion (a theory known as $U(1)_{1/2}$) is identified with the $O(2)$ Wilson-Fisher fixed point. The gauged version of that fixed point with a Chern-Simons coupling at level one is identified as a free Dirac fermion. The latter theory also has a dual version as a fermion interacting with some gauge fields. Assuming some of these dualities, other dualities can be derived. Our analysis resolves a number of confusing issues in the literature including how time reversal is realized in these theories. It also has many applications in condensed matter physics like the theory of topological insulators (and their gapped bounda...

  19. PHOTOEMISSION AS A PROBE OF THE COLLECTIVE EXCITATIONS IN CONDENSED MATTER SYSTEMS.

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON, P.D.; VALLA, T.

    2006-08-01

    New developments in instrumentation have recently allowed photoemission measurements to be performed with very high energy and momentum resolution.[1] This has allowed detailed studies of the self-energy corrections to the lifetime and mass renormalization of excitations in the vicinity of the Fermi level. These developments come at an opportune time. Indeed the discovery of high temperature superconductivity in the cuprates and related systems is presenting a range of challenges for condensed matter physics.[2] Does the mechanism of high T{sub c} superconductivity represent new physics? Do we need to go beyond Landau's concept of the Fermi liquid?[3] What, if any, is the evidence for the presence or absence of quasiparticles in the excitation spectra of these complex oxides? The energy resolution of the new instruments is comparable to or better than the energy or temperature scale of superconductivity and the energy of many collective excitations. As such, photoemission has again become recognized as an important probe of condensed matter. Studies of the high T{sub c} superconductors and related materials are aided by the observation that they are two dimensional. To understand this, we note that the photoemission process results in both an excited photoelectron and a photohole in the final state. Thus the experimentally measured photoemission peak is broadened to a width reflecting contributions from both the finite lifetime of the photohole and the momentum broadening of the outgoing photoelectron.

  20. A duality web in 2 + 1 dimensions and condensed matter physics

    Science.gov (United States)

    Seiberg, Nathan; Senthil, T.; Wang, Chong; Witten, Edward

    2016-11-01

    Building on earlier work in the high energy and condensed matter communities, we present a web of dualities in 2 + 1 dimensions that generalize the known particle/vortex duality. Some of the dualities relate theories of fermions to theories of bosons. Others relate different theories of fermions. For example, the long distance behavior of the 2 + 1-dimensional analog of QED with a single Dirac fermion (a theory known as U(1)1/2) is identified with the O(2) Wilson-Fisher fixed point. The gauged version of that fixed point with a Chern-Simons coupling at level one is identified as a free Dirac fermion. The latter theory also has a dual version as a fermion interacting with some gauge fields. Assuming some of these dualities, other dualities can be derived. Our analysis resolves a number of confusing issues in the literature including how time reversal is realized in these theories. It also has many applications in condensed matter physics like the theory of topological insulators (and their gapped boundary states) and the problem of electrons in the lowest Landau level at half filling. (Our techniques also clarify some points in the fractional Hall effect and its description using flux attachment.) In addition to presenting several consistency checks, we also present plausible (but not rigorous) derivations of the dualities and relate them to 3 + 1-dimensional S-duality.

  1. Dynamic stability and manipulation of bright matter-wave solitons by optical lattices in Bose-Einstein condensates

    Institute of Scientific and Technical Information of China (English)

    Song Chang-Sheng; Li Jing; Zong Feng-De

    2012-01-01

    An extended variation approach to describing the dynamic evolution of self-attractive Bose-Einstein condensates is developed.We consider bright matter-wave solitons in the presence of a parabolic magnetic potential and a timespace periodic optical lattice.The dynamics of condensates is shown to be well approximated by four coupled nonlinear differential equations.A noteworthy feature is that the extended variation approach gives a critical strength ratio to support multiple stable lattice sites for the condensate.We further examine the existence of the solitons and their stabilities at the multiple stable lattice sites. In this case,the analytical predictions of Bose-Einstein condensates variational dynamics are found to be in good agreement with numerical simulations.We then find a stable region for successful manipulating matter-wave solitons without collapse,which are dragged from an initial stationary to a prescribed position by a moving periodic optical lattice.

  2. All basic condensed matter physics phenomena and notions mirror in biology – A hypothesis, two examples and a novel prediction

    Indian Academy of Sciences (India)

    G Baskaran

    2002-02-01

    A few billion years of evolutionary time and the complex process of ‘selection’ has given biology an opportunity to explore a variety of condensed matter phenomena and situations, some of which have been discovered by humans in the laboratory, that too only in extreme non-biological conditions such as low temperatures, high purity, high pressure etc., in the last centuries. Biology, at some level, is a complex and self-regulated condensed matter system compared to the ‘inanimate’ condensed matter systems such as liquid 4He, liquid water or a piece of graphite. In this article I propose a hypothesis that ‘all basic condensed matter physics phenomena and notions (already known and ones yet to be discovered) mirror in biology’. I explain this hypothesis by considering the idea of ‘Bose condensation’ or ‘momentum space order’ and discuss two known example of quantum magnetism encountered in biology. I also provide some new and rather speculative possibility, from light harvesting in biological photosynthesis, of mesoscopic exciton condensation related phenomena at room temperature.

  3. EOS simulation and GRNN modeling of the constant volume depletion behavior of gas condensate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Elsharkawy, A.M.; Foda, S.G. [Kuwait University, Safat (Kuwait). Petroleum Engineering Dept.

    1998-03-01

    Currently, two approaches are being used to predict the changes in retrograde gas condensate composition and estimate the pressure depletion behavior of gas condensate reservoirs. The first approach uses the equation of states whereas the second uses empirical correlations. Equations of states (EOS) are poor predictive tools for complex hydrocarbon systems. The EOS needs adjustment against phase behavior data of reservoir fluid of known composition. The empirical correlation does not involve numerous numerical computations but their accuracy is limited. This study presents two general regression neural network (GRNN) models. The first model, GRNNM1, is developed to predict dew point pressure and gas compressibility at dew point using initial composition of numerous samples while the second model, GRNNM2, is developed to predict the changes in well stream effluent composition at any stages of pressure depletion. GRNNM2 can also be used to determine the initial reservoir fluid composition using dew point pressure, gas compressibility at dew point, and reservoir temperature. These models are based on analysis of 142 sample of laboratory studies of constant volume depletion (CVD) for gas condensate systems forming a total of 1082 depletion stages. The database represents a wide range of gas condensate systems obtained worldwide. The performance of the GRNN models has been compared to simulation results of the equation of state. The study shows that the proposed general regression neural network models are accurate, valid, and reliable. These models can be used to forecast CVD data needed for many reservoir engineering calculations in case laboratory data is unavailable. The GRNN models save computer time involved in EOS calculations. The study also show that once these models are properly trained they can be used to cut expenses of frequent sampling and laborious experimental CVD tests required for gas condensate reservoirs. 55 refs., 13 figs., 6 tabs.

  4. Neutron research on condensed matter: a study of the facilities and scientific opportunities in the United States

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    An in-depth review of the present status and future potential of the applications of low-energy neutron scattering to research in the condensed-matter sciences, including physics, chemistry, biology, and metallurgy is presented. The study shows that neutron scattering technology has proven to be of enormous importance to research in the above areas and especially to those of solid-state physics and chemistry. The main emphasis is on the scattering of low-energy neutrons by condensed matter. Since the same type of neutron source facilities can be used for the study of radiation damage, this related topic has also been included. (GHT)

  5. Characteristic size and mass of galaxies in the Bose–Einstein condensate dark matter model

    Directory of Open Access Journals (Sweden)

    Jae-Weon Lee

    2016-05-01

    Full Text Available We study the characteristic length scale of galactic halos in the Bose–Einstein condensate (or scalar field dark matter model. Considering the evolution of the density perturbation we show that the average background matter density determines the quantum Jeans mass and hence the spatial size of galaxies at a given epoch. In this model the minimum size of galaxies increases while the minimum mass of the galaxies decreases as the universe expands. The observed values of the mass and the size of the dwarf galaxies are successfully reproduced with the dark matter particle mass m≃5×10−22 eV. The minimum size is about 6×10−3m/Hλc and the typical rotation velocity of the dwarf galaxies is O(H/m c, where H is the Hubble parameter and λc is the Compton wave length of the particle. We also suggest that ultra compact dwarf galaxies are the remnants of the dwarf galaxies formed in the early universe.

  6. Piezoresistive Soft Condensed Matter Sensor for Body-Mounted Vital Function Applications.

    Science.gov (United States)

    Melnykowycz, Mark; Tschudin, Michael; Clemens, Frank

    2016-03-04

    A soft condensed matter sensor (SCMS) designed to measure strains on the human body is presented. The hybrid material based on carbon black (CB) and a thermoplastic elastomer (TPE) was bonded to a textile elastic band and used as a sensor on the human wrist to measure hand motion by detecting the movement of tendons in the wrist. Additionally it was able to track the blood pulse wave of a person, allowing for the determination of pulse wave peaks corresponding to the systole and diastole blood pressures in order to calculate the heart rate. Sensor characterization was done using mechanical cycle testing, and the band sensor achieved a gauge factor of 4-6.3 while displaying low signal relaxation when held at a strain levels. Near-linear signal performance was displayed when loading to successively higher strain levels up to 50% strain.

  7. Generalization of Classical Statistical Mechanics to Quantum Mechanics and Stable Property of Condensed Matter

    CERN Document Server

    Huang, Y C; Zhang, N

    2004-01-01

    Classical statistical average values are generally generalized to average values of quantum mechanics, it is discovered that quantum mechanics is direct generalization of classical statistical mechanics, and we generally deduce both a general new continuous eigenvalue equation and a general discrete eigenvalue equation in quantum mechanics, and discover that a eigenvalue of quantum mechanics is just an extreme value of an operator in possibility distribution, the eigenvalue f is just classical observable quantity. A general classical statistical uncertain relation is further given, the general classical statistical uncertain relation is generally generalized to quantum uncertainty principle, the two lost conditions in classical uncertain relation and quantum uncertainty principle, respectively, are found. We generally expound the relations among uncertainty principle, singularity and condensed matter stability, discover that quantum uncertainty principle prevents from the appearance of singularity of the elec...

  8. Topological Aspects of Condensed Matter Physics : Lecture Notes of the Les Houches Summer School : Session CIII

    CERN Document Server

    Chamon, Claudio; Goerbig, Mark O; Moessner, Roderich; Cugliandolo, Leticia F

    2017-01-01

    Topological condensed matter physics is a recent arrival among the disciplines of modern physics of a distinctive and substantive nature. Its roots reach far back, but much of its current importance derives from exciting developments in the last half-century. The field is advancing rapidly, growing explosively, and diversifying greatly. There is now a zoo of topological phenomena–the quantum spin Hall effect, topological insulators, Coulomb spin liquids, non-Abelian anyonic statistics and their potential application in topological quantum computing, to name but a few–as well as an increasingly sophisticated set of concepts and methods underpinning their understanding. The aim of this Les Houches Summer School was to present an overview of this field, along with a sense of its origins and its place on the map of advances in fundamental physics. The school comprised a set of basic lectures (Part I) aimed at a pedagogical introduction to the fundamental concepts, which was accompanied by more advanced lectur...

  9. Gravitational Waves as a New Probe of Bose-Einstein Condensate Dark Matter

    CERN Document Server

    Dev, P S Bhupal; Ohmer, Sebastian

    2016-01-01

    There exists a class of ultralight Dark Matter (DM) models which could form a Bose-Einstein condensate (BEC) in the early universe and behave as a single coherent wave instead of individual particles in galaxies. We show that a generic BEC DM halo intervening along the line of sight of a gravitational wave (GW) signal could induce an observable change in the speed of GW, with the effective refractive index depending only on the mass and self-interaction of the constituent DM particles and the GW frequency. Hence, we propose to use the deviation in the speed of GW as a new probe of the BEC DM parameter space. With a multi-messenger approach to GW astronomy and/or with extended sensitivity to lower GW frequencies, the entire BEC DM parameter space can be effectively probed by our new method in the near future.

  10. Perspective: Structural dynamics in condensed matter mapped by femtosecond x-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Elsaesser, T.; Woerner, M. [Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin (Germany)

    2014-01-14

    Ultrashort soft and hard x-ray pulses are sensitive probes of structural dynamics on the picometer length and femtosecond time scales of electronic and atomic motions. Recent progress in generating such pulses has initiated new directions of condensed matter research, exploiting a variety of x-ray absorption, scattering, and diffraction methods to probe photoinduced structural dynamics. Atomic motion, changes of local structure and long-range order, as well as correlated electron motion and charge transfer have been resolved in space and time, providing a most direct access to the physical mechanisms and interactions driving reversible and irreversible changes of structure. This perspective combines an overview of recent advances in femtosecond x-ray diffraction with a discussion on ongoing and future developments.

  11. Qualification of niobium materials for superconducting radio frequency cavity applications: View of a condensed matter physicist

    Energy Technology Data Exchange (ETDEWEB)

    Roy, S. B., E-mail: sbroy@rrcat.gov.in [Magnetic & Superconducting Materials Section, Materials & Advanced Accelerator Sciences Division, Raja Ramanna Centre for Advanced Technology, Indore 452013 (India); Myneni, G. R., E-mail: rao@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, Virginia (United States)

    2015-12-04

    We address the issue of qualifications of the niobium materials to be used for superconducting radio frequency (SCRF) cavity fabrications, from the point of view of a condensed matter physicist/materials scientist. We focus on the particular materials properties of niobium required for the functioning a SCRF cavity, and how to optimize the same properties for the best SCRF cavity performance in a reproducible manner. In this way the niobium materials will not necessarily be characterized by their purity alone, but in terms of those materials properties, which will define the limit of the SCRF cavity performance and also other related material properties, which will help to sustain this best SCRF cavity performance. Furthermore we point out the need of standardization of the post fabrication processing of the niobium-SCRF cavities, which does not impair the optimized superconducting and thermal properties of the starting niobium-materials required for the reproducible performance of the SCRF cavities according to the design values.

  12. Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 1997

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, M.; Bechgaard, K.; Clausen, K.N.; Feidenhans`l, R.; Johannsen, I. [eds.

    1998-01-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1997 are presented in this progress report. The research in physics in concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems in undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au). 129 ills., 213 refs.

  13. Evolution of Matter Wave Interference of Bose-Condensed Gas in a 1D Optical Lattice

    Institute of Scientific and Technical Information of China (English)

    XU Zhi-Jun; ZHANG Dong-Mei

    2007-01-01

    For a Bose-condensed gas in a combined potential consisting of an axially-symmetric harmonic magnetic trap and one-dimensional (1D) optical lattice, using the mean-field Gross-Pitaevskii (G-P) equation and the propagator method, we obtain the analytical result of the order parameter for matter wave interference at any time. The evolution of the interference pattern under a variation of the relative phase △φ between successive subcondensates trapped on an optical lattices is also studied. For △φ = π, the interference pattern is symmetric with two sharp peaks, which are symmetrically located on a straight line on both sides of a vacant central peak and moving apart from each other. This work is in agreement with available experimental results.

  14. 24th Solvay Conference on Physics on Quantum Theory of Condensed Matter

    CERN Document Server

    Sevrin, Alexander

    2010-01-01

    Ever since 1911, the Solvay Conferences have shaped modern physics. The 24th edition chaired by Bertrand Halperin did not break the tradition. Held in October 2008, it gathered in Brussels most of the leading figures working on the quantum theory of condensed matter, addressing some of the most profound open problems in the field. The proceedings contain the rapporteur talks giving a broad overview with unique insights by distinguished renowned scientists. These lectures cover the five sessions treating: mesoscopic and disordered systems; exotic phases and quantum phase transitions in model systems; experimentally realized correlated-electron materials; quantum Hall systems, and one-dimensional systems; and, systems of ultra-cold atoms, and advanced computational methods. In the Solvay tradition, the proceedings include also the prepared comments to the rapporteur talks. The discussions among the participants - some of which are quite lively and involving dramatically divergent points of view - have been care...

  15. Annual progress report of the Condensed Matter Physics and Chemistry Department. 1 January - 31 December 1999

    Energy Technology Data Exchange (ETDEWEB)

    Lebech, B. [ed.

    2000-02-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1999 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scalestructures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au)

  16. Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 1998

    Energy Technology Data Exchange (ETDEWEB)

    Bechgaard, K.; Clausen, K.N.; Feidenhans`l, R.; Johannsen, I. [eds.

    1999-04-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical properties of materials. The principal activities in the year 1998 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au) 2 tabs., 142 ills., 169 refs.

  17. A theory of gravity with preferred frame and condensed matter interpretation

    CERN Document Server

    Schmelzer, I

    2010-01-01

    Does relativistic gravity provide empirical arguments against theories with a preferred frame like de Broglie-Bohm pilot wave theory? We present here a viable metric theory of gravity with preferred frame which gives a negative answer to this question. The theory has the same equations as Logunov's "relativistic theory of gravity" (RTG) but a less restrictive causality condition. It has not only a preferred frame, but allows even a condensed matter interpretation -- a variant of the ADM decomposition splits the metric into density, velocity and stress tensor of some hypothetical medium so that continuity and Euler equations hold. The theory shares many nice properties of RTG (EEP, Einstein equations in a natural limit, no big bang and black hole singularities, local energy and momentum densities for the gravitational field and a symmetry preference for a flat universe), but is also compatible with standard $\\Lambda$CDM cosmology. We also give a first principles derivation of the Lagrangian.

  18. Annual progress report of the Condensed Matter Physics and Chemistry Department. 1 January - 31 December 2000

    Energy Technology Data Exchange (ETDEWEB)

    Lebech, B. [ed.

    2001-03-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 2000 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au)

  19. Back Matter - JTSiskom Volume 5 Nomor 2 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-05-01

    Full Text Available Artikel ini berisi back-matter JTSiskom Volume 5 Nomor 2 Tahun 2017, yaitu meliputi indeks penulis, petunjuk penulisan dan kirim artikel JTSiskom, perjanjian pengalihan hak cipta, form pengalihan hak cipta, pernyataan etika publikasi dan lisensi isi jurnal.

  20. Front Matters - JTSiskom Volume 5 Nomor 1 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-01-01

    Full Text Available Artikel ini berisi front-matters JTSiskom Volume 5 Nomor 1 Tahun 2017, yaitu meliputi halaman sampul, halaman judul, susunan tim penyunting, ucapan terima kasih, kebijakan editorial dan daftar isi. Kebijakan editorial JTSiskom meliputi fokus dan ruang lingkup, proses review, frekuensi publikasi, kebijakan open access, pengarsipan dan pernyataan biaya pemrosesan artikel.

  1. Front Matter - JTSiskom Volume 5 Nomor 2 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-05-01

    Full Text Available Artikel ini berisi front-matter JTSiskom Volume 5 Nomor 2 Tahun 2017, yaitu meliputi halaman sampul, halaman judul, susunan tim penyunting, ucapan terima kasih, kebijakan editorial dan daftar isi. Kebijakan editorial JTSiskom meliputi fokus dan ruang lingkup, proses review, frekuensi publikasi, kebijakan open access, pengarsipan dan pernyataan biaya pemrosesan artikel.

  2. Back Matters - JTSiskom Volume 5 Nomor 1 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-01-01

    Full Text Available Artikel ini berisi front-matters JTSiskom Volume 5 Nomor 1 Tahun 2017, yaitu meliputi indeks penulis, petunjuk penulisan dan kirim artikel JTSiskom, perjanjian pengalihan hak cipta, form pengalihan hak cipta, pernyataan etika publikasi dan lisensi isi jurnal.

  3. Back Matter - JTSiskom Volume 5 Nomor 3 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-07-01

    Full Text Available Artikel ini berisi back-matter JTSiskom Volume 5 Nomor 3 Tahun 2017, yaitu meliputi indeks penulis, petunjuk penulisan dan kirim artikel JTSiskom, perjanjian pengalihan hak cipta, form pengalihan hak cipta, pernyataan etika publikasi dan lisensi isi jurnal.

  4. Front Matter - JTSiskom Volume 5 Nomor 3 Tahun 2017

    Directory of Open Access Journals (Sweden)

    Ketua Editor JTSiskom

    2017-07-01

    Full Text Available Artikel ini berisi front-matter JTSiskom Volume 5 Nomor 3 Tahun 2017, yaitu meliputi halaman sampul, halaman judul, susunan tim penyunting, ucapan terima kasih, kebijakan editorial dan daftar isi. Kebijakan editorial JTSiskom meliputi fokus dan ruang lingkup, proses review, frekuensi publikasi, kebijakan open access, pengarsipan dan pernyataan biaya pemrosesan artikel.

  5. Finite Volume Effect of Baryons in Strange Hadronic Matter

    Institute of Scientific and Technical Information of China (English)

    SUN Bao-Xi; LI Lei; NING Ping-Zhi; ZHAO En-Guang

    2001-01-01

    The finite volume effect of baryons in strange hadronic matter (SHM) is studied within the framework of relativistic mean-field theory. As this effect is concerned, the saturation density of SHM turns lower, and the binding energy per baryon decreases. Its influence to the compression modulus of SHM is also discussed.

  6. Zoology of condensed matter: framids, ordinary stuff, extra-ordinary stuff

    Energy Technology Data Exchange (ETDEWEB)

    Nicolis, Alberto; Penco, Riccardo [Physics Department and Institute for Strings, Cosmology, and Astroparticle Physics,Columbia University, New York, NY 10027 (United States); Piazza, Federico [Physics Department and Institute for Strings, Cosmology, and Astroparticle Physics,Columbia University, New York, NY 10027 (United States); Paris Center for Cosmological Physics and Laboratoire APC,Université Paris 7, 75205 Paris (France); CPT, Aix Marseille Université,UMR 7332, 13288 Marseille (France); Rattazzi, Riccardo [Institut de Théorie des Phénomènes Physiques,EPFL Lausanne (Switzerland)

    2015-06-23

    We classify condensed matter systems in terms of the spacetime symmetries they spontaneously break. In particular, we characterize condensed matter itself as any state in a Poincaré-invariant theory that spontaneously breaks Lorentz boosts while preserving at large distances some form of spatial translations, time-translations, and possibly spatial rotations. Surprisingly, the simplest, most minimal system achieving this symmetry breaking pattern — the framid — does not seem to be realized in Nature. Instead, Nature usually adopts a more cumbersome strategy: that of introducing internal translational symmetries — and possibly rotational ones — and of spontaneously breaking them along with their space-time counterparts, while preserving unbroken diagonal subgroups. This symmetry breaking pattern describes the infrared dynamics of ordinary solids, fluids, superfluids, and — if they exist — supersolids. A third, “extra-ordinary”, possibility involves replacing these internal symmetries with other symmetries that do not commute with the Poincaré group, for instance the galileon symmetry, supersymmetry or gauge symmetries. Among these options, we pick the systems based on the galileon symmetry, the “galileids”, for a more detailed study. Despite some similarity, all different patterns produce truly distinct physical systems with different observable properties. For instance, the low-energy 2→2 scattering amplitudes for the Goldstone excitations in the cases of framids, solids and galileids scale respectively as E{sup 2}, E{sup 4}, and E{sup 6}. Similarly the energy momentum tensor in the ground state is “trivial' for framids (ρ+p=0), normal for solids (ρ+p>0) and even inhomogenous for galileids.

  7. Zoology of condensed matter: framids, ordinary stuff, extra-ordinary stuff

    Science.gov (United States)

    Nicolis, Alberto; Penco, Riccardo; Piazza, Federico; Rattazzi, Riccardo

    2015-06-01

    We classify condensed matter systems in terms of the spacetime symmetries they spontaneously break. In particular, we characterize condensed matter itself as any state in a Poincaré-invariant theory that spontaneously breaks Lorentz boosts while preserving at large distances some form of spatial translations, time-translations, and possibly spatial rotations. Surprisingly, the simplest, most minimal system achieving this symmetry breaking pattern — the framid — does not seem to be realized in Nature. Instead, Nature usually adopts a more cumbersome strategy: that of introducing internal translational symmetries — and possibly rotational ones — and of spontaneously breaking them along with their space-time counterparts, while preserving unbroken diagonal subgroups. This symmetry breaking pattern describes the infrared dynamics of ordinary solids, fluids, superfluids, and — if they exist — supersolids. A third, "extra-ordinary", possibility involves replacing these internal symmetries with other symmetries that do not commute with the Poincaré group, for instance the galileon symmetry, supersymmetry or gauge symmetries. Among these options, we pick the systems based on the galileon symmetry, the " galileids", for a more detailed study. Despite some similarity, all different patterns produce truly distinct physical systems with different observable properties. For instance, the low-energy 2 → 2 scattering amplitudes for the Goldstone excitations in the cases of framids, solids and galileids scale respectively as E 2, E 4, and E 6. Similarly the energy momentum tensor in the ground state is "trivial" for framids ( ρ + p = 0), normal for solids ( ρ + p > 0) and even inhomogenous for galileids.

  8. Solitonic-type excitations in laser-condensed matter interaction: additional proof by independent publications

    Science.gov (United States)

    Kudriavtsev, Eugene M.

    2000-08-01

    The goal of this report is to discuss (in addition to review) the independent literature works which come to our attention in 2 last years with experimental or theoretical proofs the existence of the solitonic type Wave of Change in Reflection and Conduction (WCRC). WCRC presents a new variety of transfer phenomena in condensed matter. It was excited by a single IR laser pulse with a threshold of more than 10 kW/cm2 and consists of a series of about 30 solitary pulses with propagation velocity of each subsequent pulse decreasing two times comparing with that of preceding one in the range from sound velocity to less than about micron/s. Each pulse has the following solitary wave features: (1) it is all the time of one sign, (2) its velocity Ui is nearly constant, (3) it reflects from sample surfaces without noticeable velocity change. So far the systematic WCRC study was made in Lebedev Physical Institute, grate deal in collaboration with group of Marseilles University (prof. M. Autric) and also with some others groups. Literature analysis showed independent works where WCRC can be seen and which was made in different institutions with different own goals in mind. As example, work on optical monitoring of laser damage in IR materials or thermocouple measurements of temperature non stability in water cooled copper shield stopped the high power e-beam, etc. We will discuss also some details of theoretical work connected with development of Frenkel-Kontorova (1937) topological soliton model. WCRC is rather universal phenomenon, it appears in many laser-condensed matter interactions and so it should be studied for the WCRC mechanism understanding and its effect evaluation for different applications.

  9. Tetrafluoroethane (R134a) hydrate formation within variable volume reactor accompanied by evaporation and condensation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, K.; Choo, Y. S.; Hong, H. J.; Yoon, Y. S.; Song, M. H., E-mail: songm@dgu.edu [Department of Mechanical, Robotics, and Energy Engineering, Dongguk University, Seoul 100-715 (Korea, Republic of)

    2015-03-15

    Vast size hydrate formation reactors with fast conversion rate are required for the economic implementation of seawater desalination utilizing gas hydrate technology. The commercial target production rate is order of thousand tons of potable water per day per train. Various heat and mass transfer enhancement schemes including agitation, spraying, and bubbling have been examined to maximize the production capacities in scaled up design of hydrate formation reactors. The present experimental study focused on acquiring basic knowledge needed to design variable volume reactors to produce tetrafluoroethane hydrate slurry. Test vessel was composed of main cavity with fixed volume of 140 ml and auxiliary cavity with variable volume of 0 ∼ 64 ml. Temperatures at multiple locations within vessel and pressure were monitored while visual access was made through front window. Alternating evaporation and condensation induced by cyclic volume change provided agitation due to density differences among water and vapor, liquid and hydrate R134a as well as extended interface area, which improved hydrate formation kinetics coupled with latent heat release and absorption. Influences of coolant temperature, piston stroke/speed, and volume change period on hydrate formation kinetics were investigated. Suggestions of reactor design improvement for future experimental study are also made.

  10. Research in the Theory of Condensed Matter and Elementary Particles: Final Report, September 1, 1984 - November 30, 1987

    Science.gov (United States)

    Friedan, D.; Kadanoff, L.; Nambu, Y.; Shenker, S.

    1988-04-01

    Progress is reported in the field of condensed matter physics in the area of two-dimensional critical phenomena, specifically results allowing complete classification of all possible two-dimensional critical phenomena in a certain domain. In the field of high energy physics, progress is reported in string and conformal field theory, and supersymmetry.

  11. Condensate flow in holographic models in the presence of dark matter

    CERN Document Server

    Rogatko, Marek

    2016-01-01

    Holographic model of a current carrying superconductor or superfluid with {\\it dark matter} sector described by the additional $U(1)$-gauge field coupled to the ordinary Maxwell one, has been studied in the probe limit. We investigated analytically by the Sturm-Liouville variational method, the holographic s-wave and p-wave models in the background of the AdS soliton as well as five-dimensional AdS black hole spacetimes. The two models of p-wave superfluids were considered, the so called $SU(2)$ and the Maxwell-vector. Special attention has been paid to the dependence of the critical chemical potential and critical transition temperature on the velocity of the condensate and {\\it dark matter} parameters. The phenomenologically observed superconductor transition to normal metal or insulator, at large super-currents values, is not easily visible within analytical approach neglecting backreaction. Some hints about the existence of such transition can be inferred from the changes of the Sturm-Liouville solution a...

  12. A novel artificial condensed matter lattice and a new platform for one-dimensional topological phases.

    Science.gov (United States)

    Belopolski, Ilya; Xu, Su-Yang; Koirala, Nikesh; Liu, Chang; Bian, Guang; Strocov, Vladimir N; Chang, Guoqing; Neupane, Madhab; Alidoust, Nasser; Sanchez, Daniel; Zheng, Hao; Brahlek, Matthew; Rogalev, Victor; Kim, Timur; Plumb, Nicholas C; Chen, Chaoyu; Bertran, François; Le Fèvre, Patrick; Taleb-Ibrahimi, Amina; Asensio, Maria-Carmen; Shi, Ming; Lin, Hsin; Hoesch, Moritz; Oh, Seongshik; Hasan, M Zahid

    2017-03-01

    Engineered lattices in condensed matter physics, such as cold-atom optical lattices or photonic crystals, can have properties that are fundamentally different from those of naturally occurring electronic crystals. We report a novel type of artificial quantum matter lattice. Our lattice is a multilayer heterostructure built from alternating thin films of topological and trivial insulators. Each interface within the heterostructure hosts a set of topologically protected interface states, and by making the layers sufficiently thin, we demonstrate for the first time a hybridization of interface states across layers. In this way, our heterostructure forms an emergent atomic chain, where the interfaces act as lattice sites and the interface states act as atomic orbitals, as seen from our measurements by angle-resolved photoemission spectroscopy. By changing the composition of the heterostructure, we can directly control hopping between lattice sites. We realize a topological and a trivial phase in our superlattice band structure. We argue that the superlattice may be characterized in a significant way by a one-dimensional topological invariant, closely related to the invariant of the Su-Schrieffer-Heeger model. Our topological insulator heterostructure demonstrates a novel experimental platform where we can engineer band structures by directly controlling how electrons hop between lattice sites.

  13. Vienna Soil-Organic-Matter Modeler--Generating condensed-phase models of humic substances.

    Science.gov (United States)

    Sündermann, Axel; Solc, Roland; Tunega, Daniel; Haberhauer, Georg; Gerzabek, Martin H; Oostenbrink, Chris

    2015-11-01

    Humic substances are ubiquitous in the environment and have manifold functions. While their composition is well known, information on the chemical structure and three-dimensional conformation is scarce. Here we describe the Vienna Soil-Organic-Matter Modeler, which is an online tool to generate condensed phase computer models of humic substances (http://somm.boku.ac.at). Many different models can be created that reflect the diversity in composition and conformations of the constituting molecules. To exemplify the modeler, 18 different models are generated based on two experimentally determined compositions, to explicitly study the effect of varying e.g. the amount of water molecules in the models or the pH. Molecular dynamics simulations were performed on the models, which were subsequently analyzed in terms of structure, interactions and dynamics, linking macroscopic observables to the microscopic composition of the systems. We are convinced that this new tool opens the way for a wide range of in silico studies on soil organic matter.

  14. Abnormal gray and white matter volume in delusional infestation.

    Science.gov (United States)

    Wolf, Robert Christian; Huber, Markus; Depping, Malte Sebastian; Thomann, Philipp Arthur; Karner, Martin; Lepping, Peter; Freudenmann, Roland W

    2013-10-01

    Little is known about the neural basis of delusional infestation (DI), the delusional belief to be infested with pathogens. Case series and the response to anti-dopaminergic medication indicate disruptions in dopaminergic neurotransmission in the striatum (caudate, putamen), but did not allow for population-based inference. Here, we report the first whole-brain structural neuroimaging study to investigate gray and white matter abnormalities in DI compared to controls. In this study, we used structural magnetic resonance imaging and voxel-based morphometry to investigate gray and white matter volume in 16 DI patients and 16 matched healthy controls. Lower gray matter volume in DI patients compared to controls was found in left medial, lateral and right superior frontal cortices, left anterior cingulate cortex, bilateral insula, left thalamus, right striatal areas and in lateral and medial temporal cortical regions (p<0.05, cluster-corrected). Higher white matter volume in DI patients compared to controls was found in right middle cingulate, left frontal opercular and bilateral striatal regions (p<0.05, cluster-corrected). This study shows that structural changes in prefrontal, temporal, insular, cingulate and striatal brain regions are associated with DI, supporting a neurobiological model of disrupted prefrontal control over somato-sensory representations. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Light in condensed matter in the upper atmosphere as the origin of homochirality: circularly polarized light from Rydberg matter.

    Science.gov (United States)

    Holmlid, Leif

    2009-01-01

    Clouds of the condensed excited Rydberg matter (RM) exist in the atmospheres of comets and planetary bodies (most easily observed at Mercury and the Moon), where they surround the entire bodies. Vast such clouds are recently proposed to exist in the upper atmosphere of Earth (giving rise to the enormous features called noctilucent clouds, polar mesospheric clouds, and polar mesospheric summer radar echoes). It has been shown in experiments with RM that linearly polarized visible light scattered from an RM layer is transformed to circularly polarized light with a probability of approximately 50%. The circular Rydberg electrons in the magnetic field in the RM may be chiral scatterers. The magnetic and anisotropic RM medium acts as a circular polarizer probably by delaying one of the perpendicular components of the light wave. The delay process involved is called Rabi-flopping and gives delays of the order of femtoseconds. This strong effect thus gives intense circularly polarized visible and UV light within RM clouds. Amino acids and other chiral molecules will experience a strong interaction with this light field in the upper atmospheres of planets. The interaction will vary with the stereogenic conformation of the molecules and in all probability promote the survival of one enantiomer. Here, this strong effect is proposed to be the origin of homochirality. The formation of amino acids in the RM clouds is probably facilitated by the catalytic effect of RM.

  16. Gray Matter Volumes in Patients with Chronic Fatigue Syndrome

    Directory of Open Access Journals (Sweden)

    Le-wei Tang

    2015-01-01

    Full Text Available Chronic fatigue syndrome (CFS is a debilitating and complex disorder characterized by profound fatigue with uncertain pathologic mechanism. Neuroimage may be an important key to unveil the central nervous system (CNS mechanism in CFS. Although most of the studies found gray matter (GM volumes reduced in some brain regions in CFS, there are many factors that could affect GM volumes in CFS, including chronic pain, stress, psychiatric disorder, physical activity, and insomnia, which may bias the results. In this paper, through reviewing recent literatures, we discussed these interferential factors, which overlap with the symptoms of CFS.

  17. Dynamics and Matter-Wave Solitons in Bose-Einstein Condensates with Two- and Three-Body Interactions

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2014-01-01

    Full Text Available By means of similarity transformation, this paper proposes the matter-wave soliton solutions and dynamics of the variable coefficient cubic-quintic nonlinear Schrödinger equation arising from Bose-Einstein condensates with time-dependent two- and three-body interactions. It is found that, under the effect of time-dependent two- and three-body interaction and harmonic potential with time-dependent frequency, the density of atom condensates will gradually diminish and finally collapse.

  18. EDITORIAL: Richard Palmer: celebrating 37 years with Journal of Physics: Condensed Matter Richard Palmer: celebrating 37 years with Journal of Physics: Condensed Matter

    Science.gov (United States)

    Ferry, David

    2009-01-01

    It is with a great deal of both happiness and sadness that I have to announce that we are losing one of the real strengths of the Journal of Physics: Condensed Matter (JPCM). Dr Richard Palmer, our Senior Publisher, announced his retirement, and this issue marks the first without his involvement. Of course, we are happy that he will get to enjoy his retirement, but we are sad to lose such a valuable member of our team. Richard first started work at IOP Publishing in March 1971 as an Editorial Assistant with Journal of Physics B: Atomic and Molecular Physics. After a few months, he transferred to Journal of Physics C: Solid State Physics. During his first year, he was sent on a residential publishing training course and asked to sign an undertaking to stay at IOP Publishing for at least two years. Although Richard refused to sign, as he did not want to commit himself, he has remained with the journal since then. The following year, the Assistant Editor of Journal of Physics C: Solid State Physics, Malcolm Haines, walked out without notice in order to work on his family vineyard in France, and Richard stepped into the breach. In those days, external editors had a much more hands-on role in IOP Publishing and he had to travel to Harwell to be interviewed by Alan Lidiard, the Honorary Editor of Journal of Physics C: Solid State Physics, before being given the job of Assistant Editor permanently. I am told that in those days the job consisted mainly of editing and proofreading and peer review. There was no journal development work. At some point in the early 1980s, production and peer review were split into separate departments and Richard then headed a group of journals consisting of Journal of Physics C: Solid State Physics, Journal of Physics D: Applied Physics and Journal of Physics F: Metal Physics, Semiconductor Science and Technology, Superconductor Science and Technology, Plasma Physics and Controlled Fusion, and later Nanotechnology and Modelling and Simulation

  19. Supermassive black holes from collapsing dark matter Bose–Einstein condensates

    Science.gov (United States)

    Das Gupta, Patrick; Thareja, Eklavya

    2017-02-01

    The discovery of active galactic nuclei at redshifts ≳ 6 suggests that supermassive black holes (SMBHs) formed early on. Growth of the remnants of population III stars by accretion of matter, both baryonic as well as collisionless dark matter (DM), leading up to formation of SMBHs is a very slow process. Therefore, such models encounter difficulties in explaining quasars detected at z≳ 6 . Furthermore, massive particles making up collisionless DM have not only so far eluded experimental detection but they also do not satisfactorily explain gravitational structures on small scales. In recent years, there has been a surge in research activities concerning cosmological structure formation that involve coherent, ultra-light bosons in a dark fluid-like or fuzzy cold DM state. In this paper, we study collapse of such ultra-light bosonic halo DM that is in a Bose–Einstein condensate (BEC) phase to give rise to SMBHs on dynamical time scales. Time evolution of such self-gravitating BECs is examined using the Gross–Pitaevskii equation in the framework of time-dependent variational method. Comprised of identical dark bosons of mass m, BECs can collapse to form black holes of mass M eff on time scales  ∼108 yrs provided m~{{M}\\text{eff}}≳ 0.64~mPl2 . In particular, ultra-light dark bosons of mass ∼ {{10}-20}~\\text{eV} can lead to SMBHs with mass ≳ {{10}10}~{{M}ȯ} at z≈ 6 . Recently observed radio-galaxies in the ELAIS-N1 deep field with aligned jets can also possibly be explained if vortices of a rotating cluster size BEC collapse to form spinning SMBHs with angular momentum J≲ 3.6~{{n}W}\\frac{G{{M}2}}{c} , where n W and M are the winding number and mass of a vortex, respectively.

  20. A firmware-defined digital direct-sampling NMR spectrometer for condensed matter physics.

    Science.gov (United States)

    Pikulski, M; Shiroka, T; Ott, H-R; Mesot, J

    2014-09-01

    We report on the design and implementation of a new digital, broad-band nuclear magnetic resonance (NMR) spectrometer suitable for probing condensed matter. The spectrometer uses direct sampling in both transmission and reception. It relies on a single, commercially-available signal processing device with a user-accessible field-programmable gate array (FPGA). Its functions are defined exclusively by the FPGA firmware and the application software. Besides allowing for fast replication, flexibility, and extensibility, our software-based solution preserves the option to reuse the components for other projects. The device operates up to 400 MHz without, and up to 800 MHz with undersampling, respectively. Digital down-conversion with ±10 MHz passband is provided on the receiver side. The system supports high repetition rates and has virtually no intrinsic dead time. We describe briefly how the spectrometer integrates into the experimental setup and present test data which demonstrates that its performance is competitive with that of conventional designs.

  1. A firmware-defined digital direct-sampling NMR spectrometer for condensed matter physics

    Energy Technology Data Exchange (ETDEWEB)

    Pikulski, M., E-mail: marekp@ethz.ch; Shiroka, T.; Ott, H.-R.; Mesot, J. [Laboratorium für Festkörperphysik, ETH Hönggerberg, CH-8093 Zürich, Switzerland and Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2014-09-15

    We report on the design and implementation of a new digital, broad-band nuclear magnetic resonance (NMR) spectrometer suitable for probing condensed matter. The spectrometer uses direct sampling in both transmission and reception. It relies on a single, commercially-available signal processing device with a user-accessible field-programmable gate array (FPGA). Its functions are defined exclusively by the FPGA firmware and the application software. Besides allowing for fast replication, flexibility, and extensibility, our software-based solution preserves the option to reuse the components for other projects. The device operates up to 400 MHz without, and up to 800 MHz with undersampling, respectively. Digital down-conversion with ±10 MHz passband is provided on the receiver side. The system supports high repetition rates and has virtually no intrinsic dead time. We describe briefly how the spectrometer integrates into the experimental setup and present test data which demonstrates that its performance is competitive with that of conventional designs.

  2. Antwerp Advanced Study Institute on Electronic Structure, Dynamics and Quantum Structural Properties of Condensed Matter

    CERN Document Server

    Camp, Piet

    1985-01-01

    The 1984 Advanced Study Institute on "Electronic Structure, Dynamics and Quantum Structural Properties of Condensed Matter" took place at the Corsendonk Conference Center, close to the City of Antwerpen, from July 16 till 27, 1984. This NATO Advanced Study Institute was motivated by the research in my Institute, where, in 1971, a project was started on "ab-initio" phonon calculations in Silicon. I~ is my pleasure to thank several instances and people who made this ASI possible. First of all, the sponsor of the Institute, the NATO Scientific Committee. Next, the co-sponsors: Agfa-Gevaert, Bell Telephone Mfg. Co. N.V., C & A, Esso Belgium·, CDC Belgium, Janssens Pharmaceutica, Kredietbank and the Scientific Office of the U.S. Army. Special thanks are due to Dr. P. Van Camp and Drs. H. Nachtegaele, who, over several months, prepared the practical aspects of the ASI with the secretarial help of Mrs. R.-M. Vandekerkhof. I also like to. thank Mrs. M. Cuyvers who prepared and organized the subject and material ...

  3. Specifications for hard condensed matter specimens for three-dimensional high-resolution tomographies.

    Science.gov (United States)

    Bleuet, P; Audoit, G; Barnes, J-P; Bertheau, J; Dabin, Y; Dansas, H; Fabbri, J-M; Florin, B; Gergaud, P; Grenier, A; Haberfehlner, G; Lay, E; Laurencin, J; Serra, R; Villanova, J

    2013-06-01

    Tomography is a standard and invaluable technique that covers a large range of length scales. It gives access to the inner morphology of specimens and to the three-dimensional (3D) distribution of physical quantities such as elemental composition, crystalline phases, oxidation state, or strain. These data are necessary to determine the effective properties of investigated heterogeneous media. However, each tomographic technique relies on severe sampling conditions and physical principles that require the sample to be adequately shaped. For that purpose, a wide range of sample preparation techniques is used, including mechanical machining, polishing, sawing, ion milling, or chemical techniques. Here, we focus on the basics of tomography that justify such advanced sample preparation, before reviewing and illustrating the main techniques. Performances and limits are highlighted, and we identify the best preparation technique for a particular tomographic scale and application. The targeted tomography techniques include hard X-ray micro- and nanotomography, electron nanotomography, and atom probe tomography. The article mainly focuses on hard condensed matter, including porous materials, alloys, and microelectronics applications, but also includes, to a lesser extent, biological considerations.

  4. MOLOCH computer code for molecular-dynamics simulation of processes in condensed matter

    Directory of Open Access Journals (Sweden)

    Derbenev I.V.

    2011-01-01

    Full Text Available Theoretical and experimental investigation into properties of condensed matter is one of the mainstreams in RFNC-VNIITF scientific activity. The method of molecular dynamics (MD is an innovative method of theoretical materials science. Modern supercomputers allow the direct simulation of collective effects in multibillion atom sample, making it possible to model physical processes on the atomistic level, including material response to dynamic load, radiation damage, influence of defects and alloying additions upon material mechanical properties, or aging of actinides. During past ten years, the computer code MOLOCH has been developed at RFNC-VNIITF. It is a parallel code suitable for massive parallel computing. Modern programming techniques were used to make the code almost 100% efficient. Practically all instruments required for modelling were implemented in the code: a potential builder for different materials, simulation of physical processes in arbitrary 3D geometry, and calculated data processing. A set of tests was developed to analyse algorithms efficiency. It can be used to compare codes with different MD implementation between each other.

  5. Correlations in condensed matter under extreme conditions a tribute to Renato Pucci on the occasion of his 70th birthday

    CERN Document Server

    2017-01-01

    This book addresses a wide range of topics relating to the properties and behavior of condensed matter under extreme conditions such as intense magnetic and electric fields, high pressures, heat and cold, and mechanical stresses. It is divided into four sections devoted to condensed matter theory, molecular chemistry, theoretical physics, and the philosophy and history of science. The main themes include electronic correlations in material systems under extreme pressure and temperature conditions, surface physics, the transport properties of low-dimensional electronic systems, applications of the density functional theory in molecular systems, and graphene. The book is the outcome of a workshop held at the University of Catania, Italy, in honor of Professor Renato Pucci on the occasion of his 70th birthday. It includes selected invited contributions from collaborators and co-authors of Professor Pucci during his long and successful career, as well as from other distinguished guest authors.

  6. Condensed-matter ab initio approach for strongly correlated electrons: Application to a quantum spin liquid candidate

    Energy Technology Data Exchange (ETDEWEB)

    Yamaji, Youhei [Quantum-Phase Electronics Center, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113-8656 (Japan)

    2015-12-31

    Recently, condensed-matter ab initio approaches to strongly correlated electrons confined in crystalline solids have been developed and applied to transition-metal oxides and molecular conductors. In this paper, an ab initio scheme based on constrained random phase approximations and localized Wannier orbitals is applied to a spin liquid candidate Na{sub 2}IrO{sub 3} and is shown to reproduce experimentally observed specific heat.

  7. Computerized Verification of New Hierarchic Theory of Condensed Matter on Examples of Water & Ice. New Optoacoustic Device Comprehensive Analyzer of Matter Properties (CAMP)

    CERN Document Server

    Kaivarainen, A

    2002-01-01

    The short version of new quantum and quantitative Hierarchic theory, general for solids and liquids (Kaivarainen, 1989, 1995, physics/0102086) is presented. Condensed matter is considered as system of 3D standing waves (collective excitations) of different nature: thermal de Broglie waves (waves B), IR photons, related to intermolecular oscilla device is that only small part of 300 parameters, yielding by CAMP system, is possible to get, using separate experimental methods, like IR spectroscopy, sound velocimetry, densitometry and refractometry.

  8. Affleck-Dine baryogenesis, condensate fragmentation and gravitino dark matter in gauge-mediation with a large messenger mass

    Energy Technology Data Exchange (ETDEWEB)

    Doddato, Francesca; McDonald, John, E-mail: f.doddato@lancaster.ac.uk, E-mail: j.mcdonald@lancaster.ac.uk [Dept. of Physics, Cosmology and Astroparticle Physics Group, University of Lancaster, Lancaster LA1 4YB (United Kingdom)

    2011-06-01

    We study the conditions for successful Affleck-Dine baryogenesis and the origin of gravitino dark matter in GMSB models. AD baryogenesis in GMSB models is ruled out by neutron star stability unless Q-balls are unstable and decay before nucleosynthesis. Unstable Q-balls can form if the messenger mass scale is larger than the flat-direction field Φ when the condensate fragments. We provide an example based on AD baryogenesis along a d = 6 flat direction for the case where m{sub 3/2} ≈ 2GeV, as predicted by gravitino dark matter from Q-ball decay. Using a phenomenological GMSB potential which models the Φ dependence of the SUSY breaking terms, we numerically solve for the evolution of Φ and show that the messenger mass can be sufficiently close to the flat-direction field when the condensate fragments. We compute the corresponding reheating temperature and the baryonic charge of the condensate fragments and show that the charge is large enough to produce late-decaying Q-balls which can be the origin of gravitino dark matter.

  9. Association of white matter hyperintensities and gray matter volume with cognition in older individuals without cognitive impairment.

    Science.gov (United States)

    Arvanitakis, Zoe; Fleischman, Debra A; Arfanakis, Konstantinos; Leurgans, Sue E; Barnes, Lisa L; Bennett, David A

    2016-05-01

    Both presence of white matter hyperintensities (WMH) and smaller total gray matter volume on brain magnetic resonance imaging (MRI) are common findings in old age, and contribute to impaired cognition. We tested whether total WMH volume and gray matter volume had independent associations with cognition in community-dwelling individuals without dementia or mild cognitive impairment (MCI). We used data from participants of the Rush Memory and Aging Project. Brain MRI was available in 209 subjects without dementia or MCI (mean age 80; education = 15 years; 74 % women). WMH and gray matter were automatically segmented, and the total WMH and gray matter volumes were measured. Both MRI-derived measures were normalized by the intracranial volume. Cognitive data included composite measures of five different cognitive domains, based on 19 individual tests. Linear regression analyses, adjusted for age, sex, and education, were used to examine the relationship of logarithmically-transformed total WMH volume and of total gray matter volume to cognition. Larger total WMH volumes were associated with lower levels of perceptual speed (p  0.10). Smaller total gray matter volumes were associated with lower levels of perceptual speed (p = 0.013) and episodic memory (p = 0.001), but not with the other three cognitive domains (all p > 0.14). Larger total WMH volume was correlated with smaller total gray matter volume (p cognitive impairment suggests that the association of larger total WMH volume with lower perceptual speed is independent of total gray matter volume. These results help elucidate the pathological processes leading to lower cognitive function in aging.

  10. PREFACE: REXS 2013 - Workshop on Resonant Elastic X-ray Scattering in Condensed Matter

    Science.gov (United States)

    Beutier, G.; Mazzoli, C.; Yakhou, F.; Brown, S. D.; Bombardi, A.; Collins, S. P.

    2014-05-01

    The aim of this workshop was to bring together experts in experimental and theoretical aspects of resonant elastic x-ray scattering, along with researchers who are new to the field, to discuss important recent results and the fundamentals of the technique. The meeting was a great success, with the first day dedicated to students and new researchers in the field, who received introductory lectures and tutorials. All conference delegates were invited either to make an oral presentation or to present a poster, accompanied by a short talk. The first two papers selected for the REXS13 proceedings (Grenier & Joly and Helliwell) give a basic background to the theory of REXS and applications across a wide range of scientific areas. The remainder of the papers report on some of the latest scientific results obtained by applying the REXS technique to contemporary problems in condensed matter, materials and x-ray physics. It is hoped that these proceedings provide a snapshot of the current status of a vibrant and diverse scientific technique that will be of value not just to those who attended the workshop but also to any other reader with an interest in the subject. Local Scientific Committee REXS13 International Scientific Advisory Committee M Altarelli, European XFEL, Germany F de Bergevin, European Synchrotron Radiation Facility, France J Garcia-Ruiz, Universidad de Zaragoza, Spain A I Goldman, Iowa State University, USA M Goldmann, Institut Nanosciences, France T Schulli, European Synchrotron Radiation Facility, France C R Natoli, Laboratori Nazionali de Frascati, Italy G Materlik, Diamond Light Source, UK L Paolasini, European Synchrotron Radiation Facility, France U Staub, Paul Scherrer Institut, Switzerland K Finkelstein, Cornell University, USA Y Murakami, Photon Factory, Japan REXS13 Local Scientific Committee G Beutier, CNRS Grenoble, France C Mazzoli, Politecnico di Milano, Italy F Yakhou, European Synchrotron Radiation Facility, France S D Brown, XMaS UK CRG

  11. Towards applications of the gauge-gravity duality to condensed matter physics

    Science.gov (United States)

    Rocha, Fabio Diales Da

    String theory offers, through the gauge-gravity dualities, powerful methods to study strongly coupled field theories. In this dissertation, we will be concerned with applying these methods to topics related to condensed matter physics. The Abelian Higgs model coupled to gravity with a negative cosmological constant provides a gravitational dual to a strongly coupled field theory that has superconducting or superfluid phases. We construct zero-temperature solutions of this model that interpolate between two copies of anti-de Sitter space and which we identify with gravitational duals of quantum critical points. We will do this both for an ad hoc Abelian Higgs model and for closely related gravitational Lagrangians arising as consistent truncations of string theory and M-theory. We also compute their frequency-dependent conductivities and find power law behavior at low frequencies. We will introduce spin-1/2 fermions in these domain wall geometries and find continuous bands of fermionic normal modes. These bands can be either partially filled or totally empty and gapped. We will consider fermionic normal modes and correlators in other gravitational backgrounds and find other interesting features. For certain dilatonic black holes in AdS5 and AdS4 in the extremal limit, we find isolated fermionic normal modes at zero frequency and finite momentum. We will also find that these dilatonic black holes have linear specific heat at low temperatures, which combined with the previous property makes them an interesting candidate for a gravitational dual of a Fermi liquid. Finally, we will consider fermion correlators in non-abelian holographic superconductors and find that their spectral function exhibits several interesting features such as support in displaced Dirac cones and an asymmetric distribution of normal modes. We compare these features to similar ones observed in angle resolved photoemission experiments on high Tc superconductors.

  12. Comparison of grey matter volume and thickness for analysing cortical changes in chronic schizophrenia: a matter of surface area, grey/white matter intensity contrast, and curvature.

    Science.gov (United States)

    Kong, Li; Herold, Christina J; Zöllner, Frank; Salat, David H; Lässer, Marc M; Schmid, Lena A; Fellhauer, Iven; Thomann, Philipp A; Essig, Marco; Schad, Lothar R; Erickson, Kirk I; Schröder, Johannes

    2015-02-28

    Grey matter volume and cortical thickness are the two most widely used measures for detecting grey matter morphometric changes in various diseases such as schizophrenia. However, these two measures only share partial overlapping regions in identifying morphometric changes. Few studies have investigated the contributions of the potential factors to the differences of grey matter volume and cortical thickness. To investigate this question, 3T magnetic resonance images from 22 patients with schizophrenia and 20 well-matched healthy controls were chosen for analyses. Grey matter volume and cortical thickness were measured by VBM and Freesurfer. Grey matter volume results were then rendered onto the surface template of Freesurfer to compare the differences from cortical thickness in anatomical locations. Discrepancy regions of the grey matter volume and thickness where grey matter volume significantly decreased but without corresponding evidence of cortical thinning involved the rostral middle frontal, precentral, lateral occipital and superior frontal gyri. Subsequent region-of-interest analysis demonstrated that changes in surface area, grey/white matter intensity contrast and curvature accounted for the discrepancies. Our results suggest that the differences between grey matter volume and thickness could be jointly driven by surface area, grey/white matter intensity contrast and curvature.

  13. MRI markers for mild cognitive impairment: comparisons between white matter integrity and gray matter volume measurements.

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    Full Text Available The aim of the study was to evaluate the value of assessing white matter integrity using diffusion tensor imaging (DTI for classification of mild cognitive impairment (MCI and prediction of cognitive impairments in comparison to brain atrophy measurements using structural MRI. Fifty-one patients with MCI and 66 cognitive normal controls (CN underwent DTI and T1-weighted structural MRI. DTI measures included fractional anisotropy (FA and radial diffusivity (DR from 20 predetermined regions-of-interest (ROIs in the commissural, limbic and association tracts, which are thought to be involved in Alzheimer's disease; measures of regional gray matter (GM volume included 21 ROIs in medial temporal lobe, parietal cortex, and subcortical regions. Significant group differences between MCI and CN were detected by each MRI modality: In particular, reduced FA was found in splenium, left isthmus cingulum and fornix; increased DR was found in splenium, left isthmus cingulum and bilateral uncinate fasciculi; reduced GM volume was found in bilateral hippocampi, left entorhinal cortex, right amygdala and bilateral thalamus; and thinner cortex was found in the left entorhinal cortex. Group classifications based on FA or DR was significant and better than classifications based on GM volume. Using either DR or FA together with GM volume improved classification accuracy. Furthermore, all three measures, FA, DR and GM volume were similarly accurate in predicting cognitive performance in MCI patients. Taken together, the results imply that DTI measures are as accurate as measures of GM volume in detecting brain alterations that are associated with cognitive impairment. Furthermore, a combination of DTI and structural MRI measurements improves classification accuracy.

  14. The possibility of formation of Supermassive Black Holes from Bose-Einstein Condensation of Bosonic Dark Matter

    CERN Document Server

    Gupta, Patrick Das

    2015-01-01

    Observed active galactic nuclei at redshifts of about 6 strongly suggest that supermassive black holes (SMBHs) had formed early on. Accretion of matter onto remnants of Population III stars leading to SMBHs is a very slow process, and therefore the model faces difficulties in explaining quasars detected at $ z \\gtrsim 6$. In this paper we invoke Bose-Einstein condensation of dark bosons to demonstrate that existence of very light ($m \\sim 10^{-23} \\ \\mbox{eV}$) spinless dark matter particles can not only lead to SMBHs of mass $\\gtrsim 10^{10} \\ M_\\odot$ at $ z \\gtrsim 6$ but also such particles can masquerade as dark matter as well as dark energy.

  15. Affleck-Dine Baryogenesis, Condensate Fragmentation and Gravitino Dark Matter in Gauge-Mediation with a Large Messenger Mass

    CERN Document Server

    Doddato, Francesca

    2011-01-01

    We study the conditions for successful Affleck-Dine baryogenesis and the origin of gravitino dark matter in GMSB models. AD baryogenesis in GMSB models is ruled out by neutron star stability unless Q-balls are unstable and decay before nucleosynthesis. Unstable Q-balls can form if the messenger mass scale is larger than the flat-direction field Phi when the condensate fragments. We provide an example based on AD baryogenesis along a d = 6 flat direction for the case where m_{3/2} \\approx 2 GeV, as predicted by gravitino dark matter from Q-ball decay. Using a phenomenological GMSB potential which models the Phi dependence of the SUSY breaking terms, we numerically solve for the evolution of Phi and show that the messenger mass can be sufficiently close to the flat-direction field when the condensate fragments. We compute the corresponding reheating temperature and the baryonic charge of the condensate fragments and show that the charge is large enough to produce late-decaying Q-balls which can be the origin of...

  16. Scalar quanta in Fermi liquids: Zero sounds, instabilities, Bose condensation, and a metastable state in dilute nuclear matter

    Science.gov (United States)

    Kolomeitsev, E. E.; Voskresensky, D. N.

    2016-12-01

    The spectrum of bosonic scalar-mode excitations in a normal Fermi liquid with local scalar interaction is investigated for various values and momentum dependence of the scalar Landau parameter f0 in the particle-hole channel. For f0 > 0 the conditions are found when the phase velocity on the spectrum of zero sound acquires a minimum at non-zero momentum. For -1 excitations, and for f0 excitations. An effective Lagrangian for the scalar excitation modes is derived after performing a bosonization procedure. We demonstrate that the instability may be tamed by the formation of a static Bose condensate of the scalar modes. The condensation may occur in a homogeneous or inhomogeneous state relying on the momentum dependence of the scalar Landau parameter. We show that in the isospin-symmetric nuclear matter there may appear a metastable state at subsaturation nuclear density owing to the condensate. Then we consider a possibility of the condensation of the zero-sound-like excitations in a state with a non-zero momentum in Fermi liquids moving with overcritical velocities, provided an appropriate momentum dependence of the Landau parameter f0(k) > 0. We also argue that in peripheral heavy-ion collisions the Pomeranchuk instability may occur already for f0 > -1.

  17. Physical activity predicts gray matter volume in late adulthood: the Cardiovascular Health Study.

    Science.gov (United States)

    Erickson, K I; Raji, C A; Lopez, O L; Becker, J T; Rosano, C; Newman, A B; Gach, H M; Thompson, P M; Ho, A J; Kuller, L H

    2010-10-19

    Physical activity (PA) has been hypothesized to spare gray matter volume in late adulthood, but longitudinal data testing an association has been lacking. Here we tested whether PA would be associated with greater gray matter volume after a 9-year follow-up, a threshold could be identified for the amount of walking necessary to spare gray matter volume, and greater gray matter volume associated with PA would be associated with a reduced risk for cognitive impairment 13 years after the PA evaluation. In 299 adults (mean age 78 years) from the Cardiovascular Health Cognition Study, we examined the association between gray matter volume, PA, and cognitive impairment. Physical activity was quantified as the number of blocks walked over 1 week. High-resolution brain scans were acquired 9 years after the PA assessment on cognitively normal adults. White matter hyperintensities, ventricular grade, and other health variables at baseline were used as covariates. Clinical adjudication for cognitive impairment occurred 13 years after baseline. Walking amounts ranged from 0 to 300 blocks (mean 56.3; SD 69.7). Greater PA predicted greater volumes of frontal, occipital, entorhinal, and hippocampal regions 9 years later. Walking 72 blocks was necessary to detect increased gray matter volume but walking more than 72 blocks did not spare additional volume. Greater gray matter volume with PA reduced the risk for cognitive impairment 2-fold. Greater amounts of walking are associated with greater gray matter volume, which is in turn associated with a reduced risk of cognitive impairment.

  18. Forty Lines of Evidence for Condensed Matter — The Sun on Trial: Liquid Metallic Hydrogen as a Solar Building Block

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-10-01

    Full Text Available Our Sun has confronted humanity with overwhelming evidence that it is comprised of condensed matter. Dismissing this reality, the standard solar models continue to be anchored on the gaseous plasma. In large measure, the endurance of these theories can be attributed to 1 the mathematical elegance of the equations for the gaseous state, 2 the apparent success of the mass-luminosity relationship, and 3 the long-lasting influence of leading proponents of these models. Unfortunately, no direct physical finding supports the notion that the solar body is gaseous. Without exception, all observations are most easily explained by recognizing that the Sun is primarily comprised of condensed matter. However, when a physical characteristic points to condensed matter, a postori arguments are invoked to account for the behavior using the gaseous state. In isolation, many of these treatments appear plausible. As a result, the gaseous models continue to be accepted. There seems to be an overarching belief in solar science that the problems with the gaseous models are few and inconsequential. In reality, they are numerous and, while often subtle, they are sometimes daunting. The gaseous equations of state have introduced far more dilemmas than they have solved. Many of the conclusions derived from these approaches are likely to have led solar physics down unproductive avenues, as deductions have been accepted which bear little or no relationship to the actual nature of the Sun. It could be argued that, for more than 100 years, the gaseous models have prevented mankind from making real progress relative to understanding the Sun and the universe. Hence, the Sun is now placed on trial. Forty lines of evidence will be presentedbthat the solar body is comprised of, and surrounded by, condensed matter. These ‘proofs’ can be divided into seven broad categories: 1 Planckian, 2 spectroscopic, 3 structural, 4 dynamic, 5 helioseismic, 6 elemental, and 7 earthly

  19. Increased cerebellar gray matter volume in head chefs

    Science.gov (United States)

    Sarica, Alessia; Martino, Iolanda; Fabbricatore, Carmelo; Tomaiuolo, Francesco; Rocca, Federico; Caracciolo, Manuela; Quattrone, Aldo

    2017-01-01

    Objective Chefs exert expert motor and cognitive performances on a daily basis. Neuroimaging has clearly shown that that long-term skill learning (i.e., athletes, musicians, chess player or sommeliers) induces plastic changes in the brain thus enabling tasks to be performed faster and more accurately. How a chef's expertise is embodied in a specific neural network has never been investigated. Methods Eleven Italian head chefs with long-term brigade management expertise and 11 demographically-/ psychologically- matched non-experts underwent morphological evaluations. Results Voxel-based analysis performed with SUIT, as well as, automated volumetric measurement assessed with Freesurfer, revealed increased gray matter volume in the cerebellum in chefs compared to non-experts. The most significant changes were detected in the anterior vermis and the posterior cerebellar lobule. The magnitude of the brigade staff and the higher performance in the Tower of London test correlated with these specific gray matter increases, respectively. Conclusions We found that chefs are characterized by an anatomical variability involving the cerebellum. This confirms the role of this region in the development of similar expert brains characterized by learning dexterous skills, such as pianists, rock climbers and basketball players. However, the nature of the cellular events underlying the detected morphological differences remains an open question. PMID:28182712

  20. 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.

  1. Insulin resistance and gray matter volume in neurodegenerative disease.

    Science.gov (United States)

    Morris, J K; Vidoni, E D; Perea, R D; Rada, R; Johnson, D K; Lyons, K; Pahwa, R; Burns, J M; Honea, R A

    2014-06-13

    The goal of this study was to compare insulin resistance in aging and aging-related neurodegenerative diseases, and to determine the relationship between insulin resistance and gray matter volume (GMV) in each cohort using an unbiased, voxel-based approach. Insulin resistance was estimated in apparently healthy elderly control (HC, n=21) and neurodegenerative disease (Alzheimer's disease (AD), n=20; Parkinson's disease (PD), n=22) groups using Homeostasis Model Assessment of Insulin Resistance 2 (HOMA2) and intravenous glucose tolerance test (IVGTT). HOMA2 and GMV were assessed within groups through General Linear Model multiple regression. We found that HOMA2 was increased in both AD and PD compared to the HC group (HC vs. AD, p=0.002, HC vs. PD, p=0.003), although only AD subjects exhibited increased fasting glucose (p=0.005). Furthermore, our voxel-based morphometry analysis revealed that HOMA2 was related to GMV in all cohorts in a region-specific manner (p<0.001, uncorrected). Significant relationships were observed in the medial prefrontal cortex (HC), medial temporal regions (AD), and parietal regions (PD). Finally, the directionality of the relationship between HOMA2 and GMV was disease-specific. Both HC and AD subjects exhibited negative relationships between HOMA2 and brain volume (increased HOMA2 associated with decreased brain volume), while a positive relationship was observed in PD. This cross-sectional study suggests that insulin resistance is increased in neurodegenerative disease, and that individuals with AD appear to have more severe metabolic dysfunction than individuals with PD or PD dementia.

  2. Brain white matter volume abnormalities in Lesch-Nyhan disease and its variants.

    Science.gov (United States)

    Schretlen, David J; Varvaris, Mark; Vannorsdall, Tracy D; Gordon, Barry; Harris, James C; Jinnah, H A

    2015-01-13

    We sought to examine brain white matter abnormalities based on MRI in adults with Lesch-Nyhan disease (LND) or an attenuated variant (LNV) of this rare, X-linked neurodevelopmental disorder of purine metabolism. In this observational study, we compared 21 adults with LND, 17 with LNV, and 33 age-, sex-, and race-matched healthy controls using voxel-based morphometry and analysis of covariance to identify white matter volume abnormalities in both patient groups. Patients with classic LND showed larger reductions of white (26%) than gray (17%) matter volume relative to healthy controls. Those with LNV showed comparable reductions of white (14%) and gray (15%) matter volume. Both patient groups demonstrated reduced volume in medial inferior white matter regions. Compared with LNV, the LND group showed larger reductions in inferior frontal white matter adjoining limbic and temporal regions and the motor cortex. These regions likely include such long association fibers as the superior longitudinal and uncinate fasciculi. Despite earlier reports that LND primarily involves the basal ganglia, this study reveals substantial white matter volume abnormalities. Moreover, white matter deficits are more severe than gray matter deficits in classic LND, and also characterize persons with LNV. The brain images acquired for these analyses cannot precisely localize white matter abnormalities or determine whether they involve changes in tract orientation or anisotropy. However, clusters of reduced white matter volume identified here affect regions that are consistent with the neurobehavioral phenotype. © 2014 American Academy of Neurology.

  3. Different scaling of white matter volume, cortical connectivity, and gyrification across rodent and primate brains

    Directory of Open Access Journals (Sweden)

    Lissa eVentura-Antunes

    2013-04-01

    Full Text Available Expansion of the cortical grey matter in evolution has been accompanied by an even faster expansion of the subcortical white matter volume and by folding of the grey matter surface, events traditionally considered to occur homogeneously across mammalian species. Here we investigate how white matter expansion and cortical folding scale across species of rodents and primates as the grey matter gains neurons. We find very different scaling rules of white matter expansion across the two orders, favoring volume conservation and smaller propagation times in primates. For a similar number of cortical neurons, primates have a smaller connectivity fraction and less white matter volume than rodents; moreover, as the cortex gains neurons, there is a much faster increase in white matter volume and in its ratio to grey matter volume in rodents than in primates. Order-specific scaling of the white matter can be attributed to different scaling of average fiber caliber and neuronal connectivity in rodents and primates. Finally, cortical folding increases as different functions of the number of cortical neurons in rodents and primates, scaling faster in the latter than in the former. While the neuronal rules that govern grey and white matter scaling are different across rodents and primates, we find that they can be explained by the same unifying model, with order-specific exponents. The different scaling of the white matter has implications for the scaling of propagation time and computational capacity in evolution, and calls for a reappraisal of developmental models of cortical expansion in evolution.

  4. BOOK REVIEW: Many-Body Quantum Theory in Condensed Matter Physics—An Introduction

    Science.gov (United States)

    Logan, D. E.

    2005-02-01

    This is undoubtedly an ambitious book. It aims to provide a wide ranging, yet self-contained and pedagogical introduction to techniques of quantum many-body theory in condensed matter physics, without losing mathematical `rigor' (which I hope means rigour), and with an eye on physical insight, motivation and application. The authors certainly bring plenty of experience to the task, the book having grown out of their graduate lectures at the Niels Bohr Institute in Copenhagen over a five year period, with the feedback and refinement this presumably brings. The book is also of course ambitious in another sense, for it competes in the tight market of general graduate/advanced undergraduate texts on many-particle physics. Prospective punters will thus want reasons to prefer it to, or at least give it space beside, well established texts in the field. Subject-wise, the book is a good mix of the ancient and modern, the standard and less so. Obligatory chapters deal with the formal cornerstones of many-body theory, from second quantization, time-dependence in quantum mechanics and linear response theory, to Green's function and Feynman diagrams. Traditional topics are well covered, including two chapters on the electron gas, chapters on phonons and electron phonon coupling, and a concise account of superconductivity (confined, no doubt judiciously, to the conventional BCS case). Less mandatory, albeit conceptually vital, subjects are also aired. These include a chapter on Fermi liquid theory, from both semi-classical and microscopic perspectives, and a freestanding account of one-dimensional electron gases and Luttinger liquids which, given the enormity of the topic, is about as concise as it could be without sacrificing clarity. Quite naturally, the authors' own interests also influence the choice of material covered. A persistent theme, which brings a healthy topicality to the book, is the area of transport in mesoscopic systems or nanostructures. Two chapters, some

  5. Regional Gray Matter Volume Deficits in Adolescents with First-Episode Psychosis

    Science.gov (United States)

    Janssen, Joost; Parellada, Mara; Moreno, Dolores; Graell, Montserrat; Fraguas, David; Zabala, Arantzazu; Vazquez, Veronica Garcia; Desco, Manuel; Arango, Celso

    2008-01-01

    The regional gray matter volumes of adolescents with first-episode psychosis are compared with those of a control group. Magnetic resonance imaging was conducted on 70 patients with early onset FEP and on 51 individuals without FEP. Findings revealed that volume deficits in the left medial frontal gray matter were common in individuals with…

  6. Subcortical Gray Matter Volume Abnormalities in Healthy Bipolar Offspring: Potential Neuroanatomical Risk Marker for Bipolar Disorder?

    Science.gov (United States)

    Ladouceur, Cecile D.; Almeida, Jorge R. C.; Birmaher, Boris; Axelson, David A.; Nau, Sharon; Kalas, Catherine; Monk, Kelly; Kupfer, David J.; Phillips, Mary L.

    2008-01-01

    A study is conducted to examine the extent to which bipolar disorder (BD) is associated with gray matter volume abnormalities in brain regions in healthy bipolar offspring relative to age-matched controls. Results show increased gray matter volume in the parahippocampus/hippocampus in healthy offspring at genetic risk for BD.

  7. Subcortical Gray Matter Volume Abnormalities in Healthy Bipolar Offspring: Potential Neuroanatomical Risk Marker for Bipolar Disorder?

    Science.gov (United States)

    Ladouceur, Cecile D.; Almeida, Jorge R. C.; Birmaher, Boris; Axelson, David A.; Nau, Sharon; Kalas, Catherine; Monk, Kelly; Kupfer, David J.; Phillips, Mary L.

    2008-01-01

    A study is conducted to examine the extent to which bipolar disorder (BD) is associated with gray matter volume abnormalities in brain regions in healthy bipolar offspring relative to age-matched controls. Results show increased gray matter volume in the parahippocampus/hippocampus in healthy offspring at genetic risk for BD.

  8. Correlation among body height, intelligence, and brain gray matter volume in healthy children.

    Science.gov (United States)

    Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Asano, Michiko; Asano, Kohei; Kotozaki, Yuka; Nouchi, Rui; Wu, Kai; Fukuda, Hiroshi; Kawashima, Ryuta

    2012-01-16

    A significant positive correlation between height and intelligence has been demonstrated in children. Additionally, intelligence has been associated with the volume of gray matter in the brains of children. Based on these correlations, we analyzed the correlation among height, full-scale intelligence quotient (IQ) and gray matter volume applying voxel-based morphometry using data from the brain magnetic resonance images of 160 healthy children aged 5-18 years of age. As a result, body height was significantly positively correlated with brain gray matter volume. Additionally, the regional gray matter volume of several regions such as the bilateral prefrontal cortices, temporoparietal region, and cerebellum was significantly positively correlated with body height and that the gray matter volume of several of these regions was also significantly positively correlated with full-scale intelligence quotient (IQ) scores after adjusting for age, sex, and socioeconomic status. Our results demonstrate that gray and white matter volume may mediate the correlation between body height and intelligence in healthy children. Additionally, the correlations among gray and white matter volume, height, and intelligence may be at least partially explained by the effect of insulin-like growth factor-1 and growth hormones. Given the importance of the effect of environmental factors, especially nutrition, on height, IQ, and gray matter volume, the present results stress the importance of nutrition during childhood for the healthy maturation of body and brain. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. The low lying modes of triplet-condensed neutron matter and their effective theory

    CERN Document Server

    Bedaque, Paulo F

    2013-01-01

    The condensation of neutrons into a 3P2 superfluid phase occurs at densities relevant for the interior of neutron stars. The triplet pairing breaks rotational symmetry spontaneously and leads to the existence of gapless modes (angulons) that are relevant for many transport coefficients and to the star's cooling properties. We derive the leading terms of the low energy effective field theory, including the leading coupling to electroweak currents, valid for a variety of possible 3P2 phases.

  10. White-matter microstructure and gray-matter volumes in adolescents with subthreshold bipolar symptoms.

    Science.gov (United States)

    Paillère Martinot, M-L; Lemaitre, H; Artiges, E; Miranda, R; Goodman, R; Penttilä, J; Struve, M; Fadai, T; Kappel, V; Poustka, L; Conrod, P; Banaschewski, T; Barbot, A; Barker, G J; Büchel, C; Flor, H; Gallinat, J; Garavan, H; Heinz, A; Ittermann, B; Lawrence, C; Loth, E; Mann, K; Paus, T; Pausova, Z; Rietschel, M; Robbins, T W; Smolka, M N; Schumann, G; Martinot, J-L

    2014-04-01

    Abnormalities in white-matter (WM) microstructure, as lower fractional anisotropy (FA), have been reported in adolescent-onset bipolar disorder and in youth at familial risk for bipolarity. We sought to determine whether healthy adolescents with subthreshold bipolar symptoms (SBP) would have early WM microstructural alterations and whether those alterations would be associated with differences in gray-matter (GM) volumes. Forty-two adolescents with three core manic symptoms and no psychiatric diagnosis, and 126 adolescents matched by age and sex, with no psychiatric diagnosis or symptoms, were identified after screening the IMAGEN database of 2223 young adolescents recruited from the general population. After image quality control, voxel-wise statistics were performed on the diffusion parameters using tract-based spatial statistics in 25 SBP adolescents and 77 controls, and on GM and WM images using voxel-based morphometry in 30 SBP adolescents and 106 controls. As compared with healthy controls, adolescents with SBP displayed lower FA values in a number of WM tracts, particularly in the corpus callosum, cingulum, bilateral superior and inferior longitudinal fasciculi, uncinate fasciculi and corticospinal tracts. Radial diffusivity was mainly higher in posterior parts of bilateral superior and inferior longitudinal fasciculi, inferior fronto-occipital fasciculi and right cingulum. As compared with controls, SBP adolescents had lower GM volume in the left anterior cingulate region. This is the first study to investigate WM microstructure and GM morphometric variations in adolescents with SBP. The widespread FA alterations in association and projection tracts, associated with GM changes in regions involved in mood disorders, suggest altered structural connectivity in those adolescents.

  11. Altered gray matter volume and white matter integrity in college students with mobile phone dependence

    Directory of Open Access Journals (Sweden)

    Yongming eWang

    2016-05-01

    Full Text Available Mobile phone dependence (MPD is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI. Gray matter volume (GMV and white matter (WM integrity (four indexes: fractional anisotropy, FA; mean diffusivity, MD; axial diffusivity, AD; and radial diffusivity, RD were calculated via voxel-based morphometry (VBM and tract-based spatial statistics (TBSS analysis, respectively. Sixty-eight college students (42 female were enrolled and separated into two groups (MPD group, N=34; control group, N=34 based on Mobile Phone Addiction Index (MPAI scale score. Trait impulsivity was also measured using the Barrett Impulsivity Scale (BIS-11. In light of underlying trait impulsivity, results revealed decreased GMV in the MPD group relative to controls in regions such as the right superior frontal gyrus (sFG, right inferior frontal gyrus (iFG, and bilateral thalamus (Thal. In the MPD group, GMV in the above mentioned regions was negatively correlated with scores on the MPAI. Results also showed significantly less FA and AD measures of white matter integrity in the MPD group relative to controls in bilateral hippocampal cingulum bundle fibers (CgH. Additionally, in the MPD group, FA of the CgH was also negatively correlated with scores on the MPAI. These findings provide the first morphological evidence of altered brain structure with phone-overuse, and may help to better understand the neural mechanisms of MPD in relation with other behavioral and substance addiction disorders.

  12. Safety analysis report for the TRUPACT-II shipping package (condensed version). Volume 1, Rev. 14

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-01

    The condensed version of the TRUPACT-II Contact Handled Transuranic Waste Safety Analysis Report for Packaging (SARP) contains essential material required by TRUPACT-II users, plus additional contents (payload) information previously submitted to the U.S. Nuclear Regulatory Commission. All or part of the following sections, which are not required by users of the TRUPACT-II, are deleted from the condensed version: (i) structural analysis, (ii) thermal analysis, (iii) containment analysis, (iv) criticality analysis, (v) shielding analysis, and (vi) hypothetical accident test results.

  13. Evolution of Matter Wave Interference of Bose-Condensed Gas in a 2D Optical Lattice

    Institute of Scientific and Technical Information of China (English)

    XUZhi-Jun; LINGuo-Cheng; XUJun; LIZhen

    2005-01-01

    We investigate the average particle-number distribution of the atoms in the combined potential of 2D optical lattices and 31) harmonic magnetic trap based on the Gross-Pitaevskii equation. After the combined potential is switched of[, and only the optical lattice is switched off, we give the analytical results of the wavefunction of the Bosecondensed gas at any time t by using a propagator method. For both disk-shaped and cigar-shaped Bose-condensed gas,we discuss the evolution process of the central and side peaks of the interference pattern.

  14. Tunable rotary orbits of matter-wave nonlinear modes in attractive Bose-Einstein condensates

    Energy Technology Data Exchange (ETDEWEB)

    He, Y J; Wang, H Z [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou, 510275 (China); Malomed, Boris A [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Mihalache, Dumitru [Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), 407 Atomistilor, Magurele-Bucharest 077125 (Romania)], E-mail: stswhz@mail.sysu.edu.cn

    2008-03-14

    We demonstrate that by spatially modulating the Bessel optical lattice where a Bose-Einstein condensate is loaded, we get tunable rotary orbits of nonlinear lattice modes. We show that the radially expanding or shrinking Bessel lattice can drag the nonlinear localized modes to orbits of either larger or smaller radii and the rotary velocity of nonlinear modes can be changed accordingly. The localized modes can even be transferred to the Bessel lattice core when the localized modes' rotations are stopped. Effects beyond the quasi-particle approximation such as destruction of the nonlinear modes by nonadiabatic dragging are also explored.

  15. Defect evolution in cosmology and condensed matter quantitative analysis with the velocity-dependent one-scale model

    CERN Document Server

    Martins, C J A P

    2016-01-01

    This book sheds new light on topological defects in widely differing systems, using the Velocity-Dependent One-Scale Model to better understand their evolution. Topological defects – cosmic strings, monopoles, domain walls or others - necessarily form at cosmological (and condensed matter) phase transitions. If they are stable and long-lived they will be fossil relics of higher-energy physics. Understanding their behaviour and consequences is a key part of any serious attempt to understand the universe, and this requires modelling their evolution. The velocity-dependent one-scale model is the only fully quantitative model of defect network evolution, and the canonical model in the field. This book provides a review of the model, explaining its physical content and describing its broad range of applicability.

  16. Dissipative self-gravitating Bose-Einstein condensates with arbitrary nonlinearity as a model of dark matter halos

    CERN Document Server

    Chavanis, Pierre-Henri

    2016-01-01

    We develop a general formalism applying to Newtonian self-gravitating Bose-Einstein condensates. This formalism may find application in the context of dark matter halos. We introduce a generalized Gross-Pitaevskii equation including a source of dissipation (damping) and an arbitrary nonlinearity. Using the Madelung transformation, we derive the hydrodynamic representation of this generalized Gross-Pitaevskii equation and obtain a damped quantum Euler equation involving a friction force proportional and opposite to the velocity and a pressure force associated with an equation of state determined by the nonlinearity present in the generalized Gross-Pitaevskii equation. In the strong friction limit, we obtain a quantum Smoluchowski equation. These equations satisfy an $H$-theorem for a free energy functional constructed with a generalized entropy. We specifically consider the Boltzmann and Tsallis entropies associated with isothermal and polytropic equations of state. We also consider the entropy associated with...

  17. Reaction Matrix Calculations in Neutron Matter with Alternating-Layer-Spin Structure under π0 Condensation. II ---Numerical Results---

    Science.gov (United States)

    Tamiya, K.; Tamagaki, R.

    1981-10-01

    Results obtained by applying a formulation based on the reaction matrix theory developed in I are given. Calculations by making use of a modified realistic potential, the Reid soft-core potential with the OPEP-part enhanced due to the isobar (Δ)-mixing, show that the transition to the [ALS] phase of quasi-neutrons corresponding to a typical π0 condensation occurs in the region of (2 ˜ 3) times the nuclear density. The most important ingredients responsible for this transition are the growth of the attractive 3P2 + 3F2 contribution mainly from the spin-parallel pairs in the same leyers and the reduction of the repulsive 3P1 contribution mainly from the spin-antiparallel pairs in the nearest layers; these mainfest themselves as the [ALS]-type localization develops. Properties of the matter under the new phase thus obtained such as the shape of the Fermi surface and the effective mass are discussed.

  18. Dispersive and dissipative effects in quantum field theory in curved space-time to model condensed matter systems

    CERN Document Server

    Busch, Xavier

    2014-01-01

    The two main predictions of quantum field theory in curved space-time, namely Hawking radiation and cosmological pair production, have not been directly tested and involve ultra high energy configurations. As a consequence, they should be considered with caution. Using the analogy with condensed matter systems, their analogue versions could be tested in the lab. Moreover, the high energy behavior of these systems is known and involves dispersion and dissipation, which regulate the theory at short distances. When considering experiments which aim to test the above predictions, there will also be a competition between the stimulated emission from thermal noise and the spontaneous emission out of vacuum. In order to measure these effects, one should thus compute the consequences of UV dispersion and dissipation, and identify observables able to establish that the spontaneous emission took place. In this thesis, we first analyze the effects of dispersion and dissipation on both Hawking radiation and pair particle...

  19. Apparatus to study matter-wave quantum optics in spin space in a sodium spinor Bose-Einstein condensate

    Science.gov (United States)

    Nematollahi, Delaram; Zhang, Qimin; Altermatt, Joseph; Zhong, Shan; Goodman, Matthew; Bhagat, Anita; Schwettmann, Arne

    2016-05-01

    We present our apparatus designed to study matter-wave quantum optics in spin space, including our recently finished vacuum system and laser systems. Microwave-dressed spin-exchange collisions in a sodium spinor Bose-Einstein condensate provide a precisely controllable nonlinear interaction that generates squeezing and acts as a source of entanglement. As a consequence of this entanglement between atoms with magnetic quantum numbers m = +1 and m = -1, the noise of population measurements can be reduced below the shot noise. Versatile microwave pulse sequences will be used to implement an interferometer, a phase-sensitive amplifier and other devices. With an added ion detector to detect Rydberg atoms via pulsed-field ionization, we plan to study the effect of Rydberg excitations on the spin evolution of the ultracold gas.

  20. Organic Synthetic Advanced Materials for Optoelectronic and Energy Applications (at Center for Condensed Matter Sciences)

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Hung-Ju [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Chemistry Division

    2016-11-14

    These slides cover Hung-Ju Yen's recent work in the synthesis and structural design of functional materials, which were further used for optoelectronic and energy applications, such as lithium ion battery, solar cell, LED, electrochromic, and fuel cells. This was for a job interview at Center for Condensed Matter Sciences. The following topics are detailed: current challenges for lithium-ion batteries; graphene, graphene oxide and nanographene; nanographenes with various functional groups; fine tune d-spacing through organic synthesis: varying functional group; schematic view of LIBs; nanographenes as LIB anode; rate performance (charging-discharging); electrochromic technology; electrochromic materials; advantages of triphenylamine; requirement of electrochromic materials for practical applications; low driving voltage and long cycle life; increasing the electroactive sites by multi-step synthetic procedures; synthetic route to starburst triarylamine-based polyamide; electrochromism ranging from visible to NIR region; transmissive to black electrochromism; RGB and CMY electrochromism.

  1. From relativistic quantum fields to condensed matter and back again: Updating the Gross-Neveu phase diagram

    CERN Document Server

    Thies, M

    2006-01-01

    During the last few years, the phase diagram of the large N Gross-Neveu model in 1+1 dimensions at finite temperature and chemical potential has undergone a major revision. Here we present a streamlined account of this development, collecting the most important results. Quasi-one-dimensional condensed matter systems like conducting polymers provide real physical systems which can be approximately described by the Gross-Neveu model and have played some role in establishing its phase structure. The kink-antikink phase found at low temperatures is closely related to inhomogeneous superconductors in the Larkin-Ovchinnikov-Fulde-Ferrell phase. With the complete phase diagram at hand, the Gross-Neveu model can now serve as a firm testing ground for new algorithms and theoretical ideas.

  2. Socioeconomic status and the cerebellar grey matter volume. Data from a well-characterised population sample.

    Science.gov (United States)

    Cavanagh, Jonathan; Krishnadas, Rajeev; Batty, G David; Burns, Harry; Deans, Kevin A; Ford, Ian; McConnachie, Alex; McGinty, Agnes; McLean, Jennifer S; Millar, Keith; Sattar, Naveed; Shiels, Paul G; Tannahill, Carol; Velupillai, Yoga N; Packard, Chris J; McLean, John

    2013-12-01

    The cerebellum is highly sensitive to adverse environmental factors throughout the life span. Socioeconomic deprivation has been associated with greater inflammatory and cardiometabolic risk, and poor neurocognitive function. Given the increasing awareness of the association between early-life adversities on cerebellar structure, we aimed to explore the relationship between early life (ESES) and current socioeconomic status (CSES) and cerebellar volume. T1-weighted MRI was used to create models of cerebellar grey matter volumes in 42 adult neurologically healthy males selected from the Psychological, Social and Biological Determinants of Ill Health study. The relationship between potential risk factors, including ESES, CSES and cerebellar grey matter volumes were examined using multiple regression techniques. We also examined if greater multisystem physiological risk index-derived from inflammatory and cardiometabolic risk markers-mediated the relationship between socioeconomic status (SES) and cerebellar grey matter volume. Both ESES and CSES explained the greatest variance in cerebellar grey matter volume, with age and alcohol use as a covariate in the model. Low CSES explained additional significant variance to low ESES on grey matter decrease. The multisystem physiological risk index mediated the relationship between both early life and current SES and grey matter volume in cerebellum. In a randomly selected sample of neurologically healthy males, poorer socioeconomic status was associated with a smaller cerebellar volume. Early and current socioeconomic status and the multisystem physiological risk index also apparently influence cerebellar volume. These findings provide data on the relationship between socioeconomic deprivation and a brain region highly sensitive to environmental factors.

  3. Dirac matter

    CERN Document Server

    Rivasseau, Vincent; Fuchs, Jean-Nöel

    2017-01-01

    This fifteenth volume of the Poincare Seminar Series, Dirac Matter, describes the surprising resurgence, as a low-energy effective theory of conducting electrons in many condensed matter systems, including graphene and topological insulators, of the famous equation originally invented by P.A.M. Dirac for relativistic quantum mechanics. In five highly pedagogical articles, as befits their origin in lectures to a broad scientific audience, this book explains why Dirac matters. Highlights include the detailed "Graphene and Relativistic Quantum Physics", written by the experimental pioneer, Philip Kim, and devoted to graphene, a form of carbon crystallized in a two-dimensional hexagonal lattice, from its discovery in 2004-2005 by the future Nobel prize winners Kostya Novoselov and Andre Geim to the so-called relativistic quantum Hall effect; the review entitled "Dirac Fermions in Condensed Matter and Beyond", written by two prominent theoreticians, Mark Goerbig and Gilles Montambaux, who consider many other mater...

  4. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere I. Continuous Emission and Condensed Matter Within the Chromosphere

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The continuous spectrum of the solar photosphere stands as the paramount observation with regard to the condensed nature of the solar body. Studies relative to Kirchhoff’s law of thermal emission (e.g. Robitaille P.-M. Kirchhoff’s law of thermal emission: 150 years. Progr. Phys., 2009, v. 4, 3–13. and a detailed analysis of the stellar opacity problem (Robitaille P.M. Stellar opacity: The Achilles’ heel of the gaseous Sun. Progr. Phys., 2011, v. 3, 93–99 have revealed that gaseous models remain unable to properly account for the generation of this spectrum. Therefore, it can be stated with certainty that the photosphere is comprised of condensed matter. Beyond the solar surface, the chromospheric layer of the Sun also generates a weak continuous spectrum in the visible region. This emission exposes the presence of material in the condensed state. As a result, above the level of the photosphere, matter exists in both gaseous and condensed forms, much like within the atmosphere of the Earth. The continuous visible spectrum associated with the chromosphere provides the twenty-sixth line of evidence that the Sun is condensed matter.

  5. Altered Gray Matter Volume and White Matter Integrity in College Students with Mobile Phone Dependence.

    Science.gov (United States)

    Wang, Yongming; Zou, Zhiling; Song, Hongwen; Xu, Xiaodan; Wang, Huijun; d'Oleire Uquillas, Federico; Huang, Xiting

    2016-01-01

    Mobile phone dependence (MPD) is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI). Gray matter volume (GMV) and white matter (WM) integrity [four indices: fractional anisotropy (FA); mean diffusivity (MD); axial diffusivity (AD); and radial diffusivity (RD)] were calculated via voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis, respectively. Sixty-eight college students (42 female) were enrolled and separated into two groups [MPD group, N = 34; control group (CG), N = 34] based on Mobile Phone Addiction Index (MPAI) scale score. Trait impulsivity was also measured using the Barratt Impulsiveness Scale (BIS-11). In light of underlying trait impulsivity, results revealed decreased GMV in the MPD group relative to controls in regions such as the right superior frontal gyrus (sFG), right inferior frontal gyrus (iFG), and bilateral thalamus (Thal). In the MPD group, GMV in the above mentioned regions was negatively correlated with scores on the MPAI. Results also showed significantly less FA and AD measures of WM integrity in the MPD group relative to controls in bilateral hippocampal cingulum bundle fibers (CgH). Additionally, in the MPD group, FA of the CgH was also negatively correlated with scores on the MPAI. These findings provide the first morphological evidence of altered brain structure with mobile phone overuse, and may help to better understand the neural mechanisms of MPD in relation to other behavioral and substance addiction disorders.

  6. White matter microstructure asymmetry: effects of volume asymmetry on fractional anisotropy asymmetry.

    Science.gov (United States)

    Takao, H; Hayashi, N; Ohtomo, K

    2013-02-12

    Diffusion tensor imaging (DTI) provides information regarding white matter microstructure; however, macroscopic fiber architectures can affect DTI measures. A larger brain (fiber tract) has a 'relatively' smaller voxel size, and the voxels are less likely to contain more than one fiber orientation and more likely to have higher fractional anisotropy (FA). Previous DTI studies report left-to-right differences in the white matter; however, these may reflect true microscopic differences or be caused purely by volume differences. Using tract-based spatial statistics, we investigated left-to-right differences in white matter microstructure across the whole brain. Voxel-wise analysis revealed a large number of white matter volume asymmetries, including leftward asymmetry of the arcuate fasciculus and cingulum. In many white matter regions, FA asymmetry was positively correlated with volume asymmetry. Voxel-wise analysis with adjustment for volume asymmetry revealed many white matter FA asymmetries, including leftward asymmetry of the arcuate fasciculus and cingulum. The voxel-wise analysis showed a reduced number of regions with significant FA asymmetry compared with analysis performed without adjustment for volume asymmetry; however, the overall trend of the results was unchanged. The results of the present study suggest that these FA asymmetries are not caused by volume differences and reflect microscopic differences in the white matter.

  7. A model for the pressure dependence of diffusion in condensed matter

    Indian Academy of Sciences (India)

    Kamal Kapoor; Rashmi Kumari; Narasingh Dass; Rajendra Kumar

    2006-09-01

    In the present paper, a model has been used to develop a simple relation to study the pressure dependence of self-diffusion in solids and liquids that has two adjustable parameters. The computation done in each substance is found to be in very good agreement with the experimental data. It is interesting to note that the present relation is also capable of giving the activation volume in solids and liquids. The activation volume computed in the solids is found to be in very good agreement with the data available.

  8. Stopping powers of energetic electrons penetrating condensed matter--theory and application

    Institute of Scientific and Technical Information of China (English)

    TAN Zhen-Yu; XIA Yue-Yuan

    2004-01-01

    In this review article, the motivation of studying inelastic energy loss for energetic electrons penetrating through matter and the corresponding technological importance have been outlined. The theoretical development and method for the calculation of stopping powers are described. The stopping power data tables for a group of polymers and bioorganic compounds are presented, and the application aspects of the stopping power data are briefly discussed.

  9. Reaction Matrix Calculations in Neutron Matter with Alternating-Layer-Spin Structure under π0 Condensation. I ---Formulation---

    Science.gov (United States)

    Tamiya, K.; Tamagaki, R.

    1981-09-01

    Based on the viewpoint that a typical π0 condensation is realized with the [ALS] (Alternating-Layer-Spin) structure of nucleon system, a framework to calculate the energy of neutron matter under such a new phase is presented in the reaction matrix theory. This enables us to treat both effects on equal footing; the long-range effect dominated by the OPEP tensor component with the enhancement due to the mixing of Δ(1236MeV) and the sort-range effect much influenced by repulsive core and spin-orbit force. Starting with the [ALS] model wave function constructed on the Bloch basis which assures to take the limit of no localization, we have the expressions for energy quantities expressed by the partial-wave contributions. This scheme provides a way to understand the mechanism of energy gain in the new phase, by making use of the notions of the ordinary unclear matter theory such as the potential picture and the partial waves. Some numerical examples are shown.

  10. Cortical grey matter volume reduction in people with schizophrenia is associated with neuro-inflammation.

    Science.gov (United States)

    Zhang, Y; Catts, V S; Sheedy, D; McCrossin, T; Kril, J J; Shannon Weickert, C

    2016-12-13

    Cortical grey matter volume deficits and neuro-inflammation exist in patients with schizophrenia, although it is not clear whether elevated cytokines contribute to the cortical volume reduction. We quantified cortical and regional brain volumes in fixed postmortem brains from people with schizophrenia and matched controls using stereology. Interleukin (IL)-6, IL-1β, IL-8 and SERPINA3 messenger RNAs (mRNAs) were quantified in the contralateral fresh frozen orbitofrontal cortex. We found a small, but significant reduction in cortical grey matter (1.3%; F(1,85)=4.478, P=0.037) and superior frontal gyrus (6.5%; F(1,80)=5.700, P=0.019) volumes in individuals with schizophrenia compared with controls. Significantly reduced cortical grey matter (9.2%; F(1,24)=8.272, P=0.008) and superior frontal gyrus (13.9%; F(1,20)=5.374, P=0.031) volumes were found in cases with schizophrenia and 'high inflammation' status relative to schizophrenia cases with 'low inflammation' status in the prefrontal cortex. The expression of inflammatory mRNAs in the orbitofrontal cortex was significantly correlated with those in dorsolateral prefrontal cortex (all r>0.417, all Pgrey matter and superior frontal gyrus volumes (all rgrey matter volume in people with schizophrenia is exaggerated in those who have high expression of inflammatory cytokines. Further, antipsychotic medication intake does not appear to ameliorate the reduction in brain volume.

  11. AIR QUALITY CRITERIA FOR PARTICULATE MATTER, VOLUMES I-III, (EXTERNAL REVIEW DRAFT, 1995)

    Science.gov (United States)

    There is no abstract available for these documents. If further information is requested, please refer to the bibliographic citation and contact the Technical Information Staff at the number listed above.Air Quality Criteria for Particulate Matter, Volume I, Extern...

  12. Differential regional gray matter volumes in patients with on-line game addiction and professional gamers.

    Science.gov (United States)

    Han, Doug Hyun; Lyoo, In Kyoon; Renshaw, Perry F

    2012-04-01

    Patients with on-line game addiction (POGA) and professional video game players play video games for extended periods of time, but experience very different consequences for their on-line game play. Brain regions consisting of anterior cingulate, thalamus and occpito-temporal areas may increase the likelihood of becoming a pro-gamer or POGA. Twenty POGA, seventeen pro-gamers, and eighteen healthy comparison subjects (HC) were recruited. All magnetic resonance imaging (MRI) was performed on a 1.5 Tesla Espree MRI scanner (SIEMENS, Erlangen, Germany). Voxel-wise comparisons of gray matter volume were performed between the groups using the two-sample t-test with statistical parametric mapping (SPM5). Compared to HC, the POGA group showed increased impulsiveness and perseverative errors, and volume in left thalamus gray matter, but decreased gray matter volume in both inferior temporal gyri, right middle occipital gyrus, and left inferior occipital gyrus, compared with HC. Pro-gamers showed increased gray matter volume in left cingulate gyrus, but decreased gray matter volume in left middle occipital gyrus and right inferior temporal gyrus compared with HC. Additionally, the pro-gamer group showed increased gray matter volume in left cingulate gyrus and decreased left thalamus gray matter volume compared with the POGA group. The current study suggests that increased gray matter volumes of the left cingulate gyrus in pro-gamers and of the left thalamus in POGA may contribute to the different clinical characteristics of pro-gamers and POGA. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol – Part 2: Composition, hygroscopicity and cloud condensation activity

    Directory of Open Access Journals (Sweden)

    E. Fuentes

    2011-03-01

    Full Text Available The effect of nanogel colloidal and dissolved organic matter <0.2 μm, secreted by marine biota, on the hygroscopic growth and droplet activation behaviour of the primary marine aerosol was studied. Seawater proxies were prepared by the combination of artificial seawater devoid of marine organics and natural seawater enriched in organic exudate released by laboratory-grown phytoplankton cultures, as described in a companion paper. The primary aerosol was produced by bubble bursting, using a plunging multijet system as an aerosol generator.

    The aerosol generated from seawater proxies enriched with marine exudate presented organic volume fractions on the order of 8–37%, as derived by applying a simple mixing rule. The hygroscopic growth and cloud condensation nuclei (CCN activity of the marine organics-enriched particles where 9–17% and 5–24% lower, respectively, than those of the aerosol produced from artificial seawater devoid of exudate. Experiments in a companion paper indicated that the cloud nuclei formation could be enhanced in diatom bloom areas because of the increase in the primary particle production induced by marine organics. The experiments in the present study, however, indicate that the impacts of such an enhancement would be counteracted by the reduction in the CCN activity of the primary particles enriched in marine organics.

    The extent of the effect of the biogenic matter on the particle behaviour was dependent on the seawater organic concentration and type of algal exudate. Aerosol produced from seawater proxies containing diatomaceous exudate presented higher hydrophobicity and lower CCN activity than those enriched with nanoplankton exudate. The organic fraction of the particles was found to correlate with the seawater organic concentration, without observing saturation of the particle organic mass fraction even for unrealistically high organic matter concentration in seawater. These findings are

  14. Cannabis, Cigarettes, and Their Co-Occurring Use: Disentangling Differences in Gray Matter Volume

    Science.gov (United States)

    Jagannathan, Kanchana; Hager, Nathan; Childress, Anna Rose; Rao, Hengyi; Franklin, Teresa R.

    2015-01-01

    Background: Structural magnetic resonance imaging techniques are powerful tools for examining the effects of drug use on the brain. The nicotine and cannabis literature has demonstrated differences between nicotine cigarette smokers and cannabis users compared to controls in brain structure; however, less is known about the effects of co-occurring cannabis and tobacco use. Methods: We used voxel-based morphometry to examine gray matter volume differences between four groups: (1) cannabis-dependent individuals who do not smoke tobacco (Cs); (2) cannabis-dependent individuals who smoke tobacco (CTs); (3) cannabis-naïve, nicotine-dependent individuals who smoke tobacco (Ts); and (4) healthy controls (HCs). We also explored associations between gray matter volume and measures of cannabis and tobacco use. Results: A significant group effect was observed in the left putamen, thalamus, right precentral gyrus, and left cerebellum. Compared to HCs, the Cs, CTs, and Ts exhibited larger gray matter volumes in the left putamen. Cs also had larger gray matter volume than HCs in the right precentral gyrus. Cs and CTs exhibited smaller gray matter volume than HCs in the thalamus, and CTs and Ts had smaller left cerebellar gray matter volume than HCs. Conclusions: This study extends previous research that independently examined the effects of cannabis or tobacco use on brain structure by including an examination of co-occurring cannabis and tobacco use, and provides evidence that cannabis and tobacco exposure are associated with alterations in brain regions associated with addiction. PMID:26045474

  15. Towards a realization of the condensed-matter-gravity correspondence in string theory via consistent Abelian truncation of the Aharony-Bergman-Jafferis-Maldacena model.

    Science.gov (United States)

    Mohammed, Asadig; Murugan, Jeff; Nastase, Horatiu

    2012-11-02

    We present an embedding of the three-dimensional relativistic Landau-Ginzburg model for condensed matter systems in an N = 6, U(N) × U(N) Chern-Simons-matter theory [the Aharony-Bergman-Jafferis-Maldacena model] by consistently truncating the latter to an Abelian effective field theory encoding the collective dynamics of O(N) of the O(N(2)) modes. In fact, depending on the vacuum expectation value on one of the Aharony-Bergman-Jafferis-Maldacena scalars, a mass deformation parameter μ and the Chern-Simons level number k, our Abelianization prescription allows us to interpolate between the Abelian Higgs model with its usual multivortex solutions and a Ø(4) theory. We sketch a simple condensed matter model that reproduces all the salient features of the Abelianization. In this context, the Abelianization can be interpreted as giving a dimensional reduction from four dimensions.

  16. Quantum Simulations of Condensed Matter Systems Using Ultra-Cold Atomic Gases

    Science.gov (United States)

    2013-03-01

    Feynman  diagrams  versus  Fermi-­‐gas   Feynman  emulator”,  Nature   Physics  8,  366...BEC-­‐BCS  Crossover  and  the  Unitary  Fermi  Gas”,   Lecture  Notes  in   Physics ,  Volume  836,  edited  by  Wilhelm... Lecture  at  100th  Anniversary  Solvay  Conference   on   Physics ,  "The  Theory  of  the

  17. Gray Matter Volume Reduction Is Associated with Cognitive Impairment in Neuromyelitis Optica.

    Science.gov (United States)

    Wang, Q; Zhang, N; Qin, W; Li, Y; Fu, Y; Li, T; Shao, J; Yang, L; Shi, F-D; Yu, C

    2015-10-01

    Whether gray matter impairment occurs in neuromyelitis optica is a matter of ongoing debate, and the association of gray matter impairment with cognitive deficits remains largely unknown. The purpose of this study was to investigate gray matter volume reductions and their association with cognitive decline in patients with neuromyelitis optica. This study included 50 patients with neuromyelitis optica and 50 sex-, age-, handedness-, and education-matched healthy subjects who underwent high-resolution structural MR imaging examinations and a battery of cognitive assessments. Gray matter volume and cognitive differences were compared between the 2 groups. The correlations of the regional gray matter volume with cognitive scores and clinical variables were explored in the patients with neuromyelitis optica. Compared with healthy controls (635.9 ± 51.18 mL), patients with neuromyelitis optica (602.8 ± 51.03 mL) had a 5.21% decrease in the mean gray matter volume of the whole brain (P optica affected the frontal and temporal cortices and the right thalamus (false discovery rate correction, P optica (Alphasim correction, P optica had impairments in memory, information processing speed, and verbal fluency (P optica and is associated with cognitive impairment and disease severity in this group. © 2015 by American Journal of Neuroradiology.

  18. Reduced thalamic volume in preterm infants is associated with abnormal white matter metabolism independent of injury

    Energy Technology Data Exchange (ETDEWEB)

    Wisnowski, Jessica L. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Ceschin, Rafael C. [University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); University of Pittsburgh, Department of Biomedical Informatics, Pittsburgh, PA (United States); Choi, So Young [University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Schmithorst, Vincent J. [University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); Painter, Michael J. [University of Pittsburgh, Department of Pediatrics, Division of Neurology, Childrens Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); Nelson, Marvin D. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Blueml, Stefan [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Rudi Schulte Research Institute, Santa Barbara, CA (United States); Panigrahy, Ashok [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States)

    2015-05-01

    Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23-36 weeks) who underwent MR examinations under clinical indications were included in this study. Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and among the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. (orig.)

  19. Paul Scherrer Institut Scientific Report 2001. Volume III: Condensed Matter Research with Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, J.; Castellazzi, D.; Shea-Braun, M. (eds.)

    2002-03-01

    The SINQ-facility stopped operation at the end of the year 2001 for the scheduled shut down. By that time the spallation target of the 'Cannelloni'-type (D{sub 2}O-cooled steel pins filled with lead) had received a total charge of more then 10 Ah at an average proton current higher than 1 mA. Thereby nearly 4 mols of neutrons had been released from this target. The two operational years with this target delivered the neutrons for about 300 experiments. During this operational period not one single interrupt caused by the spallation target has been recorded -indeed a convincing evidence for the reliability of this system. The probes inserted into the target and some of its parts will now soon be available to the materials scientists for careful investigation. SINQ as a continuous spallation neutron source was considered to be a 'high risk' project. Furthermore it was often accompanied with the suspicion to represent the 'worst of two worlds' - meaning that this facility would suffer from the disadvantages but not benefit from the advantage of a spallation neutron source - the pulse structure. According to our operational experience these fears are not justified provided the various concerns have been properly taken into consideration during design and construction. This report testifies what can be achieved at a continuous spallation neutron source. We believe that these research activities compare well with those from a beam-tube reactor of medium flux. A list of scientific publications in 2000 is also provided.

  20. Female adolescents with severe substance and conduct problems have substantially less brain gray matter volume.

    Science.gov (United States)

    Dalwani, Manish S; McMahon, Mary Agnes; Mikulich-Gilbertson, Susan K; Young, Susan E; Regner, Michael F; Raymond, Kristen M; McWilliams, Shannon K; Banich, Marie T; Tanabe, Jody L; Crowley, Thomas J; Sakai, Joseph T

    2015-01-01

    Structural neuroimaging studies have demonstrated lower regional gray matter volume in adolescents with severe substance and conduct problems. These research studies, including ours, have generally focused on male-only or mixed-sex samples of adolescents with conduct and/or substance problems. Here we compare gray matter volume between female adolescents with severe substance and conduct problems and female healthy controls of similar ages. Female adolescents with severe substance and conduct problems will show significantly less gray matter volume in frontal regions critical to inhibition (i.e. dorsolateral prefrontal cortex and ventrolateral prefrontal cortex), conflict processing (i.e., anterior cingulate), valuation of expected outcomes (i.e., medial orbitofrontal cortex) and the dopamine reward system (i.e. striatum). We conducted whole-brain voxel-based morphometric comparison of structural MR images of 22 patients (14-18 years) with severe substance and conduct problems and 21 controls of similar age using statistical parametric mapping (SPM) and voxel-based morphometric (VBM8) toolbox. We tested group differences in regional gray matter volume with analyses of covariance, adjusting for age and IQ at pbrain cluster-level threshold. Female adolescents with severe substance and conduct problems compared to controls showed significantly less gray matter volume in right dorsolateral prefrontal cortex, left ventrolateral prefrontal cortex, medial orbitofrontal cortex, anterior cingulate, bilateral somatosensory cortex, left supramarginal gyrus, and bilateral angular gyrus. Considering the entire brain, patients had 9.5% less overall gray matter volume compared to controls. Female adolescents with severe substance and conduct problems in comparison to similarly aged female healthy controls showed substantially lower gray matter volume in brain regions involved in inhibition, conflict processing, valuation of outcomes, decision-making, reward, risk-taking, and rule

  1. Female adolescents with severe substance and conduct problems have substantially less brain gray matter volume.

    Directory of Open Access Journals (Sweden)

    Manish S Dalwani

    Full Text Available Structural neuroimaging studies have demonstrated lower regional gray matter volume in adolescents with severe substance and conduct problems. These research studies, including ours, have generally focused on male-only or mixed-sex samples of adolescents with conduct and/or substance problems. Here we compare gray matter volume between female adolescents with severe substance and conduct problems and female healthy controls of similar ages.Female adolescents with severe substance and conduct problems will show significantly less gray matter volume in frontal regions critical to inhibition (i.e. dorsolateral prefrontal cortex and ventrolateral prefrontal cortex, conflict processing (i.e., anterior cingulate, valuation of expected outcomes (i.e., medial orbitofrontal cortex and the dopamine reward system (i.e. striatum.We conducted whole-brain voxel-based morphometric comparison of structural MR images of 22 patients (14-18 years with severe substance and conduct problems and 21 controls of similar age using statistical parametric mapping (SPM and voxel-based morphometric (VBM8 toolbox. We tested group differences in regional gray matter volume with analyses of covariance, adjusting for age and IQ at p<0.05, corrected for multiple comparisons at whole-brain cluster-level threshold.Female adolescents with severe substance and conduct problems compared to controls showed significantly less gray matter volume in right dorsolateral prefrontal cortex, left ventrolateral prefrontal cortex, medial orbitofrontal cortex, anterior cingulate, bilateral somatosensory cortex, left supramarginal gyrus, and bilateral angular gyrus. Considering the entire brain, patients had 9.5% less overall gray matter volume compared to controls.Female adolescents with severe substance and conduct problems in comparison to similarly aged female healthy controls showed substantially lower gray matter volume in brain regions involved in inhibition, conflict processing, valuation

  2. Ferroelectric hybrid fibers to develop flexible sensors for shape sensing of smart textiles and soft condensed matter bodies

    Science.gov (United States)

    Sebastian, Tutu; Lusiola, Tony; Clemens, Frank

    2017-04-01

    Piezoelectric fibers are widely used in composites for actuator and sensor applications due to its ability to convert electrical pulses into mechanical vibrations and transform the returned mechanical vibrations back into electrical signal. They are beneficial for the fabrication of composites especially 1–3 composites, active fiber composites (unidirectional axially aligned PZT fibers sandwiched between interdigitated electrodes and embedded in a polymer matrix) etc, with potential applications in medical imaging, structural health monitoring, energy harvesting, vibration and noise control. However, due to the brittle nature of PZT fibers, maximum strain is limited to 0.2% and cannot be integrated into flexible sensor applications. In this contribution, a new approach to develop flexible ferroelectric hybrid fibers for soft body shape sensing is investigated. Piezoelectric particles incorporated in a polymer matrix and extruded as fiber, 0–3 composite in fibrous form is studied. Commercially obtained calcined PZT and calcined BaTiO3 powders were used in the unsintered form to obtain flexible soft condensed matter ferroelectric hybrid fibers. The extruded fibers were subjected to investigation for their electromechanical behavior as a function of electric field. The hybrid fibers reached 10% of the maximum polarization of their sintered counterpart.

  3. Many-body quantum electrodynamics networks: Non-equilibrium condensed matter physics with light

    Science.gov (United States)

    Le Hur, Karyn; Henriet, Loïc; Petrescu, Alexandru; Plekhanov, Kirill; Roux, Guillaume; Schiró, Marco

    2016-10-01

    We review recent developments regarding the quantum dynamics and many-body physics with light, in superconducting circuits and Josephson analogues, by analogy with atomic physics. We start with quantum impurity models addressing dissipative and driven systems. Both theorists and experimentalists are making efforts towards the characterization of these non-equilibrium quantum systems. We show how Josephson junction systems can implement the equivalent of the Kondo effect with microwave photons. The Kondo effect can be characterized by a renormalized light frequency and a peak in the Rayleigh elastic transmission of a photon. We also address the physics of hybrid systems comprising mesoscopic quantum dot devices coupled with an electromagnetic resonator. Then, we discuss extensions to Quantum Electrodynamics (QED) Networks allowing one to engineer the Jaynes-Cummings lattice and Rabi lattice models through the presence of superconducting qubits in the cavities. This opens the door to novel many-body physics with light out of equilibrium, in relation with the Mott-superfluid transition observed with ultra-cold atoms in optical lattices. Then, we summarize recent theoretical predictions for realizing topological phases with light. Synthetic gauge fields and spin-orbit couplings have been successfully implemented in quantum materials and with ultra-cold atoms in optical lattices - using time-dependent Floquet perturbations periodic in time, for example - as well as in photonic lattice systems. Finally, we discuss the Josephson effect related to Bose-Hubbard models in ladder and two-dimensional geometries, producing phase coherence and Meissner currents. The Bose-Hubbard model is related to the Jaynes-Cummings lattice model in the large detuning limit between light and matter (the superconducting qubits). In the presence of synthetic gauge fields, we show that Meissner currents subsist in an insulating Mott phase. xml:lang="fr"

  4. Propagation and interaction of matter-wave solitons in Bose-Einstein condensates with time-dependent scattering length and varying potentials

    Energy Technology Data Exchange (ETDEWEB)

    Li Biao; Li Yuqi [Nonlinear Science Center, Ningbo University, Ningbo 315211 (China); Zhang Xiaofei; Liu, W M, E-mail: biaolee2000@yahoo.com.cn [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2011-09-14

    We present two families of one-soliton solutions and three families of two-soliton solutions for a generalized nonlinear Schroedinger equation, which is characterized by the time-dependent scattering length and varying potentials. Then, we investigate the propagation of one-soliton and interactions of two-soliton by some selected control functions. The results show that the intensities of one- and two-soliton first increase rapidly to a peak value, and then decay very slowly to the background value; thus, the lifetimes of both one-soliton and two-soliton in Bose-Einstein condensates can be extended largely at least to the order of the lifetime of a Bose-Einstein condensate in real experiments. Our results open up new ways of considerable experimental interest for the management of matter-wave solitons in Bose-Einstein condensates.

  5. Dynamics of kink, antikink, bright, generalized Jacobi elliptic function solutions of matter-wave condensates with time-dependent two- and three-body interactions.

    Science.gov (United States)

    Belobo Belobo, D; Ben-Bolie, G H; Kofane, T C

    2015-04-01

    By using the F-expansion method associated with four auxiliary equations, i.e., the Bernoulli equation, the Riccati equation, the Lenard equation, and the hyperbolic equation, we present exact explicit solutions describing the dynamics of matter-wave condensates with time-varying two- and three-body nonlinearities. Condensates are trapped in a harmonic potential and they exchange atoms with the thermal cloud. These solutions include the generalized Jacobi elliptic function solutions, hyperbolic function solutions, and trigonometric function solutions. In addition, we have also found rational function solutions. Solutions constructed here have many free parameters that can be used to manipulate and control some important features of the condensate, such as the position, width, velocity, acceleration, and homogeneous phase. The stability of the solutions is confirmed by their long-time numerical behavior.

  6. Comparison of gray matter volume and thickness for analysis of cortical changes in Alzheimer's disease

    Science.gov (United States)

    Liu, Jiachao; Li, Ziyi; Chen, Kewei; Yao, Li; Wang, Zhiqun; Li, Kunchen; Guo, Xiaojuan

    2011-03-01

    Gray matter volume and cortical thickness are two indices of concern in brain structure magnetic resonance imaging research. Gray matter volume reflects mixed-measurement information of cerebral cortex, while cortical thickness reflects only the information of distance between inner surface and outer surface of cerebral cortex. Using Scaled Subprofile Modeling based on Principal Component Analysis (SSM_PCA) and Pearson's Correlation Analysis, this study further provided quantitative comparisons and depicted both global relevance and local relevance to comprehensively investigate morphometrical abnormalities in cerebral cortex in Alzheimer's disease (AD). Thirteen patients with AD and thirteen age- and gender-matched healthy controls were included in this study. Results showed that factor scores from the first 8 principal components accounted for ~53.38% of the total variance for gray matter volume, and ~50.18% for cortical thickness. Factor scores from the fifth principal component showed significant correlation. In addition, gray matter voxel-based volume was closely related to cortical thickness alterations in most cortical cortex, especially, in some typical abnormal brain regions such as insula and the parahippocampal gyrus in AD. These findings suggest that these two measurements are effective indices for understanding the neuropathology in AD. Studies using both gray matter volume and cortical thickness can separate the causes of the discrepancy, provide complementary information and carry out a comprehensive description of the morphological changes of brain structure.

  7. Breakfast staple types affect brain gray matter volume and cognitive function in healthy children.

    Science.gov (United States)

    Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Asano, Michiko; Asano, Kohei; Kawashima, Ryuta

    2010-12-08

    Childhood diet is important for brain development. Furthermore, the quality of breakfast is thought to affect the cognitive functioning of well-nourished children. To analyze the relationship among breakfast staple type, gray matter volume, and intelligence quotient (IQ) in 290 healthy children, we used magnetic resonance images and applied voxel-based morphometry. We divided subjects into rice, bread, and both groups according to their breakfast staple. We showed that the rice group had a significantly larger gray matter ratio (gray matter volume percentage divided by intracranial volume) and significantly larger regional gray matter volumes of several regions, including the left superior temporal gyrus. The bread group had significantly larger regional gray and white matter volumes of several regions, including the right frontoparietal region. The perceptual organization index (POI; IQ subcomponent) of the rice group was significantly higher than that of the bread group. All analyses were adjusted for age, gender, intracranial volume, socioeconomic status, average weekly frequency of having breakfast, and number of side dishes eaten for breakfast. Although several factors may have affected the results, one possible mechanism underlying the difference between the bread and the rice groups may be the difference in the glycemic index (GI) of these two substances; foods with a low GI are associated with less blood-glucose fluctuation than are those with a high GI. Our study suggests that breakfast staple type affects brain gray and white matter volumes and cognitive function in healthy children; therefore, a diet of optimal nutrition is important for brain maturation during childhood and adolescence.

  8. Deployment and post-deployment experiences in OEF/OIF veterans: relationship to gray matter volume.

    Directory of Open Access Journals (Sweden)

    Robin L Aupperle

    Full Text Available BACKGROUND: Combat-related PTSD has been associated with reduced gray matter volume in regions of the prefrontal and temporal cortex, hippocampus, insula, and amygdala. However, the relationship between gray matter volume and specific deployment and post-deployment experiences has not been investigated. The aim of this study was to delineate how such experiences may contribute to structural brain changes for combat veterans. METHODS: Operation Iraqi Freedom/Operation Enduring Freedom veterans (N = 32 completed magnetic resonance imaging, the Deployment Risk and Resilience Inventory, Alcohol Use Disorders Identification Test, and Clinical Administered PTSD Scale. Voxel-wise Huber robust multiple regressions were used to quantify the relationship between gray matter volume and deployment experiences (combat experiences, military social support and post-deployment symptoms (PTSD, alcohol use. RESULTS: There was an interaction between severity of combat experiences and military social support for orbitofrontal gyrus gray matter volume. Specifically, individuals with more orbitofrontal gyrus gray matter volume reported less combat experiences and higher unit support. Individuals with more severe PTSD symptoms showed reduced gray matter volume within a large temporal region (inferior temporal and parahippocampal gyrus. CONCLUSIONS: The identified association between unit support and orbitofrontal gyrus volume supports two potential resilience mechanisms to be delineated with future longitudinal studies. First, individuals with larger orbitofrontal gyrus may engage in greater quality of social interactions and thus experience combat as less stressful. Second, individuals who experience greater unit support may preserve a larger orbitofrontal gyrus, serving to "protect" them from aversive consequences of combat.

  9. Breakfast staple types affect brain gray matter volume and cognitive function in healthy children.

    Directory of Open Access Journals (Sweden)

    Yasuyuki Taki

    Full Text Available Childhood diet is important for brain development. Furthermore, the quality of breakfast is thought to affect the cognitive functioning of well-nourished children. To analyze the relationship among breakfast staple type, gray matter volume, and intelligence quotient (IQ in 290 healthy children, we used magnetic resonance images and applied voxel-based morphometry. We divided subjects into rice, bread, and both groups according to their breakfast staple. We showed that the rice group had a significantly larger gray matter ratio (gray matter volume percentage divided by intracranial volume and significantly larger regional gray matter volumes of several regions, including the left superior temporal gyrus. The bread group had significantly larger regional gray and white matter volumes of several regions, including the right frontoparietal region. The perceptual organization index (POI; IQ subcomponent of the rice group was significantly higher than that of the bread group. All analyses were adjusted for age, gender, intracranial volume, socioeconomic status, average weekly frequency of having breakfast, and number of side dishes eaten for breakfast. Although several factors may have affected the results, one possible mechanism underlying the difference between the bread and the rice groups may be the difference in the glycemic index (GI of these two substances; foods with a low GI are associated with less blood-glucose fluctuation than are those with a high GI. Our study suggests that breakfast staple type affects brain gray and white matter volumes and cognitive function in healthy children; therefore, a diet of optimal nutrition is important for brain maturation during childhood and adolescence.

  10. Advances in studying order and dynamics in condensed matter by NMR

    Energy Technology Data Exchange (ETDEWEB)

    Voda, M.A.

    2006-07-13

    combination between the equilibrium magnetizations and the domain size ratios obtained from simulations of the spin-diffusion process using 1D, 2D, and 3D solutions of the spin-diffusion equations. The correlation between macroscopic, mesoscopic and microscopic properties of the TPU samples was also discussed. A semi-quantitative model was developed to explain the functional dependence of the residual second van Vleck moment on the effective volume of the hard segments. (orig.)

  11. The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2013-07-01

    Full Text Available The K-corona, a significant portion of the solar atmosphere, displays a continuous spectrum which closely parallels photospheric emission, though without the presence of overlying Fraunhofer lines. The E-corona exists in the same region and is characterized by weak emission lines from highly ionized atoms. For instance, the famous green emission line from coronium (FeXIV is part of the E-corona. The F-corona exists beyond the K/E-corona and, like the photospheric spectrum, is characterized by Fraunhofer lines. The F-corona represents photospheric light scattered by dust particles in the interplanetary medium. Within the gaseous models of the Sun, the K-corona is viewed as photospheric radiation which has been scattered by relativistic electrons. This scattering is thought to broaden the Fraunhofer lines of the solar spectrum such that they can no longer be detected in the K-corona. Thus, the gaseous models of the Sun account for the appearance of the K-corona by distorting photospheric light, since they are unable to have recourse to condensed matter to directly produce such radiation. Conversely, it is now advanced that the continuous emission of the K-corona and associated emission lines from the E-corona must be interpreted as manifestations of the same phenomenon: condensed matter exists in the corona. It is well-known that the Sun expels large amounts of material from its surface in the form of flares and coronal mass ejections. Given a liquid metallic hydrogen model of the Sun, it is logical to assume that such matter, which exists in the condensed state on the solar surface, continues to manifest its nature once expelled into the corona. Therefore, the continuous spectrum of the K-corona provides the twenty-seventh line of evidence that the Sun is composed of condensed matter.

  12. Discussion on the energy content of the galactic dark matter Bose-Einstein condensate halo in the Thomas-Fermi approximation

    Energy Technology Data Exchange (ETDEWEB)

    De Souza, J.C.C.; Pires, M.O.C., E-mail: jose.souza@ufabc.edu.br, E-mail: marcelo.pires@ufabc.edu.br [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adélia 166, Santo André, SP, 09210-170 (Brazil)

    2014-03-01

    We show that the galactic dark matter halo, considered composed of an axionlike particles Bose-Einstein condensate [6] trapped by a self-graviting potential [5], may be stable in the Thomas-Fermi approximation since appropriate choices for the dark matter particle mass and scattering length are made. The demonstration is performed by means of the calculation of the potential, kinetic and self-interaction energy terms of a galactic halo described by a Boehmer-Harko density profile. We discuss the validity of the Thomas-Fermi approximation for the halo system, and show that the kinetic energy contribution is indeed negligible.

  13. Rotation-translation device for condensed-phase spectroscopy with small sample volumes

    Science.gov (United States)

    Nuernberger, Patrick; Krampert, Gerhard; Brixner, Tobias; Vogt, Gerhard

    2006-08-01

    We present and characterize an experimental device for optical spectroscopy with small sample volumes contained in a thin film. Employing rotational and translational motion, the sample transport speeds are high enough to offer a new sample volume for each interaction in time-resolved spectroscopy experiments working with a 1kHz repetition rate. This is especially suited for ultrafast femtosecond spectroscopy such as transient absorption spectroscopy or fluorescence upconversion. To reduce photodegradation and effects from local thermal heating, a large sample area is scanned in contrast to conventional devices with either only rotation or translation movements. For characterization of the setup, transient absorption experiments are carried out using the rotation-translation device and a conventional flow-cell setup, which exhibit similar signal-to-noise ratio in the two cases. The effects of photodegradation and diffusion are also investigated, demonstrating the suitability of the device for time-resolved spectroscopic experiments. The transient absorption data show that the setup is well suited for biomolecular samples, which are often only available in small amounts and are very sensitive to thermal heating.

  14. Externalizing personality traits, empathy, and gray matter volume in healthy young drinkers.

    Science.gov (United States)

    Charpentier, Judith; Dzemidzic, Mario; West, John; Oberlin, Brandon G; Eiler, William J A; Saykin, Andrew J; Kareken, David A

    2016-02-28

    Externalizing psychopathology has been linked to prefrontal abnormalities. While clinically diagnosed subjects show altered frontal gray matter, it is unknown if similar deficits relate to externalizing traits in non-clinical populations. We used voxel-based morphometry (VBM) to retrospectively analyze the cerebral gray matter volume of 176 young adult social to heavy drinkers (mean age=24.0±2.9, male=83.5%) from studies of alcoholism risk. We hypothesized that prefrontal gray matter volume and externalizing traits would be correlated. Externalizing personality trait components-Boredom Susceptibility-Impulsivity (BS/IMP) and Empathy/Low Antisocial Behaviors (EMP/LASB)-were tested for correlations with gray matter partial volume estimates (gmPVE). Significantly large clusters (pFWEyoung adults, antisocial behavior/low empathy corresponded with reduced prefrontal and occipital gray matter, while impulsivity correlated with increased inferior frontal and anterior insula cortical volume. These findings add to a literature indicating that externalizing personality features involve altered frontal architecture.

  15. On the impacts of phytoplankton-derived organic matter on the properties of the primary marine aerosol – Part 2: Composition, hygroscopicity and cloud condensation activity

    Directory of Open Access Journals (Sweden)

    E. Fuentes

    2010-11-01

    Full Text Available The effect of colloidal and dissolved organic matter <0.2 μm, secreted by marine biota, on the hygroscopic growth and droplet activation behaviour of the primary marine aerosol was studied. Seawater proxies were prepared by the combination of artificial seawater devoid of marine organics and natural seawater enriched in organic exudate released by laboratory-grown phytoplankton cultures, as described in a companion paper. The primary aerosol was produced by bubble bursting, using a plunging multijet system as an aerosol generator.

    The aerosol generated from seawater proxies enriched with marine exudate presented organic volume fractions on the order of 5–37%, as derived by applying a simple mixing rule. The hygroscopic growth and cloud condensation nuclei (CCN activity of the marine organics-enriched particles where 9–17% and 5–24% lower, respectively, than those of the aerosol produced from artificial seawater devoid of exudate. Experiments in a companion paper indicated that the cloud nuclei formation could be enhanced in diatom bloom areas because of the increase in the primary particle production induced by marine organics. The experiments in the present study, however, indicate that the impacts of such an enhancement would be counteracted by the reduction in the CCN activity of the primary particles enriched in marine organics.

    The extent of the effect of the biogenic matter on the particle behaviour was dependent on the seawater organic concentration and type of algal exudate. Aerosol produced from seawater proxies containing diatomaceous exudate presented higher hydrophobicity and lower CCN activity than those enriched with nanoplankton exudate. The organic fraction of the particles increased with increasing seawater organic concentration, with the highest organic enrichment found for the diatomaceous exudate. These findings are indicative that, besides the differences induced by the aerosol generator employed

  16. Isotopes in Condensed Matter

    CERN Document Server

    G Plekhanov, Vladimir

    2013-01-01

    This book provides a concise introduction to the newly created sub-discipline of solid state physics isotopetronics. The role of isotopes in materials and their properties are describe  in this book. The problem of the enigma of the atomic mass in microphysics is briefly discussed.  The range of the applications of isotopes is wide: from biochemical process in living organisms to modern technical applications in quantum information. Isotopetronics promises to improve nanoelectronic and optoelectronic devices. With numerous illustrations this book is useful to researchers, engineers and graduate students.

  17. White-matter microstructure and gray-matter volumes in adolescents with subthreshold bipolar symptoms

    DEFF Research Database (Denmark)

    Paillère Martinot, M-L; Lemaitre, Henri Charles Francois; Artiges, E;

    2014-01-01

    Abnormalities in white-matter (WM) microstructure, as lower fractional anisotropy (FA), have been reported in adolescent-onset bipolar disorder and in youth at familial risk for bipolarity. We sought to determine whether healthy adolescents with subthreshold bipolar symptoms (SBP) would have earl...

  18. Structural covariance of the neostriatum with regional gray matter volumes.

    Science.gov (United States)

    Soriano-Mas, C; Harrison, B J; Pujol, J; López-Solà, M; Hernández-Ribas, R; Alonso, P; Contreras-Rodríguez, O; Giménez, M; Blanco-Hinojo, L; Ortiz, H; Deus, J; Menchón, J M; Cardoner, N

    2013-05-01

    The caudate and putamen nuclei have been traditionally divided into dorsal and ventral territories based on their segregated patterns of functional and anatomical connectivity with distributed cortical regions. Activity-dependent structural plasticity may potentially lead to the development of regional volume correlations, or structural covariance, between the different components of each cortico-striatal circuit. Here, we studied the whole-brain structural covariance patterns of four neostriatal regions belonging to distinct cortico-striatal circuits. We also assessed the potential modulating influence of laterality, age and gender. T1-weighted three-dimensional magnetic resonance images were obtained from ninety healthy participants (50 females). Following data pre-processing, the mean signal value per hemisphere was calculated for the 'seed' regions of interest, located in the dorsal and ventral caudate and the dorsal-caudal and ventral-rostral putamen. Statistical parametric mapping was used to estimate whole-brain voxel-wise structural covariance patterns for each striatal region, controlling for the shared anatomical variance between regions in order to obtain maximally specific structural covariance patterns. As predicted, segregated covariance patterns were observed. Age was found to be a relevant modulator of the covariance patterns of the right caudate regions, while laterality effects were observed for the dorsal-caudal putamen. Gender effects were only observed via an interaction with age. The different patterns of structural covariance are discussed in detail, as well as their similarities with the functional and anatomical connectivity patterns reported for the same striatal regions in other studies. Finally, the potential mechanisms underpinning the phenomenon of volume correlations between distant cortico-striatal structures are also discussed.

  19. Dynamic cortical gray matter volume changes after botulinum toxin in cervical dystonia

    NARCIS (Netherlands)

    Delnooz, C.C.S.; Pasman, J.W.; Warrenburg, B.P.C. van de

    2015-01-01

    Previous electrophysiological and functional imaging studies in focal dystonia have reported on cerebral reorganization after botulinum toxin (BoNT) injections. With the exception of microstructural changes, alterations in gray matter volume after BoNT have not been explored. In this study, we

  20. Correlation between Gray/White Matter Volume and Cognition in Healthy Elderly People

    Science.gov (United States)

    Taki, Yasuyuki; Kinomura, Shigeo; Sato, Kazunori; Goto, Ryoi; Wu, Kai; Kawashima, Ryuta; Fukuda, Hiroshi

    2011-01-01

    This study applied volumetric analysis and voxel-based morphometry (VBM) of brain magnetic resonance (MR) images to assess whether correlations exist between global and regional gray/white matter volume and the cognitive functions of semantic memory and short-term memory, which are relatively well preserved with aging, using MR image data from 109…

  1. Molecular view modeling of atmospheric organic particulate matter: Incorporating molecular structure and co-condensation of water

    Science.gov (United States)

    Pankow, James F.; Marks, Marguerite C.; Barsanti, Kelley C.; Mahmud, Abdullah; Asher, William E.; Li, Jingyi; Ying, Qi; Jathar, Shantanu H.; Kleeman, Michael J.

    2015-12-01

    Most urban and regional models used to predict levels of organic particulate matter (OPM) are based on fundamental equations for gas/particle partitioning, but make the highly simplifying, anonymized-view (AV) assumptions that OPM levels are not affected by either: a) the molecular characteristics of the condensing organic compounds (other than simple volatility); or b) co-condensation of water as driven by non-zero relative humidity (RH) values. The simplifying assumptions have allowed parameterized chamber results for formation of secondary organic aerosol (SOA) (e.g., ;two-product; (2p) coefficients) to be incorporated in chemical transport models. However, a return towards a less simplistic (and more computationally demanding) molecular view (MV) is needed that acknowledges that atmospheric OPM is a mixture of organic compounds with differing polarities, water, and in some cases dissolved salts. The higher computational cost of MV modeling results from a need for iterative calculations of the composition-dependent gas/particle partition coefficient values. MV modeling of OPM that considered water uptake (but not dissolved salts) was carried out for the southeast United States for the period August 29 through September 7, 2006. Three model variants were used at three universities: CMAQ-RH-2p (at PSU), UCD/CIT-RH-2p (at UCD), and CMAQ-RH-MCM (at TAMU). With the first two, MV structural characteristics (carbon number and numbers of functional groups) were assigned to each of the 2p products used in CMAQv.4.7.1 such that resulting predicted Kp,i values matched those in CMAQv.4.7.1. When water uptake was allowed, most runs assumed that uptake occurred only into the SOA portion, and imposed immiscibility of SOA with primary organic aerosol (POA). (POA is often viewed as rather non-polar, while SOA is commonly viewed as moderately-to-rather polar. Some runs with UCD/CIT-RH-2p were used to investigate the effects of POA/SOA miscibility.) CMAQ-RH-MCM used MCM to

  2. Parental Praise Correlates with Posterior Insular Cortex Gray Matter Volume in Children and Adolescents.

    Science.gov (United States)

    Matsudaira, Izumi; Yokota, Susumu; Hashimoto, Teruo; Takeuchi, Hikaru; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Taki, Yasuyuki; Kawashima, Ryuta

    2016-01-01

    A positive parenting style affects psychological and cognitive development in children. Neuroimaging studies revealed that a positive parenting style influenced brain structure in children. Parental praise is a concrete behavior observed in positive parenting. Although previous psychological studies revealed a positive effect of parental praise on children, little is known about the relationship between parental praise and brain structure in children. Thus, the purpose of the present study was to determine whether there was a correlation between the parental attitude towards praising their child and gray matter volume in the children (116 boys and 109 girls; mean age, 10.6 years old). We examined the correlation between regional gray matter volume and parental praise using voxel-based morphometry (VBM) following magnetic resonance imaging (MRI). In addition, to confirm the positive effects of parental praise, we analyzed the correlation between the frequency of parental praise and personality traits in children. We showed that the parental attitude towards praising their child was significantly and positively correlated with the gray matter volume of the left posterior insular cortex in children. Moreover, we found a significant positive correlation between parental attitude towards praising their child and the personality traits of conscientiousness and openness to experience in the children. Prior studies said that gray matter volume in the posterior insula was correlated with empathy, and the functional connectivity between this area and the amygdala was associated with emotional regulation. Furthermore, the posterior insula relates to auditory function, and therefore, was likely involved in the processing of parental praise. Considering the possibility of experience-dependent plasticity, frequent parental praise would lead to increased posterior insular gray matter volume in children. Our study is the first to elucidate the relationship between a specific

  3. Brain gray matter volume changes associated with motor symptoms in patients with Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    Dezhi Kang; Fuyong Chen; Fangyu Wang; Guorong Wu; Ying Liu; Gang Wu; Lianghong Yu

    2016-01-01

    Background:Parkinson's disease (PD) is a common neurodegenerative disease.Most studies have found that the histopathological lesion is not only localized at the extrapyramidal area (basal ganglia) but also at the cortex in PD patients.Voxel-based morphometry (VBM) based on the voxel as a unit is described for quantitative detection of density and volume of brain tissue.In this study,VBM was used to investigate the brain gray matter changes associated with motor symptoms in PD patients.Methods:Twelve outpatients with PD and 12 healthy controls were recruited in our hospital from September 2013 to March 2014.VBM was performed on the whole brain of all subjects.Image processing and statistical analysis were performed using SPM8.A two-sample t test and multiple regression analysis were performed.Results were displayed with a threshold of P < 0.01,corrected by false discovery rate (FDR) correction and cluster size >30 voxels.Results:Comparing control healthy subjects with the patients,the data showed that PD patients had reduced gray matter volume in the postcentral gyrus,the right supramarginal center,superior temporal gyrus,precentral gyrus,Brodmann area 41,transverse temporal gyrus,Brodmann area 3,and inferior parietal Iobule.The data also found that between gray matter volume and UPDRSIII in PD patients,there were negative correlations in the right middle frontal gyrus,BA06,right precentral gyrus,right superior frontal gyrus,and medial frontal gyrus,and between gray matter volume and Hoehn-Yahr (HY) in PD patients,there were negative correlations in the right middle frontal gyrus,right superior frontal gyrus,BA6,and right precentral gyrus.Conclusions:These data supported that extensive changes associated with motor symptoms in the gray matter volume was mainly located in the related area of movement,which had obvious relevance with the progression of PD.

  4. Physical Exercise Habits Correlate with Gray Matter Volume of the Hippocampus in Healthy Adult Humans

    Science.gov (United States)

    Killgore, William D. S.; Olson, Elizabeth A.; Weber, Mareen

    2013-12-01

    Physical activity facilitates neurogenesis of dentate cells in the rodent hippocampus, a brain region critical for memory formation and spatial representation. Recent findings in humans also suggest that aerobic exercise can lead to increased hippocampal volume and enhanced cognitive functioning in children and elderly adults. However, the association between physical activity and hippocampal volume during the period from early adulthood through middle age has not been effectively explored. Here, we correlated the number of minutes of self-reported exercise per week with gray matter volume of the hippocampus using voxel-based morphometry (VBM) in 61 healthy adults ranging from 18 to 45 years of age. After controlling for age, gender, and total brain volume, total minutes of weekly exercise correlated significantly with volume of the right hippocampus. Findings highlight the relationship between regular physical exercise and brain structure during early to middle adulthood.

  5. Physical exercise habits correlate with gray matter volume of the hippocampus in healthy adult humans.

    Science.gov (United States)

    Killgore, William D S; Olson, Elizabeth A; Weber, Mareen

    2013-12-12

    Physical activity facilitates neurogenesis of dentate cells in the rodent hippocampus, a brain region critical for memory formation and spatial representation. Recent findings in humans also suggest that aerobic exercise can lead to increased hippocampal volume and enhanced cognitive functioning in children and elderly adults. However, the association between physical activity and hippocampal volume during the period from early adulthood through middle age has not been effectively explored. Here, we correlated the number of minutes of self-reported exercise per week with gray matter volume of the hippocampus using voxel-based morphometry (VBM) in 61 healthy adults ranging from 18 to 45 years of age. After controlling for age, gender, and total brain volume, total minutes of weekly exercise correlated significantly with volume of the right hippocampus. Findings highlight the relationship between regular physical exercise and brain structure during early to middle adulthood.

  6. Age dependent white matter lesions and brain volume changes in healthy volunteers

    DEFF Research Database (Denmark)

    Christiansen, P; Larsson, H B; Thomsen, C

    1994-01-01

    The brain of 142 healthy volunteers aged 21 to 80 years were investigated using MR imaging. The number and size of the white matter hyperintensity lesions (WMHL) in the cerebral hemispheres were determined. Furthermore, the volume of the cerebral hemispheres and of the lateral ventricles...... was measured. An almost linear increase in the number of volunteers with WMHL was seen with aging for males and females. With aging a significant decrease in the volume of the cerebral hemispheres was found for males, and a significant increase in the volume of the lateral ventricles was seen for both males...... and females. Our results suggest that with aging central atrophy increases more (relatively) than cortical atrophy. No correlation was found between the decreasing volume of the cerebral hemispheres and the increasing number and size of WMHL, nor between the increasing volume of the lateral ventricles...

  7. Association of regional gray matter volumes in the brain with disruptive behavior disorders in male and female children

    Directory of Open Access Journals (Sweden)

    Kalina J. Michalska

    2015-01-01

    The present findings did not replicate previous findings of reduced gray matter volumes in the anterior insula, amygdala, and frontal cortex in youth with CD, but are consistent with previous findings of reduced gray matter volumes in temporal regions, particularly in girls.

  8. Postoperative increase in grey matter volume in visual cortex after unilateral cataract surgery

    DEFF Research Database (Denmark)

    Lou, Astrid R.; Madsen, Kristoffer Hougaard; Julian, Hanne O.

    2013-01-01

    surgery induces a regional increase in grey matter in areas V1 and V2 of the visual cortex. Results:  In all patients, cataract surgery immediately improved visual acuity, contrast sensitivity and mean sensitivity in the visual field of the operated eye. The improvement in vision was stable throughout...... the 6 weeks after operation. VBM revealed a regional expansion of grey matter volume in area V2 contralateral to the operated eye during the 6-week period after surgery. Individual increases in grey matter were predicted by the symmetry in visual acuity between the operated eye and nonoperated eye....... The more symmetrical visual acuity became after unilateral cataract surgery, the more pronounced was the grey matter increase in visual cortex. Conclusion:  The data suggest that cataract surgery triggered a use-dependent structural plasticity in V2 presumably through improved binocular integration...

  9. Processing speed in normal aging: effects of white matter hyperintensities and hippocampal volume loss.

    Science.gov (United States)

    Papp, Kathryn V; Kaplan, Richard F; Springate, Beth; Moscufo, Nicola; Wakefield, Dorothy B; Guttmann, Charles R G; Wolfson, Leslie

    2014-01-01

    Changes in cognitive functioning are said to be part of normal aging. Quantitative MRI has made it possible to measure structural brain changes during aging which may underlie these decrements which include slowed information processing and memory loss. Much has been written on white matter hyperintensities (WMH), which are associated with cognitive deficits on tasks requiring processing speed and executive functioning, and hippocampal volume loss, which is associated with memory decline. Here we examine volumetric MRI measures of WMH and hippocampal volume loss together in relation to neuropsychological tests considered to be measures of executive functioning and processing speed in 81 non-demented elderly individuals, aged 75-90. Correlational analysis showed that when controlling for age, both greater WMH volume and smaller hippocampal volume were correlated with slower performances on most tests with the exception of a battery of continuous performance tests in which only WMH was correlated with slower reaction time (RT). We then performed a series of hierarchical multiple regression analyses to examine the independent contributions of greater WMH volume and reduced hippocampal volume to executive functioning and processing speed. The results showed that for the four measures requiring executive functioning and speed of processing, WMH volume and hippocampal volume combined predicted between 21.4% and 37% of the explained variance. These results suggest that WM integrity and hippocampal volume influence cognitive decline independently on tasks involving processing speed and executive function independent of age.

  10. Frontal white matter volume is associated with brain enlargement and higher structural connectivity in anthropoid primates.

    Directory of Open Access Journals (Sweden)

    Jeroen Bert Smaers

    Full Text Available Previous research has indicated the importance of the frontal lobe and its 'executive' connections to other brain structures as crucial in explaining primate neocortical adaptations. However, a representative sample of volumetric measurements of frontal connective tissue (white matter has not been available. In this study, we present new volumetric measurements of white and grey matter in the frontal and non-frontal neocortical lobes from 18 anthropoid species. We analyze this data in the context of existing theories of neocortex, frontal lobe and white versus grey matter hyperscaling. Results indicate that the 'universal scaling law' of neocortical white to grey matter applies separately for frontal and non-frontal lobes; that hyperscaling of both neocortex and frontal lobe to rest of brain is mainly due to frontal white matter; and that changes in frontal (but not non-frontal white matter volume are associated with changes in rest of brain and basal ganglia, a group of subcortical nuclei functionally linked to 'executive control'. Results suggest a central role for frontal white matter in explaining neocortex and frontal lobe hyperscaling, brain size variation and higher neural structural connectivity in anthropoids.

  11. A History of Psychosis in Bipolar Disorder is Associated With Gray Matter Volume Reduction.

    Science.gov (United States)

    Ekman, Carl Johan; Petrovic, Predrag; Johansson, Anette G M; Sellgren, Carl; Ingvar, Martin; Landén, Mikael

    2017-01-01

    Psychotic symptoms are prevalent in schizophrenia, bipolar disorder, and other psychiatric and neurological disorders, yet the neurobiological underpinnings of psychosis remain obscure. In the last decade, a large number of magnetic resonance imaging studies have shown differences in local gray matter volume between patients with different psychiatric syndromes and healthy controls. Few studies have focused on the symptoms, which these syndromes are constituted of. Here, we test the association between psychosis and gray matter volume by using a sample of 167 subjects with bipolar disorder, with and without a history of psychosis, and 102 healthy controls. Magnetic resonance images were analyzed on group level using a voxel-wise mass univariate analysis (Voxel-Based Morphometry). We found that patients with a history of psychosis had smaller gray matter volume in left fusiform gyrus, the right rostral dorsolateral prefrontal cortex, and the left inferior frontal gyrus compared with patients without psychosis and with healthy controls. There was no volume difference in these areas between the no-psychosis group and healthy controls. These areas have previously been structurally and functionally coupled to delusions and hallucinations. Our finding adds further evidence to the probability of these regions as key areas in the development of psychotic symptoms. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. Matter-wave solutions of Bose-Einstein condensates with three-body interaction in linear magnetic and time-dependent laser fields

    Institute of Scientific and Technical Information of China (English)

    Etienne Wamba; Timoléon C. Kofané; Alidou Mohamadou

    2012-01-01

    We construct,through a further extension of the tanh-function method,the matter-wave solutions of Bose-Einstein condensates (BECs) with a three-body interaction.The BECs are trapped in a potential comprising the linear magnetic and the time-dependent laser fields.The exact solutions obtained include soliton solutions,such as kink and antikink as well as bright,dark,multisolitonic modulated waves.We realize that the motion and the shape of the solitary wave can be manipulated by controlling the strengths of the fields.

  13. Global and regional associations of smaller cerebral gray and white matter volumes with gait in older people.

    Directory of Open Access Journals (Sweden)

    Michele L Callisaya

    Full Text Available BACKGROUND: Gait impairments increase with advancing age and can lead to falls and loss of independence. Brain atrophy also occurs in older age and may contribute to gait decline. We aimed to investigate global and regional relationships of cerebral gray and white matter volumes with gait speed, and its determinants step length and cadence, in older people. METHODS: In a population-based study, participants aged >60 years without Parkinson's disease or brain infarcts underwent magnetic resonance imaging and gait measurements using a computerized walkway. Linear regression was used to study associations of total gray and white matter volumes with gait, adjusting for each other, age, sex, height and white matter hyperintensity volume. Other covariates considered in analyses included weight and vascular disease history. Voxel-based morphometry was used to study regional relationships of gray and white matter with gait. RESULTS: There were 305 participants, mean age 71.4 (6.9 years, 54% male, mean gait speed 1.16 (0.22 m/s. Smaller total gray matter volume was independently associated with poorer gait speed (p = 0.001 and step length (p<0.001, but not cadence. Smaller volumes of cortical and subcortical gray matter in bilateral regions important for motor control, vision, perception and memory were independently associated with slower gait speed and shorter steps. No global or regional associations were observed between white matter volume and gait independent of gray matter volume, white matter hyperintensity volume and other covariates. CONCLUSION: Smaller gray matter volume in bilaterally distributed brain networks serving motor control was associated with slower gait speed and step length, but not cadence.

  14. Regional grey matter volume abnormalities in bulimia nervosa and binge-eating disorder.

    Science.gov (United States)

    Schäfer, Axel; Vaitl, Dieter; Schienle, Anne

    2010-04-01

    This study investigated whether bulimia nervosa (BN) and binge-eating disorder (BED) are associated with structural brain abnormalities. Both disorders share the main symptom binge-eating, but are considered differential diagnoses. We attempted to identify alterations in grey matter volume (GMV) that are present in both psychopathologies as well as disorder-specific GMV characteristics. Such information can help to improve neurobiological models of eating disorders and their classification. A total of 50 participants (patients suffering from BN (purge type), BED, and normal-weight controls) underwent structural MRI scanning. GMV for specific brain regions involved in food/reinforcement processing was analyzed by means of voxel-based morphometry. Both patient groups were characterized by greater volumes of the medial orbitofrontal cortex (OFC) compared to healthy controls. In BN patients, who had increased ventral striatum volumes, body mass index and purging severity were correlated with striatal grey matter volume. Altogether, our data implicate a crucial role of the medial OFC in the studied eating disorders. The structural abnormality might be associated with dysfunctions in food reward processing and/or self-regulation. The bulimia-specific volume enlargement of the ventral striatum is discussed in the framework of negative reinforcement through purging and associated weight regulation.

  15. Variability of exhaled breath condensate (EBC) volume and pH using a feedback regulated breathing pattern

    Science.gov (United States)

    Exhaled breath condensate (EBC) is a valuable biological medium for non-invasively measuring biomarkers with the potential to reflect organ systems responses to environmental and dietary exposures and disease processes. Collection of EBC has typically been with spontaneous breat...

  16. Relationship between Prolactin Plasma Levels and White Matter Volume in Women with Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    L. De Giglio

    2015-01-01

    two months. There was no difference in PRL plasma levels between patients with and without gadolinium enhancement on MRI. PRL plasma levels correlated with white matter volume (WMV (rho = 0.284, p=0.014 but not with grey matter volume (GMV. Moreover, PRL levels predicted changes in WMV (Beta: 984, p=0.034. Conclusions. Our data of a positive association between PRL serum levels and WMV support the role of PRL in promoting myelin repair as documented in animal models of demyelination. The lack of an increase of PRL in the presence of gadolinium enhancement, contrasts with the view considering this hormone as an immune-stimulating and detrimental factor in the inflammatory process associated with MS.

  17. Facebook usage on smartphones and gray matter volume of the nucleus accumbens.

    Science.gov (United States)

    Montag, Christian; Markowetz, Alexander; Blaszkiewicz, Konrad; Andone, Ionut; Lachmann, Bernd; Sariyska, Rayna; Trendafilov, Boris; Eibes, Mark; Kolb, Julia; Reuter, Martin; Weber, Bernd; Markett, Sebastian

    2017-06-30

    A recent study has implicated the nucleus accumbens of the ventral striatum in explaining why online-users spend time on the social network platform Facebook. Here, higher activity of the nucleus accumbens was associated with gaining reputation on social media. In the present study, we touched a related research field. We recorded the actual Facebook usage of N=62 participants on their smartphones over the course of five weeks and correlated summary measures of Facebook use with gray matter volume of the nucleus accumbens. It appeared, that in particular higher daily frequency of checking Facebook on the smartphone was robustly linked with smaller gray matter volumes of the nucleus accumbens. The present study gives additional support for the rewarding aspects of Facebook usage. Moreover, it shows the feasibility to include real life behavior variables in human neuroscientific research. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Normal gray and white matter volume after weight restoration in adolescents with anorexia nervosa.

    Science.gov (United States)

    Lázaro, Luisa; Andrés, Susana; Calvo, Anna; Cullell, Clàudia; Moreno, Elena; Plana, M Teresa; Falcón, Carles; Bargalló, Núria; Castro-Fornieles, Josefina

    2013-12-01

    The aim of this study was to determine whether treated, weight-stabilized adolescents with anorexia nervosa (AN) present brain volume differences in comparison with healthy controls. Thirty-five adolescents with weight-recovered AN and 17 healthy controls were assessed by means of psychopathology scales and magnetic resonance imaging. Axial three-dimensional T1-weighted images were obtained in a 1.5 Tesla scanner and analyzed using optimized voxel-based morphometry (VBM). There were no significant differences between controls and weight-stabilized AN patients with regard to global volumes of either gray or white brain matter, or in the regional VBM study. Differences were not significant between patients with psychopharmacological treatment and without, between those with amenorrhea and without, as well as between patients with restrictive versus purgative AN. The present findings reveal no global or regional gray or white matter abnormalities in this sample of adolescents following weight restoration. Copyright © 2013 Wiley Periodicals, Inc.

  19. Physical activity and inflammation: effects on gray-matter volume and cognitive decline in aging.

    Science.gov (United States)

    Papenberg, Goran; Ferencz, Beata; Mangialasche, Francesca; Mecocci, Patrizia; Cecchetti, Roberta; Kalpouzos, Grégoria; Fratiglioni, Laura; Bäckman, Lars

    2016-10-01

    Physical activity has been positively associated with gray-matter integrity. In contrast, pro-inflammatory cytokines seem to have negative effects on the aging brain and have been related to dementia. It was investigated whether an inactive lifestyle and high levels of inflammation resulted in smaller gray-matter volumes and predicted cognitive decline across 6 years in a population-based study of older adults (n = 414). Self-reported physical activity (fitness-enhancing, health-enhancing, inadequate) was linked to gray-matter volume, such that individuals with inadequate physical activity had the least gray matter. There were no overall associations between different pro-and anti-inflammatory markers (IL-1β, IL-6, IL-10, IL-12p40, IL-12p70, G-CSF, and TNF-α) and gray-matter integrity. However, persons with inadequate activity and high levels of the pro-inflammatory marker IL-12p40 had smaller volumes of lateral prefrontal cortex and hippocampus and declined more on the Mini-Mental State Examination test over 6 years compared with physically inactive individuals with low levels of IL-12p40 and to more physically active persons, irrespective of their levels of IL-12p40. These patterns of data suggested that inflammation was particularly detrimental in inactive older adults and may exacerbate the negative effects of physical inactivity on brain and cognition in old age. Hum Brain Mapp 37:3462-3473, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Attenuation of brain grey matter volume in brachial plexus injury patients.

    Science.gov (United States)

    Lu, Yechen; Liu, Hanqiu; Hua, Xuyun; Xu, Jian-Guang; Gu, Yu-Dong; Shen, Yundong

    2016-01-01

    Brachial plexus injury (BPI) causes functional changes in the brain, but the structural changes resulting from BPI remain unknown. In this study, we compared grey matter volume between nine BPI patients and ten healthy controls by means of voxel-based morphometry. This was the first study of cortical morphology in BPI. We found that brain regions including the cerebellum, anterior cingulate cortex, bilateral inferior, medial, superior frontal lobe, and bilateral insula had less grey matter in BPI patients. Most of the affected brain regions of BPI patients are closely related to motor function. We speculate that the loss of grey matter in multiple regions might be the neural basis of the difficulties in the motor rehabilitation of BPI patients. The mapping result might provide new target regions for interventions of motor rehabilitation.

  1. Sex-specific Gray Matter Volume Differences in Females with Developmental Dyslexia

    OpenAIRE

    Evans, Tanya M.; Flowers, D. Lynn; Napoliello, Eileen M.; Eden, Guinevere F.

    2013-01-01

    Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques,...

  2. Magnetic resonance morphometry of the loss of gray matter volume in Parkinson’s disease patients****

    Institute of Scientific and Technical Information of China (English)

    Jianguo Xia; Lemin Tang; Juan Wang; Weizhong Tian; Hongbin Ding; Qilin Wei; Huanxin Huang; Jun Wang; Jinli Zhao; Hongmei Gu

    2013-01-01

    Voxel-based morphometry can be used to quantitatively compare structural differences and func-tional changes of gray matter in subjects. In the present study, we compared gray matter images of 32 patients with Parkinson’s disease and 25 healthy controls using voxel-based morphometry based on 3.0 T high-field magnetic resonance T1-weighted imaging and clinical neurological scale scores. Results showed that the scores in Mini-Mental State Examination and Montreal Cognitive Assessment were lower in patients compared with controls. In particular, the scores of visuospatial/executive function items in Montreal Cognitive Assessment were significantly reduced, but mean scores of non-motor symptoms significantly increased, in patients with Parkinson’s dis-ease. In addition, gray matter volume was significantly diminished in Parkinson’s disease patients compared with normal controls, including bilateral temporal lobe, bilateral occipital lobe, bilateral parietal lobe, bilateral frontal lobe, bilateral insular lobe, bilateral parahippocampal gyrus, bilateral amygdale, right uncus, and right posterior lobe of the cerebel um. These findings indicate that voxel-based morphometry can accurately and quantitatively assess the loss of gray matter volume in patients with Parkinson's disease, and provide essential neuroimaging evidence for multisystem pathological mechanisms involved in Parkinson’s disease.

  3. Age effects on gray matter volume and attentional performance in Zen meditation.

    Science.gov (United States)

    Pagnoni, Giuseppe; Cekic, Milos

    2007-10-01

    Zen meditation, a Buddhist practice centered on attentional and postural self-regulation, has been speculated to bring about beneficial long-term effects for the individual, ranging from stress reduction to improvement of cognitive function. In this study, we examined how the regular practice of meditation may affect the normal age-related decline of cerebral gray matter volume and attentional performance observed in healthy individuals. Voxel-based morphometry for MRI anatomical brain images and a computerized sustained attention task were employed in 13 regular practitioners of Zen meditation and 13 matched controls. While control subjects displayed the expected negative correlation of both gray matter volume and attentional performance with age, meditators did not show a significant correlation of either measure with age. The effect of meditation on gray matter volume was most prominent in the putamen, a structure strongly implicated in attentional processing. These findings suggest that the regular practice of meditation may have neuroprotective effects and reduce the cognitive decline associated with normal aging.

  4. The relation between 1st grade grey matter volume and 2nd grade math competence.

    Science.gov (United States)

    Price, Gavin R; Wilkey, Eric D; Yeo, Darren J; Cutting, Laurie E

    2016-01-01

    Mathematical and numerical competence is a critical foundation for individual success in modern society yet the neurobiological sources of individual differences in math competence are poorly understood. Neuroimaging research over the last decade suggests that neural mechanisms in the parietal lobe, particularly the intraparietal sulcus (IPS) are structurally aberrant in individuals with mathematical learning disabilities. However, whether those same brain regions underlie individual differences in math performance across the full range of math abilities is unknown. Furthermore, previous studies have been exclusively cross-sectional, making it unclear whether variations in the structure of the IPS are caused by or consequences of the development of math skills. The present study investigates the relation between grey matter volume across the whole brain and math competence longitudinally in a representative sample of 50 elementary school children. Results show that grey matter volume in the left IPS at the end of 1st grade relates to math competence a year later at the end of 2nd grade. Grey matter volume in this region did not change over that year, and was still correlated with math competence at the end of 2nd grade. These findings support the hypothesis that the IPS and its associated functions represent a critical foundation for the acquisition of mathematical competence.

  5. Improved estimates for the role of grey matter volume and GABA in bistable perception.

    Science.gov (United States)

    Sandberg, Kristian; Blicher, Jakob Udby; Del Pin, Simon Hviid; Andersen, Lau Møller; Rees, Geraint; Kanai, Ryota

    2016-10-01

    Across a century or more, ambiguous stimuli have been studied scientifically because they provide a method for studying the internal mechanisms of the brain while ensuring an unchanging external stimulus. In recent years, several studies have reported correlations between perceptual dynamics during bistable perception and particular brain characteristics such as the grey matter volume of areas in the superior parietal lobule (SPL) and the relative GABA concentration in the occipital lobe. Here, we attempt to replicate previous results using similar paradigms to those used in the studies first reporting the correlations. Using the original findings as priors for Bayesian analyses, we found strong support for the correlation between structure-from-motion percept duration and anterior SPL grey matter volume. Correlations between percept duration and other parietal areas as well as occipital GABA, however, were not directly replicated or appeared less strong than previous studies suggested. Inspection of the posterior distributions (current "best guess" based on new data given old data as prior) revealed that several original findings may reflect true relationships although no direct evidence was found in support of them in the current sample. Additionally, we found that multiple regression models based on grey matter volume at 2-3 parietal locations (but not including GABA) were the best predictors of percept duration, explaining approximately 35% of the inter-individual variance. Taken together, our results provide new estimates of correlation strengths, generally increasing confidence in the role of the aSPL while decreasing confidence in some of the other relationships.

  6. Motor fMRI and cortical grey matter volume in adults born very preterm

    Directory of Open Access Journals (Sweden)

    E.J. Lawrence

    2014-10-01

    Full Text Available The primary aim of this study was to investigate the functional neuroanatomy of motor planning, initiation and execution in a cohort of young adults (mean age 20 years who were born very preterm (VPT; <33 weeks of gestation, as these individuals are at increased risk of experiencing neuromotor difficulties compared to controls. A cued motor task was presented to 20 right-handed VPT individuals and 20 controls within a functional magnetic resonance imaging (fMRI paradigm. Whole-brain grey matter volume was also quantified and associations with functional data were examined. Despite comparable task performance, fMRI results showed that the VPT group displayed greater brain activation compared to controls in a region comprising the right cerebellum and the lingual, parahippocampal and middle temporal gyri. The VPT group also displayed decreased grey matter volume in the right superior frontal/premotor cortex and left middle temporal gyri. Grey matter volume in the premotor and middle temporal clusters was significantly negatively correlated with BOLD activation in the cerebellum. Overall, these data suggest that preterm birth is associated with functional neuronal differences that persist into adulthood, which are likely to reflect neural reorganisation following early brain injury.

  7. Hemispheric asymmetries of functional connectivity and grey matter volume in the default mode network.

    Science.gov (United States)

    Saenger, Victor M; Barrios, Fernando A; Martínez-Gudiño, María L; Alcauter, Sarael

    2012-06-01

    Resting state networks such as the default mode network have been widely reported. Although a plethora of information on its functional relevance has been generated, little is known about lateralization or hemisphere asymmetry within the DMN. We used high-resolution resting state fMRI and T1 3D data to investigate such asymmetries in two groups of healthy subjects, one right-handed and one left-handed. Independent component analysis and the dual regression approach were carried out to identify functional asymmetries, while voxel-based morphometry was used to identify structural asymmetries in grey matter volume within the DMN. Greater leftward functional connectivity was observed in the posterior cingulate gyrus (PCG) for both groups. Leftward functional asymmetry was observed in the thalamus and rightward functional asymmetries were observed in the middle frontal and middle/superior temporal gyrus in the right-handed group. Rightward asymmetries in grey matter volume were observed in the posterior portion of the PCG for both groups. The right-handed group exhibited leftward structural asymmetries in the anterior portion of the PCG and in the middle frontal and posterior portion of the middle temporal gyrus, while rightward asymmetries were observed in the posterior portion of the PCG and anterior portions of temporal regions. These results suggest that functional connectivity and grey matter volume are not equally distributed between hemispheres within the DMN, and that functional asymmetries are not always reflected or determined by structural asymmetries.

  8. Localized brain volume and white matter integrity alterations in adolescent anorexia nervosa.

    Science.gov (United States)

    Frank, Guido K W; Shott, Megan E; Hagman, Jennifer O; Yang, Tony T

    2013-10-01

    The neurobiological underpinnings of anorexia nervosa (AN) are poorly understood. In this study, we tested whether brain gray matter (GM) and white matter (WM) in adolescents with AN would show alterations comparable to those in adults. We used magnetic resonance imaging to study GM and WM volume, and diffusion tensor imaging to assess fractional anisotropy for WM integrity in 19 adolescents with AN and 22 controls. Individuals with AN showed greater left orbitofrontal, right insular, and bilateral temporal cortex GM, as well as temporal lobe WM volumes compared to controls. WM integrity in adolescents with AN was lower (lower fractional anisotropy) in fornix, posterior frontal, and parietal areas, but higher in anterior frontal, orbitofrontal, and temporal lobes. In individuals with AN, orbitofrontal GM volume correlated negatively with sweet taste pleasantness. An additional comparison of this study cohort with adult individuals with AN and healthy controls supported greater orbitofrontal cortex and insula volumes in AN across age groups. This study indicates larger orbitofrontal and insular GM volumes, as well as lower fornix WM integrity in adolescents with AN, similar to adults. The pattern of larger anteroventral GM and WM volume as well as WM integrity, but lower WM integrity in posterior frontal and parietal regions may indicate that developmental factors such as GM pruning and WM growth could contribute to brain alterations in AN. The negative correlation between taste pleasantness and orbitofrontal cortex volume in individuals with AN could contribute to food avoidance in this disorder. Copyright © 2013 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  9. Association of ideomotor apraxia with frontal gray matter volume loss in corticobasal syndrome.

    Science.gov (United States)

    Huey, Edward D; Pardini, Matteo; Cavanagh, Alyson; Wassermann, Eric M; Kapogiannis, Dimitrios; Spina, Salvatore; Ghetti, Bernardino; Grafman, Jordan

    2009-10-01

    To determine the brain areas associated with specific components of ideomotor apraxia (IMA) in corticobasal syndrome (CBS). Case-control and cross-sectional study. Forty-eight patients with CBS and 14 control subjects. Intervention Administration of the Test of Oral and Limb Apraxia. Differences between patients with CBS and healthy controls and associations between areas of gray matter volume and IMA determined by voxel-based morphometry in patients with CBS. Overall, IMA was associated with decreased gray matter volume in the left supplemental motor area, premotor cortex, and caudate nucleus of patients with CBS. The overall degree of apraxia was independent of the side of motor impairment. Praxis to imitation (vs command) was particularly impaired in the patients with CBS. Patients demonstrated equal impairment in transitive and intransitive praxis. In patients with CBS, IMA is associated with left posterior frontal cortical and subcortical volume loss. Despite showing left frontal volume loss associated with IMA, patients with CBS have particularly impaired imitation of gestures. These findings suggest either that the IMA of CBS affects a route of praxis that bypasses motor engrams or that motor engrams are affected but that they exist in areas other than the inferior parietal cortex.

  10. A combined VBM and DTI study of schizophrenia: bilateral decreased insula volume and cerebral white matter disintegrity corresponding to subinsular white matter projections unlinked to clinical symptomatology.

    Science.gov (United States)

    Onay, Aslıhan; Yapıcı Eser, Hale; Ulaşoğlu Yıldız, Çiğdem; Aslan, Selçuk; Talı, Erhan Turgut

    2017-01-01

    Grey matter and white matter changes within the brain are well defined in schizophrenia. However, most studies focused on either grey matter changes or white matter integrity separately; only in limited number of studies these changes were interpreted in the same frame. In addition, the relationship of these findings with clinical variables is not clearly established. Here, we aimed to investigate the grey matter and white matter changes in schizophrenia patients and exhibit the relation of these imaging findings with clinical variables. A total of 20 schizophrenia patients and 16 matched healthy controls underwent magnetic resonance imaging to investigate the grey matter and white matter alterations that occur in schizophrenia patients using voxel-based morphometry (VBM) and whole brain voxel-wise analysis of diffusion tensor imaging (DTI) parameters with SPM8, respectively. While the preprocessing steps of VBM were performed with the default parameters of VBM8 toolbox, the preprocessing steps of DTI were carried out using FSL. Additionally, VBM results were correlated with clinical variables. Bilateral insula showed decreased grey matter volume in schizophrenia patients compared with healthy controls (P < 0.01). The opposite contrast did not show a significant difference. Psychiatric scores, duration of illness, and age were not correlated with the decreased grey matter volume of insula in schizophrenia patients. DTI analysis revealed a significant increase in mean, radial, and axial diffusivity, mainly of the fibers of bilateral anterior thalamic radiation and superior longitudinal fasciculus with left predominance, which intersected with bilateral subinsular white matter (P < 0.05). Our findings suggest that insula may be the main affected brain region in schizophrenia, which is also well supported by the literature. Our results were independent of disease duration and schizophrenia symptoms. White matter alterations were observed within bilateral anterior

  11. Lithium and GSK-3β promoter gene variants influence cortical gray matter volumes in bipolar disorder.

    Science.gov (United States)

    Benedetti, Francesco; Poletti, Sara; Radaelli, Daniele; Locatelli, Clara; Pirovano, Adele; Lorenzi, Cristina; Vai, Benedetta; Bollettini, Irene; Falini, Andrea; Smeraldi, Enrico; Colombo, Cristina

    2015-04-01

    Lithium is the mainstay for the treatment of bipolar disorder (BD) and inhibits glycogen synthase kinase-3β (GSK-3β). The less active GSK-3β promoter gene variants have been associated with less detrimental clinical features of BD. GSK-3β gene variants and lithium can influence brain gray and white matter structure in psychiatric conditions, so we studied their combined effect in BD. The aim of this study is to investigate the effects of ongoing long-term lithium treatment and GSK-3β promoter rs334558 polymorphism on regional gray matter (GM) volumes of patients with BD. GM volumes were estimated with 3.0 Tesla MRI in 150 patients affected by a major depressive episode in course of BD. Duration of lifetime lithium treatment was retrospectively assessed. Analyses were performed by searching for significant effects of lithium and rs334558 in the whole brain. The less active GSK-3β rs334558*G gene promoter variant and the long-term administration of lithium were synergistically associated with increased GM volumes in the right frontal lobe, in a large cluster encompassing the boundaries of subgenual and orbitofrontal cortex (including Brodmann areas 25, 11, and 47). Effects of lithium on GM revealed in rs334558*G carriers only, consistent with previously reported clinical effects in these genotype groups, and were proportional to the duration of treatment. Lithium and rs334558 influenced GM volumes in areas critical for the generation and control of affect, which have been widely implicated in the process of BD pathophysiology. In the light of the protective effects of lithium on white matter integrity, our results suggest that the clinical effects of lithium associate with a neurotrophic effect on the whole brain, probably mediated by GSK-3β inhibition.

  12. Multimodal evidence of regional midcingulate gray matter volume underlying conflict monitoring

    Directory of Open Access Journals (Sweden)

    Muhammad A. Parvaz

    2014-01-01

    Full Text Available Functional neuroimaging studies have long implicated the mid-cingulate cortex (MCC in conflict monitoring, but it is not clear whether its structural integrity (i.e., the gray matter volume influences its conflict monitoring function. In this multimodal study, we used T1-weighted MRI scans as well as event-related potentials (ERPs to test whether the MCC gray matter volume is associated with the electrocortical marker (i.e., No-go N200 ERP component of conflict monitoring in healthy individuals. The specificity of such a relationship in health was determined in two ways: by (A acquiring the same data from individuals with cocaine use disorder (CUD, known to have deficits in executive function including behavioral monitoring; and (B acquiring the P300 ERP component that is linked with attention allocation and not specifically with conflict monitoring. Twenty-five (39.1 ± 8.4 years; 8 females healthy individuals and 25 (42.7 ± 5.9 years; 6 females individuals with CUD underwent a rewarded Go/No-go task during which the ERP data was collected, and they also underwent a structural MRI scan. The whole brain regression analysis showed a significant correlation between MCC structural integrity and the well-known ERP measure of conflict monitoring (N200, but not the P300 in healthy individuals, which was absent in CUD who were characterized by reduced MCC gray matter volume, N200 abnormalities as well as reduced task accuracy. In individuals with CUD instead, the N200 amplitude was associated with drug addiction symptomatology. These results show that the integrity of MCC volume is directly associated with the electrocortical correlates of conflict monitoring in healthy individuals, and such an association breaks down in psychopathologies that impact these brain processes. Taken together, this MCC–N200 association may serve as a biomarker of improved behavioral monitoring processes in diseased populations.

  13. Reduced cortical gray matter volume in male adolescents with substance and conduct problems.

    Science.gov (United States)

    Dalwani, Manish; Sakai, Joseph T; Mikulich-Gilbertson, Susan K; Tanabe, Jody; Raymond, Kristen; McWilliams, Shannon K; Thompson, Laetitia L; Banich, Marie T; Crowley, Thomas J

    2011-11-01

    Boys with serious conduct and substance problems (Antisocial Substance Dependence (ASD)) repeatedly make impulsive and risky decisions in spite of possible negative consequences. Because prefrontal cortex (PFC) is involved in planning behavior in accord with prior rewards and punishments, structural abnormalities in PFC could contribute to a person's propensity to make risky decisions. We acquired high-resolution structural images of 25 male ASD patients (ages 14-18 years) and 19 controls of similar ages using a 3T MR system. We conducted whole-brain voxel-based morphometric analysis (pbrain cluster-level) using Statistical Parametric Mapping version-5 and tested group differences in regional gray matter (GM) volume with analyses of covariance, adjusting for total GM volume, age, and IQ; we further adjusted between-group analyses for ADHD and depression. As secondary analyses, we tested for negative associations between GM volume and impulsivity within groups and separately, GM volume and symptom severity within patients using whole-brain regression analyses. ASD boys had significantly lower GM volume than controls in left dorsolateral PFC (DLPFC), right lingual gyrus and bilateral cerebellum, and significantly higher GM volume in right precuneus. Left DLPFC GM volume showed negative association with impulsivity within controls and negative association with substance dependence severity within patients. ASD boys show reduced GM volumes in several regions including DLPFC, a region highly relevant to impulsivity, disinhibition, and decision-making, and cerebellum, a region important for behavioral regulation, while they showed increased GM in precuneus, a region associated with self-referential and self-centered thinking. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. The effect of lifelong bilingualism on regional grey and white matter volume.

    Science.gov (United States)

    Olsen, Rosanna K; Pangelinan, Melissa M; Bogulski, Cari; Chakravarty, M Mallar; Luk, Gigi; Grady, Cheryl L; Bialystok, Ellen

    2015-07-01

    Lifelong bilingualism is associated with the delayed diagnosis of dementia, suggesting bilingual experience is relevant to brain health in aging. While the effects of bilingualism on cognitive functions across the lifespan are well documented, less is known about the neural substrates underlying differential behaviour. It is clear that bilingualism affects brain regions that mediate language abilities and that these regions are at least partially overlapping with those that exhibit age-related decline. Moreover, the behavioural advantages observed in bilingualism are generally found in executive function performance, suggesting that the frontal lobes may also be sensitive to bilingualism, which exhibit volume reductions with age. The current study investigated structural differences in the brain of lifelong bilingual older adults (n=14, mean age=70.4) compared with older monolinguals (n=14, mean age=70.6). We employed two analytic approaches: 1) we examined global differences in grey and white matter volumes; and, 2) we examined local differences in volume and cortical thickness of specific regions of interest previously implicated in bilingual/monolingual comparisons (temporal pole) or in aging (entorhinal cortex and hippocampus). We expected bilinguals would exhibit greater volume of the frontal lobe and temporal lobe (grey and white matter), given the importance of these regions in executive and language functions, respectively. We further hypothesized that regions in the medial temporal lobe, which demonstrate early changes in aging and exhibit neural pathology in dementia, would be more preserved in the bilingual group. As predicted, bilinguals exhibit greater frontal lobe white matter compared with monolinguals. Moreover, increasing age was related to decreasing temporal pole cortical thickness in the monolingual group, but no such relationship was observed for bilinguals. Finally, Stroop task performance was positively correlated with frontal lobe white

  15. Insular Gray Matter Volume and Objective Quality of Life in Schizophrenia.

    Science.gov (United States)

    Uwatoko, Teruhisa; Yoshizumi, Miho; Miyata, Jun; Ubukata, Shiho; Fujiwara, Hironobu; Kawada, Ryosaku; Kubota, Manabu; Sasamoto, Akihiko; Sugihara, Genichi; Aso, Toshihiko; Urayama, Shinichi; Fukuyama, Hidenao; Murai, Toshiya; Takahashi, Hidehiko

    2015-01-01

    Improving quality of life has been recognized as an important outcome for schizophrenia treatment, although the fundamental determinants are not well understood. In this study, we investigated the association between brain structural abnormalities and objective quality of life in schizophrenia patients. Thirty-three schizophrenia patients and 42 age-, sex-, and education-matched healthy participants underwent magnetic resonance imaging. The Quality of Life Scale was used to measure objective quality of life in schizophrenia patients. Voxel-based morphometry was performed to identify regional brain alterations that correlate with Quality of Life Scale score in the patient group. Schizophrenia patients showed gray matter reductions in the frontal, temporal, limbic, and subcortical regions. We then performed voxel-based multiple regression analysis in these regions to identify any correlations between regional gray matter volume and Quality of Life Scale scores. We found that among four subcategories of the scale, the Instrumental Role category score correlated with gray matter volume in the right anterior insula in schizophrenia patients. In addition, this correlation was shown to be mediated by negative symptoms. Our findings suggest that the neural basis of objective quality of life might differ topographically from that of subjective QOL in schizophrenia.

  16. Metric-Independent Spacetime Volume-Forms and Dark Energy/Dark Matter Unification

    CERN Document Server

    Guendelman, Eduardo; Pacheva, Svetlana

    2015-01-01

    The method of non-Riemannian (metric-independent) spacetime volume-forms (alternative generally-covariant integration measure densities) is applied to construct a modified model of gravity coupled to a single scalar field providing an explicit unification of dark energy (as a dynamically generated cosmological constant) and dust fluid dark matter flowing along geodesics as an exact sum of two separate terms in the scalar field energy-momentum tensor. The fundamental reason for the dark species unification is the presence of a non-Riemannian volume-form in the scalar field action which both triggers the dynamical generation of the cosmological constant as well as gives rise to a hidden nonlinear Noether symmetry underlying the dust dark matter fluid nature. Upon adding appropriate perturbation breaking the hidden "dust" Noether symmetry we preserve the geodesic flow property of the dark matter while we suggest a way to get growing dark energy in the present universe' epoch free of evolution pathologies. Also, ...

  17. Dyslexia and voxel-based morphometry: correlations between five behavioural measures of dyslexia and gray and white matter volumes

    NARCIS (Netherlands)

    Tamboer, P.; Scholte, H.S.; Vorst, H.C.M.

    2015-01-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in

  18. Dyslexia and Voxel-Based Morphometry: Correlations between Five Behavioural Measures of Dyslexia and Gray and White Matter Volumes

    Science.gov (United States)

    Tamboer, Peter; Scholte, H. Steven; Vorst, Harrie C. M.

    2015-01-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in a large sample of Dutch students (37 dyslexics…

  19. Nucleon Finite Volume Effect and Nuclear Matter Properties in a Relativistic Mean-Field Theory

    Institute of Scientific and Technical Information of China (English)

    R. Costa; A.J. Santiago; H. Rodrigues; J. Sa Borges

    2006-01-01

    Effects of excluded volume of nucleons on nuclear matter are studied, and the nuclear properties that follow from different relativistic mean-field model parametrizations are compared. We show that, for all tested parametrizations,the resulting volume energy a1 and the symmetry energy J are around the acceptable values of 16 MeV and 30 MeV,and the density symmetry L is around 100 Me V. On the other hand, models that consider only linear terms lead to incompressibility K0 much higher than expected. For most parameter sets there exists a critical point (ρc,δc), where the minimum and the maximum of the equation of state are coincident and the incompressibility equals zero. This critical point depends on the excluded volume parameter r. If this parameter is larger than 0.5 fm, there is no critical point and the pure neutron matter is predicted to be bound. The maximum value for neutron star mass is 1.85M⊙, which is in agreement with the mass of the heaviest observed neutron star 4U0900-40 and corresponds to r = 0.72 fm. We also show that the light neutron star mass (1.2M⊙) is obtained for r (≌) 0.9 fm.

  20. Alcohol exposure in utero is associated with decreased gray matter volume in neonates.

    Science.gov (United States)

    Donald, Kirsten A; Fouche, J P; Roos, Annerine; Koen, Nastassja; Howells, Fleur M; Riley, Edward P; Woods, Roger P; Zar, Heather J; Narr, Katherine L; Stein, Dan J

    2016-02-01

    Neuroimaging studies have indicated that prenatal alcohol exposure is associated with alterations in the structure of specific brain regions. However, the temporal specificity of such changes and their behavioral consequences are less known. Here we explore the brain structure of infants with in utero exposure to alcohol shortly after birth. T2 structural MRI images were acquired from 28 alcohol-exposed infants and 45 demographically matched healthy controls at 2-4 weeks of age on a 3T Siemens Allegra system as part of large birth cohort study, the Drakenstein Child Health Study (DCHS). Neonatal neurobehavior was assessed at this visit; early developmental outcome assessed on the Bayley Scales of Infant Development III at 6 months of age. Volumes of gray matter regions were estimated based on the segmentations of the University of North Carolina neonatal atlas. Significantly decreased total gray matter volume was demonstrated for the alcohol-exposed cohort compared to healthy control infants (p smoking status. Both early neurobehavioral and developmental adverse outcomes at 6 months across multiple domains were significantly associated with regional volumes primarily in the temporal and frontal lobes in infants with prenatal alcohol exposure. Alcohol exposure during the prenatal period has potentially enduring neurobiological consequences for exposed children. These findings suggest the effects of prenatal alcohol exposure on brain growth is present very early in the first year of life, a period during which the most rapid growth and maturation occurs.

  1. White matter volume mediates the relationship between self-efficacy and mobility in older women

    Science.gov (United States)

    Nagamatsu, Lindsay S.; Hsu, Chun Liang; Davis, Jennifer C.; Best, John R.; Liu-Ambrose, Teresa

    2017-01-01

    Background With our aging population, understanding determinants of healthy aging is a priority. One essential component of healthy aging is mobility. While self-efficacy can directly impact mobility in older adults, it is unknown what role brain health may play in this relationship. Methods We conducted a cross-sectional pilot analysis of community-dwelling women (n = 80, mean age = 69 years) to examine whether brain volume mediates the relationship between falls-related self-efficacy, as measured by the Activities-specific Balance Confidence (ABC) scale, and mobility, as measured by the Timed Up and Go (TUG) test. Age, depression, education, functional comorbidities, and Montreal Cognitive Assessment (MoCA) were included in the model as covariates. Results We report that total white matter volume, specifically, significantly mediates the relationship between self-efficacy and mobility, where higher self-efficacy was associated with greater white matter volume (r=0.28), which in turn, was associated with better mobility (r=−0.30). Conclusions Our pilot study extends our understanding of the psychosocial and neurological factors that contribute to mobility, and provides insight into effective strategies that may be used to improve functional independence among older adults. Future prospective and intervention studies are required to further elucidate the nature of the relationship between self-efficacy, mobility, and brain health. PMID:27749206

  2. Combination of volume and perfusion parameters reveals different types of grey matter changes in schizophrenia.

    Science.gov (United States)

    Xu, Lixue; Qin, Wen; Zhuo, Chuanjun; Liu, Huaigui; Zhu, Jiajia; Yu, Chunshui

    2017-03-27

    Diverse brain structural and functional changes have been reported in schizophrenia. Identifying different types of brain changes may help to understand the neural mechanisms and to develop reliable biomarkers in schizophrenia. We aimed to categorize different grey matter changes in schizophrenia based on grey matter volume (GMV) and cerebral blood flow (CBF). Structural and perfusion magnetic resonance imaging data were acquired in 100 schizophrenia patients and 95 healthy comparison subjects. Voxel-based GMV comparison was used to show structural changes, CBF analysis was used to demonstrate functional changes. We identified three types of grey matter changes in schizophrenia: structural and functional impairments in the anterior cingulate cortex and insular cortex, displaying reduction in both GMV and CBF; structural impairment with preserved function in the frontal and temporal cortices, demonstrating decreased GMV with normal CBF; pure functional abnormality in the anterior cingulate cortex and lateral prefrontal cortex and putamen, showing altered CBF with normal GMV. By combination of GMV and CBF, we identified three types of grey matter changes in schizophrenia. These findings may help to understand the complex manifestations and to develop reliable biomarkers in schizophrenia.

  3. Gender versus brain size effects on subcortical gray matter volumes in the human brain.

    Science.gov (United States)

    Tang, Tianyu; Jiao, Yun; Wang, Xunheng; Lu, Zuhong

    2013-11-27

    Previous studies had reported that volume differences of gray matter (GM) in subcortical regions of the human brain were mainly caused by gender. Meanwhile, other studies had found that the distribution of GM in the human brain varied based on individual brain sizes. Main effects of volume differences of GM in subcortical regions remain unclear. Therefore, the goals of this study are twofold, namely, to determine the main effects of volume differences of GM in subcortical regions of the human brain and to investigate the independent or joint contribution of gender and brain size to subcortical volume differences. In this study, 40 male and 40 female subjects with comparable brain sizes were selected from a population of 198 individuals. The sample was divided into the following four groups: male and female groups with comparably large brain sizes and male and female groups with comparably small brain sizes. The main effects of gender and of brain size and interactions between both factors in subcortical GM volumes were examined by analyses of covariance (ANCOVAs) using a 2×2 design matrix. Volumes of GM in subcortical regions were extracted and measured by an automatic segmentation method. Furthermore, we used two datasets to test the reliability of our methods. In both datasets, we found significant brain size effects in the right amygdala and the bilateral caudate nucleus and significant gender effects in the bilateral putamen. No interactions between brain size and gender were found. In conclusion, both gender and brain size independently contributed to volume distribution in different subcortical areas of the human brain.

  4. Gray-white matter and cerebrospinal fluid volume differences in children with Specific Language Impairment and/or Reading Disability.

    Science.gov (United States)

    Girbau-Massana, Dolors; Garcia-Marti, Gracian; Marti-Bonmati, Luis; Schwartz, Richard G

    2014-04-01

    We studied gray-white matter and cerebrospinal fluid (CSF) alterations that may be critical for language, through an optimized voxel-based morphometry evaluation in children with Specific Language Impairment (SLI), compared to Typical Language Development (TLD). Ten children with SLI (8;5-10;9) and 14 children with TLD (8;2-11;8) participated. They received a comprehensive language and reading test battery. We also analyzed a subgroup of six children with SLI+RD (Reading Disability). Brain images from 3-Tesla MRIs were analyzed with intelligence, age, gender, and total intracranial volume as covariates. Children with SLI or SLI+RD exhibited a significant lower overall gray matter volume than children with TLD. Particularly, children with SLI showed a significantly lower volume of gray matter compared to children with TLD in the right postcentral parietal gyrus (BA4), and left and right medial occipital gyri (BA19). The group with SLI also exhibited a significantly greater volume of gray matter in the right superior occipital gyrus (BA19), which may reflect a brain reorganization to compensate for their lower volumes at medial occipital gyri. Children with SLI+RD, compared to children with TLD, showed a significantly lower volume of: (a) gray matter in the right postcentral parietal gyrus; and (b) white matter in the right inferior longitudinal fasciculus (RILF), which interconnects the temporal and occipital lobes. Children with TLD exhibited a significantly lower CSF volume than children with SLI and children with SLI+RD respectively, who had somewhat smaller volumes of gray matter allowing for more CSF volume. The significant lower gray matter volume at the right postcentral parietal gyrus and greater cerebrospinal fluid volume may prove to be unique markers for SLI. We discuss the association of poor knowledge/visual representations and language input to brain development. Our comorbid study showed that a significant lower volume of white matter in the right

  5. Gray and white matter volume abnormalities in monozygotic and same-gender dizygotic twins discordant for schizophrenia

    DEFF Research Database (Denmark)

    Hilshoff, Hilleke E.; Brans, Rachel G. H.; van Haren, Neeltje E. M.

    2004-01-01

    in gray or white matter volume change is not known. METHODS: Magnetic resonance imaging (1.5 T) brain scans of 11 monozygotic and 11 same-gender dizygotic twin pairs discordant for schizophrenia were acquired and compared with 11 monozygotic and 11 same-gender dizygotic healthy control twin pairs. RESULTS...... in the monozygotic twin pairs. A decrease in gray matter was found in the patients compared with their co-twins and compared with the healthy twins. CONCLUSIONS: The results suggest that the decreases in white matter volume reflect the increased genetic risk to develop schizophrenia, whereas the decreases in gray...

  6. International Conference on Neutrino Mass, Dark Matter and Gravitational Waves, Condensation of Atoms and Monopoles, Light-cone Quantization : Orbis Scientiae '96

    CERN Document Server

    Mintz, Stephan; Perlmutter, Arnold; Neutrino Mass, Dark Matter and Gravitational Waves, Condensation of Atoms and Monopoles, Light-cone Quantization : Orbis Scientiae '96

    1996-01-01

    The International Conference, Orbis Scientiae 1996, focused on the topics: The Neutrino Mass, Light Cone Quantization, Monopole Condensation, Dark Matter, and Gravitational Waves which we have adopted as the title of these proceedings. Was there any exciting news at the conference? Maybe, it depends on who answers the question. There was an almost unanimous agreement on the overall success of the conference as was evidenced by the fact that in the after-dinner remarks by one of us (BNK) the suggestion of organizing the conference on a biannual basis was presented but not accepted: the participants wanted the continuation of the tradition to convene annually. We shall, of course, comply. The expected observation of gravitational waves will constitute the most exciting vindication of Einstein's general relativity. This subject is attracting the attention of the experimentalists and theorists alike. We hope that by the first decade of the third millennium or earlier, gravitational waves will be detected,...

  7. The Early Years of Condensed Matter Physics at Illinois -- in Celebration of the 80th Birth Year of Charles P. Slichter -- Charlie Slichter & the gang at Urbana

    CERN Document Server

    Kadanoff, Leo P

    2014-01-01

    The 1950s-- and perhaps also the 1960s-- were very special times for the development of solid-state/condensed-matter physics. The University of Illinois at Urbana was at the center of these activities. In areas like NMR and superconductivity, methods were developed which would form the basis for the next half century of science and technology. Experimentalists, including Charlie and John Wheatley, worked hand in hand with theorists, including the incomparable John Bardeen. They worked cooperatively to develop ideas, often born in Urbana, but with godparents at Harvard and Moscow and Paris. A characteristic style of broad collaboration and spirited exchange developed and spread from Illinois. This development was not an accident but the result of the vision of leaders like Wheeler Loomis, Fred Seitz, and later Gerald Almy1. The strong leadership saved the other scientists from expending their time on departmental decision-making. The style of the scientific activity was set by Fred, who strongly encouraged joi...

  8. Overlapping decline in orbitofrontal gray matter volume related to cocaine use and body mass index.

    Science.gov (United States)

    Smith, Dana G; Jones, P Simon; Williams, Guy B; Bullmore, Edward T; Robbins, Trevor W; Ersche, Karen D

    2015-01-01

    Loss of control over hedonically motivated actions is a defining component of impulse control disorders, such as drug dependence and the proposed 'food addiction' model of obesity. Devolution from goal-directed to compulsively maintained behaviors is partially attributed to abnormalities in the orbitofrontal cortex, an area critical in reward valuation. In the current study, overlapping reductions in orbitofrontal gray matter volume relating to body mass index were seen in healthy control and cocaine-dependent individuals, as well as in relation to duration of cocaine abuse, providing support for a shared neuropathology between the two conditions potentially related to dysfunctional reward-seeking behavior.

  9. Dissipative properties of hot and dense hadronic matter in excluded volume hadron resonance gas model

    CERN Document Server

    Kadam, Guru Prakash

    2015-01-01

    We estimate dissipative properties viz: shear and bulk viscosities of hadronic matter using rel- ativistic Boltzmann equation in relaxation time approximation within ambit of excluded volume hadron resonance gas (EHRG) model. We find that at zero baryon chemical potential the shear viscosity to entropy ratio ({\\eta}/s) decreases with temperature and reaches very close to Kovtun-Son- Starinets (KSS) bound. At sufficiently large baryon chemical potential this ratio shows same behav- ior as a function of temperature but goes below KSS bound. We further find that along chemical freezout line {\\eta}/s increases monotonically while the bulk viscosity to entropy ratio ({\\zeta}/s) decreases monotonically.

  10. A preliminary study on the alterations of grey matter volume in patients with early adulthood episode schizophrenia

    Institute of Scientific and Technical Information of China (English)

    刘萍萍

    2012-01-01

    Objective To investigate the grey matter volume in patients with early adulthood episode (18-25 ages)schizophrenia and the correlations between regional volume and symptoms severity. Methods Twenty-one schizophrenia patients with early adulthood episode and twenty-one normal controls matched with age,sex and education

  11. A white matter lesion-filling approach to improve brain tissue volume measurements

    Directory of Open Access Journals (Sweden)

    Sergi Valverde

    2014-01-01

    Full Text Available Multiple sclerosis white matter (WM lesions can affect brain tissue volume measurements of voxel-wise segmentation methods if these lesions are included in the segmentation process. Several authors have presented different techniques to improve brain tissue volume estimations by filling WM lesions before segmentation with intensities similar to those of WM. Here, we propose a new method to refill WM lesions, where contrary to similar approaches, lesion voxel intensities are replaced by random values of a normal distribution generated from the mean WM signal intensity of each two-dimensional slice. We test the performance of our method by estimating the deviation in tissue volume between a set of 30 T1-w 1.5 T and 30 T1-w 3 T images of healthy subjects and the same images where: WM lesions have been previously registered and afterwards replaced their voxel intensities to those between gray matter (GM and WM tissue. Tissue volume is computed independently using FAST and SPM8. When compared with the state-of-the-art methods, on 1.5 T data our method yields the lowest deviation in WM between original and filled images, independently of the segmentation method used. It also performs the lowest differences in GM when FAST is used and equals to the best method when SPM8 is employed. On 3 T data, our method also outperforms the state-of-the-art methods when FAST is used while performs similar to the best method when SPM8 is used. The proposed technique is currently available to researchers as a stand-alone program and as an SPM extension.

  12. Low HDL cholesterol is associated with lower gray matter volume in cognitively healthy adults

    Directory of Open Access Journals (Sweden)

    Michael A Ward

    2010-07-01

    Full Text Available Dyslipidemia is common in adults and contributes to high rates of cardiovascular disease and may be linked to subsequent neurodegenerative and neurovascular diseases. This study examined whether lower brain volumes and cognition associated with dyslipidemia could be observed in cognitively healthy adults, and whether apolipoprotein E (APOE genotype or family history of Alzheimer’s disease (FHAD alters this effect. Methods: T1-weighted MRI was used to examine regional brain gray matter (GM and white matter (WM in 183 individuals (58.4 ± 8.0 years using voxel-based morphometry. A nonparametric multiple linear regression model was used to assess the effect of high-density lipoprotein (HDL and non-HDL cholesterol, APOE, and FHAD on regional GM and WM volume. A post hoc analysis was used to assess whether any significant correlations found within the volumetric analysis had an effect on cognition. Results: HDL was positively correlated with GM volume in the bilateral temporal poles, middle temporal gyri, temporo-occipital gyri, and left superior temporal gyrus and parahippocampal region. This effect was independent of APOE and FHAD. A significant association between HDL and the Brief Visuospatial Memory Test was found. Additionally, GM volume within the right middle temporal gyrus, the region most affected by HDL, was significantly associated with the Controlled Oral Word Association Test and the Center of Epidemiological Studies Depression Scale. Conclusions: These findings suggest that adults with decreased levels of HDL cholesterol may be experiencing cognitive changes and GM reductions in regions associated with neurodegenerative disease and therefore, may be at greater risk for future cognitive decline.

  13. Toxicity of TNT Wastewaters to Aquatic Organisms. Volume 2. Acute Toxicity of Condensate Wastewater and 2,4-Dinitrotoluene

    Science.gov (United States)

    1983-03-01

    condensate wastewater. Fourteen-day static algal assays, performed with Selenastrum capricornutum, Anabaena flos- aguae , Microcystis aeruginosa, and...days ......... ...................... 44 17 Effect of 2,4-DNT on Population Growth of A. flos- aguae and N. pelliculosa Exposed under Static Conditions...stand until the aqueous and benzene fractions separated. The aqueous fractions were drawn off, and benzene residues in those fractions removed by heating

  14. Gray and white matter volume abnormalities in generalized anxiety disorder by categorical and dimensional characterization.

    Science.gov (United States)

    Hilbert, Kevin; Pine, Daniel S; Muehlhan, Markus; Lueken, Ulrike; Steudte-Schmiedgen, Susann; Beesdo-Baum, Katja

    2015-12-30

    Increasing efforts have been made to investigate the underlying pathophysiology of generalized anxiety disorder (GAD), but only limited consistent information is available on gray (GM) and white matter (WM) volume changes in affected adults. Additionally, few studies employed dimensional approaches to GAD pathology. This study compares structural brain imaging data from n=19 GAD subjects and n=24 healthy comparison (HC) subjects, all medication-free and matched on age, sex and education. Separate categorical and dimensional models were employed using voxel-based morphometry for GM and WM. Significantly higher GM volumes were found in GAD subjects mainly in basal ganglia structures and less consistently in the superior temporal pole. For WM, GAD subjects showed significantly lower volumes in the dlPFC. Largely consistent findings in dimensional and categorical models point toward these structural alterations being reliable and of importance for GAD. While lower volume in the dlPFC could reflect impaired emotional processing and control over worry in GAD, basal ganglia alterations may be linked to disturbed gain and loss anticipation as implicated in previous functional GAD studies. As perturbations in anticipation processes are central to GAD, these areas may warrant greater attention in future studies.

  15. Altered Gray Matter Volume and School Age Anxiety in Children Born Late Preterm

    Science.gov (United States)

    Rogers, Cynthia E; Barch, Deanna M; Sylvester, Chad M; Pagliaccio, David; Harms, Michael P; Botteron, Kelly N; Luby, Joan L

    2014-01-01

    Objectives To determine if late preterm (LP) children differ from full term (FT) children in volumes of the cortex, hippocampus, corpus callosum, or amygdala and whether these differences are associated with anxiety symptoms at school-age. Study design LP children born between 34 and 36 weeks gestation and FT children born between 39 and 41 weeks gestation from a larger longitudinal cohort had MRI scans at school-age. Brain volumes, cortical surface area and thickness measures were obtained. Anxiety symptoms were assessed using a structured diagnostic interview annually beginning at preschool-age and following the MRI. Results LP children (n=21) had a smaller percentage of total, right parietal, and right temporal lobe gray matter volume than FT children (n=87). There were no differences in hippocampal, callosal, or amygdala volumes or cortical thickness. LP children also had a relative decrease in right parietal lobe cortical surface area. LP children had greater anxiety symptoms over all assessments. The relationship between late prematurity and school-age anxiety symptoms was mediated by the relative decrease in right temporal lobe volume. Conclusion LP children, comprising 70% of preterm children, are also at increased risk for altered brain development particularly in the right temporal and parietal cortices. Alterations in the right temporal lobe cortical volume may underlie the increased rate of anxiety symptoms among these LP children. These findings suggest that LP delivery may disrupt temporal and parietal cortical development that persists until school-age with the right temporal lobe conferring risk for elevated anxiety symptoms. PMID:25108541

  16. COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers. Volume 1, Equations and numerics

    Energy Technology Data Exchange (ETDEWEB)

    Chien, T.H.; Domanus, H.M.; Sha, W.T.

    1993-02-01

    The COMMIX-PPC computer pregrain is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex Industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional equations of conservation of mass, momentum, and energy on the tube stile and the proper accounting for the thermal interaction between shell and tube side through the porous-medium approach. The other added feature is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient. Three-dimensional analysis of fluid flow with heat transfer tn a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification, it can be used to analyze processes in any heat exchanger or other single-phase engineering applications. Volume I (Equations and Numerics) of this report describes in detail the basic equations, formulation, solution procedures, and models for a phenomena. Volume II (User`s Guide and Manual) contains the input instruction, flow charts, sample problems, and descriptions of available options and boundary conditions.

  17. Gray and white matter volume abnormalities in monozygotic and same-gender dizygotic twins discordant for schizophrenia

    DEFF Research Database (Denmark)

    Hilshoff, Hilleke E.; Brans, Rachel G. H.; van Haren, Neeltje E. M.;

    2004-01-01

    BACKGROUND: Whole brain tissue volume decreases in schizophrenia have been related to both genetic risk factors and disease-related (possibly nongenetic) factors; however, whether genetic and environmental risk factors in the brains of patients with schizophrenia are differentially reflected in g...... matter volume are related to environmental risk factors. Study of genes involved in the (maintenance) of white matter structures may be particularly fruitful in schizophrenia......BACKGROUND: Whole brain tissue volume decreases in schizophrenia have been related to both genetic risk factors and disease-related (possibly nongenetic) factors; however, whether genetic and environmental risk factors in the brains of patients with schizophrenia are differentially reflected...... in gray or white matter volume change is not known. METHODS: Magnetic resonance imaging (1.5 T) brain scans of 11 monozygotic and 11 same-gender dizygotic twin pairs discordant for schizophrenia were acquired and compared with 11 monozygotic and 11 same-gender dizygotic healthy control twin pairs. RESULTS...

  18. Emotion recognition and theory of mind are related to gray matter volume of the prefrontal cortex in schizophrenia.

    Science.gov (United States)

    Maat, Arija; van Haren, Neeltje E M; Bartholomeusz, Cali F; Kahn, René S; Cahn, Wiepke

    2016-02-01

    Investigations of social cognition in schizophrenia have demonstrated consistent impairments compared to healthy controls. Functional imaging studies in schizophrenia patients and healthy controls have revealed that social cognitive processing depends critically on the amygdala and the prefrontal cortex (PFC). However, the relationship between social cognition and structural brain abnormalities in these regions in schizophrenia patients is less well understood. Measures of facial emotion recognition and theory of mind (ToM), two key social cognitive abilities, as well as face perception and IQ, were assessed in 166 patients with schizophrenia and 134 healthy controls. MRI brain scans were acquired. Automated parcellation of the brain to determine gray matter volume of the amygdala and the superior, middle, inferior and orbital PFC was performed. Between-group analyses showed poorer recognition of angry faces and ToM performance, and decreased amygdala and PFC gray matter volumes in schizophrenia patients as compared to healthy controls. Moreover, in schizophrenia patients, recognition of angry faces was associated with inferior PFC gray matter volume, particularly the pars triangularis (p=0.006), with poor performance being related to reduced pars triangularis gray matter volume. In addition, ToM ability was related to PFC gray matter volume, particularly middle PFC (p=0.001), in that poor ToM skills in schizophrenia patients were associated with reduced middle PFC gray matter volume. In conclusion, reduced PFC, but not amygdala, gray matter volume is associated with social cognitive deficits in schizophrenia. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  19. Reduced anterior cingulate gray matter volume in treatment-naïve clinically depressed adolescents

    Directory of Open Access Journals (Sweden)

    Justine Nienke Pannekoek

    2014-01-01

    Full Text Available Adolescent depression is associated with increased risk for suicidality, social and educational impairment, smoking, substance use, obesity, and depression in adulthood. It is of relevance to further our insight in the neurobiological mechanisms underlying this disorder in the developing brain, as this may be essential to optimize treatment and prevention of adolescent depression and its negative clinical trajectories. The equivocal findings of the limited number of studies on neural abnormalities in depressed youth stress the need for further neurobiological investigation of adolescent depression. We therefore performed a voxel-based morphometry study of the hippocampus, amygdala, superior temporal gyrus, and anterior cingulate cortex (ACC in 26 treatment-naïve, clinically depressed adolescents and 26 pair-wise matched healthy controls. Additionally, an exploratory whole-brain analysis was performed. Clinically depressed adolescents showed a volume reduction of the bilateral dorsal ACC compared to healthy controls. However, no association was found between gray matter volume of the ACC and clinical severity scores for depression or anxiety. Our finding of a smaller ACC in clinically depressed adolescents is consistent with literature on depressed adults. Future research is needed to investigate if gray matter abnormalities precede or follow clinical depression in adolescents.

  20. Reduced anterior cingulate gray matter volume in treatment-naïve clinically depressed adolescents☆

    Science.gov (United States)

    Pannekoek, Justine Nienke; van der Werff, Steven J.A.; van den Bulk, Bianca G.; van Lang, Natasja D.J.; Rombouts, Serge A.R.B.; van Buchem, Mark A.; Vermeiren, Robert R.J.M.; van der Wee, Nic J.A.

    2014-01-01

    Adolescent depression is associated with increased risk for suicidality, social and educational impairment, smoking, substance use, obesity, and depression in adulthood. It is of relevance to further our insight in the neurobiological mechanisms underlying this disorder in the developing brain, as this may be essential to optimize treatment and prevention of adolescent depression and its negative clinical trajectories. The equivocal findings of the limited number of studies on neural abnormalities in depressed youth stress the need for further neurobiological investigation of adolescent depression. We therefore performed a voxel-based morphometry study of the hippocampus, amygdala, superior temporal gyrus, and anterior cingulate cortex (ACC) in 26 treatment-naïve, clinically depressed adolescents and 26 pair-wise matched healthy controls. Additionally, an exploratory whole-brain analysis was performed. Clinically depressed adolescents showed a volume reduction of the bilateral dorsal ACC compared to healthy controls. However, no association was found between gray matter volume of the ACC and clinical severity scores for depression or anxiety. Our finding of a smaller ACC in clinically depressed adolescents is consistent with literature on depressed adults. Future research is needed to investigate if gray matter abnormalities precede or follow clinical depression in adolescents. PMID:24501702

  1. Detecting Boosted Dark Matter from the Sun with Large Volume Neutrino Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua; /SLAC; Cui, Yanou; /Perimeter Inst. Theor. Phys.; Zhao, Yue; /Stanford U., ITP /Stanford U., Phys. Dept.

    2015-04-02

    We study novel scenarios where thermal dark matter (DM) can be efficiently captured in the Sun and annihilate into boosted dark matter. In models with semi-annihilating DM, where DM has a non-minimal stabilization symmetry, or in models with a multi-component DM sector, annihilations of DM can give rise to stable dark sector particles with moderate Lorentz boosts. We investigate both of these possibilities, presenting concrete models as proofs of concept. Both scenarios can yield viable thermal relic DM with masses O(1)-O(100) GeV. Taking advantage of the energetic proton recoils that arise when the boosted DM scatters off matter, we propose a detection strategy which uses large volume terrestrial detectors, such as those designed to detect neutrinos or proton decays. In particular, we propose a search for proton tracks pointing towards the Sun. We focus on signals at Cherenkov-radiation-based detectors such as Super-Kamiokande (SK) and its upgrade Hyper-Kamiokande (HK). We find that with spin-dependent scattering as the dominant DM-nucleus interaction at low energies, boosted DM can leave detectable signals at SK or HK, with sensitivity comparable to DM direct detection experiments while being consistent with current constraints. Our study provides a new search path for DM sectors with non-minimal structure.

  2. Forces, Growth and Form in Soft Condensed Matter: At the Interface between Physics and Biology NATO Advanced Study Institute, Geilo, Norway, 24 March - 3 April 2003

    Energy Technology Data Exchange (ETDEWEB)

    Helgesen, G. ed.

    2003-05-01

    The goal of this ASI was to bring together a group of disparate sciences to discuss areas of research related to competition between interactions of different ranges, for it is this that creates local structure on which complexity depends in soft condensed matter, biological systems and their synthetic models. The starting point, and the underlying theme throughout the ASI, was thus a thorough discussion of the relative role of the various fundamental interactions in such systems (electrostatic, hydrophobic, steric, conformational, van der Waals, etc.). The next focus was on how these competing interactions influence the form and topology of soft and biological matter, like polymers and proteins, leading to hierarchical structures in self-assembling systems and folding patterns sometimes described in terms of chirality, braids and knots. Finally, focus was on how the competing interactions influence various bio processes like genetic regulation and biological evolution taking place in systems like biopolymers, macromolecules and cell membranes. The report includes the abstracts of the posters presented, two of which are given in this database: (1) Precise characterisation of nano channels in track etched membranes by SAXS and SANS, and (2) Cisplatin binding to DNA: Structure, bonding and NMR properties from CarParrinello/Classical MD simulations.

  3. Effect of Bcl-2 rs956572 polymorphism on age-related gray matter volume changes.

    Directory of Open Access Journals (Sweden)

    Mu-En Liu

    Full Text Available The anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2 gene is a major regulator of neural plasticity and cellular resilience. Recently, the Bcl-2 rs956572 single nucleotide polymorphism was proposed to be a functional allelic variant that modulates cellular vulnerability to apoptosis. Our cross-sectional study investigated the genetic effect of this Bcl-2 polymorphism on age-related decreases in gray matter (GM volume across the adult lifespan. Our sample comprised 330 healthy volunteers (191 male, 139 female with a mean age of 56.2±22.0 years (range: 21-92. Magnetic resonance imaging and genotyping of the Bcl-2 rs956572 were performed for each participant. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. The association between the Bcl-2 rs956572 polymorphism and age was a predictor of regional GM volumes in the right cerebellum, bilateral lingual gyrus, right middle temporal gyrus, and right parahippocampal gyrus. We found that the volume of these five regions decreased with increasing age (all P<.001. Moreover, the downward slope was steeper among the Bcl-2 rs956572 A-allele carriers than in the G-homozygous participants. Our data provide convergent evidence for the genetic effect of the Bcl-2 functional allelic variant in brain aging. The rs956572 G-allele, which is associated with significantly higher Bcl-2 protein expression and diminished cellular sensitivity to stress-induced apoptosis, conferred a protective effect against age-related changes in brain GM volume, particularly in the cerebellum.

  4. Effects of prenatal alcohol exposure on the development of white matter volume and change in executive function

    Directory of Open Access Journals (Sweden)

    P. Gautam

    2014-01-01

    Full Text Available Prenatal alcohol exposure can cause a wide range of deficits in executive function that persist throughout life, but little is known about how changes in brain structure relate to cognition in affected individuals. In the current study, we predicted that the rate of white matter volumetric development would be atypical in children with fetal alcohol spectrum disorders (FASD when compared to typically developing children, and that the rate of change in cognitive function would relate to differential white matter development between groups. Data were available for 103 subjects [49 with FASD, 54 controls, age range 6–17, mean age = 11.83] with 153 total observations. Groups were age-matched. Participants underwent structural magnetic resonance imaging (MRI and an executive function (EF battery. Using white matter volumes measured bilaterally for frontal and parietal regions and the corpus callosum, change was predicted by modeling the effects of age, intracranial volume, sex, and interactions with exposure status and EF measures. While both groups showed regional increases in white matter volumes and improvement in cognitive performance over time, there were significant effects of exposure status on age-related relationships between white matter increases and EF measures. Specifically, individuals with FASD consistently showed a positive relationship between improved cognitive function and increased white matter volume over time, while no such relationships were seen in controls. These novel results relating improved cognitive function with increased white matter volume in FASD suggest that better cognitive outcomes could be possible for FASD subjects through interventions that enhance white matter plasticity.

  5. Childhood maltreatment is associated with larger left thalamic gray matter volume in adolescents with generalized anxiety disorder.

    Science.gov (United States)

    Liao, Mei; Yang, Fan; Zhang, Yan; He, Zhong; Song, Ming; Jiang, Tianzi; Li, Zexuan; Lu, Shaojia; Wu, Weiwei; Su, Linyan; Li, Lingjiang

    2013-01-01

    Generalized anxiety disorder (GAD) is a common anxiety disorder that usually begins in adolescence. Childhood maltreatment is highly prevalent and increases the possibility for developing a variety of mental disorders including anxiety disorders. An earlier age at onset of GAD is significantly related to maltreatment in childhood. Exploring the underpinnings of the relationship between childhood maltreatment and adolescent onset GAD would be helpful in identifying the potential risk markers of this condition. Twenty-six adolescents with GAD and 25 healthy controls participated in this study. A childhood trauma questionnaire (CTQ) was introduced to assess childhood maltreatment. All subjects underwent high-resolution structural magnetic resonance scans. Voxel-based morphometry (VBM) was used to investigate gray matter alterations. Significantly larger gray matter volumes of the right putamen were observed in GAD patients compared to healthy controls. In addition, a significant diagnosis-by-maltreatment interaction effect for the left thalamic gray matter volume was revealed, as shown by larger volumes of the left thalamic gray matter in GAD patients with childhood maltreatment compared with GAD patients without childhood maltreatment as well as with healthy controls with/without childhood maltreatment. A significant positive association between childhood maltreatment and left thalamic gray matter volume was only seen in GAD patients. These findings revealed an increased volume in the subcortical regions in adolescent GAD, and the alterations in the left thalamus might be involved in the association between childhood maltreatment and the occurrence of GAD.

  6. Condensation Energy of a Spacetime Condensate

    CERN Document Server

    de Matos, Clovis Jacinto

    2010-01-01

    Starting from an analogy between the Planck-Einstein scale and the dual length scales in Ginzburg-Landau theory of superconductivity, and assuming that space-time is a condensate of neutral fermionic particles with Planck mass, we derive the baryonic mass of the universe. In that theoretical framework baryonic matter appears to be associated with the condensation energy gained by spacetime in the transition from its normal (symetric) to its (less symetric) superconducting-like phase. It is shown however that the critical transition temperature cannot be the Planck temperature. Thus leaving open the enigma of the microscopic description of spacetime at quantum level.

  7. Does white matter structure or hippocampal volume mediate associations between cortisol and cognitive ageing?

    Science.gov (United States)

    Cox, Simon R; MacPherson, Sarah E; Ferguson, Karen J; Royle, Natalie A; Maniega, Susana Muñoz; Hernández, Maria Del C Valdés; Bastin, Mark E; MacLullich, Alasdair M J; Wardlaw, Joanna M; Deary, Ian J

    2015-12-01

    Elevated glucocorticoid (GC) levels putatively damage specific brain regions, which in turn may accelerate cognitive ageing. However, many studies are cross-sectional or have relatively short follow-up periods, making it difficult to relate GCs directly to changes in cognitive ability with increasing age. Moreover, studies combining endocrine, MRI and cognitive variables are scarce, measurement methods vary considerably, and formal tests of the underlying causal hypothesis (cortisol→brain→cognition) are absent. In this study, 90 men, aged 73 years, provided measures of fluid intelligence, processing speed and memory, diurnal and reactive salivary cortisol and two measures of white matter (WM) structure (WM hyperintensity volume from structural MRI and mean diffusivity averaged across 12 major tracts from diffusion tensor MRI), hippocampal volume, and also cognitive ability at age 11. We tested whether negative relationships between cognitive ageing differences (over more than 60 years) and salivary cortisol were significantly mediated by WM and hippocampal volume. Significant associations between reactive cortisol at 73 and cognitive ageing differences between 11 and 73 (r=-.28 to -.36, pageing differences from childhood to the early 70s, partly via brain WM structure. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Correlations between ventricular enlargement and gray and white matter volumes of cortex, thalamus, striatum, and internal capsule in schizophrenia.

    Science.gov (United States)

    Horga, Guillermo; Bernacer, Javier; Dusi, Nicola; Entis, Jonathan; Chu, Kingwai; Hazlett, Erin A; Haznedar, M Mehmet; Kemether, Eileen; Byne, William; Buchsbaum, Monte S

    2011-10-01

    Ventricular enlargement is one of the most consistent abnormal structural brain findings in schizophrenia and has been used to infer brain shrinkage. However, whether ventricular enlargement is related to local overlying cortex and/or adjacent subcortical structures or whether it is related to brain volume change globally has not been assessed. We systematically assessed interrelations of ventricular volumes with gray and white matter volumes of 40 Brodmann areas (BAs), the thalamus and its medial dorsal nucleus and pulvinar, the internal capsule, caudate and putamen. We acquired structural MRI ( patients with schizophrenia (n = 64) and healthy controls (n = 56)) and diffusion tensor fractional anisotropy (FA) (untreated schizophrenia n = 19, controls n = 32). Volumes were assessed by manual tracing of central structures and a semi-automated parcellation of BAs. Patients with schizophrenia had increased ventricular size associated with decreased cortical gray matter volumes widely across the brain; a similar but less pronounced pattern was seen in normal controls; local correlations (e.g. temporal horn with temporal lobe volume) were not appreciably higher than non-local correlations (e.g. temporal horn with prefrontal volume). White matter regions adjacent to the ventricles similarly did not reveal strong regional relationships. FA and center of mass of the anterior limb of the internal capsule also appeared differentially influenced by ventricular volume but findings were similarly not regional. Taken together, these findings indicate that ventricular enlargement is globally interrelated with gray matter volume diminution but not directly correlated with volume loss in the immediately adjacent caudate, putamen, or internal capsule.

  9. Methods for studying the coherent 4D structural dynamics of free molecules and condensed state of matter

    Energy Technology Data Exchange (ETDEWEB)

    Ishchenko, A. A., E-mail: aischenko@yasenevo.ru [Moscow State Technological University (Russian Federation); Bagratashvili, V. N. [Russian Academy of Sciences, Institute of Laser and Information Technologies (Russian Federation); Avilov, A. S. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2011-09-15

    Studies in the coupled 4D spatial and temporal continuum are necessary for understanding the dynamic features of molecular systems with a complex profile of the potential energy surface. The introduction of time sweep into diffraction methods and the development of principles for studying coherent processes have revealed new approaches to the analysis of the dynamics of wave packets, the intermediate products and the transition state of the reaction center, and short-lived compounds in gaseous and condensed media. The use of picosecond and femtosecond electron probe pulses, synchronized with excitation laser pulses, determined the development of ultrafast electron crystallography, time-resolved X-ray diffraction, and dynamic transmission electron microscopy (DTEM). One of the most promising applications of the developed diffraction methods is the characterization and visualization of the processes occurring upon the photoexcitation of free molecules and biological objects and the analysis of surface and thin films. The whole set of spectral and diffraction methods based on different physical principles, which are complementary and make it possible to perform the photoexcitation of nuclei and electrons and carry out diagnostics of their dynamics at ultrashort time sequences, reveal new possibilities for studies with the necessary integration of the 'structure-dynamics-function' triad in chemistry, biology, and materials science.

  10. The Association of Type 2 Diabetes Mellitus with Cerebral Gray Matter Volume Is Independent of Retinal Vascular Architecture and Retinopathy

    Directory of Open Access Journals (Sweden)

    C. Moran

    2016-01-01

    Full Text Available It is uncertain whether small vessel disease underlies the relationship between Type 2 Diabetes Mellitus (T2DM and brain atrophy. We aimed to study whether retinal vascular architecture, as a proxy for cerebral small vessel disease, may modify or mediate the associations of T2DM with brain volumes. In this cross-sectional study using Magnetic Resonance Imaging (MRI scans and retinal photographs in 451 people with and without T2DM, we measured brain volumes, geometric measures of retinal vascular architecture, clinical retinopathy, and MRI cerebrovascular lesions. There were 270 people with (mean age 67.3 years and 181 without T2DM (mean age 72.9 years. T2DM was associated with lower gray matter volume (p=0.008. T2DM was associated with greater arteriolar diameter (p=0.03 and optimality ratio (p=0.04, but these associations were attenuated by adjustments for age and sex. Only optimality ratio was associated with lower gray matter volume (p=0.03. The inclusion of retinal measures in regression models did not attenuate the association of T2DM with gray matter volume. The association of T2DM with lower gray matter volume was independent of retinal vascular architecture and clinical retinopathy. Retinal vascular measures or retinopathy may not be sufficiently sensitive to confirm a microvascular basis for T2DM-related brain atrophy.

  11. Quantifying the link between anatomical connectivity, gray matter volume and regional cerebral blood flow: an integrative MRI study.

    Directory of Open Access Journals (Sweden)

    Bálint Várkuti

    Full Text Available BACKGROUND: In the graph theoretical analysis of anatomical brain connectivity, the white matter connections between regions of the brain are identified and serve as basis for the assessment of regional connectivity profiles, for example, to locate the hubs of the brain. But regions of the brain can be characterised further with respect to their gray matter volume or resting state perfusion. Local anatomical connectivity, gray matter volume and perfusion are traits of each brain region that are likely to be interdependent, however, particular patterns of systematic covariation have not yet been identified. METHODOLOGY/PRINCIPAL FINDINGS: We quantified the covariation of these traits by conducting an integrative MRI study on 23 subjects, utilising a combination of Diffusion Tensor Imaging, Arterial Spin Labeling and anatomical imaging. Based on our hypothesis that local connectivity, gray matter volume and perfusion are linked, we correlated these measures and particularly isolated the covariation of connectivity and perfusion by statistically controlling for gray matter volume. We found significant levels of covariation on the group- and regionwise level, particularly in regions of the Default Brain Mode Network. CONCLUSIONS/SIGNIFICANCE: Connectivity and perfusion are systematically linked throughout a number of brain regions, thus we discuss these results as a starting point for further research on the role of homology in the formation of functional connectivity networks and on how structure/function relationships can manifest in the form of such trait interdependency.

  12. Photon condensation: A new paradigm for Bose-Einstein condensation

    Science.gov (United States)

    Rajan, Renju; Ramesh Babu, P.; Senthilnathan, K.

    2016-10-01

    Bose-Einstein condensation is a state of matter known to be responsible for peculiar properties exhibited by superfluid Helium-4 and superconductors. Bose-Einstein condensate (BEC) in its pure form is realizable with alkali atoms under ultra-cold temperatures. In this paper, we review the experimental scheme that demonstrates the atomic Bose-Einstein condensate. We also elaborate on the theoretical framework for atomic Bose-Einstein condensation, which includes statistical mechanics and the Gross-Pitaevskii equation. As an extension, we discuss Bose-Einstein condensation of photons realized in a fluorescent dye filled optical microcavity. We analyze this phenomenon based on the generalized Planck's law in statistical mechanics. Further, a comparison is made between photon condensate and laser. We describe how photon condensate may be a possible alternative for lasers since it does not require an energy consuming population inversion process.

  13. Gray Matter Volume Decreases in Elderly Patients with Schizophrenia: A Voxel-based Morphometry Study

    Science.gov (United States)

    Schuster, Caroline; Schuller, Anne Marie; Paulos, Carlos; Namer, Izzie; Pull, Charles; Danion, Jean Marie; Foucher, Jack René

    2012-01-01

    Background: Aged patients (>50 years old) with residual schizophrenic symptoms differ from young patients. They represent a subpopulation with a more unfavorable Kraepelinian course and have an increased risk (up to 30%) for dementia of unknown origin. However, our current understanding of age-related brain changes in schizophrenia is derived from studies that included less than 17% of patients who were older than 50 years of age. This study investigated the anatomical distribution of gray matter (GM) brain deficits in aged patients with ongoing schizophrenia. Methods: Voxel-based morphometry was applied to 3D-T1 magnetic resonance images obtained from 27 aged patients with schizophrenia (mean age of 60 years) and 40 age-matched normal controls. Results: Older patients with schizophrenia showed a bilateral reduction of GM volume in the thalamus, the prefrontal cortex, and in a large posterior region centered on the occipito-temporo-parietal junction. Only the latter region showed accelerated GM volume loss with increasing age. None of these results could be accounted for by institutionalization, antipsychotic medication, or cognitive scores. Conclusions: This study replicated most common findings in patients with schizophrenia with regard to thalamic and frontal GM deficits. However, it uncovered an unexpected large region of GM atrophy in the posterior tertiary cortices. The latter observation may be specific to this aged and chronically symptomatic subpopulation, as atrophy in this region is rarely reported in younger patients and is accelerated with age. PMID:21205677

  14. Anorexia Nervosa during Adolescence Is Associated with Decreased Gray Matter Volume in the Inferior Frontal Gyrus.

    Directory of Open Access Journals (Sweden)

    Takashi X Fujisawa

    Full Text Available Anorexia nervosa (AN is an eating disorder characterized by the relentless pursuit to lose weight, mostly through self-starvation, and a distorted body image. AN tends to begin during adolescence among women. However, the underlying neural mechanisms related to AN remain unclear. Using voxel-based morphometry based on magnetic resonance imaging scans, we investigated whether the presence of AN was associated with discernible changes in brain morphology. Participants were 20 un-medicated, right-handed patients with early-onset AN and 14 healthy control subjects. Group differences in gray matter volume (GMV were assessed using high-resolution, T1-weighted, volumetric magnetic resonance imaging datasets (3T Trio scanner; Siemens AG and analyzed after controlling for age and total GMV, which was decreased in the bilateral inferior frontal gyrus (IFG (left IFG: FWE corrected, p < 0.05; right IFG: uncorrected, p < 0.05 of patients with AN. The GMV in the bilateral IFG correlated significantly with current age (left IFG: r = -.481, p < .05; right IFG: r = -.601, p < .01 and was limited to the AN group. We speculate that decreased IFG volume might lead to deficits in executive functioning or inhibitory control within neural reward systems. Precocious or unbalanced neurological trimming within this particular region might be an important factor for the pathogenesis of AN onset.

  15. The correlation between emotional intelligence and gray matter volume in university students.

    Science.gov (United States)

    Tan, Yafei; Zhang, Qinglin; Li, Wenfu; Wei, Dongtao; Qiao, Lei; Qiu, Jiang; Hitchman, Glenn; Liu, Yijun

    2014-11-01

    A number of recent studies have investigated the neurological substrates of emotional intelligence (EI), but none of them have considered the neural correlates of EI that are measured using the Schutte Self-Report Emotional Intelligence Scale (SSREIS). This scale was developed based on the EI model of Salovey and Mayer (1990). In the present study, SSREIS was adopted to estimate EI. Meanwhile, magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) were used to evaluate the gray matter volume (GMV) of 328 university students. Results found positive correlations between Monitor of Emotions and VBM measurements in the insula and orbitofrontal cortex. In addition, Utilization of Emotions was positively correlated with the GMV in the parahippocampal gyrus, but was negatively correlated with the VBM measurements in the fusiform gyrus and middle temporal gyrus. Furthermore, Social Ability had volume correlates in the vermis. These findings indicate that the neural correlates of the EI model, which primarily focuses on the abilities of individuals to appraise and express emotions, can also regulate and utilize emotions to solve problems.

  16. The dielectric function of condensed systems

    CERN Document Server

    Keldysh, LV; Kirzhnitz, DA

    1989-01-01

    Much progress has been made in the understanding of the general properties of the dielectric function and in the calculation of this quantity for many classes of media. This volume gathers together the considerable information available and presents a detailed overview of the present status of the theory of electromagnetic response functions, whilst simultaneously covering a wide range of problems in its application to condensed matter physics.The following subjects are covered:- the dielectric function of the homogeneous electron gas, of crystalline systems, and of inh

  17. Decrease in temporal gyrus gray matter volume in first-episode, early onset schizophrenia: an MRI study.

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    Jinsong Tang

    Full Text Available BACKGROUND: Loss of gray matter has been previously found in early-onset schizophrenic patients. However, there are no consistent findings between studies due to different methods used to measure grey matter volume/density and influences of confounding factors. METHODS: The volume of gray matter (GM was measured in 29 first episode early-onset schizophrenia (EOS and 34 well-matched healthy controls by using voxel-based morphometry (VBM. Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS. The correlations between the GM volume and PANSS scores, age of psychosis onset, duration of psychosis, and chlorpromazine (CPZ equivalent value were investigated. RESULTS: Relative to healthy subjects, the patients with first episode EOS showed significantly lower GM volume in the left middle and superior temporal gyrus. The loss of GM volume negatively correlated with PANSS-positive symptoms (p = 0.002, but not with PANSS-negative symptoms, PANSS-general psychopathology, and PANSS-total score. No significant correlation was found between GM volume and age of psychosis onset, duration of psychosis, and CPZ equivalent value. CONCLUSION: Patients with first episode EOS have evidence of reduced GM in the left middle and superior temporal gyrus. Structural abnormalities in the left middle and superior temporal gyrus may contribute to the pathophysiology of schizophrenia.

  18. Dyslexia and voxel-based morphometry: correlations between five behavioural measures of dyslexia and gray and white matter volumes.

    Science.gov (United States)

    Tamboer, Peter; Scholte, H Steven; Vorst, Harrie C M

    2015-10-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in a large sample of Dutch students (37 dyslexics and 57 non-dyslexics) with two analyses: group differences in local GM and total GM and WM volume and correlations between GM and WM volumes and five behavioural measures. We found no significant group differences after corrections for multiple comparisons although total WM volume was lower in the group of dyslexics when age was partialled out. We presented an overview of uncorrected clusters of voxels (p  200) with reduced or increased GM volume. We found four significant correlations between factors of dyslexia representing various behavioural measures and the clusters found in the first analysis. In the whole sample, a factor related to performances in spelling correlated negatively with GM volume in the left posterior cerebellum. Within the group of dyslexics, a factor related to performances in Dutch-English rhyme words correlated positively with GM volume in the left and right caudate nucleus and negatively with increased total WM volume. Most of our findings were in accordance with previous reports. A relatively new finding was the involvement of the caudate nucleus. We confirmed the multiple cognitive nature of dyslexia and suggested that experience greatly influences anatomical alterations depending on various subtypes of dyslexia, especially in a student sample.

  19. Changes in gray matter volume after microsurgical lumbar discectomy: A longitudinal analysis

    Directory of Open Access Journals (Sweden)

    Michael eLuchtmann

    2015-02-01

    Full Text Available People around the world suffer chronic lower back pain. Because spine imaging often does not explain the degree of perceived pain reported by patients, the role of the processing of nociceptor signals in the brain as the basis of pain perception is gaining increased attention. Modern neuroimaging techniques (including functional and morphometric methods have produced results that suggest which brain areas may play a crucial role in the perception of acute and chronic pain. In this study, we examined twelve patients with chronic low back pain and sciatica, both resulting from lumbar disc herniation. Structural magnetic resonance imaging (MRI of the brain was performed one day prior to and about four weeks after microsurgical lumbar discectomy. The subsequent MRI revealed an increase in gray matter volume in the basal ganglia but a decrease in volume in the hippocampus, which suggests the complexity of the network that involves movement, pain processing, and aspects of memory. Interestingly, volume changes in the hippocampus were significantly correlated to preoperative pain intensity but not to the duration of chronic pain. Mapping structural changes of the brain that result from lumbar disc herniation has the potential to enhance our understanding of the neuropathology of chronic low back pain and sciatica and therefore may help to optimize the decisions we make about conservative and surgical treatments in the future. The possibility of illuminating more of the details of central pain processing in lumbar disc herniation, as well as the accompanying personal and economic impact of pain relief worldwide, calls for future large-scale clinical studies.

  20. Distinct effects of late adulthood cognitive and physical activities on gray matter volume.

    Science.gov (United States)

    Arenaza-Urquijo, Eider M; de Flores, Robin; Gonneaud, Julie; Wirth, Miranka; Ourry, Valentin; Callewaert, William; Landeau, Brigitte; Egret, Stéphanie; Mézenge, Florence; Desgranges, Béatrice; Chételat, Gaël

    2017-04-01

    Engagement in cognitive activity (CA) and physical activity (PA) during the lifespan may counteract brain atrophy later in life. Here, we investigated engagement in CA and PA during late adulthood in association with gray matter volume (GM) in normal older adults, with special focus on the hippocampus. Forty-five cognitively normal older individuals (mean age: 72) underwent T1-weighted MRI and self-reported CA and PA assessment. Whole brain voxel-wise multiple regression models were carried out to assess the relationships between CA, PA and GM volume adjusted by age and sex. Further adjustment for years of education and risk factors were performed. Voxel-wise analyses were projected on 3D hippocampal surface views. Cognitive activity and PA demonstrated independent regional associations with GM after adjustment for confounders. Cognitive activity was related to greater GM in extended brain areas including frontal, temporal and parietal cortices, while PA was associated with increased GM in the prefrontal, insular and motor cortices. Regression maps projected on the hippocampal surface showed a common association of PA and CA within the anterior part of the hippocampus, although the effect of CA was more subtle and also extended to the posterior part. Engagement in PA and CA in late adulthood were independently related to regional GM volume, notably in aging and AD vulnerable areas. These results support the idea that both PA and CA- based interventions may be suitable to promote brain health in late adulthood. The potential synergistic effects of PA and CA need to be addressed in future studies including larger samples.

  1. Topology of genetic associations between regional gray matter volume and intellectual ability: Evidence for a high capacity network.

    Science.gov (United States)

    Bohlken, Marc M; Brouwer, Rachel M; Mandl, René C W; Hedman, Anna M; van den Heuvel, Martijn P; van Haren, Neeltje E M; Kahn, René S; Pol, Hilleke E Hulshoff

    2016-01-01

    Intelligence is associated with a network of distributed gray matter areas including the frontal and parietal higher association cortices and primary processing areas of the temporal and occipital lobes. Efficient information transfer between gray matter regions implicated in intelligence is thought to be critical for this trait to emerge. Genetic factors implicated in intelligence and gray matter may promote a high capacity for information transfer. Whether these genetic factors act globally or on local gray matter areas separately is not known. Brain maps of phenotypic and genetic associations between gray matter volume and intelligence were made using structural equation modeling of 3T MRI T1-weighted scans acquired in 167 adult twins of the newly acquired U-TWIN cohort. Subsequently, structural connectivity analyses (DTI) were performed to test the hypothesis that gray matter regions associated with intellectual ability form a densely connected core. Gray matter regions associated with intellectual ability were situated in the right prefrontal, bilateral temporal, bilateral parietal, right occipital and subcortical regions. Regions implicated in intelligence had high structural connectivity density compared to 10,000 reference networks (p=0.031). The genetic association with intelligence was for 39% explained by a genetic source unique to these regions (independent of total brain volume), this source specifically implicated the right supramarginal gyrus. Using a twin design, we show that intelligence is genetically represented in a spatially distributed and densely connected network of gray matter regions providing a high capacity infrastructure. Although genes for intelligence have overlap with those for total brain volume, we present evidence that there are genes for intelligence that act specifically on the subset of brain areas that form an efficient brain network.

  2. Basic concept for an accelerator-driven subcritical system to be used as a long-pulse neutron source for Condensed Matter research

    Energy Technology Data Exchange (ETDEWEB)

    Vivanco, R., E-mail: raul.vivanco.sanchez@gmail.com [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Ghiglino, A.; Vicente, J.P. de; Sordo, F.; Terrón, S.; Magán, M. [ESS-BILBAO, Parque Tecnológico Bizkaia, Laida Bidea, Edificio 207 B Planta Baja, 48160 Derio (Spain); Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Perlado, J.M. [Instituto de Fusión Nuclear - UPM, ETS Ingenieros Industriales, C/ José Gutiérrez Abascal, 2, 28006 Madrid Spain (Spain); Bermejo, F.J. [Instituto de Estructura de la Materia, IEM-CSIC, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid (Spain)

    2014-12-11

    A model for an accelerator-driven subcritical system to be operated as a source of cold neutrons for Condensed Matter research is developed at the conceptual level. Its baseline layout relies upon proven accelerator, spalattion target and fuel array technologies, and consists in a proton accelerator able to deliver some 67.5 mA of proton beam with kinetic energy 0.6 GeV, a pulse length of 2.86 ms, and repetition rate of 14 Hz. The particle beam hits a target of conventional design that is surrounded by a multiplicative core made of fissile/fertile material, composed by a subcritical array of fuel bars made of aluminium Cermet cooled by light water poisoned with boric acid. Relatively low enriched uranium is chosen as fissile material. An optimisation of several parameters is carried out, using as components of the objective function several characteristics pertaining the cold neutron pulse. The results show that the optimal device will deliver up to 80% of the cold neutron flux expected for some of the ongoing projects using a significantly lower proton beam power than that managed in such projects. The total power developed within the core rises up to 22.8 MW, and the criticality range shifts to a final k{sub eff} value of around 0.9 after the 50 days cycle.

  3. An overview of Experimental Condensed Matter Physics in Argentina by 2014, and Oxides for Non Volatile Memory Devices: The MeMOSat Project

    Science.gov (United States)

    Levy, Pablo

    2015-03-01

    In the first part of my talk, I will describe the status of the experimental research in Condensed Matter Physics in Argentina, biased towards developments related to micro and nanotechnology. In the second part, I will describe the MeMOSat Project, a consortium aimed at producing non-volatile memory devices to work in aggressive environments, like those found in the aerospace and nuclear industries. Our devices rely on the Resistive Switching mechanism, which produces a permanent but reversible change in the electrical resistance across a metal-insulator-metal structure by means of a pulsed protocol of electrical stimuli. Our project is devoted to the study of Memory Mechanisms in Oxides (MeMO) in order to establish a technological platform that tests the Resistive RAM (ReRAM) technology for aerospace applications. A review of MeMOSat's activities is presented, covering the initial Proof of Concept in ceramic millimeter sized samples; the study of different oxide-metal couples including (LaPr)2/3Ca1/3MnO, La2/3Ca1/3MnO3, YBa2Cu3O7, TiO2, HfO2, MgO and CuO; and recent miniaturized arrays of micrometer sized devices controlled by in-house designed electronics, which were launched with the BugSat01 satellite in June2014 by the argentinian company Satellogic.

  4. Mathematical models of granular matter

    CERN Document Server

    Mariano, Paolo; Giovine, Pasquale

    2008-01-01

    Granular matter displays a variety of peculiarities that distinguish it from other appearances studied in condensed matter physics and renders its overall mathematical modelling somewhat arduous. Prominent directions in the modelling granular flows are analyzed from various points of view. Foundational issues, numerical schemes and experimental results are discussed. The volume furnishes a rather complete overview of the current research trends in the mechanics of granular matter. Various chapters introduce the reader to different points of view and related techniques. New models describing granular bodies as complex bodies are presented. Results on the analysis of the inelastic Boltzmann equations are collected in different chapters. Gallavotti-Cohen symmetry is also discussed.

  5. Small gray matter volume in orbitofrontal cortex in Prader-Willi syndrome: a voxel-based MRI study.

    Science.gov (United States)

    Ogura, Kaeko; Fujii, Toshikatsu; Abe, Nobuhito; Hosokai, Yoshiyuki; Shinohara, Mayumi; Takahashi, Shoki; Mori, Etsuro

    2011-07-01

    Prader-Willi syndrome (PWS) is a genetically determined neurodevelopmental disorder presenting with behavioral symptoms including hyperphagia, disinhibition, and compulsive behavior. The behavioral problems in individuals with PWS are strikingly similar to those in patients with frontal pathologies, particularly those affecting the orbitofrontal cortex (OFC). However, neuroanatomical abnormalities in the frontal lobe have not been established in PWS. The aim of this study was to look, using volumetric analysis, for morphological changes in the frontal lobe, especially the OFC, of the brains of individuals with PWS. Twelve adults with PWS and 13 age- and gender-matched control subjects participated in structural magnetic resonance imaging (MRI) scans. The whole-brain images were segmented and normalized to a standard stereotactic space. Regional gray matter volumes were compared between the PWS group and the control group using voxel-based morphometry. The PWS subjects showed small gray-matter volume in several regions, including the OFC, caudate nucleus, inferior temporal gyrus, precentral gyrus, supplementary motor area, postcentral gyrus, and cerebellum. The small gray-matter volume in the OFC remained significant in a separate analysis that included total gray matter volume as a covariate. These preliminary findings suggest that the neurobehavioral symptoms in individuals with PWS are related to structural brain abnormalities in these areas.

  6. Nonspecific Effect of Stress on Brain Gray Matter Volume in Drug-naive Female Patients with First Depressive Episode

    Directory of Open Access Journals (Sweden)

    Chuan-Jun Zhuo

    2016-01-01

    Conclusions: Although the results of the present study suggest the absence of significant differences in brain gray matter volume between female drug-naive patients after the first episode of major depression with and without SLEs after FDR correction, the study provides useful information for exploring the definitive role of stress in the onset of depression.

  7. Change Matters: Critical Essays on Moving Social Justice Research from Theory to Policy. Critical Qualitative Research. Volume 1

    Science.gov (United States)

    Miller, S. J., Ed.; Kirkland, David E., Ed.

    2010-01-01

    "Change Matters," written by leading scholars committed to social justice in English education, provides researchers, university instructors, and preservice and inservice teachers with a framework that pivots social justice toward policy. The chapters in this volume detail rationales about generating social justice theory in what Freire calls "the…

  8. Set-Shifting Ability Is Associated with Gray Matter Volume in Older People with Mild Cognitive Impairment

    Directory of Open Access Journals (Sweden)

    Kota Tsutsumimoto

    2015-10-01

    Full Text Available Background/Aims: An understanding of the association between gray matter volume and executive functioning could provide strategies to reduce dementia risk in older people with mild cognitive impairment (MCI. Methods: In a cross-sectional analysis, we assessed executive functioning in 83 older people with MCI using three standard neuropsychological tests: set shifting (difference between Trail Making Test Parts B and A, working memory (difference between Digit Span forward and backward from the Wechsler Adult Intelligence Scale-IV, and selective attention/response inhibition (difference between the second and third conditions of the color- and picture-word Stroop test. Gray matter volume was computed from brain MRIs and SIENAX from FSL software. Results: Gray matter volume was significantly associated with set-shifting performance after accounting for age, gender, body mass index, education, and global cognition (standardized β = -0.376, p = 0.001, but not with working memory or selective attention/response inhibition. Conclusion: The executive function of set-shifting ability was correlated with gray matter volume in older people with MCI.

  9. Nonspecific Effect of Stress on Brain Gray Matter Volume in Drug-naive Female Patients with First Depressive Episode

    Institute of Scientific and Technical Information of China (English)

    Chuan-Jun Zhuo; Hai-Man Bian; Yan-Jie Gao; Xiao-Lei Ma; Sheng-Zhang Ji; Meng-Yuan Yao; Ning Zhai

    2016-01-01

    Background: This study aimed to observe the differences in brain gray matter volume in drug-naive female patients after the first episode of major depression with and without stressful life events (SLEs) before the onset of depression.Methods: Forty-three drug-naive female patients voluntarily participated in the present study after the first major depressive episode.The life event scale was used to evaluate the severity of the impact of SLEs during 6 months before the onset of the major depressive episode.High-field magnetic resonance imaging (MRI) scans were obtained, and the VBM and SPM8 software process were used to process and analyze the MRI.Results: Compared to that in patients without SLEs, the volume of brain gray matter was lower in the bilateral temporal lobe, right occipital lobe, and right limbic lobe in the SLE group.However, the gray matter volume did not differ significantly between the two groups after the application of false discovery rate (FDR) correction.Conclusions: Although the results of the present study suggest the absence of significant differences in brain gray matter volume between female drug-naive patients after the first episode of major depression with and without SLEs after FDR correction, the study provides useful information for exploring the definitive role of stress in the onset of depression.

  10. Sex-related difference in human white matter volumes studied: Inspection of the corpus callosum and other white matter by VBM

    Science.gov (United States)

    Shiino, Akihiko; Chen, Yen-Wei; Tanigaki, Kenji; Yamada, Atsushi; Vigers, Piers; Watanabe, Toshiyuki; Tooyama, Ikuo; Akiguchi, Ichiro

    2017-01-01

    It has been contended that any observed difference of the corpus callosum (CC) size between men and women is not sex-related but brain-size-related. A recent report, however, showed that the midsagittal CC area was significantly larger in women in 37 brain-size-matched pairs of normal young adults. Since this constituted strong evidence of sexual dimorphism and was obtained from publicly available data in OASIS, we examined volume differences within the CC and in other white matter using voxel-based morphometry (VBM). We created a three-dimensional region of interest of the CC and measured its volume. The VBM statistics were analyzed by permutation test and threshold-free cluster enhancement (TFCE) with the significance levels at FWER sex-related difference. We also found that white matter in the bilateral anterior frontal regions and the left lateral white matter near to Broca’s area were larger in women, whereas there were no significant larger regions in men. Since we used brain-size-matched subjects, our results gave strong volumetric evidence of localized sexual dimorphism of white matter.

  11. Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Correa, D.G.; Ventura, N.; Tukamoto, G.; Gasparetto, E.L. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro (Brazil); Zimmermann, N. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Pontifical Catholic University of Rio Grande do Sul, Department of Psychology, Porto Alegre (Brazil); Doring, T.M. [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro (Brazil); Leme, J.; Pereira, M. [Federal University of Rio de Janeiro, Department of Radiology, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil); Andrea, I. d' ; Rego, C.; Alves-Leon, S.V. [Federal University of Rio de Janeiro, Department of Neurology, Epilepsy Center, Hospital Universitario Clementino Fraga Filho, Rio de Janeiro (Brazil)

    2017-03-15

    The objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE). Patients (n = 19) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (n = 19), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton. Patients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls. Abnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies. (orig.)

  12. Quantitative analysis of the corpus callosum in children with cerebral palsy and developmental delay: correlation with cerebral white matter volume

    Energy Technology Data Exchange (ETDEWEB)

    Panigrahy, Ashok [Childrens Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Barnes, Patrick D. [Stanford University Medical Center, Department of Radiology, Lucile Salter Packard Children' s Hospital, Palo Alto, CA (United States); Robertson, Robert L. [Children' s Hospital Boston, Department of Radiology, Boston, MA (United States); Sleeper, Lynn A. [New England Research Institute, Watertown, MA (United States); Sayre, James W. [UCLA Medical Center, Departments of Radiology and Biostatistics, Los Angeles, CA (United States)

    2005-12-01

    This study was conducted to quantitatively correlate the thickness of the corpus callosum with the volume of cerebral white matter in children with cerebral palsy and developmental delay. Material and methods: A clinical database of 70 children with cerebral palsy and developmental delay was established with children between the ages of 1 and 5 years. These children also demonstrated abnormal periventricular T2 hyperintensities associated with and without ventriculomegaly. Mid-sagittal T1-weighted images were used to measure the thickness (genu, mid-body, and splenium) and length of the corpus callosum. Volumes of interest were digitized based on gray-scale densities to define the hemispheric cerebral white matter on axial T2-weighted and FLAIR images. The thickness of the mid-body of the corpus callosum was correlated with cerebral white matter volume. Subgroup analysis was also performed to examine the relationship of this correlation with both gestational age and neuromotor outcome. Statistical analysis was performed using analysis of variance and Pearson correlation coefficients. There was a positive correlation between the thickness of the mid-body of the corpus callosum and the volume of cerebral white matter across all children studied (R=0.665, P=0.0001). This correlation was not dependent on gestational age. The thickness of the mid-body of the corpus callosum was decreased in the spastic diplegia group compared to the two other groups (hypotonia and developmental delay only; P<0.0001). Within each neuromotor subgroup, there was a positive correlation between thickness of the mid-body of the corpus callosum and volume of the cerebral white matter. (orig.)

  13. Association of television violence exposure with executive functioning and white matter volume in young adult males.

    Science.gov (United States)

    Hummer, Tom A; Kronenberger, William G; Wang, Yang; Anderson, Caitlin C; Mathews, Vincent P

    2014-07-01

    Prior research has indicated that self-reported violent media exposure is associated with poorer performance on some neuropsychological tests in adolescents. This study aimed to examine the relationship of executive functioning to violent television viewing in healthy young adult males and examine how brain structure is associated with media exposure measures. Sixty-five healthy adult males (ages 18-29) with minimal video game experience estimated their television viewing habits over the past year and, during the subsequent week, recorded television viewing time and characteristics in a daily media diary. Participants then completed a battery of neuropsychological laboratory tests quantifying executive functions and underwent a magnetic resonance imaging (MRI) scan. Aggregate measures of executive functioning were not associated with measures of overall television viewing (any content type) during the past week or year. However, the amount of television viewing of violent content only, as indicated by both past-year and daily diary measures, was associated with poorer scores on an aggregate score of inhibition, interference control and attention, with no relationship to a composite working memory score. In addition, violent television exposure, as measured with daily media diaries, was associated with reduced frontoparietal white matter volume. Future longitudinal work is necessary to resolve whether individuals with poor executive function and slower white matter growth are more drawn to violent programming, or if extensive media violence exposure modifies cognitive control mechanisms mediated primarily via prefrontal cortex. Impaired inhibitory mechanisms may be related to reported increases in aggression with higher media violence exposure. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Water Condensation

    DEFF Research Database (Denmark)

    Jensen, Kasper Risgaard; Fojan, Peter; Jensen, Rasmus Lund

    2014-01-01

    The condensation of water is a phenomenon occurring in multiple situations in everyday life, e.g., when fog is formed or when dew forms on the grass or on windows. This means that this phenomenon plays an important role within the different fields of science including meteorology, building physics......, and chemistry. In this review we address condensation models and simulations with the main focus on heterogeneous condensation of water. The condensation process is, at first, described from a thermodynamic viewpoint where the nucleation step is described by the classical nucleation theory. Further, we address...

  15. Reduced visual cortex grey matter volume in children and adolescents with reactive attachment disorder.

    Science.gov (United States)

    Shimada, Koji; Takiguchi, Shinichiro; Mizushima, Sakae; Fujisawa, Takashi X; Saito, Daisuke N; Kosaka, Hirotaka; Okazawa, Hidehiko; Tomoda, Akemi

    2015-01-01

    Child maltreatment increases the risk for psychiatric disorders throughout childhood and into adulthood. One negative outcome of child maltreatment can be a disorder of emotional functioning, reactive attachment disorder (RAD), where the child displays wary, watchful, and emotionally withdrawn behaviours. Despite its clinical importance, little is known about the potential neurobiological consequences of RAD. The aim of this study was to elucidate whether RAD was associated with alterations in grey matter volume (GMV). High-resolution magnetic resonance imaging datasets were obtained for children and adolescents with RAD (n = 21; mean age = 12.76 years) and typically developing (TD) control subjects (n = 22; mean age = 12.95 years). Using a whole-brain voxel-based morphometry approach, structural images were analysed controlling for age, gender, full scale intelligence quotient, and total brain volume. The GMV was significantly reduced by 20.6% in the left primary visual cortex (Brodmann area 17) of the RAD group compared to the TD group (p = .038, family-wise error-corrected cluster level). This GMV reduction was related to an internalising problem measure of the Strength and Difficulties Questionnaire. The visual cortex has been viewed as part of the neurocircuit regulating the stress response to emotional visual images. Combined with previous studies of adults with childhood maltreatment, early adverse experience (e.g. sensory deprivation) may affect the development of the primary visual system, reflecting in the size of the visual cortex in children and adolescents with RAD. These visual cortex GMV abnormalities may also be associated with the visual emotion regulation impairments of RAD, leading to an increased risk for later psychopathology.

  16. Reduced visual cortex grey matter volume in children and adolescents with reactive attachment disorder

    Directory of Open Access Journals (Sweden)

    Koji Shimada

    2015-01-01

    Full Text Available Child maltreatment increases the risk for psychiatric disorders throughout childhood and into adulthood. One negative outcome of child maltreatment can be a disorder of emotional functioning, reactive attachment disorder (RAD, where the child displays wary, watchful, and emotionally withdrawn behaviours. Despite its clinical importance, little is known about the potential neurobiological consequences of RAD. The aim of this study was to elucidate whether RAD was associated with alterations in grey matter volume (GMV. High-resolution magnetic resonance imaging datasets were obtained for children and adolescents with RAD (n = 21; mean age = 12.76 years and typically developing (TD control subjects (n = 22; mean age = 12.95 years. Using a whole-brain voxel-based morphometry approach, structural images were analysed controlling for age, gender, full scale intelligence quotient, and total brain volume. The GMV was significantly reduced by 20.6% in the left primary visual cortex (Brodmann area 17 of the RAD group compared to the TD group (p = .038, family-wise error-corrected cluster level. This GMV reduction was related to an internalising problem measure of the Strength and Difficulties Questionnaire. The visual cortex has been viewed as part of the neurocircuit regulating the stress response to emotional visual images. Combined with previous studies of adults with childhood maltreatment, early adverse experience (e.g. sensory deprivation may affect the development of the primary visual system, reflecting in the size of the visual cortex in children and adolescents with RAD. These visual cortex GMV abnormalities may also be associated with the visual emotion regulation impairments of RAD, leading to an increased risk for later psychopathology.

  17. Decay of Ultralight Axion Condensates

    Energy Technology Data Exchange (ETDEWEB)

    Eby, Joshua; Ma, Michael; Suranyi, Peter; Wijewardhana, L. C.R.

    2017-05-15

    Axion particles can form macroscopic condensates, whose size can be galactic in scale for models with very small axion masses $m\\sim10^{-22}$ eV, and which are sometimes referred to under the name of Fuzzy Dark Matter. Many analyses of these condensates are done in the non-interacting limit, due to the weakness of the self-interaction coupling of axions. We investigate here how certain results change upon inclusion of these interactions, finding a decreased maximum mass and a modified mass-radius relationship. Further, these condensates are, in general, unstable to decay through number-changing interactions. We analyze the stability of galaxy-sized condensates of axion-like particles, and sketch the parameter space of stable configurations as a function of a binding energy parameter. We find a strong lower bound on the size of Fuzzy Dark Matter condensates which are stable to decay, with lifetimes longer than the age of the universe.

  18. Baryonic matter and beyond

    CERN Document Server

    Fukushima, Kenji

    2014-01-01

    We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.

  19. Gray matter volume changes in chronic subcortical stroke: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Qingqing Diao

    2017-01-01

    Full Text Available This study aimed to investigate the effects of lesion side and degree of motor recovery on gray matter volume (GMV difference relative to healthy controls in right-handed subcortical stroke. Structural MRI data were collected in 97 patients with chronic subcortical ischemic stroke and 79 healthy controls. Voxel-wise GMV analysis was used to investigate the effects of lesion side and degree of motor recovery on GMV difference in right-handed chronic subcortical stroke patients. Compared with healthy controls, right-lesion patients demonstrated GMV increase (P < 0.05, voxel-wise false discovery rate correction in the bilateral paracentral lobule (PCL and supplementary motor area (SMA and the right middle occipital gyrus (MOG; while left-lesion patients did not exhibit GMV difference under the same threshold. Patients with complete and partial motor recovery showed similar degree of GMV increase in right-lesion patients. However, the motor recovery was correlated with the GMV increase in the bilateral SMA in right-lesion patients. These findings suggest that there exists a lesion-side effect on GMV difference relative to healthy controls in right-handed patients with chronic subcortical stroke. The GMV increase in the SMA may facilitate motor recovery in subcortical stroke patients.

  20. Elasticity of microscale volumes of viscoelastic soft matter by cavitation rheometry.

    Science.gov (United States)

    Pavlovsky, Leonid; Ganesan, Mahesh; Younger, John G; Solomon, Michael J

    2014-09-15

    Measurement of the elastic modulus of soft, viscoelastic liquids with cavitation rheometry is demonstrated for specimens as small as 1 μl by application of elasticity theory and experiments on semi-dilute polymer solutions. Cavitation rheometry is the extraction of the elastic modulus of a material, E, by measuring the pressure necessary to create a cavity within it [J. A. Zimberlin, N. Sanabria-DeLong, G. N. Tew, and A. J. Crosby, Soft Matter 3, 763-767 (2007)]. This paper extends cavitation rheometry in three ways. First, we show that viscoelastic samples can be approximated with the neo-Hookean model provided that the time scale of the cavity formation is measured. Second, we extend the cavitation rheometry method to accommodate cases in which the sample size is no longer large relative to the cavity dimension. Finally, we implement cavitation rheometry to show that the theory accurately measures the elastic modulus of viscoelastic samples with volumes ranging from 4 ml to as low as 1 μl.

  1. The alteration of gray matter volume and cognitive control in adolescents with internet gaming disorder

    Directory of Open Access Journals (Sweden)

    Hongmei eWang

    2015-03-01

    Full Text Available Objective: Internet gaming disorder (IGD has been investigated by many behavioral and neuroimaging studies, for it has became one of the main behavior disorders among adolescents. However, few studies focused on the relationship between alteration of gray matter volume (GMV and cognitive control feature in IGD adolescents. Methods: Twenty-eight participants with IAD and twenty-eight healthy age and gender matched controls participated in the study. Brain morphology of adolescents with IGD and healthy controls was investigated using an optimized voxel-based morphometry (VBM technique. Cognitive control performances were measured by Stroop task, and correlation analysis was performed between brain structural change and behavioral performance in IGD group. Results: The results showed that GMV of the bilateral anterior cingulate cortex (ACC, precuneus, supplementary motor area (SMA, superior parietal cortex, left dorsal lateral prefrontal cortex (DLPFC, left insula, and bilateral cerebellum decreased in the IGD participants compared with healthy controls. Moreover, GMV of the ACC was negatively correlated with the incongruent response errors of Stroop task in IGD group. Conclusion: Our results suggest that the alteration of GMV is associated with the performance change of cognitive control in adolescents with IGD, which indicating substantial brain image effects induced by IGD.

  2. Structural brain anomalies and chronic pain: a quantitative meta-analysis of gray matter volume.

    Science.gov (United States)

    Smallwood, Rachel F; Laird, Angela R; Ramage, Amy E; Parkinson, Amy L; Lewis, Jeffrey; Clauw, Daniel J; Williams, David A; Schmidt-Wilcke, Tobias; Farrell, Michael J; Eickhoff, Simon B; Robin, Donald A

    2013-07-01

    The diversity of chronic pain syndromes and the methods employed to study them make integrating experimental findings challenging. This study performed coordinate-based meta-analyses using voxel-based morphometry imaging results to examine gray matter volume (GMV) differences between chronic pain patients and healthy controls. There were 12 clusters where GMV was decreased in patients compared with controls, including many regions thought to be part of the "pain matrix" of regions involved in pain perception, but also including many other regions that are not commonly regarded as pain-processing areas. The right hippocampus and parahippocampal gyrus were the only regions noted to have increased GMV in patients. Functional characterizations were implemented using the BrainMap database to determine which behavioral domains were significantly represented in these regions. The most common behavioral domains associated with these regions were cognitive, affective, and perceptual domains. Because many of these regions are not classically connected with pain and because there was such significance in functionality outside of perception, it is proposed that many of these regions are related to the constellation of comorbidities of chronic pain, such as fatigue and cognitive and emotional impairments. Further research into the mechanisms of GMV changes could provide a perspective on these findings. Quantitative meta-analyses revealed structural differences between brains of individuals with chronic pain and healthy controls. These differences may be related to comorbidities of chronic pain. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  3. Condensed matter astrophysics: A prescription for determining the species-specific composition and quantity of interstellar dust using x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Julia C.; Xiang, Jingen; Ravel, Bruce; Kortright, Jeffrey B; Flanagan, Kathryn

    2009-01-05

    We present a newtechnique for determining the quantity and composition of dust in astrophysical environments using<6 keV X-rays.We argue that high-resolution X-ray spectra as enabled by the Chandra and XMM-Newton gratings should be considered a powerful and viable new resource for delving into a relatively unexplored regime for directlydetermining dust properties: composition, quantity, and distribution.We present initial cross section measurements of astrophysically likely iron-based dust candidates taken at the Lawrence Berkeley National Laboratory Advanced Light Source synchrotron beamline, as an illustrative tool for the formulation of our technique for determining the quantity and composition of interstellar dust with X-rays. (Cross sections for the materials presented here will be made available for astrophysical modeling in the near future.) Focused at the 700 eV Fe LIII and LII photoelectric edges, we discuss a technique for modeling dust properties in the soft X-rays using L-edge data to complement K-edge X-ray absorption fine structure analysis techniques discussed by Lee& Ravel. The paper is intended to be a techniques paper of interest and useful to both condensed matter experimentalists andastrophysicists. For the experimentalists, we offer a new prescription for normalizing relatively low signal-to-noise ratio L-edge cross section measurements. For astrophysics interests, we discuss the use of X-ray absorption spectra for determining dust composition in cold and ionized astrophysical environments and a new method for determining species-specific gas and dust ratios. Possible astrophysical applications of interest, including relevance to Sagittarius A*, are offered. Prospects for improving on this work in future X-ray missions with higher throughput and spectral resolution are also presented in the context of spectral resolution goals for gratings and calorimeters, for proposed and planned missions such as Astro-H and the International X

  4. Gray matter volume and white matter lesions in chronic kidney disease : exploring the association with depressive symptoms

    NARCIS (Netherlands)

    Meurs, Maaike; Roest, Annelieke M.; Groenewold, Nynke A.; Franssen, Casper F. M.; Westerhuis, Ralf; Kloppenburg, Wybe Douwe; Doornbos, Bennard; Beukema, Lindy; Lindmae, Hanna; de Groot, Jan Cees; van Tol, Marie-Jose; de Jonge, Peter

    2016-01-01

    Objective: Chronic kidney disease (CKD) is associated with structural brain damage and with a high prevalence of depression. We therefore investigated structural brain alterations in both gray and white matter in CKD patients, focusing on depression-related (frontal-subcortical) regions. Method: Thi

  5. Independent and interactive effects of blood pressure and cardiac function on brain volume and white matter hyperintensities in heart failure.

    Science.gov (United States)

    Alosco, Michael L; Brickman, Adam M; Spitznagel, Mary Beth; Griffith, Erica Y; Narkhede, Atul; Raz, Naftali; Cohen, Ronald; Sweet, Lawrence H; Hughes, Joel; Rosneck, Jim; Gunstad, John

    2013-01-01

    Reduced systemic perfusion and comorbid medical conditions are key contributors to adverse brain changes in heart failure (HF). Hypertension, the most common co-occurring condition in HF, accelerates brain atrophy in aging populations. However, the independent and interactive effects of blood pressure and systemic perfusion on brain structure in HF have yet to be investigated. Forty-eight older adults with HF underwent impedance cardiography to assess current systolic blood pressure status and cardiac index to quantify systemic perfusion. All participants underwent brain magnetic resonance imaging to quantify total brain, total and subcortical gray matter volume, and white matter hyperintensities (WMH) volume. Regression analyses adjusting for medical and demographic factors showed decreased cardiac index was associated with smaller subcortical gray matter volume (P cardiac index exacerbated WMH (P = .048). Higher blood pressure and systemic hypoperfusion are associated with smaller brain volume, and these factors interact to exacerbate WMH in HF. Prospective studies are needed to clarify the effects of blood pressure on the brain in HF, including the role of long-term blood pressure fluctuations. Copyright © 2013 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  6. Larger mid-dorsolateral prefrontal gray matter volume in young binge drinkers revealed by voxel-based morphometry.

    Directory of Open Access Journals (Sweden)

    Sonia Doallo

    Full Text Available Binge drinking or heavy episodic drinking is a high prevalent pattern of alcohol consumption among young people in several countries. Despite increasing evidence that binge drinking is associated with impairments in executive aspects of working memory (i.e. self-ordered working memory, processes known to depend on the mid-dorsolateral prefrontal cortex (Brodmann areas 46 and 9, less is known about the impact of binge drinking on prefrontal gray matter integrity. Here, we investigated the effects of binge drinking on gray matter volume of mid- dorsolateral prefrontal cortex in youths. We used voxel-based morphometry on the structural magnetic resonance images of subjects reporting a persistent (at least three years binge drinking pattern of alcohol use (n = 11; age 22.43 ± 1.03 and control subjects (n = 21; age 22.18 ± 1.08 to measure differences in gray matter volume between both groups. In a region of interest analysis of the mid-dorsolateral prefrontal cortex, after co-varying for age and gender, we observed significantly larger gray matter volume in the left mid-dorsolateral prefrontal cortex (Brodmann areas 46 and 9 in binge drinkers in comparison with control subjects. Furthermore, there was a significant positive correlation between left mid-dorsolateral prefrontal cortex volume and Self-Ordered Pointing Test (SOPT total errors score in binge drinkers. The left mid-dorsolateral prefrontal cortex volume also correlated with the quantity and speed of alcohol intake. These findings indicate that a repeated exposure to alcohol -that does not meet criteria for alcohol dependence- throughout post-adolescent years and young adulthood is linked with structural anomalies in mid-dorsolateral prefrontal regions critically involved in executive aspects of working memory.

  7. Condensed matter physics and chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Nellis, W.J.

    1995-10-01

    The proposed Los Alamos Neutron Science Center (LANSCE) upgrade is ideally suited for science-based stockpile stewardship (SBSS) because LANSCE is a highly-intensity pulsed neutron source located at a nuclear weapons design laboratory. The attributes of a high-intensity pulsed source are essential for performing experiments on Pu and other materials important for SBSS. Neutrons can accurately probe thick bulk specimens, probe thin layers both freestanding and embedded in thicker specimens, and provide time-resolution for some phenomena. Both ordered structures and disorder in solids, liquids, and amorphous materials can be characterized, as well as phase transition. Because LANSCE is at a nuclear design laboratory, specimens important for SBSS issues are available. Los Alamos National Laboratory is an appropriate place to develop the requisite hardware to accommodate SBSS specimens, such as Pu.

  8. Photoacoustic spectroscopy of condensed matter

    Science.gov (United States)

    Somoano, R. B.

    1978-01-01

    Photoacoustic spectroscopy is a new analytical tool that provides a simple nondestructive technique for obtaining information about the electronic absorption spectrum of samples such as powders, semisolids, gels, and liquids. It can also be applied to samples which cannot be examined by conventional optical methods. Numerous applications of this technique in the field of inorganic and organic semiconductors, biology, and catalysis have been described. Among the advantages of photoacoustic spectroscopy, the signal is almost insensitive to light scattering by the sample and information can be obtained about nonradiative deactivation processes. Signal saturation, which can modify the intensity of individual absorption bands in special cases, is a drawback of the method.

  9. Symmetry and Condensed Matter Physics

    Science.gov (United States)

    El-Batanouny, M.; Wooten, F.

    2008-03-01

    Preface; 1. Symmetry and physics; 2. Symmetry and group theory; 3. Group representations: concepts; 4. Group representations: formalism and methodology; 5. Dixon's method for computing group characters; 6. Group action and symmetry projection operators; 7. Construction of the irreducible representations; 8. Product groups and product representations; 9. Induced representations; 10. Crystallographic symmetry and space-groups; 11. Space groups: Irreps; 12. Time-reversal symmetry: color groups and the Onsager relations; 13. Tensors and tensor fields; 14. Electronic properties of solids; 15. Dynamical properties of molecules, solids and surfaces; 16. Experimental measurements and selection rules; 17. Landau's theory of phase transitions; 18. Incommensurate systems and quasi-crystals; References; Bibliography; Index.

  10. Fundamentals of Condensed Matter Physics

    Science.gov (United States)

    Cohen, Marvin L.; Louie, Steven G.

    2016-05-01

    Part I. Basic Concepts: Electrons and Phonons: 1. Concept of a solid: qualitative introduction and overview; 2. Electrons in crystals; 3. Electronic energy bands; 4. Lattice vibrations and phonons; Part II. Electron Intercations, Dynamics and Responses: 5. Electron dynamics in crystals; 6. Many-electron interactions: the interacting electron gas and beyond; 7. Density functional theory; 8. The dielectric function for solids; Part III. Optical and Transport Phenomena: 9. Electronic transitions and optical properties of solids; 10. Electron-phonon interactions; 11. Dynamics of crystal electrons in a magnetic field; 12. Fundamentals of transport phenomena in solids; Part IV. Superconductivity, Magnetism, and Lower Dimensional Systems: 13. Using many-body techniques; 14. Superconductivity; 15. Magnetism; 16. Reduced-dimensional systems and nanostructures; Index.

  11. Dark Energy and Dark Matter From Hidden Symmetry of Gravity Model with a Non-Riemannian Volume Form

    CERN Document Server

    Guendelman, Eduardo; Pacheva, Svetlana

    2015-01-01

    We show that dark energy and dark matter can be described simultaneously by ordinary Einstein gravity interacting with a single scalar field provided the scalar field Lagrangian couples in a symmetric fashion to two different spacetime volume-forms (covariant integration measure densities) on the spacetime manifold - one standard Riemannian given by the square-root of the determinant of the pertinent Riemannian metric and another non-Riemannian volume-form independent of the Riemannian metric, defined in terms of an auxiliary antisymmetric tensor gauge field of maximal rank. Integration of the equations of motion of the latter auxiliary gauge field produce an a priori arbitrary integration constant that plays the role of a dynamically generated cosmological constant or dark energy. Moreover, the above modified scalar field action turns out to possess a hidden Noether symmetry whose associated conserved current describes a pressureless "dust" fluid which we can identify with the dark matter completely decouple...

  12. A study on cognitive impairment and gray matter volume abnormalities in silent cerebral infarction patients

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wei; Wei, Xiaofeng; Li, Mengxiong [The First Affiliated Hospital of Yangtze University, Biomedical Engineering Laboratory, Jingzhou, Hubei (China); Jiang, Xun [Renmin Hospital of Wuhan University, Biomedical Engineering Laboratory, Wuhan, Hubei (China); Li, Shanshan [JingZhou City Central Blood Bank, Jingzhou, Hubei (China)

    2015-08-15

    The relationship between silent cerebral infarction (SCI) and the integrity of cognitive function is unknown. We intended to investigate whether cognitive impairment is associated with gray matter volume (GMV) in the SCI patients. Sixty-two patients with SCI and 62 age- and gender-matched healthy controls (HC) were evaluated with P300 test, Montreal Cognitive Assessment (MoCA) test, Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HDRS). Whole brain high-resolution T1-weighted images were processed with SPM12b software and analyzed by voxel-based morphometry (VBM). Correlation analysis was performed between the GMV and the scores of MoCA Scale, P300 latency, P300 amplitude, HAMA, HDRS, age, and educational level. The brains of the SCI patients have a significant reduction in GMV in the left superior and inferior frontal gyrus, left superior temporal gyrus, right middle temporal gyrus, and bilateral hippocampus gyrus (p < 0.01, FDR correction). No significant increase of GMV was detected. The GMV of their frontal and temporal lobes is positively correlated with the score of MoCA scale and P300 amplitude (r ≥ 0.62, p < 0.01). The GMV of frontal, temporal, and hippocampus is negatively correlated with P300 latency (r ≤ -0.71, p < 0.05). No significant correlation between the GMV of abnormal brain regions and another two clinical characteristics was found. SCI patients have impaired cognitive function and reduced GMV compared to the HC subjects. The neuropathological basis of such cognitive deficits in SCI patients might be a reduced GMV. (orig.)

  13. Sex-specific gray matter volume differences in females with developmental dyslexia.

    Science.gov (United States)

    Evans, Tanya M; Flowers, D Lynn; Napoliello, Eileen M; Eden, Guinevere F

    2014-05-01

    Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men, we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences, and instead, we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e., motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia.

  14. Conscientiousness is Negatively Associated with Grey Matter Volume in Young APOE ɛ4-Carriers.

    Science.gov (United States)

    Kunz, Lukas; Reuter, Martin; Axmacher, Nikolai; Montag, Christian

    2017-01-01

    The etiology of late onset Alzheimer's disease (LOAD) depends on multiple factors, among which the APOE ɛ4 allele is the most adverse genetic determinant and conscientiousness represents an influential personality trait. A potential association of both factors with brain structure in young adulthood may constitute a constellation that sets the course toward or against the subtle disease progression of LOAD that starts decades before clinical manifestation. Hence, in the present study, we examined the modulating effects of APOE ɛ4 on the relation between personality dimensions, including conscientiousness, and total grey matter volume (GMV) in young healthy adults using an a priori genotyping design. 105 participants completed an inventory assessing the Five Factor Model of Personality (NEO-FFI) and a structural MRI scan. Total GMV was estimated using both Freesurfer as well as VBM8. Across all participants, total GMV was positively associated with extraversion and negatively related to age. In APOE ɛ4-carriers- but not in APOE ɛ4-non-carriers- conscientiousness was negatively associated with total GMV. In line with the hypothesis of antagonistic pleiotropy of the APOE ɛ4 allele, this result suggests that young APOE ɛ4-carriers with increased total GMV may particularly benefit from cognitive advantages and thus have a lower need to engage in conscientious behavior. In this subset of young APOE ɛ4-carriers, the reduction in conscientiousness could then bring along adverse health behavior in the long run, potentiating the risk for LOAD. Hence, young APOE ɛ4-carriers with increased total GMV may be at a particularly high risk for LOAD.

  15. Sex-specific Gray Matter Volume Differences in Females with Developmental Dyslexia

    Science.gov (United States)

    Evans, Tanya M.; Flowers, D. Lynn; Napoliello, Eileen M.; Eden, Guinevere F.

    2013-01-01

    Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences and instead we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e. motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia. PMID:23625146

  16. Altered Regional Gray Matter Volume in Obese Men: A Structural MRI Study

    Science.gov (United States)

    Zhang, Bin; Tian, Xiao; Tian, Derun; Wang, Jinhong; Wang, Qiming; Yu, Chunshui; Li, Chunbo; Wang, Jijun

    2017-01-01

    Obesity is associated with a number of health problems, especial insulin resistance and Type 2 diabetes. Our previous study showed that obese males had decreased neural activity in the orbital frontal cortex (OFC) and increased activity in the left putamen (Zhang et al., 2015b), which could indicate altered eating behaviors in obesity related to a hyper-functioning striatum and hypo-functioning inhibitory control. Accordingly, our goal of the current study was to determine whether there are alterations in the brain structures within these two neural systems in obese individuals. Twenty obese men (age: 20–28 years) and 20 age-matched lean male subjects were involved in the current study. Plasma glucose and insulin were tested during hunger state, and homeostasis model assessment of insulin resistance (HOMA-IR) was based on the blood samples. In the study, we used structural MRI and a voxel-based morphometry (VBM) method to investigate regional structures in obese subjects and find out whether there are correlations between the insulin and the brain structures. We found that obese men only showed a significantly increased gray matter volume (GMV) in the left putamen and that the GMV of the left putamen was positively correlated with body mass index, plasma insulin and HOMA-IR. The putamen is a core region participating in insulin signal regulation, and our results showed an abnormal GMV of the putamen is a core alternation in aberrant insulin. Furthermore, the GMV of the OFC was negatively correlated with hunger rating, despite there being no significant difference between the two groups in the OFC. In conclusion, the altered structure and function of the putamen could play important roles in obesity and aberrant insulin. PMID:28197123

  17. Alterations in white matter volume and its correlation with clinical characteristics in patients with generalized anxiety disorder

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Chung-Man [Chonnam National University Hospital, Research Institute for Medical Imaging, Gwangju (Korea, Republic of); Jeong, Gwang-Woo [Chonnam National University Hospital, Research Institute for Medical Imaging, Gwangju (Korea, Republic of); Chonnam National University Medical School, Department of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2015-11-15

    Only a few morphological studies have focused on changes in white matter (WM) volume in patients with generalized anxiety disorder (GAD). We evaluated alterations in WM volume and its correlation with symptom severity and duration of illness in adults with GAD. The 44 subjects were comprised of 22 patients with GAD (13 males and nine females) diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and 22 age-matched healthy controls (13 males and nine females). High-resolution magnetic resonance imaging (MRI) data were processed by voxel-based morphometry (VBM) analysis based on diffeomorphic anatomical registration using the exponentiated Lie algebra (DARTEL) algorithm in SPM8. Patients with GAD showed significantly reduced WM volume, particularly in the dorsolateral prefrontal cortex (DLPFC), anterior limb of the internal capsule (ALIC), and midbrain. In addition, DLPFC volume was negatively correlated with GAD-7 score and illness duration. ALIC volume was negatively correlated with GAD-7 score. Female patients had significantly less orbitofrontal cortex volume compared to that in male patients. The findings demonstrate localized changes in WM volume associated with cognitive and emotional dysfunction in patients with GAD. The finding will be helpful for understanding the neuropathology in patients with GAD. (orig.)

  18. Is Gray Matter Volume an Intermediate Phenotype for Schizophrenia? A VBM Study of Patients with Schizophrenia and their Healthy Siblings

    Science.gov (United States)

    Honea, Robyn A.; Meyer-Lindenberg, Andreas; Hobbs, Katherine B.; Pezawas, Lukas; Mattay, Venkata S.; Egan, Michael F.; Verchinski, Beth; Passingham, Richard E.; Weinberger, Daniel R.; Callicott, Joseph H.

    2008-01-01

    Objective: Shared neuropathological characteristics of patients with schizophrenia and their siblings may represent intermediate phenotypes that could be used to investigate genetic susceptibility to the illness. We sought to discover previously unidentified gray matter volume differences in patients with schizophrenia and their siblings using optimized Voxel-Based Morphometry (VBM). Methods: We studied 169 patients with schizophrenia, 213 of their unaffected siblings, and 212 healthy volunteers from the CBDB/NIMH Genetic Study of Schizophrenia with magnetic resonance imaging (MRI). Results: Patients with schizophrenia had significant regional gray matter decreases in the frontal, temporal, and parietal cortices compared with healthy volunteers. Their unaffected siblings tended to share gray matter decreases in the medial frontal, superior temporal and insular cortices, but these decreases were not significant after correction for multiple comparisons, even when we looked at a subgroup of siblings with a past history of mood disorder. As an exploratory analysis, we estimated heritability using regions of interest from the VBM analysis, as well as from the hippocampus. Hippocampal volume was significantly correlated within sibling-pairs. Conclusions: Our findings confirm and extend previous VBM analyses in ill subjects with schizophrenia. Furthermore, these data argue that while siblings may share some regional gray matter decreases with their affected siblings, the pattern of regional differences may be a weak intermediate phenotype for schizophrenia. PMID:17689500

  19. Dark energy and dark matter from hidden symmetry of gravity model with a non-Riemannian volume form

    Energy Technology Data Exchange (ETDEWEB)

    Guendelman, Eduardo [Ben-Gurion University of the Negev, Department of Physics, Beersheba (Israel); Nissimov, Emil; Pacheva, Svetlana [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria)

    2015-10-15

    We show that dark energy and dark matter can be described simultaneously by ordinary Einstein gravity interacting with a single scalar field provided the scalar field Lagrangian couples in a symmetric fashion to two different spacetime volume forms (covariant integration measure densities) on the spacetime manifold - one standard Riemannian given by √(-g) (square root of the determinant of the pertinent Riemannian metric) and another non-Riemannian volume form independent of the Riemannian metric, defined in terms of an auxiliary antisymmetric tensor gauge field of maximal rank. Integration of the equations of motion of the latter auxiliary gauge field produce an a priori arbitrary integration constant that plays the role of a dynamically generated cosmological constant or dark energy. Moreover, the above modified scalar field action turns out to possess a hidden Noether symmetry whose associated conserved current describes a pressureless ''dust'' fluid which we can identify with the dark matter completely decoupled from the dark energy. The form of both the dark energy and dark matter that results from the above class of models is insensitive to the specific form of the scalar field Lagrangian. By adding an appropriate perturbation, which breaks the above hidden symmetry and along with this couples dark matter and dark energy, we also suggest a way to obtain growing dark energy in the present universe's epoch without evolution pathologies. (orig.)

  20. A prospective pilot investigation of brain volume, white matter hyperintensities and haemorrhagic lesions after mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Michael eJarrett

    2016-02-01

    Full Text Available Traumatic brain injury (TBI is among the most common neurological disorders. Haemorrhagic lesions and white matter hyperintensities (WMH are radiological features associated with moderate and severe traumatic brain injury TBI. Brain volume reductions have also been observed during the months following injury. In concussion, no signs of injury are observed on conventional MRI, which may be a true feature of concussion or merely due to the limited sensitivity of imaging techniques used so far. Moreover, it is not known whether volume reductions are due to the resolution of trauma related edema or a true volume loss. Forty five collegiate level ice hockey players (20 female and 15 controls (9 female 40 players underwent 3T MRI for haemorrhages (multi echo susceptibility weighted imaging (SWI, WMH (three dimensional FLAIR and brain volume at the beginning and the end of the hockey season. Concussed athletes underwent additional imaging and neuropsychological testing atthree days, two weeks, and two months after injury. At the end of the hockey season, brain volume was reduced compared to controls by 0.32% (p<0.034 in the whole cohort and by 0.26% (p<0.09 in the concussed athletes. Two weeks and two months after concussion, brain volume was reduced by -0.08% (p=0.027 and -0.23% (p=0.035, respectively. In athletes, the WMH were significantly closer to the interface between grey matter and white matter compared to controls. No significant changes in thenumber of WMH over the duration of the study were found in athletes. No microhaemorrhages were detected as a result of concussion or playing a season of ice hockey. We conclude that mild TBI does not lead to transient increases in brain volume and no new microbleeds or WMH are detectable after concussion. Brain volume reductions appear by two weeks after concussion and persist until at least two months after concussion. Brain volume is reduced between the beginning and the end of the icehockey season.

  1. Partial volume effect-corrected FDG PET and grey matter volume loss in patients with mild Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Samuraki, Miharu; Yanase, Daisuke; Yamada, Masahito [Kanazawa University Graduate School of Medical Science, Department of Neurology and Neurobiology of Aging, Kanazawa (Japan); Matsunari, Ichiro; Chen, Wei-Ping; Yajima, Kazuyoshi; Fujikawa, Akihiko; Takeda, Nozomi; Nishimura, Shintaro [The Medical and Pharmacological Research Center Foundation, Hakui-City, Ishikawa (Japan); Matsuda, Hiroshi [Saitama Medical School Hospital, Department of Nuclear Medicine, Saitama (Japan)

    2007-10-15

    Although{sup 18}F-fluorodeoxyglucose (FDG) PET is an established imaging technique to assess brain glucose utilisation, accurate measurement of tracer concentration is confounded by the presence of partial volume effect (PVE) due to the limited spatial resolution of PET, which is particularly true in atrophic brains such as those encountered in patients with Alzheimer's disease (AD). Our aim was to investigate the effects of PVE correction on FDG PET in conjunction with voxel-based morphometry (VBM) in patients with mild AD. Thirty-nine AD patients and 73 controls underwent FDG PET and MRI. The PVE-corrected grey matter PET images were obtained using an MRI-based three-compartment method. Additionally, the results of PET were compared with grey matter loss detected by VBM. Before PVE correction, reduced FDG uptake was observed in posterior cingulate gyri (PCG) and parieto-temporal lobes (PTL) in AD patients, which persisted after PVE correction. Notably, PVE correction revealed relatively preserved FDG uptake in hippocampal areas, despite the grey matter loss in medial temporal lobe (MTL) revealed by VBM. FDG uptake in PCG and PTL is reduced in AD regardless of whether or not PVE correction is applied, supporting the notion that the reduced FDG uptake in these areas is not the result of atrophy. Furthermore, FDG uptake by grey matter tissue in the MTL, including hippocampal areas, is relatively preserved, suggesting that compensatory mechanisms may play a role in patients with mild AD. (orig.)

  2. Abnormalities in gray and white matter volumes associated with explicit memory dysfunction in patients with generalized anxiety disorder.

    Science.gov (United States)

    Moon, Chung-Man; Jeong, Gwang-Woo

    2017-03-01

    Background The neuroanatomical abnormalities associated with behavioral dysfunction on explicit memory in patients generalized anxiety disorder (GAD) have not yet been clearly identified. Purpose To investigate the regional gray matter (GM) and white matter (WM) volume alterations over the whole brain in patients with GAD, as well as the correlation between the brain structural abnormality and explicit memory dysfunction. Material and Methods Twenty patients with GAD and 20 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted magnetic resonance imaging (MRI). The participants performed the explicit memory tasks with the neutral and anxiety-inducing words. Results Patients with GAD showed significantly reduced GM volumes in the midbrain (MB), thalamus, hippocampus (Hip), insula, and superior temporal gyrus (STG); and reduced WM volumes in the MB, anterior limb of the internal capsule (ALIC), dorsolateral prefrontal cortex (DLPFC), and precentral gyrus (PrG). It is important to note that the GM volume of the Hip and the WM volume of the DLPFC were positively correlated with the recognition accuracy (%) in the explicit memory tasks with neutral and anxiety-inducing words, respectively. On the other hand, the WM volume of the PrG was negatively correlated with the reaction time in the same memory tasks. Conclusion This study demonstrated the regional volume changes on whole-brain GM and WM and the correlation between the brain structural alteration and explicit memory dysfunction in GAD patients. These findings would be helpful to understand the association between the brain structure abnormality and the functional deficit in the explicit memory in GAD.

  3. Investigation of Bose Condensation in Ideal Bose Gas Trapped under Generic Power Law Potential in d Dimension

    Science.gov (United States)

    Mehedi Faruk, Mir; Sazzad Hossain, Md.; Muktadir Rahman, Md.

    2016-02-01

    The changes in characteristics of Bose condensation of ideal Bose gas due to an external generic power law potential U=\\sumi=1dci\\vert xi/ai\\vertni are studied carefully. Detailed calculation of Kim et al. (J. Phys. Condens. Matter 11 (1999) 10269) yielded the hierarchy of condensation transitions with changing fractional dimensionality. In this manuscript, some theorems regarding specific heat at constant volume CV are presented. Careful examination of these theorems reveal the existence of hidden hierarchy of the condensation transition in trapped systems as well.

  4. Mixing subattolitre volumes in a quantitative and highly parallel manner with soft matter nanofluidics

    DEFF Research Database (Denmark)

    Christensen, Sune M.; Bolinger, Pierre-Yves; Hatzakis, Nikos;

    2012-01-01

    Handling and mixing ultrasmall volumes of reactants in parallel can increase the throughput and complexity of screening assays while simultaneously reducing reagent consumption. Microfabricated silicon and plastic can provide reliable fluidic devices, but cannot typically handle total volumes sma...

  5. Quantification of γ-aminobutyric acid (GABA) in (1) H MRS volumes composed heterogeneously of grey and white matter.

    Science.gov (United States)

    Mikkelsen, Mark; Singh, Krish D; Brealy, Jennifer A; Linden, David E J; Evans, C John

    2016-11-01

    The quantification of γ-aminobutyric acid (GABA) concentration using localised MRS suffers from partial volume effects related to differences in the intrinsic concentration of GABA in grey (GM) and white (WM) matter. These differences can be represented as a ratio between intrinsic GABA in GM and WM: rM . Individual differences in GM tissue volume can therefore potentially drive apparent concentration differences. Here, a quantification method that corrects for these effects is formulated and empirically validated. Quantification using tissue water as an internal concentration reference has been described previously. Partial volume effects attributed to rM can be accounted for by incorporating into this established method an additional multiplicative correction factor based on measured or literature values of rM weighted by the proportion of GM and WM within tissue-segmented MRS volumes. Simulations were performed to test the sensitivity of this correction using different assumptions of rM taken from previous studies. The tissue correction method was then validated by applying it to an independent dataset of in vivo GABA measurements using an empirically measured value of rM . It was shown that incorrect assumptions of rM can lead to overcorrection and inflation of GABA concentration measurements quantified in volumes composed predominantly of WM. For the independent dataset, GABA concentration was linearly related to GM tissue volume when only the water signal was corrected for partial volume effects. Performing a full correction that additionally accounts for partial volume effects ascribed to rM successfully removed this dependence. With an appropriate assumption of the ratio of intrinsic GABA concentration in GM and WM, GABA measurements can be corrected for partial volume effects, potentially leading to a reduction in between-participant variance, increased power in statistical tests and better discriminability of true effects.

  6. White matter volume change and its correlation with symptom severity in patients with schizophrenia: a VBM-DARTEL study.

    Science.gov (United States)

    Kim, Gwang-Won; Jeong, Gwang-Woo

    2015-12-16

    The aim of this study was to evaluate the white matter (WM) volume change and its correlation with symptom severity in patients with schizophrenia using voxel-based morphometry. A total of 20 patients with schizophrenia and 20 age-matched healthy controls participated in this study. MR image data were processed using SPM8 software with diffeomorphic anatomical registration through an exponentiated Lie algebra (DARTEL) algorithm. The patients with schizophrenia showed significant decreases (P=0.042) in the WM volumes of the temporal lobe and superior frontal gyrus compared with the healthy controls. The WM volumes of the middle temporal gyrus were negatively correlated with the scores of both the Positive Subscale (Pearson's ρ=-0.68, P=0.001) and the Negative Subscale (ρ=-0.71, P=0.0005) in the Positive and Negative Syndrome Scale. In addition, the scores of the General Psychopathology Subscale were negatively correlated with the WM volumes of the superior frontal gyrus (ρ=-0.68, P=0.0009). This study evaluated the WM volume of patients with schizophrenia compared with healthy controls using DARTEI-based voxel-based morphometry and also assessed the correlation of the localized WM volume changes with the Positive and Negative Syndrome Scale. These findings will be useful to understand the neuropathology associated with WM abnormality in schizophrenia.

  7. Whole-brain gray matter volume abnormalities in patients with generalized anxiety disorder: voxel-based morphometry.

    Science.gov (United States)

    Moon, Chung-Man; Kim, Gwang-Won; Jeong, Gwang-Woo

    2014-02-12

    Patients with generalized anxiety disorder (GAD) experience psychological distress because of excessive and uncontrollable anxiety in everyday life. Only a few morphological studies have so far focused on specific brain regions of interest as well as the gray matter volume changes in GAD patients. This study evaluated gray matter volume alterations in whole-brain areas between GAD patients and healthy controls, and sex differences between the specific brain areas with significant volume changes in GAD patients using voxel-based morphometry. Twenty-two patients with GAD (13 men and nine women), who were diagnosed using the DSM-IV-TR, and 22 age-matched healthy controls (13 men and nine women) participated in this study. The high-resolution MRI data were processed using voxel-based morphometry analysis on the basis of diffeomorphic anatomical registration through an exponentiated Lie algebra algorithm in Statistical Parametric Mapping 8. There was no significant difference in the total intracranial volume between GAD patients and controls, but a significant difference was observed between sexes (Psuperior temporal gyrus compared with the controls. As for the sex comparison, female patients showed a significant increase in the volume of the dorsolateral prefrontal cortex relative to male patients. Also, the volume of the dorsolateral prefrontal cortex in female patients was correlated positively with the Hamilton Anxiety Rating Scale score (γ=0.68, P=0.04). The specific morphological variations in patient with GAD will be helpful to understand the neural mechanism associated with a symptom of GAD. Furthermore, the findings would be valuable for the diagnostic accuracy of GAD using morphometric MRI analysis.

  8. Association between waist circumference and gray matter volume in 2344 individuals from two adult community-based samples.

    Science.gov (United States)

    Janowitz, Deborah; Wittfeld, Katharina; Terock, Jan; Freyberger, Harald Jürgen; Hegenscheid, Katrin; Völzke, Henry; Habes, Mohamad; Hosten, Norbert; Friedrich, Nele; Nauck, Matthias; Domanska, Grazyna; Grabe, Hans Jörgen

    2015-11-15

    We analyzed the putative association between abdominal obesity (measured in waist circumference) and gray matter volume (Study of Health in Pomerania: SHIP-2, N=758) adjusted for age and gender by applying volumetric analysis and voxel-based morphometry (VBM) with VBM8 to brain magnetic resonance (MR) imaging. We sought replication in a second, independent population sample (SHIP-TREND, N=1586). In a combined analysis (SHIP-2 and SHIP-TREND) we investigated the impact of hypertension, type II diabetes and blood lipids on the association between waist circumference and gray matter. Volumetric analysis revealed a significant inverse association between waist circumference and gray matter volume. VBM in SHIP-2 indicated distinct inverse associations in the following structures for both hemispheres: frontal lobe, temporal lobes, pre- and postcentral gyrus, supplementary motor area, supramarginal gyrus, insula, cingulate gyrus, caudate nucleus, olfactory sulcus, para-/hippocampus, gyrus rectus, amygdala, globus pallidus, putamen, cerebellum, fusiform and lingual gyrus, (pre-) cuneus and thalamus. These areas were replicated in SHIP-TREND. More than 76% of the voxels with significant gray matter volume reduction in SHIP-2 were also distinct in TREND. These brain areas are involved in cognition, attention to interoceptive signals as satiety or reward and control food intake. Due to our cross-sectional design we cannot clarify the causal direction of the association. However, previous studies described an association between subjects with higher waist circumference and future cognitive decline suggesting a progressive brain alteration in obese subjects. Pathomechanisms may involve chronic inflammation, increased oxidative stress or cellular autophagy associated with obesity.

  9. Grey-matter volume as a potential feature for the classification of Alzheimer's disease and mild cognitive impairment: an exploratory study.

    Science.gov (United States)

    Guo, Yane; Zhang, Zengqiang; Zhou, Bo; Wang, Pan; Yao, Hongxiang; Yuan, Minshao; An, Ningyu; Dai, Haitao; Wang, Luning; Zhang, Xi; Liu, Yong

    2014-06-01

    Specific patterns of brain atrophy may be helpful in the diagnosis of Alzheimer's disease (AD). In the present study, we set out to evaluate the utility of grey-matter volume in the classification of AD and amnestic mild cognitive impairment (aMCI) compared to normal control (NC) individuals. Voxel-based morphometric analyses were performed on structural MRIs from 35 AD patients, 27 aMCI patients, and 27 NC participants. A two-sample two-tailed t-test was computed between the NC and AD groups to create a map of abnormal grey matter in AD. The brain areas with significant differences were extracted as regions of interest (ROIs), and the grey-matter volumes in the ROIs of the aMCI patients were included to evaluate the patterns of change across different disease severities. Next, correlation analyses between the grey-matter volumes in the ROIs and all clinical variables were performed in aMCI and AD patients to determine whether they varied with disease progression. The results revealed significantly decreased grey matter in the bilateral hippocampus/parahippocampus, the bilateral superior/middle temporal gyri, and the right precuneus in AD patients. The grey-matter volumes were positively correlated with clinical variables. Finally, we performed exploratory linear discriminative analyses to assess the classifying capacity of grey-matter volumes in the bilateral hippocampus and parahippocampus among AD, aMCI, and NC. Leave-one-out cross-validation analyses demonstrated that grey-matter volumes in hippocampus and parahippocampus accurately distinguished AD from NC. These findings indicate that grey-matter volumes are useful in the classification of AD.

  10. Antikaon condensation in neutron stars

    CERN Document Server

    Pal, S; Greiner, W

    2000-01-01

    We investigate the condensation of charged K sup - meson and neutral anti-K sup 0 meson in dense neutron star matter. Calculations are performed in relativistic mean field models in which both the baryon-baryon and (anti)kaon-baryon interactions are mediated by meson exchange. It is found that anti-K sup 0 condensation is quite sensitive to the antikaon optical potential and depends more strongly on the nucleonic equation of state. For moderate values of antikaon potential and a rather stiff equation of state, a significant region of maximum mass star will contain anti-K sup 0 meson. The critical density of anti-K sup 0 condensation is always higher than that of K sup - condensation. With the appearance of K sup - and anti-K sup 0 condensates, pairs of p-K sup - and n-Kbar sup 0 are produced with equal proportion leading to a perfectly symmetric matter of nucleons and antikaons in neutron stars. Along with K sup - condensate, anti-K sup 0 condensate makes the equation of state much softer resulting in smaller...

  11. Progressive volume loss and white matter degeneration in cstb-deficient mice: a diffusion tensor and longitudinal volumetry MRI study.

    Directory of Open Access Journals (Sweden)

    Otto Manninen

    Full Text Available Unverricht-Lundborg type progressive myoclonus epilepsy (EPM1, OMIM 254800 is an autosomal recessive disorder characterized by onset at the age of 6 to 16 years, incapacitating stimulus-sensitive myoclonus and tonic-clonic epileptic seizures. It is caused by mutations in the gene encoding cystatin B. Previously, widespread white matter changes and atrophy has been detected both in adult EPM1 patients and in 6-month-old cystatin B-deficient mice, a mouse model for the EPM1 disease. In order to elucidate the spatiotemporal dynamics of the brain atrophy and white matter changes in EPM1, we conducted longitudinal in vivo magnetic resonance imaging and ex vivo diffusion tensor imaging accompanied with tract-based spatial statistics analysis to compare volumetric changes and fractional anisotropy in the brains of 1 to 6 months of age cystatin B-deficient and control mice. The results reveal progressive but non-uniform volume loss of the cystatin B-deficient mouse brains, indicating that different neuronal populations possess distinct sensitivity to the damage caused by cystatin B deficiency. The diffusion tensor imaging data reveal early and progressive white matter alterations in cystatin B-deficient mice affecting all major tracts. The results also indicate that the white matter damage in the cystatin B-deficient brain is most likely secondary to glial activation and neurodegenerative events rather than a primary result of CSTB deficiency. The data also show that diffusion tensor imaging combined with TBSS analysis provides a feasible approach not only to follow white matter damage in neurodegenerative mouse models but also to detect fractional anisotropy changes related to normal white matter maturation and reorganisation.

  12. Cerebral gray matter volume variation in female-to-male transsexuals: a voxel-based morphometric study.

    Science.gov (United States)

    Kim, Tae-Hoon; Kim, Seok-Kwun; Jeong, Gwang-Woo

    2015-12-16

    Several studies seem to support the hypothesis that brain anatomy is associated with transsexualism. However, these studies were still limited because few neuroanatomical findings have been obtained from female-to-male (FtM) transsexuals. This study compared the cerebral regional volumes of gray matter (GM) between FtM transsexuals and female controls using a voxel-based morphometry. Twelve FtM transsexuals who had undergone sex-reassignment surgery and 15 female controls participated in this study. Both groups were age matched and right-handed, with no history of neurological illness. Fifteen female controls were recruited to determine whether GM volumes in FtM transsexuals more closely resembled individuals who shared their biological sex. MRI data were processed using SPM 8 with the diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL). FtM transsexuals showed significantly larger volumes of the thalamus, hypothalamus, midbrain, gyrus rectus, head of caudate nucleus, precentral gyrus, and subcallosal area compared with the female controls. However, the female controls showed a significantly larger volume in the superior temporal gyrus including Heschl's gyrus and Rolandic operculum. These findings confirm that the volume difference in brain substructures in FtM transsexuals is likely to be associated with transsexualism and that transsexualism is probably associated with distinct cerebral structures, determining gender identity.

  13. ZNF804A risk allele is associated with relatively intact gray matter volume in patients with schizophrenia.

    LENUS (Irish Health Repository)

    Donohoe, Gary

    2011-02-01

    ZNF804A rs1344706 is the first genetic risk variant to achieve genome wide significance for psychosis. Following earlier evidence that patients carrying the ZNF804A risk allele had relatively spared memory function compared to patient non-carriers, we investigated whether ZNF804A was also associated with variation in brain volume. In a sample of 70 patients and 38 healthy participants we used voxel based morphometry to compare homozygous (AA) carriers of the ZNF804A risk allele to heterozygous and homozygous (AC\\/CC) non-carriers for both whole brain volume and specific regions implicated in earlier ZNF804A studies-the dorsolateral pre-frontal cortex, the hippocampus, and the amygdala. For patients, but not for controls, we found that homozygous \\'AA\\' risk carriers had relatively larger gray matter volumes than heterozygous\\/homozygous non-carriers (AC\\/CC), particularly for hippocampal volumes. These data are consistent with our earlier behavioral data and suggest that ZNF804A is delineating a schizophrenia subtype characterized by relatively intact brain volume. Establishing if this represents a discrete molecular pathogenesis with consequences for nosology and treatment will be an important next step in understanding ZNF084A\\'s role in illness risk.

  14. Voxel-based morphometry in opera singers: Increased gray-matter volume in right somatosensory and auditory cortices.

    Science.gov (United States)

    Kleber, Boris; Veit, Ralf; Moll, Christina Valérie; Gaser, Christian; Birbaumer, Niels; Lotze, Martin

    2016-06-01

    In contrast to instrumental musicians, professional singers do not train on a specific instrument but perfect a motor system that has already been extensively trained during speech motor development. Previous functional imaging studies suggest that experience with singing is associated with enhanced somatosensory-based vocal motor control. However, experience-dependent structural plasticity in vocal musicians has rarely been studied. We investigated voxel-based morphometry (VBM) in 27 professional classical singers and compared gray matter volume in regions of the "singing-network" to an age-matched group of 28 healthy volunteers with no special singing experience. We found right hemispheric volume increases in professional singers in ventral primary somatosensory cortex (larynx S1) and adjacent rostral supramarginal gyrus (BA40), as well as in secondary somatosensory (S2) and primary auditory cortices (A1). Moreover, we found that earlier commencement with vocal training correlated with increased gray-matter volume in S1. However, in contrast to studies with instrumental musicians, this correlation only emerged in singers who began their formal training after the age of 14years, when speech motor development has reached its first plateau. Structural data thus confirm and extend previous functional reports suggesting a pivotal role of somatosensation in vocal motor control with increased experience in singing. Results furthermore indicate a sensitive period for developing additional vocal skills after speech motor coordination has matured.

  15. Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors.

    Directory of Open Access Journals (Sweden)

    Gillian E Cooke

    Full Text Available Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment.

  16. Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors.

    Science.gov (United States)

    Cooke, Gillian E; Wetter, Nathan C; Banducci, Sarah E; Mackenzie, Michael J; Zuniga, Krystle E; Awick, Elizabeth A; Roberts, Sarah A; Sutton, Brad P; McAuley, Edward; Kramer, Arthur F

    2016-01-01

    Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment.

  17. Some typical self-organization phenomena in soft condensed matter physics%一些典型的软物质物理中的非平衡自组织现象

    Institute of Scientific and Technical Information of China (English)

    谭鹏; 徐磊

    2012-01-01

    Self-organization is a common phenomenon in soft condensed matter, which often oc non equilibrium processes and results in beautiful patterns. Specific examples include diffusion aggregation, pattern formation in Hele Shaw cells, gelation, patterns in granular materials, and so We will briefly describe these interesting processes in soft condensed matter.%在软物质物理中经常有自组织(self-organization)现象发生.这一现象通常在非平衡的过程中产生,并生成非常美丽和有趣的图案与结构.具体例子包括胶体颗粒的扩散限制凝聚(diffusion limited aggregation, DLA), Helemshaw盒中产生的流体分形结构,凝胶的形成(gelation),生物体自组织聚集,以及颗粒类物质(granula rmaterial)运动产生的规则图案等.这些现象在软物质物理研究中产生了很多重要结果.文章以比较浅显的文字介绍这些软物质物理中的非平衡自组织现象.

  18. Reduced Gray Matter Volume in Patients with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Jia Liu

    2017-05-01

    Full Text Available Background and Purpose: Previous studies of voxel-based morphometry (VBM have found that patients with type 2 diabetes mellitus (T2DM exhibit gray matter alterations, but these findings are inconsistent and have not been quantitatively reviewed. Therefore, the aim of this study was to conduct a quantitative meta-analysis of VBM studies of patients with T2DM.Materials and Methods: The seed-based d mapping method was applied to quantitatively estimate the regional gray matter abnormalities in T2DM patients. We also used meta-regression to explore the effects of some demographics and clinical characteristics.Results: Seven studies, with 8 datasets comprising 530 participants with T2DM and 549 non-T2DM controls, were included. The pooled and subgroup meta-analyses found that T2DM patients showed robustly reduced gray matter in the bilateral superior temporal gyrus, middle temporal gyrus, medial superior frontal gyrus, insula, median cingulate cortex, precuneus cortex and the left lentiform nucleus extending into the parahippocampus. The meta-regression also found that the percentage of female patients with T2DM was negatively associated with gray matter in the right superior temporal gyrus and illness duration was negatively associated with gray matter in the right middle temporal gyrus.Conclusion: This meta-analysis indicates that T2DM patients have significantly and robustly reduced gray matter mainly in the cortical-striatal-limbic networks, which are associated with human cognition. Thereby implicating this finding in the pathophysiology of cognitive impairment in T2DM patients.

  19. Grey matter volume abnormalities in patients with bipolar I depressive disorder and unipolar depressive disorder: a voxel-based morphometry study.

    Science.gov (United States)

    Cai, Yi; Liu, Jun; Zhang, Li; Liao, Mei; Zhang, Yan; Wang, Lifeng; Peng, Hongjun; He, Zhong; Li, Zexuan; Li, Weihui; Lu, Shaojia; Ding, Yuqiang; Li, Lingjiang

    2015-02-01

    Bipolar disorder and unipolar depressive disorder (UD) may be different in brain structure. In the present study, we performed voxel-based morphometry (VBM) to quantify the grey matter volumes in 23 patients with bipolar I depressive disorder (BP1) and 23 patients with UD, and 23 age-, gender-, and education-matched healthy controls (HCs) using magnetic resonance imaging. We found that compared with the HC and UD groups, the BP1 group showed reduced grey matter volumes in the right inferior frontal gyrus and middle cingulate gyrus, while the UD group showed reduced volume in the right inferior frontal gyrus compared to HCs. In addition, correlation analyses revealed that the grey matter volumes of these regions were negatively correlated with the Hamilton depression rating scores. Taken together, the results of our study suggest that decreased grey matter volume of the right inferior frontal gyrus is a common abnormality in BP1 and UD, and decreased grey matter volume in the right middle cingulate gyrus may be specific to BP1.

  20. A longitudinal study of the relationship between personality traits and the annual rate of volume changes in regional gray matter in healthy adults.

    Science.gov (United States)

    Taki, Yasuyuki; Thyreau, Benjamin; Kinomura, Shigeo; Sato, Kazunori; Goto, Ryoi; Wu, Kai; Kawashima, Ryuta; Fukuda, Hiroshi

    2013-12-01

    To investigate whether personality traits affect the rate of decline of gray matter volume, we analyzed the relationships between personality traits and the annual rate of changes of gray matter volume in 274 healthy community dwelling subjects with a large age range by applying a longitudinal design over 6 years, using brain magnetic resonance images (MRI) and the Revised NEO Personality Inventory (NEO-PI-R) at baseline. Brain MRI data were processed using voxel-based morphometry with a custom template by applying the DARTEL diffeomorphic registration tool. For each subject, we used NEO-PI-R to evaluate the five major personality traits, including neuroticism, extraversion, openness, agreeableness, and conscientiousness. The results show that the annual rate of change in regional gray matter volume in the right inferior parietal lobule was correlated significantly and negatively with a personality of openness, which is known to be related to intellect, intellectual curiosity, and creativity adjusting for age, gender, and intracranial volume. This result indicates that subjects with a personality trait of less openness have an accelerated loss of gray matter volume in the right inferior parietal lobule, compared with subjects with a personality trait of more openness. Because the right inferior parietal lobule is involved in higher cognitive function such as working memory and creativity, a personality trait of openness is thought to be important for preserving gray matter volume and cognitive function of the right inferior parietal lobule in healthy adults.

  1. Does mode mixing matter in EMD-based highlight volume methods for hydrocarbon detection? Experimental evidence

    Science.gov (United States)

    Xue, Ya-juan; Cao, Jun-xing; Du, Hao-kun; Zhang, Gu-lan; Yao, Yao

    2016-09-01

    Empirical mode decomposition (EMD)-based spectral decomposition methods have been successfully used for hydrocarbon detection. However, mode mixing that occurs during the sifting process of EMD causes the 'true' intrinsic mode function (IMF) to be extracted incorrectly and blurs the physical meaning of the IMF. We address the issue of how the mode mixing influences the EMD-based methods for hydrocarbon detection by introducing mode-mixing elimination methods, specifically ensemble EMD (EEMD) and complete ensemble EMD (CEEMD)-based highlight volumes, as feasible tools that can identify the peak amplitude above average volume and the peak frequency volume. Three schemes, that is, using all IMFs, selected IMFs or weighted IMFs, are employed in the EMD-, EEMD- and CEEMD-based highlight volume methods. When these methods were applied to seismic data from a tight sandstone gas field in Central Sichuan, China, the results demonstrated that the amplitude anomaly in the peak amplitude above average volume captured by EMD, EEMD and CEEMD combined with Hilbert transforms, whether using all IMFs, selected IMFs or weighted IMFs, are almost identical to each other. However, clear distinctions can be found in the peak frequency volume when comparing results generated using all IMFs, selected IMFs, or weighted IMFs. If all IMFs are used, the influence of mode mixing on the peak frequency volume is not readily discernable. However, using selected IMFs or a weighted IMFs' scheme affects the peak frequency in relation to the reservoir thickness in the EMD-based method. Significant improvement in the peak frequency volume can be achieved in EEMD-based highlight volumes using selected IMFs. However, if the weighted IMFs' scheme is adopted (i.e., if the undesired IMFs are included with reduced weights rather than excluded from the analysis entirely), the CEEMD-based peak frequency volume provides a more accurate reservoir thickness estimate compared with the other two methods. This

  2. Age of second language acquisition in multilinguals has an impact on grey matter volume in language-associated brain areas

    Directory of Open Access Journals (Sweden)

    Anelis eKaiser

    2015-06-01

    Full Text Available Numerous structural studies have established that experience shapes and reshapes the brain throughout a lifetime. The impact of early development, however, is still a matter of debate. Further clues may come from studying multilinguals who acquired their second language at different ages. We investigated adult multilinguals who spoke three languages fluently, where the third language was learned in classroom settings, not before the age of 9 years. Multilinguals exposed to 2 languages simultaneously from birth (SiM were contrasted with multinguals who acquired their first two languages successively (SuM. Whole brain voxel based morphometry revealed that, relative to SuM, SiM have significantly lower grey matter volume in several language-associated cortical areas in both hemispheres: bilaterally in medial and inferior frontal gyrus, in the right medial temporal gyrus and inferior posterior parietal gyrus, as well as in the left inferior frontal gyrus. Thus, as shown by others, successive language learning increases the volume of language-associated cortical areas. In brains exposed early on and simultaneously to more than one language, however, learning of additional languages seems to have less impact. We conclude that - at least with respect to language acquisition - early developmental influences are maintained and influence experience-dependent plasticity well into adulthood.

  3. Association between regional white and gray matter volume and ambiguity tolerance: Evidence from voxel-based morphometry.

    Science.gov (United States)

    Tong, Dandan; Yang, Wenjing; Zhang, Qinglin; Li, Wenfu; Wei, Dongtao; Che, Xianwei; Zhang, Meng; Hitchman, Glenn; Qiu, Jiang; Liu, Yijun; Cao, Guikang

    2015-08-01

    The concept of tolerance of ambiguity (AT) is defined as the way in which an individual tends to perceive and deal with confusing, vague, and unclear situations. AT is generally considered as an important personality trait, but the neural mechanisms underlying individual differences in AT have never been investigated. Using voxel-based morphometry and MSTAT-II scale, we investigated the correlations between AT and regional white matter volume (rWMV) and regional gray matter volume (rGMV) in 351 young healthy subjects. We found AT to be positively correlated with rGMV in the dorsolateral prefrontal cortex (DLPFC), and negatively correlated with rGMV in the precuneus. These results indicate that increased rGMV in the left DLPFC may lead to characteristics of ambiguous stimuli consideration from multiple contexts and risk taking. Decreased rGMV in the left precuneus may be associated with a high tolerance for ambiguity, which attributes uncertainty to self-related factors.

  4. Age of second language acquisition in multilinguals has an impact on gray matter volume in language-associated brain areas.

    Science.gov (United States)

    Kaiser, Anelis; Eppenberger, Leila S; Smieskova, Renata; Borgwardt, Stefan; Kuenzli, Esther; Radue, Ernst-Wilhelm; Nitsch, Cordula; Bendfeldt, Kerstin

    2015-01-01

    Numerous structural studies have established that experience shapes and reshapes the brain throughout a lifetime. The impact of early development, however, is still a matter of debate. Further clues may come from studying multilinguals who acquired their second language at different ages. We investigated adult multilinguals who spoke three languages fluently, where the third language was learned in classroom settings, not before the age of 9 years. Multilinguals exposed to two languages simultaneously from birth (SiM) were contrasted with multinguals who acquired their first two languages successively (SuM). Whole brain voxel based morphometry revealed that, relative to SuM, SiM have significantly lower gray matter volume in several language-associated cortical areas in both hemispheres: bilaterally in medial and inferior frontal gyrus, in the right medial temporal gyrus and inferior posterior parietal gyrus, as well as in the left inferior temporal gyrus. Thus, as shown by others, successive language learning increases the volume of language-associated cortical areas. In brains exposed early on and simultaneously to more than one language, however, learning of additional languages seems to have less impact. We conclude that - at least with respect to language acquisition - early developmental influences are maintained and have an effect on experience-dependent plasticity well into adulthood.

  5. Sex differences in socioemotional functioning, attentional bias, and gray matter volume in maltreated children: A multilevel investigation.

    Science.gov (United States)

    Kelly, Philip A; Viding, Essi; Puetz, Vanessa B; Palmer, Amy L; Mechelli, Andrea; Pingault, Jean-Baptiste; Samuel, Sophie; McCrory, Eamon J

    2015-11-01

    While maltreatment is known to impact social and emotional functioning, threat processing, and neural structure, the potentially dimorphic influence of sex on these outcomes remains relatively understudied. We investigated sex differences across these domains in a large community sample of children aged 10 to 14 years (n = 122) comprising 62 children with verified maltreatment experience and 60 well-matched nonmaltreated peers. The maltreated group relative to the nonmaltreated comparison group exhibited poorer social and emotional functioning (more peer problems and heightened emotional reactivity). Cognitively, they displayed a pattern of attentional avoidance of threat in a visual dot-probe task. Similar patterns were observed in males and females in these domains. Reduced gray matter volume was found to characterize the maltreated group in the medial orbitofrontal cortex, bilateral middle temporal lobes, and bilateral supramarginal gyrus; sex differences were observed only in the supramarginal gyrus. In addition, a disordinal interaction between maltreatment exposure and sex was found in the postcentral gyrus. Finally, attentional avoidance to threat mediated the relationship between maltreatment and emotional reactivity, and medial orbitofrontal cortex gray matter volume mediated the relationship between maltreatment and peer functioning. Similar mediation patterns were observed across sexes. This study highlights the utility of combining multiple levels of analysis when studying the "latent vulnerability" engendered by childhood maltreatment and yields tentative findings regarding a neural basis of sex differences in long-term outcomes for maltreated children.

  6. Visceral sensitivity correlates with decreased regional gray matter volume in healthy volunteers: a voxel-based morphometry study.

    Science.gov (United States)

    Elsenbruch, Sigrid; Schmid, Julia; Kullmann, Jennifer S; Kattoor, Joswin; Theysohn, Nina; Forsting, Michael; Kotsis, Vassilios

    2014-02-01

    Regional changes in brain structure have been reported in patients with altered visceral sensitivity and chronic abdominal pain, such as in irritable bowel syndrome. It remains unknown whether structural brain changes are associated with visceral sensitivity. Therefore, we present the first study in healthy individuals to address whether interindividual variations in gray matter volume (GMV) in pain-relevant regions correlate with visceral sensitivity. In 92 healthy young adults (52 female), we assessed rectal sensory and pain thresholds and performed voxel-based morphometry (VBM) to compute linear regression models with visceral sensory and pain thresholds, respectively, as independent variable and GMV in a priori-defined regions of interest (ROIs) as dependent variable. All results were familywise error (FWE) corrected at a level of PFWEpain, without evidence of sex differences. Lower rectal sensory threshold (ie, increased sensitivity) correlated significantly with reduced GMV in the thalamus, insula, posterior cingulate cortex, ventrolateral and orbitofrontal prefrontal cortices, amygdala, and basal ganglia (all PFWEpain threshold was associated with reduced GMV in the right thalamus (PFWE=.051). These are the first data supporting that increased visceral sensitivity correlates with decreased gray matter volume in pain-relevant brain regions. These findings support that alterations in brain morphology not only occur in clinical pain conditions but also occur according to normal interindividual variations in visceral sensitivity. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  7. Differences in prefrontal, limbic, and white matter lesion volumes according to cognitive status in elderly patients with first-onset subsyndromal depression.

    Directory of Open Access Journals (Sweden)

    Jun-Young Lee

    Full Text Available The purpose of this preliminary study was to test the hypothesis that subsyndromal depression is associated with the volume of medial prefrontal regional gray matter and that of white matter lesions (WMLs in the brains of cognitively normal older people. We also explored the relationships between subsyndromal depression and medial prefrontal regional gray matter volume, limbic regional gray matter volume, and lobar WMLs in the brains of patients with mild cognitive impairment (MCI and Alzheimer's disease (AD. We performed a cross-sectional study comparing patients with subsyndromal depression and nondepressed controls with normal cognition (n = 59, MCI (n = 27, and AD (n = 27, adjusting for sex, age, years of education, and results of the Mini-Mental State Examination. Frontal WML volume was greater, and right medial orbitofrontal cortical volume was smaller in cognitively normal participants with subsyndromal depression than in those without subsyndromal depression. No volume differences were observed in medial prefrontal, limbic, or WML volumes according to the presence of subsyndromal depression in cognitively impaired patients. The absence of these changes in patients with MCI and AD suggests that brain changes associated with AD pathology may override the changes associated with subsyndromal depression.

  8. Condensation Polymerization

    Indian Academy of Sciences (India)

    S Ramakrishnan

    2017-04-01

    The very idea that large polymer molecules can indeed existwas hotly debated during the early part of the 20th century.As highlighted by Sivaram in his articles on Carothersand Flory, Staudinger’s macromolecular hypothesis was finallyaccepted, and the study of polymers gained momentumbecause of the remarkable efforts of the these two individualswho laid down the foundations concerning the processes thatled to the formation of large polymer molecules, and to thosethat led to an understanding of many of their extraordinaryphysical properties. Condensation polymerizations, as thename suggests, utilizes bond-forming reactions that generatea small molecule condensate, which often needs to be continuouslyremoved to facilitate the formation of the polymer. Inthis article, I shall describe some of the essential principles ofcondensation polymerizations or more appropriately calledstep-growth polymerizations; and I will also describe someinteresting extensions that lead to the formation of polymernetworks and highly branched polymers.

  9. Joint Coupling of Awake EEG Frequency Activity and MRI Gray Matter Volumes in the Psychosis Dimension: A BSNIP Study.

    Science.gov (United States)

    Soh, Pauline; Narayanan, Balaji; Khadka, Sabin; Calhoun, Vince D; Keshavan, Matcheri S; Tamminga, Carol A; Sweeney, John A; Clementz, Brett A; Pearlson, Godfrey D

    2015-01-01

    Many studies have examined either electroencephalogram (EEG) frequency activity or gray matter volumes (GMV) in various psychoses [including schizophrenia (SZ), schizoaffective (SZA), and psychotic bipolar disorder (PBP)]. Prior work demonstrated similar EEG and gray matter abnormalities in both SZ and PBP. Integrating EEG and GMV and jointly analyzing the combined data fully elucidates the linkage between the two and may provide better biomarker- or endophenotype-specificity for a particular illness. Joint exploratory investigations of EEG and GMV are scarce in the literature and the relationship between the two in psychosis is even less explored. We investigated a joint multivariate model to test whether the linear relationship or linkage between awake EEG (AEEG) frequency activity and GMV is abnormal across the psychosis dimension and if such effects are also present in first-degree relatives. We assessed 607 subjects comprising 264 probands [105 SZ, 72 SZA, and 87 PBP], 233 of their first degree relatives [82 SZ relatives (SZR), 71 SZA relatives (SZAR), and 80 PBP relatives (PBPR)], and 110 healthy comparison subjects (HC). All subjects underwent structural MRI (sMRI) and EEG scans. Frequency activity and voxel-based morphometric GMV were derived from EEG and sMRI data, respectively. Seven AEEG frequency and gray matter components were extracted using Joint independent component analysis (jICA). The loading coefficients (LC) were examined for group differences using analysis of covariance. Further, the LCs were correlated with psychopathology scores to identify relationship with clinical symptoms. Joint ICA revealed a single component differentiating SZ from HC (p < 0.006), comprising increased posterior alpha activity associated with decreased volume in inferior parietal lobe, supramarginal, parahippocampal gyrus, middle frontal, inferior temporal gyri, and increased volume of uncus and culmen. No components were aberrant in either PBP or SZA or any

  10. Joint Coupling of Awake EEG Frequency Activity and MRI Gray Matter Volumes in the Psychosis Dimension; A BSNIP Study

    Directory of Open Access Journals (Sweden)

    Pauline eSoh

    2015-11-01

    Full Text Available Many studies have examined either electroencephalogram (EEG frequency activity or gray matter volumes (GMV in various psychoses (including schizophrenia, schizoaffective and psychotic bipolar disorder. Prior work demonstrated similar EEG and gray matter abnormalities in both schizophrenia and psychotic bipolar disorder. Integrating EEG and GMV and jointly analyzing the combined data fully elucidates the linkage between the two and may provide better biomarker- or endophenotype-specificity for a particular illness. Joint exploratory investigations of EEG and GMV are scarce in the literature and the relationship between the two in psychosis is even less explored. We investigated a joint multivariate model to test whether the linear relationship or linkage between awake EEG (AEEG frequency activity and GMV is abnormal across the psychosis dimension and if such effects are also present in first-degree relatives.We assessed 607 subjects comprising 264 probands (105 schizophrenia (SZ, 72 schizoaffective (SZA and 87 psychotic bipolar disorder (PBP, 233 of their first degree relatives (82 SZ relatives (SZR, 71 SZA relatives (SZAR and 80 PBP relatives (PBPR and 110 healthy comparison subjects (HC. All subjects underwent structural MRI (sMRI and EEG scans. Frequency activity and voxel based morphometric GMV were derived from EEG and sMRI data respectively. Seven AEEG frequency and gray matter components were extracted using Joint independent component analysis (jICA. The loading coefficients (LC were examined for group differences using analysis of covariance. Further, the LCs were correlated with psychopathology scores to identify relationship with clinical symptoms. Joint ICA revealed a single component differentiating SZ from HC (p<0.006, comprising increased posterior alpha activity associated with decreased volume in inferior parietal lobe, supra-marginal, parahippocampal gyrus, middle frontal, inferior temporal gyri and increased volume of uncus and

  11. Relationship between white matter hyperintensities volume and the circle of Willis configurations in patients with carotid artery pathology.

    Science.gov (United States)

    Saba, Luca; Sanfilippo, Roberto; Porcu, Michele; Lucatelli, Pierleone; Montisci, Roberto; Zaccagna, Fulvio; Suri, Jasjit; Anzidei, Michele; Wintermark, Max

    2017-04-01

    We aimed to assess if there is a difference of distribution and volume of white matter hyperintensities (WMH) in the brain according to the Circle of Willis (CoW) configuration in patients with carotid artery pathology. One-hundred consecutive patients (79 males, 21 females; mean age 70 years; age range 46-84 years) that underwent brain MRI before carotid endarterectomy (CEA) were included. FLAIR-WMH lesion volume was performed using a semi-automated segmentation technique and the status of the circle of Willis was assessed by two neuroradiologists in consensus. We found a prevalence of 55% of variants in the CoW configuration; 22 cases had one variants (40%); 25 cases had two variants (45.45%) and 8 cases showed 3 variants (14.55%). The configuration that was associated with the biggest WMH volume and number of lesions was the A1+PcoA+PcoA. The PcoA variants were the most prevalent and there was no statistically significant difference in number of lesions and WMH for each vascular territory assessed and the same results were found for AcoA and A1 variants. Results of our study suggest that the more common CoW variants are not associated with the presence of an increased WMH or number of lesions whereas uncommon configurations, in particular when 2 or more segment are missing increase the WMH volume and number of lesions. The WHM volume of the MCA territory seems to be more affected by the CoW configuration. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Linear and curvilinear correlations of brain gray matter volume and density with age using voxel-based morphometry with the Akaike information criterion in 291 healthy children.

    Science.gov (United States)

    Taki, Yasuyuki; Hashizume, Hiroshi; Thyreau, Benjamin; Sassa, Yuko; Takeuchi, Hikaru; Wu, Kai; Kotozaki, Yuka; Nouchi, Rui; Asano, Michiko; Asano, Kohei; Fukuda, Hiroshi; Kawashima, Ryuta

    2013-08-01

    We examined linear and curvilinear correlations of gray matter volume and density in cortical and subcortical gray matter with age using magnetic resonance images (MRI) in a large number of healthy children. We applied voxel-based morphometry (VBM) and region-of-interest (ROI) analyses with the Akaike information criterion (AIC), which was used to determine the best-fit model by selecting which predictor terms should be included. We collected data on brain structural MRI in 291 healthy children aged 5-18 years. Structural MRI data were segmented and normalized using a custom template by applying the diffeomorphic anatomical registration using exponentiated lie algebra (DARTEL) procedure. Next, we analyzed the correlations of gray matter volume and density with age in VBM with AIC by estimating linear, quadratic, and cubic polynomial functions. Several regions such as the prefrontal cortex, the precentral gyrus, and cerebellum showed significant linear or curvilinear correlations between gray matter volume and age on an increasing trajectory, and between gray matter density and age on a decreasing trajectory in VBM and ROI analyses with AIC. Because the trajectory of gray matter volume and density with age suggests the progress of brain maturation, our results may contribute to clarifying brain maturation in healthy children from the viewpoint of brain structure.

  13. Late-life obesity is associated with smaller global and regional gray matter volumes: a voxel-based morphometric study.

    Science.gov (United States)

    Brooks, S J; Benedict, C; Burgos, J; Kempton, M J; Kullberg, J; Nordenskjöld, R; Kilander, L; Nylander, R; Larsson, E-M; Johansson, L; Ahlström, H; Lind, L; Schiöth, H B

    2013-02-01

    Obesity adversely affects frontal lobe brain structure and function. Here we sought to show that people who are obese versus those who are of normal weight over a 5-year period have differential global and regional brain volumes. Using voxel-based morphometry, contrasts were done between those who were recorded as being either obese or of normal weight over two time points in the 5 years prior to the brain scan. In a post-hoc preliminary analysis, we compared scores for obese and normal weight people who completed the trail-making task. A total of 292 subjects were examined following exclusions (for example, owing to dementia, stroke and cortical infarcts) from the Prospective Investigation of the Vasculature in Uppsala Seniors cohort with a body mass index of normal weight (obese (30 kg m(-2)). People who were obese had significantly smaller total brain volumes and specifically, significantly reduced total gray matter (GM) volume (GMV) (with no difference in white matter or cerebrospinal fluid). Initial exploratory whole brain uncorrected analysis revealed that people who were obese had significantly smaller GMV in the bilateral supplementary motor area, bilateral dorsolateral prefrontal cortex (DLPFC), left inferior frontal gyrus and left postcentral gyrus. Secondary more stringent corrected analyses revealed a surviving cluster of GMV difference in the left DLPFC. Finally, post-hoc contrasts of scores on the trail-making task, which is linked to DLPFC function, revealed that obese people were significantly slower than those of normal weight. These findings suggest that in comparison with normal weight, people who are obese have smaller GMV, particularly in the left DLPFC. Our results may provide evidence for a potential working memory mechanism for the cognitive suppression of appetite that may lower the risk of developing obesity in later life.

  14. Impact of 5-Hz rTMS over the primary sensory cortex is related to white matter volume in individuals with chronic stroke.

    Science.gov (United States)

    Brodie, Sonia M; Borich, Michael R; Boyd, Lara A

    2014-11-01

    Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that may facilitate mechanisms of motor learning. In a recent single-blind, pseudo-randomized study, we showed that 5-Hz rTMS over ipsilesional primary somatosensory cortex followed by practice of a skilled motor task enhanced motor learning compared with sham rTMS + practice in individuals with chronic stroke. However, the beneficial effect of stimulation was inconsistent. The current study examined how differences in sensorimotor cortex morphology might predict rTMS-related improvements in motor learning in these individuals. High-resolution T1-weighted magnetic resonance images were acquired and processed in FreeSurfer using a newly developed automated, whole brain parcellation technique. Gray matter and white matter volumes of the ipsilesional primary somatosensory and motor cortices were extracted. A significant positive association was observed between the volume of white matter in the primary somatosensory cortex and motor learning-related change, exclusively in the group that received active 5-Hz rTMS. A regression model with age, gray matter and white matter volumes as predictors was significant for predicting motor learning-related change in individuals who received active TMS. White matter volume predicted the greatest amount of variance (47.6%). The same model was non-significant when volumes of the primary motor cortex were considered. We conclude that white matter volume in the cortex underlying the TMS coil may be a novel predictor for behavioral response to 5-Hz rTMS over the ipsilesional primary somatosensory followed by motor practice.

  15. Thermophysical Properties of Matter - The TPRC Data Series. Volume 1. Thermal Conductivity - Metallic Elements and Alloys

    Science.gov (United States)

    1970-01-01

    graduate level may also use it as a teaching tool to 401011111111111 Contents Foreword Vii Preface ix. Introduction to Volume I xiii Grouping of...34’The Calory and the g. Pages Joule in Thermodynamics and Thermochemistry ," Am. J. h. Year Phys., 12 (1), 1-7, 1944. •l -"e i 44a Numerical Data . - 4

  16. Optimism and the brain: trait optimism mediates the protective role of the orbitofrontal cortex gray matter volume against anxiety.

    Science.gov (United States)

    Dolcos, Sanda; Hu, Yifan; Iordan, Alexandru D; Moore, Matthew; Dolcos, Florin

    2016-02-01

    Converging evidence identifies trait optimism and the orbitofrontal cortex (OFC) as personality and brain factors influencing anxiety, but the nature of their relationships remains unclear. Here, the mechanisms underlying the protective role of trait optimism and of increased OFC volume against symptoms of anxiety were investigated in 61 healthy subjects, who completed measures of trait optimism and anxiety, and underwent structural scanning using magnetic resonance imaging. First, the OFC gray matter volume (GMV) was associated with increased optimism, which in turn was associated with reduced anxiety. Second, trait optimism mediated the relation between the left OFC volume and anxiety, thus demonstrating that increased GMV in this brain region protects against symptoms of anxiety through increased optimism. These results provide novel evidence about the brain-personality mechanisms protecting against anxiety symptoms in healthy functioning, and identify potential targets for preventive and therapeutic interventions aimed at reducing susceptibility and increasing resilience against emotional disturbances. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  17. Supersize my brain: A cross-sectional voxel-based morphometry study on the association between self-reported dietary restraint and regional grey matter volumes.

    Science.gov (United States)

    van der Laan, Laura N; Charbonnier, Lisette; Griffioen-Roose, Sanne; Kroese, Floor M; van Rijn, Inge; Smeets, Paul A M

    2016-05-01

    Restrained eaters do not eat less than their unrestrained counterparts. Proposed underlying mechanisms are that restrained eaters are more reward sensitive and that they have worse inhibitory control. Although fMRI studies assessed these mechanisms, it is unknown how brain anatomy relates to dietary restraint. Voxel-based morphometry was performed on anatomical scans from 155 normal-weight females to investigate how regional grey matter volume correlates with restraint. A positive correlation was found in several areas, including the parahippocampal gyrus, hippocampus, striatum and the amygdala (bilaterally, pgrey matter volume in reward-related areas and lower grey matter volume in regions involved in inhibition, provides a neuroanatomical underpinning of theories relating restraint to increased reward sensitivity and reduced inhibitory capacity.

  18. Alpha particle clusters and their condensation in nuclear systems

    Science.gov (United States)

    Schuck, Peter; Funaki, Yasuro; Horiuchi, Hisashi; Röpke, Gerd; Tohsaki, Akihiro; Yamada, Taiichi

    2016-12-01

    In this article we review the present status of α clustering in nuclear systems. First of all, an important aspect is condensation in nuclear matter. Like for pairing, quartetting in matter is at the root of similar phenomena in finite nuclei. Cluster approaches for finite nuclei are shortly recapitulated in historical order. The α container model, recently been proposed by Tohsaki-Horiuchi-Schuck-Röpke (THSR), will be outlined and the ensuing condensate aspect of the Hoyle state at 7.65 MeV in 12C is investigated in some detail. A special case will be made with respect to the very accurate reproduction of the inelastic form factor from the ground to Hoyle state with the THSR description. The extended volume will be deduced. New developments concerning excitations of the Hoyle state will be discussed. After 15 years since the proposal of the α condensation concept a critical assessment of this idea will be given. Alpha gas states in other nuclei like 16O and 13C will be considered. An important aspect is the experimental evidence, both present and future ones. The THSR wave function can also describe configurations of one α particle on top of a doubly magic core. The cases of 20Ne and 212Po will be investigated.

  19. Extrastriatal dopamine D2/3 receptors and cortical grey matter volumes in antipsychotic-naïve schizophrenia patients before and after initial antipsychotic treatment

    DEFF Research Database (Denmark)

    Nørbak-Emig, Henrik; Pinborg, Lars H; Raghava, Jayachandra M

    2017-01-01

    blockade at follow-up, was related to regional cortical volume changes. In post-hoc analyses excluding three patients with cannabis use we found that higher D2/3 receptor occupancy was significantly associated with an increase in right frontal grey matter volume. CONCLUSIONS: The present data do...... not support an association between extrastriatal D2/3 receptor blockade and extrastriatal grey matter loss in the early phases of schizophrenia. Although inconclusive, our exclusion of patients tested positive for cannabis use speaks to keeping attention to potential confounding factors in imaging studies....

  20. Paul Scherrer Institute Scientific Report 1998. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Baltensperger, U.; Herlach, D.; Kettle, P.-R.; Lorenzen, R. [eds.

    1999-09-01

    The new department Particles and Matter, created 1 October 1998 aims to strengthen the two pillars of PSI, research at large facilities and research with interdisciplinary teams. Particle Physics and Astrophysics at PSI have an established tradition in the field of particle and Xray detectors and both co-operate with the Laboratory for Micro and Nano Technology. The research of the latter is focussed on Si/SiGe and Si/SiC nano structures, with the aim of both understanding their nano technology properties and eventually producing light from silicon, and on interdisciplinary molecular nano technology. The Laboratory for Radio and Environmental Chemistry concentrates on the chemical analysis of super heavy elements and their homologues produced with ion beams at the proton accelerator and at the spallation neutron source (SINQ), and on the investigation of agglomerates formed from nanoparticles (aerosols) in the atmosphere for environmental and climate research. (author) figs., tabs., refs.

  1. Thermophysical Properties of Matter - the TPRC Data Series. Volume 5. Specific Heat - Nonmetallic Solids

    Science.gov (United States)

    1970-01-01

    of the volume consists of the ate level may also use it as a teaching tool to point presentation of numerical data compiled over the out to his...46, Chemistry, Chap. X, Interscience, New York, 1959. 1966. 61. Skinner, H. A. (Editor), Experinental Thermochemistry , 47. Wallace, W. E., Craig, R. S...tMuel!er, E. F. and Rossini, F. D., "The Calory and the Joule in Thermodynamics and Thermochemistry ," Am. J. etc. Phys. 12(1), 1-7, 19,14. e. Number

  2. Cerebellar gray matter and lobular volumes correlate with core autism symptoms

    Directory of Open Access Journals (Sweden)

    Anila M. D'Mello

    2015-01-01

    Full Text Available Neuroanatomical differences in the cerebellum are among the most consistent findings in autism spectrum disorder (ASD, but little is known about the relationship between cerebellar dysfunction and core ASD symptoms. The newly-emerging existence of cerebellar sensorimotor and cognitive subregions provides a new framework for interpreting the functional significance of cerebellar findings in ASD. Here we use two complementary analyses — whole-brain voxel-based morphometry (VBM and the SUIT cerebellar atlas — to investigate cerebellar regional gray matter (GM and volumetric lobular measurements in 35 children with ASD and 35 typically-developing (TD children (mean age 10.4 ± 1.6 years; range 8–13 years. To examine the relationships between cerebellar structure and core ASD symptoms, correlations were calculated between scores on the Autism Diagnostic Observation Schedule (ADOS and Autism Diagnostic Interview (ADI and the VBM and volumetric data. Both VBM and the SUIT analyses revealed reduced GM in ASD children in cerebellar lobule VII (Crus I/II. The degree of regional and lobular gray matter reductions in different cerebellar subregions correlated with the severity of symptoms in social interaction, communication, and repetitive behaviors. Structural differences and behavioral correlations converged on right cerebellar Crus I/II, a region which shows structural and functional connectivity with fronto-parietal and default mode networks. These results emphasize the importance of the location within the cerebellum to the potential functional impact of structural differences in ASD, and suggest that GM differences in cerebellar right Crus I/II are associated with the core ASD profile.

  3. International journal of quantum chemistry. Quantum Chemistry Symposium Number 27: Proceedings of the International Symposium on Atomic, Molecular, and Condensed Matter Theory and Computational Methods

    Science.gov (United States)

    Lowdin, Per-Olov; Ohrn, N. Y.; Sabin, John R.; Zerner, Michael C.

    1993-03-01

    The topics covered at the 33rd annual Sanibel Symposium, organized by the faculty and staff of the Quantum Theory Project of the University of Florida, and held March 13 - 20, 1993, include advanced scientific computing, interaction of photons and matter, quantum molecular dynamics, electronic structure methods, polymeric systems, and quantum chemical methods for extended systems.

  4. Regional white matter volume and the relation with attentional functioning in survivors of malignant pediatric brain tumors

    Science.gov (United States)

    Glass, John O.; Mulhern, Raymond K.; White, Holly A.; Wilkinson, Gina M.; Reddick, Wilburn E.

    2003-05-01

    Quantitative assessment of MR examinations in 37 survivors of childhood cancer treated with central nervous system prophylaxis revealed that normal appearing white matter (NAWM) volume is associated with attention-related problems, localized specifically in the right prefrontal region. T1-, T2-, and PD-weighted images were segmented and divided into pre-frontal, frontal, parietal/temporal, and parietal/occipital regions for each hemisphere. These eight regions were analyzed in five slices centered at the level of the basal ganglia. The patient's age at diagnosis and time elapsed from diagnosis were used as covariates in the regressions. Attentional measures showed significant deficiency when compared to age and gender normative values. Total, frontal and/or prefrontal NAWM volumes from the range of slices examined were significantly associated with 5 of the 8 attentional measures. The frontal/prefrontal region of the brain is associated with executive functioning tasks and could potentially be spared as much as possible during therapy planning. The results of the present study further support the contention that NAWM is an important substrate for treatment-induced neurocognitive problems among survivors of malignant brain tumors of childhood.

  5. Effects of parental emotional warmth on the relationship between regional gray matter volume and depression-related personality traits.

    Science.gov (United States)

    Yang, Junyi; Yin, Ping; Wei, Dongtao; Wang, Kangcheng; Li, Yongmei; Qiu, Jiang

    2017-06-01

    The depression-related personality trait is associated with the severity of patients' current depressive symptoms and with the vulnerability to depression within the nonclinical groups. However, little is known about the anatomical structure associated with the depression-related personality traits within the nonclinical sample. Parenting behavior is associated with the depression symptoms; however, whether or not parenting behavior influence the neural basis of the depression-related personality traits is unclear. Thus in current study, first, we used voxel-based morphometry to identify the brain regions underlying individual differences in depression-related personality traits, as measured by the revised Neuroticism-Extraversion-Openness Personality Inventory, in a large sample of young healthy adults. Second, we use mediation analysis to investigate the relationship between parenting behavior and neural basis of depression-related personality traits. The results revealed that depression-related personality traits were positively correlated with gray matter volume mainly in medial frontal gyrus (MFG) that is implicated in the self-referential processing and emotional regulation. Furthermore, parental emotional warmth acted as a mediational mechanism underlying the association between the MFG volume and the depression-related personality trait. Together, our findings suggested that the family environment might play an important role in the acquisition and process of the depression-related personality traits.

  6. Higher Adolescent Body Mass Index is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality

    Directory of Open Access Journals (Sweden)

    James T Kennedy

    2016-09-01

    Full Text Available Adolescent obesity is associated with an increased chance of developing serious health risks later in life. Identifying the neurobiological and personality factors related to increases in adiposity is important to understanding what drives maladaptive consummatory and exercise behaviors that result in obesity. Previous research has largely focused on adults with few findings published on interactions among adiposity, brain structure, and personality. In this study, Voxel Based Morphometry (VBM was used to identify associations between gray and white matter volumes and increasing adiposity, as measured by Body Mass Index percentile (BMI%, in 137 adolescents (age range: 9-20 years, Body Mass Index percentile range: 5.16-99.56. Variations in gray and white matter volume and BMI% were then linked to individual differences in personality measures from the Multidimensional Personality Questionnaire (MPQ. After controlling for age and other covariates, BMI% correlated negatively with gray matter volume in the bilateral caudate (right: partial r = -0.338, left: r -0.404, medial prefrontal cortex (partial r = -0.339, anterior cingulate (partial r = -0.312, bilateral frontal pole (right: partial r = -0.368, left: r= -0.316, and uncus (partial r = -0.475 as well as white matter volume bilaterally in the anterior limb of the internal capsule (right: partial r = -0.34, left: r = -0.386, extending to the left middle frontal subgyral white matter. Agentic Positive Emotionality (PEM-AG was correlated negatively with BMI% (partial r = -0.384. PEM-AG was correlated positively with gray matter volume in the right uncus (partial r = 0.329. These results suggest that higher levels of adiposity in adolescents are associated with lower trait levels in reward-related personality domains, as well as structural variations in brain regions associated with reward processing, control, and sensory integration.

  7. Higher Adolescent Body Mass Index Is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality.

    Science.gov (United States)

    Kennedy, James T; Collins, Paul F; Luciana, Monica

    2016-01-01

    Adolescent obesity is associated with an increased chance of developing serious health risks later in life. Identifying the neurobiological and personality factors related to increases in adiposity is important to understanding what drives maladaptive consummatory and exercise behaviors that result in obesity. Previous research has largely focused on adults with few findings published on interactions among adiposity, brain structure, and personality. In this study, Voxel Based Morphometry (VBM) was used to identify associations between gray and white matter volumes and increasing adiposity, as measured by Body Mass Index percentile (BMI%), in 137 adolescents (age range: 9-20 years, BMI% range: 5.16-99.56). Variations in gray and white matter volume and BMI% were then linked to individual differences in personality measures from the Multidimensional Personality Questionnaire (MPQ). After controlling for age and other covariates, BMI% correlated negatively with gray matter volume in the bilateral caudate (right: partial r = -0.338, left: r = -0.404), medial prefrontal cortex (partial r = -0.339), anterior cingulate (partial r = -0.312), bilateral frontal pole (right: partial r = -0.368, left: r = -0.316), and uncus (partial r = -0.475) as well as white matter volume bilaterally in the anterior limb of the internal capsule (right: partial r = -0.34, left: r = -0.386), extending to the left middle frontal subgyral white matter. Agentic Positive Emotionality (PEM-AG) was correlated negatively with BMI% (partial r = -0.384). PEM-AG was correlated positively with gray matter volume in the right uncus (partial r = 0.329). These results suggest that higher levels of adiposity in adolescents are associated with lower trait levels in reward-related personality domains, as well as structural variations in brain regions associated with reward processing, control, and sensory integration.

  8. Imaging of olfactory bulb and gray matter volumes in brain areas associated with olfactory function in patients with Parkinson's disease and multiple system atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shun, E-mail: shchen_2013@163.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Tan, Hong-yu, E-mail: honhyutan@21cn.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Wu, Zhuo-hua, E-mail: zhh88@126.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China); Sun, Chong-peng, E-mail: Suncp2002@gmail.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); He, Jian-xun, E-mail: xundog@163.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); Li, Xin-chun, E-mail: xinchunli@163.com [Imaging Center, The First Affiliated Hospital of Guangzhou Medical College (China); Shao, Ming, E-mail: yimshao@126.com [Department of Neurology, The First Affiliated Hospital of Guangzhou Medical College (China)

    2014-03-15

    We explored if magnetic resonance imaging sequences might aid in the clinical differential diagnosis of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA). We measured the volumes of the olfactory bulb, the olfactory tract, and olfaction-associated cortical gray matter in 20 IPD patients, 14 MSA patients, and 12 normal subjects, using high-resolution magnetic resonance imaging sequences in combination with voxel-based statistical analysis. We found that, compared to normal subjects and MSA patients, the volumes of the olfactory bulb and tract were significantly reduced in IPD patients. The gray matter volume of IPD patients decreased in the following order: the olfactory area to the right of the piriform cortex, the right amygdala, the left entorhinal cortex, and the left occipital lobe. Further, the total olfactory bulb volume of IPD patients was associated with the duration of disease. The entorhinal cortical gray matter volume was negatively associated with the UPDRS III score. Conclusion: Structural volumes measured by high-resolution magnetic resonance imaging may potentially be used for differential diagnosis of IPD from MSA.

  9. Influence of condensation temperature on selected exhaled breath parameters

    Directory of Open Access Journals (Sweden)

    Manini Paola

    2005-09-01

    Full Text Available Abstract Background The effects of changes in cooling temperature on biomarker levels in exhaled breath condensate have been little investigated. The aim of the study was to test the effect of condensation temperature on the parameters of exhaled breath condensate and the levels of selected biomarkers. Methods Exhaled breath condensate was collected from 24 healthy subjects at temperatures of -10, -5, 0 and +5 C degrees. Selected parameters (condensed volume and conductivity and biomarkers (hydrogen peroxide, malondialdehyde were measured. Results There was a progressive increase in hydrogen peroxide and malondialdehyde concentrations, and condensate conductivity as the cooling temperature increased; total condensate volume increased as the cooling temperature decreased. Conclusion The cooling temperature of exhaled breath condensate collection influenced selected biomarkers and potential normalizing factors (particularly conductivity in different ways ex vivo. The temperature of exhaled breath condensate collection should be controlled and reported.

  10. Asymmetry of cerebral grey and white matter and structural volumes in relation to sex hormones and chromosomes

    Directory of Open Access Journals (Sweden)

    Ivanka eSavic

    2014-11-01

    Full Text Available Whilst many studies show sex differences in cerebral asymmetry, their mechanisms are still unknown. This report describes the potential impact of sex hormones and sex chromosomes by comparing MR data from 39 male and 47 female controls and 33 men with an extra X-chromosome (47,XXY Methods: Regional asymmetry in grey and white matter volumes (GMV and WMV was calculated using voxel based moprhometry (SPM5, by contrasting the unflipped and flipped individual GMV and WMV images. In addition, structural volumes were calculated for the thalamus, caudate, putamen, amygdala, and hippocampus, using the FreeSurfer software. Effects of plasma testosterone and estrogen on the GMV and WMV, as well on the right/left ratios of the subcortical volumes were tested by multi-regression analysis.Results: All three groups showed a leftward asymmetry in the motor cortex and the planum temporale, and a rightward asymmetry of the middle occipital cortex. Both asymmetries were more pronounced in 46,XY males than 46,XX females and 47,XXY males, and were positively correlated with testosterone levels. There was also a rightward asymmetry of the vermis and leftward asymmetry in the cerebellar hemispheres in all groups. Notably, cerebellar asymmetries were larger in 46,XX females and 47,XXY males, but were not related to sex hormone levels. No asymmetry differences between 46,XX females and 47,XXY males, and no overall effects of brain size were detected.Conclusion: The asymmetry in the planum temporale area and the occipital cortex seem related to processes associated with testosterone, whereas the observed cerebellar asymmetries suggest a link with X-chromosome escapee genes. Sex differences in cerebral asymmetry are moderated by sex hormones and X-chromosome genes, in a regionally differentiated manner.

  11. Diffuse Matter from Star Forming Regions to Active Galaxies A Volume Honouring John Dyson

    CERN Document Server

    Hartquist, T W

    2006-01-01

    John Dyson has contributed to the study of the hydrodynamic processes that govern a wide variety of astrophysical sources which he has helped explain. In this volume dedicated to him, introductory reviews to a number of the key processes and to the sources themselves are given by leading experts. The mechanisms in which the multi-component natures of media affect their dynamics receive particular attention, but the roles of hydromagnetic effects are also highlighted. The importance of cosmic ray moderation and mass transfer between different thermal phases for cosmic ray moderation and mass transfer between different thermal phases for the evolution of flows are amongst the topics treated. The main types of regions considered include those where stars form, the circumstellar environments of evolved stars, the larger scale interstellar structures caused by the mass loss of stars, and those where the lines of AGNs form. The reviews complement one another and together provide a coherent introduction to the astro...

  12. Neutrino emissivity under neutral kaon condensation

    CERN Document Server

    Kubis, S

    2006-01-01

    Neutrino emissivity from neutron star matter with neutral kaon condensate is considered. It is shown that a new cooling channel is opened, and what is more, all previously known channels acquire the greater emissivity reaching the level of the direct URCA cycle in normal matter.

  13. Neutrino emissivity under neutral kaon condensation

    OpenAIRE

    Kubis, Sebastian

    2005-01-01

    Neutrino emissivity from neutron star matter with neutral kaon condensate is considered. It is shown that a new cooling channel is opened, and what is more, all previously known channels acquire the greater emissivity reaching the level of the direct URCA cycle in normal matter.

  14. Bose-Einstein-condensed scalar field dark matter and the gravitational wave background from inflation: new cosmological constraints and its detectability by LIGO

    CERN Document Server

    Li, Bohua; Rindler-Daller, Tanja

    2016-01-01

    We consider an alternative dark matter candidate, ultralight bosonic dark matter ($m>10^{-22}$eV) described by a complex scalar field (SFDM) with a global U(1) symmetry, for which the associated charge density is conserved after particle production during standard reheating (w=0). We allow for a repulsive self-interaction. In a Lambda-SFDM universe, SFDM starts relativistic, evolving from stiff (w=1) to radiationlike (w=1/3), before becoming nonrelativistic at late times (w=0). Thus, before the radiation-dominated era, there is an earlier era of stiff-SFDM-domination. Transitions between these eras, determined by SFDM particle mass $m$ and the quartic self-interaction coupling strength $\\lambda$, are thus constrained by cosmological observables, particularly N_{eff}, the effective number of neutrino species during BBN, and z_{eq}, the redshift of matter-radiation equality. Furthermore, since the stochastic gravitational wave background (SGWB) from inflation is amplified during the stiff era, it can contribute...

  15. Investigation of Bose condensation in ideal Bose gas trapped under generic power law potential in $d$ dimension

    OpenAIRE

    Faruk, Mir Mehedi; Hossain, Md Sazzad; Rahman, Md. Muktadir

    2015-01-01

    The changes in characteristics of Bose condensation of ideal Bose gas due to an external generic power law potential $U=\\sum_{i=1} ^d c_i |\\frac{x_i}{a_i}|^{n_i}$ are studied carefully. Detailed calculation of Kim $et$ $al.$ (S. H. Kim, C. K. Kim and K. Nahm, J Phys. Condens. Matter 11 10269 (1999).) yielded the hierarchy of condensation transitions with changing fractional dimensionality. In this manuscript, some theorems regarding specific heat at constant volume $C_V$ are presented. Carefu...

  16. High density matter in AGS, SPS and RHIC collisions: Proceedings. Volume 9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This 1-day workshop focused on phenomenological models regarding the specific question of the maximum energy density achievable in collisions at AGS, SPS and RHIC. The idea was to have 30-minute (or less) presentations of each model--but not the model as a whole, rather then that strongly narrowed to the above physics question. The key topics addressed were: (1) to estimate the energy density in heavy-ion collisions within a model, and to discuss its physical implications; (2) to suggest experimental observables that may confirm the correctness of a model approach--with respect to the energy density estimate; (3) to compare with existing data from AGS and SPS heavy-ion collisions, and to give predictions for the future RHIC experiments. G. Ogilvie started up the workshop with a critical summary of experimental manifestations of high-density matter at the AGS, and gave a personal outlook on RHIC physics. R. Mattiello talked about his newly developed hadron cascade model for applications to AGS and SPS collisions. Next, D. Kharzeev gave a nice introduction of the Glauber approach to high-energy collisions and illustrated the predictive power of this approach in nucleus-nucleus collisions at the SPS. It followed S. Vance with a presentation of the baryon-junction model to explain the observed baryon stopping phenomenon in collisions of heavy nuclei. S. Bass continued with a broad perspective of the UrQMD model, and provided insight into the details of the microscopic dynamical features of nuclear collisions at high energy. J. Sandweiss and J. Kapusta addressed the interesting aspect of photon production in peripherical nuclear collisions due to intense electromagnetic bremstrahlung by the highly charged, fast moving ions. Finally, H. Sorge closed up the one-day workshop with a presentation of his recent work with the RQMD model. This report consists of a summary and vugraphs of the presentations.

  17. Paul Scherrer Institute Scientific Report 2000. Volume I: Particles and Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gobrecht, J.; Gaeggeler, H.; Herlach, D.; Junker, K.; Kettle, P.-R.; Kubik, P.; Zehnder, A. [eds.

    2001-07-01

    Although originally planned for fundamental research in nuclear physics, the particle beams of pions, muons, protons and neutrons are now used in a large variety of disciplines in both natural science and medicine. The beams at PSI have the world's highest intensities and therefore allow certain experiments to be performed, which would not be possible elsewhere. One of the characteristic developments in the Department for Particles and Matter at PSI in 2000 has been a stronger collaboration within the institute. Excellent examples are the collaboration of scientists and technicians from Particle Physics, Micro- and Nanotechnology and SLS to produce pixel detectors for use at SLS, the development of advanced x-ray optics for SLS and other light sources by people from Nanotechnology, an increased collaboration between Radiochemistry and Ion Beam Physics. Also collaborations beyond the department are increasing in strength where we like to mention common users meetings of the Muon Spin Rotation ({mu}SR) and Neutron Scattering communities, the help of the detector group of Particle Physics for instruments at SINQ, and the collaboration between Molecular Nanotechnology and Electrochemistry from the General Energy Department. Links to the industry have also been strengthened. One of the highlights of this year is the demonstration of the first electrically stimulated light emission from SiGe-heterostructures with a largely recognized publication in Science and several spontaneous reactions from semiconductor industries. Also other techniques and devices could be transferred to industry as for instance superconducting tunnel junction detectors developed for astrophysics with application in photon Time-of-Flight Mass Spectrometry to mention one. Progress in 2000 in all these topical areas is described in this report. A list of scientific publications in 2000 is also provided.

  18. HPA-axis function and grey matter volume reductions: imaging the diathesis-stress model in individuals at ultra-high risk of psychosis.

    Science.gov (United States)

    Valli, I; Crossley, N A; Day, F; Stone, J; Tognin, S; Mondelli, V; Howes, O; Valmaggia, L; Pariante, C; McGuire, P

    2016-05-03

    The onset of psychosis is thought to involve interactions between environmental stressors and the brain, with cortisol as a putative mediator. We examined the relationship between the cortisol stress response and brain structure in subjects at ultra-high risk (UHR) for psychosis. Waking salivary cortisol was measured in 22 individuals at UHR for psychosis and 17 healthy controls. Grey matter volume was assessed using magnetic resonance imaging at 3 T. The relationship between the stress response and grey matter volume was investigated using voxel-based analyses. Our predictions of the topography of cortisol action as a structural brain modulator were informed by measures of brain glucocorticoid and mineralcorticoid receptor distribution obtained from the multimodal neuroanatomical and genetic Allen Brain Atlas. Across all subjects, reduced responsivity of the hypothalamus-pituitary-adrenal (HPA) axis was correlated with smaller grey matter volumes in the frontal, parietal and temporal cortex and in the hippocampus. This relationship was particularly marked in the UHR subjects in the right prefrontal, left parahippocampal/fusiform and parietal cortices. The subgroup that subsequently developed psychosis showed a significant blunting of HPA stress response, observed at trend level also in the whole UHR sample. Altered responses to stress in people at high risk of psychosis are related to reductions in grey matter volume in areas implicated in the vulnerability to psychotic disorders. These areas may represent the neural components of a stress vulnerability model.

  19. Neuroprotection after a first episode of mania: a randomized controlled maintenance trial comparing the effects of lithium and quetiapine on grey and white matter volume.

    Science.gov (United States)

    Berk, M; Dandash, O; Daglas, R; Cotton, S M; Allott, K; Fornito, A; Suo, C; Klauser, P; Liberg, B; Henry, L; Macneil, C; Hasty, M; McGorry, P; Pantelis, Cs; Yücel, M

    2017-01-24

    Lithium and quetiapine are effective treatments for bipolar disorder, but their potential neuroprotective effects in humans remain unclear. A single blinded equivalence randomized controlled maintenance trial was conducted in a prospective cohort of first-episode mania (FEM) patients (n=26) to longitudinally compare the putative protective effects of lithium and quetapine on grey and white matter volume. A healthy control sample was also collected (n=20). Using structural MRI scans, voxel-wise grey and white matter volumes at baseline and changes over time in response to treatment were investigated. Patients were assessed at three time points (baseline, 3 and 12-month follow-up), whereas healthy controls were assessed at two time points (baseline and 12-month follow-up). Patients were randomized to lithium (serum level 0.6 mmol l(-1), n=20) or quetiapine (flexibly dosed up to 800 mg per day, n=19) monotherapy. At baseline, compared with healthy control subjects, patients with FEM showed reduced grey matter in the orbitofrontal cortex, anterior cingulate, inferior frontal gyrus and cerebellum. In addition, patients had reduced internal capsule white matter volume bilaterally (t1,66>3.20, Pmatter of the left internal capsule (F2,112=8.54, Pmatter volume reduction after 12 months (t1,24=3.76, Pmatter reduction early in the illness course after FEM.

  20. Gray Matter Volume in Adolescent Anxiety: An Impact of the Brain-Derived Neurotrophic Factor Val[superscript 66]Met Polymorphism?

    Science.gov (United States)

    Mueller, Sven C.; Aouidad, Aveline; Gorodetsky, Elena; Goldman, David; Pine, Daniel S.; Ernst, Monique

    2013-01-01

    Objective: Minimal research links anxiety disorders in adolescents to regional gray matter volume (GMV) abnormalities and their modulation by genetic factors. Prior research suggests that a brain-derived neurotrophic factor (BNDF) Val[superscript 66]Met polymorphism may modulate such brain morphometry profiles. Method: Using voxel-based…

  1. Gray Matter Volume in Adolescent Anxiety: An Impact of the Brain-Derived Neurotrophic Factor Val[superscript 66]Met Polymorphism?

    Science.gov (United States)

    Mueller, Sven C.; Aouidad, Aveline; Gorodetsky, Elena; Goldman, David; Pine, Daniel S.; Ernst, Monique

    2013-01-01

    Objective: Minimal research links anxiety disorders in adolescents to regional gray matter volume (GMV) abnormalities and their modulation by genetic factors. Prior research suggests that a brain-derived neurotrophic factor (BNDF) Val[superscript 66]Met polymorphism may modulate such brain morphometry profiles. Method: Using voxel-based…

  2. Volume of white matter hyperintensities is an independent predictor of intelligence quotient and processing speed in children with sickle cell disease.

    Science.gov (United States)

    van der Land, Veronica; Hijmans, Channa T; de Ruiter, Marieke; Mutsaerts, Henri J M M; Cnossen, Marjon H; Engelen, Marc; Majoie, Charles B L M; Nederveen, Aart J; Grootenhuis, Martha A; Fijnvandraat, Karin

    2015-02-01

    Sickle cell disease can be complicated by cerebral white matter hyperintensities (WMHs), which are associated with diminished neurocognitive functioning. The influence of the total volume of WMHs on the degree of neurocognitive dysfunction has not yet been characterized. In our study of 38 patients (mean age 12·5 years) we demonstrated that a higher volume of WMHs was associated with lower full-scale intelligence quotient (IQ), verbal IQ, Processing Speed Index and more fatigue. Our results suggest that volume of WMHs is an additional parameter to take into account when planning individual diagnostic and treatment options. © 2014 John Wiley & Sons Ltd.

  3. Condensation heat transfer

    Science.gov (United States)

    Rose, J. W.

    The paper gives a brief description of some of the better understood aspects of condensation heat transfer and includes discussion of the liquid-vapour interface, natural and forced convection laminar film condensation and dropwise condensation.

  4. COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers. Volume 2, User`s guide and manual

    Energy Technology Data Exchange (ETDEWEB)

    Chien, T.H.; Domanus, H.M.; Sha, W.T.

    1993-02-01

    The COMMIX-PPC computer program is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional conservation of mass. momentum, and energy equations on the tube side, and the proper accounting for the thermal interaction between shell and tube side through the porous medium approach. The other added feature is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient three-dimensional analysis of fluid flow with heat transfer in a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification. it can be used to analyze processes in any heat exchanger or other single-phase engineering applications.

  5. Species, diaspore volume and body mass matter in gastropod seed feeding behavior.

    Directory of Open Access Journals (Sweden)

    Manfred Türke

    Full Text Available BACKGROUND: Seed dispersal of ant-dispersed plants (myrmecochores is a well studied ecosystem function. Recently, slugs have been found to act as seed dispersers of myrmecochores. The aim of our study was to (1 further generalize the finding that gastropods feed on seeds of myrmecochores and hence may act as seed dispersers, (2 to test whether gastropod body mass and the volume of diaspores have an influence on the seed dispersal potential. METHODOLOGY AND PRINCIPAL FINDINGS: We assessed the seed dispersal potential of four slug and snail species with a set of seven myrmecochorous plant species from seven different plant families common to Central European beech forests. Diaspores differed in shape and size. Gastropods differed in their readiness to feed on diaspores and in the proportion of seeds that were swallowed as a whole, and this readiness generally decreased with increasing diaspore size. Smaller Arionid slugs (58 mm body length; mean mostly fed on the elaiosome but also swallowed small diaspores and therefore not only act as elaiosome consumers, a nutrient rich appendage on myrmecochorous diaspores, but may also disperse seeds. Large Arionid slugs (>100 mm body length swallowed diaspores of all sizes. Diaspores swallowed by gastropods were defecated without damage. Within-species variability in body size also affect seed dispersal potential, as larger individuals of the red slug (Arion rufus swallowed more diaspores of wood anemone (Anemone nemorosa than smaller ones. CONCLUSIONS AND SIGNIFICANCE: Our results help to generalize the finding that gastropods consume and potentially disperse seeds of myrmecochores. The dispersal potential of gastropods is strongly influenced by diaspore size in relation to gastropod size.

  6. The Impact of the in utero and Early Postnatal Environments on Grey and White Matter Volume: A Study with Adolescent Monozygotic Twins.

    Science.gov (United States)

    Levesque, Melissa L; Fahim, Cherine; Ismaylova, Elmira; Verner, Marie-Pier; Casey, Kevin F; Vitaro, Frank; Brendgen, Mara; Dionne, Ginette; Boivin, Michel; Tremblay, Richard E; Booij, Linda

    2015-01-01

    Prenatal and early postnatal adversities have been shown to be associated with brain development. However, we do not know how much of this association is confounded by genetics, nor whether the postnatal environment can moderate the impact of in utero adversity. This study used a monozygotic (MZ) twin design to assess (1) the association between birth weight (BW) and brain volume in adolescence, (2) the association between within-twin-pair BW discordance and brain volume discordance in adolescence, and (3) whether the association between BW and brain volume in adolescence is mediated or moderated by early negative maternal parenting behaviours. These associations were assessed in a sample of 108 MZ twins followed longitudinally since birth and scanned at age 15. The total grey matter (GM) and white matter (WM) volumes were obtained using the Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) toolbox in the Statistical Parametric Mapping version 8 (SPM8). We found that the BW was significantly associated with the total GM and WM volumes, particularly in the superior frontal gyrus and thalamus. Within-twin-pair discordance in BW was also significantly associated with within-pair discordance in both the GM and the WM volumes, supporting the hypothesis that the specific in utero environment is associated with brain development independently of genetics. Early maternal hostile parenting behaviours and depressive symptoms were associated with total GM volume but not WM volume. Finally, greater early maternal hostility may moderate the association between the BW and GM volume in adolescence, since the positive association between the BW and total GM volume appeared stronger at higher levels of maternal hostility (trend). Together, these findings support the importance of the in utero and early environments for brain development. © 2015 S. Karger AG, Basel.

  7. New LIGO Constraints on Bose-Einstein-Condensed Scalar Field Dark Matter and the Stochastic Gravitational-Wave Background from Inflation

    Science.gov (United States)

    Li, Bohua; Shapiro, Paul R.; Rindler-Daller, Tanja

    2017-06-01

    We consider an alternative to WIMP cold dark matter (CDM), ultralight bosonic dark matter (m≥10-22eV) described by a complex scalar field (SFDM) with global U(1) symmetry, for which the comoving particle number density is conserved after particle production during standard reheating. We allow for a repulsive self-interaction. In a ΛSFDM universe, SFDM starts relativistic, evolving from stiff (w=1) to radiationlike (w=1/3), before becoming nonrelativistic at late times (w=0). Thus, before the familiar radiation-dominated era, there is an earlier era of stiff-SFDM-domination, during which the expansion rate is higher than in ΛCDM. SFDM particle mass m and coupling strength λ, of a quartic self-interaction, are therefore constrained by cosmological observables, particularly Neff, the effective number of neutrino species during BBN, and zeq, the redshift of matter-radiation equality. Furthermore, since the stochastic gravitational-wave background (SGWB) from inflation is amplified during the stiff era, it can contribute a radiationlike component large enough to affect these observables by further boosting the expansion rate. Remarkably, this same amplification makes detection of the SGWB possible at high frequencies by current laser interferometer experiments, e.g., aLIGO/Virgo and LISA. For SFDM particle parameters that satisfy these cosmological constraints, the amplified SGWB is detectable by LIGO for a broad range of reheat temperatures Treheat, for values of tensor-to-scalar ratio r currently allowed by CMB polarization measurements. The SGWB is maximally detectable if modes that reentered the horizon when reheating ended have frequencies today in the LIGO sensitive band. For r=0.01, if SFDM parameters are chosen which marginally satisfy the above constraints, the maximally detectable model for (λ/(mc2)2, m)=(10-18eV-1cm3, 8×10-20eV) corresponds to Treheat≈104GeV, for which we predict an aLIGO O1 run detection with SNR~10. Upper limits on the SGWB

  8. Relationship between personality and gray matter volume in healthy young adults: a voxel-based morphometric study.

    Science.gov (United States)

    Lu, Fengmei; Huo, Yajun; Li, Meiling; Chen, Heng; Liu, Feng; Wang, Yifeng; Long, Zhiliang; Duan, Xujun; Zhang, Jiang; Zeng, Ling; Chen, Huafu

    2014-01-01

    This study aims to investigate the neurostructural foundations of the human personality in young adults. High-resolution structural T1-weighted MR images of 71 healthy young individuals were processed using voxel-based morphometric (VBM) approach. Multiple regression analyses were performed to identify the associations between personality traits and gray matter volume (GMV). The Eysenck Personality Questionnaire-Revised, Short Scale for Chinese was chosen to assess the personality traits. This scale includes four dimensions, namely, extraversion, neuroticism, psychoticism, and lie. Particularly, we studied on two dimensions (extraversion and neuroticism) of Eysenck's personality. Our results showed that extraversion was negatively correlated with GMV of the bilateral amygdala, the bilateral parahippocampal gyrus, the right middle temporal gyrus, and the left superior frontal gyrus, all of which are involved in emotional and social cognitive processes. These results might suggest an association between extraversion and affective processing. In addition, a positive correlation was detected between neuroticism and GMV of the right cerebellum, a key brain region for negative affect coordination. Meanwhile, a negative association was revealed between GMV of the left superior frontal gyrus and neuroticism. These results may prove that neuroticism is related to several brain regions involved in regulating negative emotions. Based on those findings, we concluded that brain regions involved in social cognition and affective process accounted for modulation and shaping of personality traits among young individuals. Results of this study may serve as a basis for elucidating the anatomical factors of personality.

  9. Free D-aspartate regulates neuronal dendritic morphology, synaptic plasticity, gray matter volume and brain activity in mammals.

    Science.gov (United States)

    Errico, F; Nisticò, R; Di Giorgio, A; Squillace, M; Vitucci, D; Galbusera, A; Piccinin, S; Mango, D; Fazio, L; Middei, S; Trizio, S; Mercuri, N B; Teule, M A; Centonze, D; Gozzi, A; Blasi, G; Bertolino, A; Usiello, A

    2014-01-01

    D-aspartate (D-Asp) is an atypical amino acid, which is especially abundant in the developing mammalian brain, and can bind to and activate N-methyl-D-Aspartate receptors (NMDARs). In line with its pharmacological features, we find that mice chronically treated with D-Asp show enhanced NMDAR-mediated miniature excitatory postsynaptic currents and basal cerebral blood volume in fronto-hippocampal areas. In addition, we show that both chronic administration of D-Asp and deletion of the gene coding for the catabolic enzyme D-aspartate oxidase (DDO) trigger plastic modifications of neuronal cytoarchitecture in the prefrontal cortex and CA1 subfield of the hippocampus and promote a cytochalasin D-sensitive form of synaptic plasticity in adult mouse brains. To translate these findings in humans and consistent with the experiments using Ddo gene targeting in animals, we performed a hierarchical stepwise translational genetic approach. Specifically, we investigated the association of variation in the gene coding for DDO with complex human prefrontal phenotypes. We demonstrate that genetic variation predicting reduced expression of DDO in postmortem human prefrontal cortex is mapped on greater prefrontal gray matter and activity during working memory as measured with MRI. In conclusion our results identify novel NMDAR-dependent effects of D-Asp on plasticity and physiology in rodents, which also map to prefrontal phenotypes in humans.

  10. Relationship between personality and gray matter volume in healthy young adults: a voxel-based morphometric study.

    Directory of Open Access Journals (Sweden)

    Fengmei Lu

    Full Text Available This study aims to investigate the neurostructural foundations of the human personality in young adults. High-resolution structural T1-weighted MR images of 71 healthy young individuals were processed using voxel-based morphometric (VBM approach. Multiple regression analyses were performed to identify the associations between personality traits and gray matter volume (GMV. The Eysenck Personality Questionnaire-Revised, Short Scale for Chinese was chosen to assess the personality traits. This scale includes four dimensions, namely, extraversion, neuroticism, psychoticism, and lie. Particularly, we studied on two dimensions (extraversion and neuroticism of Eysenck's personality. Our results showed that extraversion was negatively correlated with GMV of the bilateral amygdala, the bilateral parahippocampal gyrus, the right middle temporal gyrus, and the left superior frontal gyrus, all of which are involved in emotional and social cognitive processes. These results might suggest an association between extraversion and affective processing. In addition, a positive correlation was detected between neuroticism and GMV of the right cerebellum, a key brain region for negative affect coordination. Meanwhile, a negative association was revealed between GMV of the left superior frontal gyrus and neuroticism. These results may prove that neuroticism is related to several brain regions involved in regulating negative emotions. Based on those findings, we concluded that brain regions involved in social cognition and affective process accounted for modulation and shaping of personality traits among young individuals. Results of this study may serve as a basis for elucidating the anatomical factors of personality.

  11. Emotional intelligence moderates the relationship between regional gray matter volume in the bilateral temporal pole and critical thinking disposition.

    Science.gov (United States)

    Yao, Xiaonan; Yuan, Shuge; Yang, Wenjing; Chen, Qunlin; Wei, Dongtao; Hou, Yuling; Zhang, Lijie; Qiu, Jiang; Yang, Dong

    2017-03-29

    Critical thinking enables people to form sound beliefs and provides a basis for emotional life. Research has indicated that individuals with better critical thinking disposition can better recognize and regulate their emotions, though the neuroanatomical mechanisms involved in this process remain to be elucidated. Further, the influence of emotional intelligence on the relationship between brain structure and critical thinking disposition has not been examined. The present study utilized voxel-based morphometry (VBM) to investigate the neural structures underlying critical thinking disposition in a large sample of college students (N = 296). Regional gray matter volume (rGMV) in the bilateral temporal pole, which reflects an individual's ability to process social and emotional information, was negatively correlated with critical thinking disposition. In addition, rGMV in bilateral para hippocampal regions -regions involved in contextual association/emotional regulation-exhibited negative correlation with critical thinking disposition. Further analysis revealed that emotional intelligence moderated the relationship between rGMV of the temporal pole and critical thinking disposition. Specifically, critical thinking disposition was associated with decreased GMV of the temporal pole for individuals who have relatively higher emotional intelligence rather than lower emotional intelligence. The results of the present study indicate that people who have higher emotional intelligence exhibit more effective and automatic processing of emotional information and tend to be strong critical thinkers.

  12. Gray matter volume in adolescent anxiety: an impact of the brain-derived neurotrophic factor Val(66)Met polymorphism?

    Science.gov (United States)

    Mueller, Sven C; Aouidad, Aveline; Gorodetsky, Elena; Goldman, David; Pine, Daniel S; Ernst, Monique

    2013-02-01

    Minimal research links anxiety disorders in adolescents to regional gray matter volume (GMV) abnormalities and their modulation by genetic factors. Prior research suggests that a brain-derived neurotrophic factor (BNDF) Val(66)Met polymorphism may modulate such brain morphometry profiles. Using voxel-based morphometry and magnetic resonance imaging, associations of BDNF and clinical anxiety with regional GMVs of anterior cingulate cortex, insula, amygdala, and hippocampus were examined in 39 affected (17 Met allele carriers, 22 Val/Val homozygotes) and 63 nonaffected adolescents (27 [corrected] Met allele carriers, 36 [corrected] Val/Val homozygotes). Amygdala and anterior hippocampal GMVs were significantly smaller in patients than in healthy comparison adolescents, with a reverse pattern for the insula. Post-hoc regression analyses indicated a specific contribution of social phobia to the GMV reductions in the amygdala and hippocampus. In addition, insula and dorsal-anterior cingulate cortex (ACC) GMVs were modulated by BDNF genotype. In both regions, and GMVs were larger in the Val/Val homozygote patients than in individuals carrying the Met allele. These results implicate reduced GMV in the amygdala and hippocampus in pediatric anxiety, particularly social phobia. In addition, the data suggest that genetic factors may modulate differences in the insula and dorsal ACC. Published by Elsevier Inc.

  13. Grey Matter Volume in Adolescent Anxiety: An Impact of the Brain-Derived Neurotropic Factor Val66Met Polymorphism?

    Science.gov (United States)

    Mueller, Sven C.; Aouidad, Aveline; Gorodetsky, Elena; Goldman, David; Pine, Daniel S.; Ernst, Monique

    2013-01-01

    Objective Minimal research links anxiety disorders in adolescents to regional gray matter volume (GMV) abnormalities and their modulation by genetic factors. Prior research suggests that a brain-derived neurotrophic factor (BNDF) Val66Met polymorphism may modulate such brain morphometry profiles. Method Using voxel-based morphometry and magnetic resonance imaging, associations of BDNF and clinical anxiety with regional GMVs of anterior cingulate cortex, insula, amygdala, and hippocampus were examined in 39 affected (17 Met allele carriers, 22 Val/Val homozygotes) and 63 nonaffected adolescents (27 Met allele carriers, 36 Val/Val homozygotes). Results Amygdala and anterior hippocampal GMVs were significantly smaller in patients than healthy adolescents, with a reverse pattern for the insula. Post-hoc regression analyses indicated a specific contribution of social phobia to the GMV reductions in the amygdala and hippocampus. Additionally, insula and dorsal– anterior cingulate cortex (ACC) GMVs were modulated by BDNF genotype. In both regions, GMVs were larger in the Val/Val homozygote patients than in those carrying the Met allele. Conclusions These results implicate reduced GMV in the amygdala and hippocampus in pediatric anxiety, particularly social phobia. In addition, the data suggest that genetic factors may modulate differences in the insula and dorsal ACC. PMID:23357445

  14. Lower total and regional grey matter brain volumes in youth with perinatally-acquired HIV infection: Associations with HIV disease severity, substance use, and cognition.

    Science.gov (United States)

    Lewis-de Los Angeles, C Paula; Williams, Paige L; Huo, Yanling; Wang, Shirlene D; Uban, Kristina A; Herting, Megan M; Malee, Kathleen; Yogev, Ram; Csernansky, John G; Nichols, Sharon; Van Dyke, Russell B; Sowell, Elizabeth R; Wang, Lei

    2017-05-01

    Despite improved survival due to combination antiretroviral therapy (cART), youth with perinatally-acquired HIV (PHIV) show cognitive deficits and developmental delay at increased rates. HIV affects the brain during critical periods of development, and the brain may be a persistent reservoir for HIV due to suboptimal blood brain barrier penetration of cART. We conducted structural magnetic resonance imaging (sMRI) and cognitive testing in 40 PHIV youth (mean age=16.7years) recruited from the NIH Pediatric HIV/AIDS Cohort Study (PHACS) who are part of the first generation of PHIV youth surviving into adulthood. Historical and current HIV disease severity and substance use measures were also collected. Total and regional cortical grey matter brain volumes were compared to a group of 334 typically-developing, HIV-unexposed and uninfected youth (frequency-matched for age and sex) from the Pediatric Imaging, Neurocognition, and Genetics (PING) study (mean age=16.1years). PHIV youth had smaller (2.8-5.1%) total and regional grey matter volumes than HIV-unexposed and uninfected youth, with smallest volumes seen among PHIV youth with higher past peak viral load (VL) and recent unsuppressed VL. In PHIV youth, worse cognitive performance correlated with smaller volumes. This pattern of smaller grey matter volumes suggests that PHIV infection may influence brain development and underlie cognitive dysfunction seen in this population. Among PHIV youth, smaller volumes were also linked to substance use (alcohol use: 9.0-13.4%; marijuana use: 10.1-16.0%). In this study, collection of substance use information was limited to the PHIV cohort; future studies should also collect substance use information in controls to further address interactions between HIV and substance use on brain volume.

  15. Regional frontal gray matter volume associated with executive function capacity as a risk factor for vehicle crashes in normal aging adults.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Sakai

    Full Text Available Although low executive functioning is a risk factor for vehicle crashes among elderly drivers, the neural basis of individual differences in this cognitive ability remains largely unknown. Here we aimed to examine regional frontal gray matter volume associated with executive functioning in normal aging individuals, using voxel-based morphometry (VBM. To this end, 39 community-dwelling elderly volunteers who drove a car on a daily basis participated in structural magnetic resonance imaging, and completed two questionnaires concerning executive functioning and risky driving tendencies in daily living. Consequently, we found that participants with low executive function capacity were prone to risky driving. Furthermore, VBM analysis revealed that lower executive function capacity was associated with smaller gray matter volume in the supplementary motor area (SMA. Thus, the current data suggest that SMA volume is a reliable predictor of individual differences in executive function capacity as a risk factor for vehicle crashes among elderly persons. The implication of our results is that regional frontal gray matter volume might underlie the variation in driving tendencies among elderly drivers. Therefore, detailed driving behavior assessments might be able to detect early neurodegenerative changes in the frontal lobe in normal aging adults.

  16. Thermodynamics of Condensed Phases: Formula Unit Volume, "V[subscript m]", and the Determination of the Number of Formula Units, "Z", in a Crystallographic Unit Cell

    Science.gov (United States)

    Glasser, Leslie

    2011-01-01

    Formula unit (or molecular) volume, "V[subscript m]", is related to many thermodynamic and physical properties of materials, so that knowledge of "V[subscript m]" is useful in prediction of such properties for known and even hypothetical materials. The symbol "Z" represents the number of formula units in a crystallographic unit cell; "Z" thus…

  17. Microscopic theory of equilibrium polariton condensates

    Science.gov (United States)

    Xue, Fei; Wu, Fengcheng; Xie, Ming; Su, Jung-Jung; MacDonald, A. H.

    2016-12-01

    We present a microscopic theory of the equilibrium polariton condensate state of a semiconductor quantum well in a planar optical cavity. The theory accounts for the adjustment of matter excitations to the presence of a coherent photon field, predicts effective polariton-polariton interaction strengths that are weaker and condensate exciton fractions that are smaller than in the commonly employed exciton-photon model, and yields effective Rabi coupling strengths that depend on the detuning of the cavity-photon energy relative to the bare exciton energy. The dressed quasiparticle bands that appear naturally in the theory provide a mechanism for electrical manipulation of polariton condensates.

  18. Topological phases and transitions in condensed matter systems%凝聚态材料中的拓扑相与拓扑相变--2016年诺贝尔物理学奖解读

    Institute of Scientific and Technical Information of China (English)

    戴希

    2016-01-01

    Two months ago, three physicists won the Nobel physics prize for their discov-ery of topological phases and transitions. In this paper, we review the origin of the concept of topol-ogy in condensed matter physics, then present a brief introduction to the main classes of topologi-cal states in solid-state materials, including topological insulators, the quantum anomalous Hall ef-fect, topological crystalline insulators, and topological semimetals.%凝聚态物理中拓扑相变和拓扑物态的发现,获得了2016年度诺贝尔物理学奖。文章系统介绍了凝聚态物理中拓扑性的起源,并简要介绍了目前凝聚态物理中发现的主要几类拓扑态:拓扑绝缘体、量子反常霍尔效应、拓扑晶体绝缘体和拓扑半金属。

  19. Correlating anterior insula gray matter volume changes in young people with clinical and neurocognitive outcomes: an MRI study

    Directory of Open Access Journals (Sweden)

    Hatton Sean N

    2012-05-01

    Full Text Available Abstract Background The anterior insula cortex is considered to be both the structural and functional link between experience, affect, and behaviour. Magnetic resonance imaging (MRI studies have shown changes in anterior insula gray matter volume (GMV in psychosis, bipolar, depression and anxiety disorders in older patients, but few studies have investigated insula GMV changes in young people. This study examined the relationship between anterior insula GMV, clinical symptom severity and neuropsychological performance in a heterogeneous cohort of young people presenting for mental health care. Methods Participants with a primary diagnosis of depression (n = 43, bipolar disorder (n = 38, psychosis (n = 32, anxiety disorder (n = 12 or healthy controls (n = 39 underwent structural MRI scanning, and volumetric segmentation of the bilateral anterior insula cortex was performed using the FreeSurfer application. Statistical analysis examined the linear and quadratic correlations between anterior insula GMV and participants’ performance in a battery of clinical and neuropsychological assessments. Results Compared to healthy participants, patients had significantly reduced GMV in the left anterior insula (t = 2.05, p = .042 which correlated with reduced performance on a neuropsychological task of attentional set-shifting (ρ = .32, p = .016. Changes in right anterior insula GMV was correlated with increased symptom severity (r = .29, p = .006 and more positive symptoms (r = .32, p = .002. Conclusions By using the novel approach of examining a heterogeneous cohort of young depression, anxiety, bipolar and psychosis patients together, this study has demonstrated that insula GMV changes are associated with neurocognitive deficits and clinical symptoms in such young patients.

  20. Reduced visual cortex gray matter volume and thickness in young adults who witnessed domestic violence during childhood.

    Directory of Open Access Journals (Sweden)

    Akemi Tomoda

    Full Text Available Exposure to interparental violence is associated with negative outcomes, such as depression, post-traumatic stress disorder and reduced cognitive abilities. However, little is known about the potential effects of witnessing domestic violence during childhood on gray matter volume (GMV or cortical thickness. High-resolution 3.0 T volumetric scans (Siemens Trio Scanner were obtained on 52 subjects (18-25 years including 22 (6 males/16 females with a history of visually witnessing episodes of domestic violence, and 30 (8 males/22 females unexposed control subjects, with neither a current nor past DSM-IV Axis I or II disorder. Potential confounding effects of age, gender, level of parental verbal aggression, parental education, financial stress, full scale IQ, and total GMV, or average thickness were modeled using voxel based morphometry and FreeSurfer. Witnessing domestic violence subjects had a 6.1% GMV reduction in the right lingual gyrus (BA18 (P = 0.029, False Discovery Rate corrected peak level. Thickness in this region was also reduced, as was thickness in V2 bilaterally and left occipital pole. Theses regions were maximally sensitive to exposure to witnessing domestic violence between 11-13 years of age. Regional reductions in GMV and thickness were observed in both susceptible and resilient witnessing domestic violence subjects. Results in subjects witnessing domestic violence were similar to previously reported results in subjects with childhood sexual abuse, as the primary region affected was visual cortex. Brain regions that process and convey the adverse sensory input of the abuse may be specifically modified by this experience, particularly in subjects exposed to a single type of maltreatment. Exposure to multiple types of maltreatment is more commonly associated with morphological alterations in corticolimbic regions. These findings fit with preclinical studies showing that visual cortex is a highly plastic structure.