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Sample records for matter theories volume

  1. Condensed Matter Theories - Volume 22

    NASA Astrophysics Data System (ADS)

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

    2007-09-01

    pt. A. Fermi liquids. Pressure comparison between the spherical cellular model and the Thomas-Fermi model / G.A. Baker, Jr. Pair excitations and vertex corrections in Fermi fluids and the dynamic structure function of two-dimension 3He / H.M. Böhm, H. Godfrin, E. Krotscheck, H.J. Lauter, M. Meschke and M. Panholzer. Condensation of helium in wedges / E.S. Hernádez ... [et al.]. Non-Fermi liquid behavior from the Fermi-liquid approach / V.A. Khodel ... [et al.]. Theory of third sound and stability of thin 3He-4He superfluid films / E. Krotscheck and M.D. Miller. Pairing in asymmetrical Fermi systems / K.F. Quader and R. Liao. Ground-state properties of small 3He drops from quantum Monte Carlo simulations / E. Sola, J. Casulleras and J. Boronat. Ground-state energy and compressibility of a disordered two-dimensional electron gas / Tanatar ... [et al.]. Quasiexcitons in photoluminescence of incompressible quantum liquids / A. Wójs, A.G ladysiewicz and J.J. Quinn -- pt. B. Bose liquids. Quantum Boltzmann liquids / K.A. Gernoth, M L. Ristig and T. Lindenau. Condensate fraction in the dynamic structure function of Bose fluids / M. Saarela, F. Mazzanti and V. Apaja -- pt. C. Strongly-correlated electronic systems. Electron gas in high-field nanoscopic transport: metallic carbon nanotubes / F. Green and D. Neilson. Evolution and destruction of the Kondo effect in a capacitively coupled double dot system / D.E. Logan and M.R. Galpin. The method of increments-a wavefunction-based Ab-Initio correlation method for solids / B. Paulus. Fractionally charged excitations on frustrated lattices / E. Runge, F. Pollmann and P. Fulde. 5f Electrons in actinides: dual nature and photoemission spectra / G. Zwicknagl -- pt. D. Magnetism. Magnetism in disordered two-dimensional Kondo-Necklace / W. Brenig. On the de Haas-can Alphen oscillation in 2D / S. Fujita and D.L. Morabito. Dynamics in one-dimensional spin systems-density matrix reformalization group study / S. Nishimoto and M

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

    PubMed

    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.

  3. Change Matters: Critical Essays on Moving Social Justice Research from Theory to Policy. Critical Qualitative Research. Volume 1

    ERIC Educational Resources Information Center

    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…

  4. Front Matter: Volume 8454

    NASA Astrophysics Data System (ADS)

    SPIE, Proceedings of

    2012-05-01

    This PDF file contains the front matter associated with SPIE Proceedings Volume 8454, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

  5. Dark Matter Effective Theory

    NASA Astrophysics Data System (ADS)

    Del Nobile, Eugenio; Sannino, Francesco

    2012-05-01

    We organize the effective (self-)interaction terms for complex scalar dark matter candidates which are either an isosinglet, isodoublet or an isotriplet with respect to the weak interactions. The classification has been performed ordering the operators in inverse powers of the dark matter (DM) cutoff scale. We assume Lorentz invariance, color and charge neutrality. We also introduce potentially interesting DM induced flavor-changing operators. Our general framework allows for model independent investigations of DM properties.

  6. The Particle Theory of Matter

    ERIC Educational Resources Information Center

    Widick, Paul R.

    1969-01-01

    Described are activities that are designed to help elementary children understand the possibility of the particle theory of matter. Children work with beads, marbles, B-B shot and sand; by mixing these materials and others they are led to see that it is highly possible for the existence of particles which are not visible. (BR)

  7. Volume integral theorem for exotic matter

    SciTech Connect

    Nandi, Kamal Kanti; Zhang Yuanzhong; Kumar, K.B. Vijaya

    2004-12-15

    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 by arbitrarily small quantities of exotic matter.

  8. Physical activity, fitness, and gray matter volume

    PubMed Central

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

    2014-01-01

    In this review we explore the association between 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 to 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. PMID:24952993

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

    PubMed

    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.

  10. Variational Theory of Hot Dense Matter

    ERIC Educational Resources Information Center

    Mukherjee, Abhishek

    2009-01-01

    We develop a variational theory of hot nuclear matter in neutron stars and supernovae. It can also be used to study charged, hot nuclear matter which may be produced in heavy-ion collisions. This theory is a generalization of the variational theory of cold nuclear and neutron star matter based on realistic models of nuclear forces and pair…

  11. Number-theory dark matter

    NASA Astrophysics Data System (ADS)

    Nakayama, Kazunori; Takahashi, Fuminobu; Yanagida, Tsutomu T.

    2011-05-01

    We propose that the stability of dark matter is ensured by a discrete subgroup of the U(1)B-L gauge symmetry, Z(B-L). We introduce a set of chiral fermions charged under the U(1)B-L in addition to the right-handed neutrinos, and require the anomaly-cancellation conditions associated with the U(1)B-L gauge symmetry. We find that the possible number of fermions and their charges are tightly constrained, and that non-trivial solutions appear when at least five additional chiral fermions are introduced. The Fermat theorem in the number theory plays an important role in this argument. Focusing on one of the solutions, we show that there is indeed a good candidate for dark matter, whose stability is guaranteed by Z(B-L).

  12. Theory of dark matter superfluidity

    NASA Astrophysics Data System (ADS)

    Berezhiani, Lasha; Khoury, Justin

    2015-11-01

    We propose a novel theory of dark matter (DM) superfluidity that matches the successes of the Λ cold dark matter (Λ CDM ) model on cosmological scales while simultaneously reproducing the modified Newtonian dynamics (MOND) phenomenology on galactic scales. The DM and MOND components have a common origin, representing different phases of a single underlying substance. DM consists of axionlike particles with mass of order eV and strong self-interactions. The condensate has a polytropic equation of state P ˜ρ3 giving rise to a superfluid core within galaxies. Instead of behaving as individual collisionless particles, the DM superfluid is more aptly described as collective excitations. Superfluid phonons, in particular, are assumed to be governed by a MOND-like effective action and mediate a MONDian acceleration between baryonic matter particles. Our framework naturally distinguishes between galaxies (where MOND is successful) and galaxy clusters (where MOND is not); due to the higher velocity dispersion in clusters, and correspondingly higher temperature, the DM in clusters is either in a mixture of superfluid and the normal phase or fully in the normal phase. The rich and well-studied physics of superfluidity leads to a number of observational signatures: an array of low-density vortices in galaxies; merger dynamics that depend on the infall velocity vs phonon sound speed; distinct mass peaks in bulletlike cluster mergers, corresponding to superfluid and normal components; and interference patters in supercritical mergers. Remarkably, the superfluid phonon effective theory is strikingly similar to that of the unitary Fermi gas, which has attracted much excitement in the cold atom community in recent years. The critical temperature for DM superfluidity is of order mK, comparable to known cold atom Bose-Einstein condensates. Identifying a precise cold atom analog would give important insights on the microphysical interactions underlying DM superfluidity

  13. Theory into Practice: A Matter of Transfer

    ERIC Educational Resources Information Center

    Randi, Judi; Corno, Lyn

    2007-01-01

    This article explores a new approach to taking theory into practice--one that offers a direct route from research to practice. Traditionally, theory makes its way to practice cloaked in particular curriculum interventions. We argue that taking theory into practice is essentially a matter of transfer--applying teaching and learning principles in…

  14. Mapping gray matter volume and cortical thickness in Alzheimer's disease

    NASA Astrophysics Data System (ADS)

    Guo, Xiaojuan; Li, Ziyi; Chen, Kewei; Yao, Li; Wang, Zhiqun; Li, Kuncheng

    2010-03-01

    Gray matter volume and cortical thickness are two important indices widely used to detect neuropathological changes in brain structural magnetic resonance imaging. Using optimized voxel-based morphometry (VBM) protocol and surface-based cortical thickness measure, this study comprehensively investigated the regional changes in cortical gray matter volume and cortical thickness in Alzheimer's disease (AD). Thirteen patients with AD and fourteen age- and gender-matched healthy controls were included in this study. Results showed that voxel-based gray matter volume and cortical thickness reductions were highly correlated in the temporal lobe and its medial structure in AD. Moreover significant reduced cortical regions of gray matter volume were obviously more than that of cortical thickness. These findings suggest that gray matter volume and cortical thickness, as two important imaging markers, are effective indices for detecting the neuroanatomical alterations and help us understand the neuropathology from different views in AD.

  15. Interstitialcy theory of simple condensed matter

    NASA Astrophysics Data System (ADS)

    Granato, Andrew V.

    2014-01-01

    A simple, more physical and compelling version of the Interstitialcy Theory of Simple Condensed Matter than that given previously is provided here. Also, computer simulation and direct and indirect experimental evidence is updated and reviewed. The theory is based on the properties of an interstitial in the interstitialcy, sometimes known as the dumbbell configuration. A free energy is derived, taking account of the unusually large shear susceptibility and vibrational entropy of the dumbbell to find the thermodynamic and kinetic properties of simple liquids and glasses. The connection between theory and experiment for some of the more notable properties of simple condensed matter found later is also discussed. The direct visual observation of interstitial diffusion to the surface in platinum near 20 K in irradiated thin films by Morgenstern et al. [M. Morgenstern, T. Michely, G. Comsa, Phys. Rev. Lett. 79, 1305 (1997)] is found to be sufficient compelling evidence for the interstitialcy theory.

  16. Dark matter dispersion tensor in perturbation theory

    NASA Astrophysics Data System (ADS)

    Aviles, Alejandro

    2016-03-01

    We compute the dark matter velocity dispersion tensor up to third order in perturbation theory using the Lagrangian formalism, revealing growing solutions at the third and higher orders. Our results are general and can be used for any other perturbative formalism. As an application, corrections to the matter power spectrum are calculated, and we find that some of them have the same structure as those in the effective field theory of large-scale structure, with "EFT-like" coefficients that grow quadratically with the linear growth function and are further suppressed by powers of the logarithmic linear growth factor f ; other corrections present additional k dependence. Due to the velocity dispersions, there exists a free-streaming scale that suppresses the whole 1-loop power spectrum. Furthermore, we find that as a consequence of the nonlinear evolution, the free-streaming length is shifted towards larger scales, wiping out more structure than that expected in linear theory. Therefore, we argue that the formalism developed here is better suited for a perturbation treatment of warm dark matter or neutrino clustering, where the velocity dispersion effects are well known to be important. We discuss implications related to the nature of dark matter.

  17. APOL1 renal-risk variants associate with reduced cerebral white matter lesion volume and increased gray matter volume.

    PubMed

    Freedman, Barry I; Gadegbeku, Crystal A; Bryan, R Nick; Palmer, Nicholette D; Hicks, Pamela J; Ma, Lijun; Rocco, Michael V; Smith, S Carrie; Xu, Jianzhao; Whitlow, Christopher T; Wagner, Benjamin C; Langefeld, Carl D; Hawfield, Amret T; Bates, Jeffrey T; Lerner, Alan J; Raj, Dominic S; Sadaghiani, Mohammad S; Toto, Robert D; Wright, Jackson T; Bowden, Donald W; Williamson, Jeff D; Sink, Kaycee M; Maldjian, Joseph A; Pajewski, Nicholas M; Divers, Jasmin

    2016-08-01

    To assess apolipoprotein L1 gene (APOL1) renal-risk-variant effects on the brain, magnetic resonance imaging (MRI)-based cerebral volumes and cognitive function were assessed in 517 African American-Diabetes Heart Study (AA-DHS) Memory IN Diabetes (MIND) and 2568 hypertensive African American Systolic Blood Pressure Intervention Trial (SPRINT) participants without diabetes. Within these cohorts, 483 and 197 had cerebral MRI, respectively. AA-DHS participants were characterized as follows: 60.9% female, mean age of 58.6 years, diabetes duration 13.1 years, estimated glomerular filtration rate of 88.2 ml/min/1.73 m(2), and a median spot urine albumin to creatinine ratio of 10.0 mg/g. In additive genetic models adjusting for age, sex, ancestry, scanner, intracranial volume, body mass index, hemoglobin A1c, statins, nephropathy, smoking, hypertension, and cardiovascular disease, APOL1 renal-risk-variants were positively associated with gray matter volume (β = 3.4 × 10(-3)) and negatively associated with white matter lesion volume (β = -0.303) (an indicator of cerebral small vessel disease) and cerebrospinal fluid volume (β= -30707) (all significant), but not with white matter volume or cognitive function. Significant associations corresponding to adjusted effect sizes (β/SE) were observed with gray matter volume (0.16) and white matter lesion volume (-0.208), but not with cerebrospinal fluid volume (-0.251). Meta-analysis results with SPRINT Memory and Cognition in Decreased Hypertension (MIND) participants who had cerebral MRI were confirmatory. Thus, APOL1 renal-risk-variants are associated with larger gray matter volume and lower white matter lesion volume suggesting lower intracranial small vessel disease.

  18. APOL1 renal-risk variants associate with reduced cerebral white matter lesion volume and increased gray matter volume.

    PubMed

    Freedman, Barry I; Gadegbeku, Crystal A; Bryan, R Nick; Palmer, Nicholette D; Hicks, Pamela J; Ma, Lijun; Rocco, Michael V; Smith, S Carrie; Xu, Jianzhao; Whitlow, Christopher T; Wagner, Benjamin C; Langefeld, Carl D; Hawfield, Amret T; Bates, Jeffrey T; Lerner, Alan J; Raj, Dominic S; Sadaghiani, Mohammad S; Toto, Robert D; Wright, Jackson T; Bowden, Donald W; Williamson, Jeff D; Sink, Kaycee M; Maldjian, Joseph A; Pajewski, Nicholas M; Divers, Jasmin

    2016-08-01

    To assess apolipoprotein L1 gene (APOL1) renal-risk-variant effects on the brain, magnetic resonance imaging (MRI)-based cerebral volumes and cognitive function were assessed in 517 African American-Diabetes Heart Study (AA-DHS) Memory IN Diabetes (MIND) and 2568 hypertensive African American Systolic Blood Pressure Intervention Trial (SPRINT) participants without diabetes. Within these cohorts, 483 and 197 had cerebral MRI, respectively. AA-DHS participants were characterized as follows: 60.9% female, mean age of 58.6 years, diabetes duration 13.1 years, estimated glomerular filtration rate of 88.2 ml/min/1.73 m(2), and a median spot urine albumin to creatinine ratio of 10.0 mg/g. In additive genetic models adjusting for age, sex, ancestry, scanner, intracranial volume, body mass index, hemoglobin A1c, statins, nephropathy, smoking, hypertension, and cardiovascular disease, APOL1 renal-risk-variants were positively associated with gray matter volume (β = 3.4 × 10(-3)) and negatively associated with white matter lesion volume (β = -0.303) (an indicator of cerebral small vessel disease) and cerebrospinal fluid volume (β= -30707) (all significant), but not with white matter volume or cognitive function. Significant associations corresponding to adjusted effect sizes (β/SE) were observed with gray matter volume (0.16) and white matter lesion volume (-0.208), but not with cerebrospinal fluid volume (-0.251). Meta-analysis results with SPRINT Memory and Cognition in Decreased Hypertension (MIND) participants who had cerebral MRI were confirmatory. Thus, APOL1 renal-risk-variants are associated with larger gray matter volume and lower white matter lesion volume suggesting lower intracranial small vessel disease. PMID:27342958

  19. Matter, Motion, and Man, Volume II.

    ERIC Educational Resources Information Center

    Montag, Betty Jo

    Volume Two of the three-volume experimental program in general science attempts to provide preparation for the new approaches in biology, chemistry, and physics and to give those who will not continue in science a realistic way of understanding themselves, the world, and the role of science in society. Chapters on classification, heredity, light,…

  20. Students' Conceptual Representations of Gas Volume in Relation to Particulate Model of Matter.

    ERIC Educational Resources Information Center

    Hwang, Bao-tyan

    Most high school chemistry curricula contain a unit on gas volume and a unit on the particulate nature of matter. The existence and persistence of adolescent preconceptions about the material nature of gases is an important factor to be considered in the teaching of principles or theories related to gases. The purpose of the study reported in this…

  1. Transport in Chern-Simons-matter theories

    NASA Astrophysics Data System (ADS)

    Gur-Ari, Guy; Hartnoll, Sean; Mahajan, Raghu

    2016-07-01

    The frequency-dependent longitudinal and Hall conductivities — σ xx and σ xy — are dimensionless functions of ω/T in 2+1 dimensional CFTs at nonzero temperature. These functions characterize the spectrum of charged excitations of the theory and are basic experimental observables. We compute these conductivities for large N Chern-Simons theory with fermion matter. The computation is exact in the 't Hooft coupling λ at N = ∞. We describe various physical features of the conductivity, including an explicit relation between the weight of the delta function at ω = 0 in σ xx and the existence of infinitely many higher spin conserved currents in the theory. We also compute the conductivities perturbatively in Chern-Simons theory with scalar matter and show that the resulting functions of ω/T agree with the strong coupling fermionic result. This provides a new test of the conjectured 3d bosonization duality. In matching the Hall conductivities we resolve an outstanding puzzle by carefully treating an extra anomaly that arises in the regularization scheme used.

  2. On constructing purely affine theories with matter

    NASA Astrophysics Data System (ADS)

    Cervantes-Cota, Jorge L.; Liebscher, D.-E.

    2016-08-01

    We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schrödinger's purely affine theory (Schrödinger in Space-time structure. Cambridge UP, Cambridge, 1950), where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.

  3. Cardiorespiratory fitness and brain volume and white matter integrity

    PubMed Central

    Zhu, Na; Schreiner, Pamela J.; Launer, Lenore J.; Whitmer, Rachel A.; Sidney, Stephen; Demerath, Ellen; Thomas, William; Bouchard, Claude; He, Ka; Erus, Guray; Battapady, Harsha; Bryan, R. Nick

    2015-01-01

    Objective: We hypothesized that greater cardiorespiratory fitness is associated with lower odds of having unfavorable brain MRI findings. Methods: We studied 565 healthy, middle-aged, black and white men and women in the CARDIA (Coronary Artery Risk Development in Young Adults) Study. The fitness measure was symptom-limited maximal treadmill test duration (Maxdur); brain MRI was measured 5 years later. Brain MRI measures were analyzed as means and as proportions below the 15th percentile (above the 85th percentile for white matter abnormal tissue volume). Results: Per 1-minute-higher Maxdur, the odds ratio for having less whole brain volume was 0.85 (p = 0.04) and for having low white matter integrity was 0.80 (p = 0.02), adjusted for age, race, sex, clinic, body mass index, smoking, alcohol, diet, physical activity, education, blood pressure, diabetes, total cholesterol, and lung function (plus intracranial volume for white matter integrity). No significant associations were observed between Maxdur and abnormal tissue volume or blood flow in white matter. Findings were similar for associations with continuous brain MRI measures. Conclusions: Greater physical fitness was associated with more brain volume and greater white matter integrity measured 5 years later in middle-aged adults. PMID:25957331

  4. Size Matters: Cerebral Volume Influences Sex Differences in Neuroanatomy

    PubMed Central

    Towler, Stephen; Welcome, Suzanne; Halderman, Laura K.; Otto, Ron; Eckert, Mark A.; Chiarello, Christine

    2008-01-01

    Biological and behavioral differences between the sexes range from obvious to subtle or nonexistent. Neuroanatomical differences are particularly controversial, perhaps due to the implication that they might account for behavioral differences. In this sample of 200 men and women, large effect sizes (Cohen's d > 0.8) were found for sex differences in total cerebral gray and white matter, cerebellum, and gray matter proportion (women had a higher proportion of gray matter). The only one of these sex differences that survived adjustment for the effect of cerebral volume was gray matter proportion. Individual differences in cerebral volume accounted for 21% of the difference in gray matter proportion, while sex accounted for an additional 4%. The relative size of the corpus callosum was 5% larger in women, but this difference was completely explained by a negative relationship between relative callosal size and cerebral volume. In agreement with Jancke et al., individuals with higher cerebral volume tended to have smaller corpora callosa. There were few sex differences in the size of structures in Broca's and Wernicke's area. We conclude that individual differences in brain volume, in both men and women, account for apparent sex differences in relative size. PMID:18440950

  5. Computational Theory of Warm Condensed Matter

    SciTech Connect

    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.

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

    ERIC Educational Resources Information Center

    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…

  7. Effective theories for dark matter nucleon scattering

    NASA Astrophysics Data System (ADS)

    Hisano, Junji; Nagai, Ryo; Nagata, Natsumi

    2015-05-01

    We reformulate the calculation of the dark matter-nucleon scattering cross sections based on the method of effective field theories. We assume that the scatterings are induced by the exchange of colored mediators, and construct the effective theories by integrating out the colored particles. All of the leading order matching conditions as well as the renormalization group equations are presented. We consider a Majorana fermion, and real scalar and vector bosons for the dark matter and show the results for each case. The treatment for the twist-2 operators is discussed in detail, and it is shown that the scale of evaluating their nucleon matrix elements does not have to be the hadronic scale. The effects of the QCD corrections are evaluated on the assumption that the masses of the colored mediators are much heavier than the electroweak scale. Our formulation is systematic and model-independent, and thus suitable to be implemented in numerical packages, such as micrOMEGAs and DarkSUSY.

  8. The Theory of Sound 2 Volume Set

    NASA Astrophysics Data System (ADS)

    Strutt Baron Rayleigh, John William

    2011-08-01

    Volume 1: Preface; 1. Sound due to vibrations; 2. Composition of harmonic motions of like period; 3. Systems with one degree of freedom; 4. Generalized co-ordinates; 5. Cases in which the three functions, T, F, V are simultaneously reducible to sums of squares; 6. Law of extension of a string; 7. Classification of the vibrations of bars; 8. Potential energy of bending; 9. Tension of a membrane; 10. Vibrations of plates. Volume 2: 11. Aerial vibrations; 12. Vibrations in tubes; 13. Aerial vibrations in a rectangular chamber; 14. Arbitrary initial disturbance in an unlimited atmosphere; 15. Secondary waves due to a variation in the medium; 16. Theory of resonators; 17. Applications of Laplace's functions to acoustical problems; 18. Problem of a spherical layer of air; 19. Fluid friction; Appendix.

  9. Antennas in matter: Fundamentals, theory, and applications

    NASA Technical Reports Server (NTRS)

    King, R. W. P.; Smith, G. S.; Owens, M.; Wu, T. T.

    1981-01-01

    The volume provides an introduction to antennas and probes embedded within or near material bodies such as the earth, the ocean, or a living organism. After a fundamental analysis of insulated and bare antennas, an advanced treatment of antennas in various media is presented, including a detailed study of the electromagnetic equations in homogeneous isotropic media, the complete theory of the bare dipole in a general medium, and a rigorous analysis of the insulated antenna as well as bare and insulated loop antennas. Finally, experimental models and measuring techniques related to antennas and probes in a general dissipative or dielectric medium are examined.

  10. Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes.

    PubMed

    Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

    2016-06-01

    The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients.A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume.Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P < 0.05; voxel threshold: 33). Gray matter volume in the right anterior cingulate was also negatively correlated with the preprandial serum glucose level gyrus in a voxel-dependent manner (r = -0.501; 2-tailed P = 0.001).The cingulo-temporal and insula gray matter alterations may be associated with the glucose dysregulation in prediabetic patients.

  11. Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes

    PubMed Central

    Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

    2016-01-01

    Abstract The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients. A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume. Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P < 0.05; voxel threshold: 33). Gray matter volume in the right anterior cingulate was also negatively correlated with the preprandial serum glucose level gyrus in a voxel-dependent manner (r = –0.501; 2-tailed P = 0.001). The cingulo-temporal and insula gray matter alterations may be associated with the glucose dysregulation in prediabetic patients. PMID:27336893

  12. Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes.

    PubMed

    Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

    2016-06-01

    The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients.A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume.Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P < 0.05; voxel threshold: 33). Gray matter volume in the right anterior cingulate was also negatively correlated with the preprandial serum glucose level gyrus in a voxel-dependent manner (r = -0.501; 2-tailed P = 0.001).The cingulo-temporal and insula gray matter alterations may be associated with the glucose dysregulation in prediabetic patients. PMID:27336893

  13. Gray Matter Volume Changes in the Apathetic Elderly.

    PubMed

    Yan, Hongjie; Onoda, Keiichi; Yamaguchi, Shuhei

    2015-01-01

    This study is to test the hypothesis that apathy in healthy participants is closely related to the prefrontal-basal-ganglia circuit and associated structural changes. We selected 36 healthy aged participants with (n = 18) or without apathy (n = 18) from our database. Participants underwent structural MRI scanning, providing data for voxel-based morphometric analysis to explore gray matter changes associated with apathy. Compared to the non-apathy group, the apathy group showed reduced gray matter volume of the right putamen, whereas volumes of the bilateral inferior frontal gyri and left inferior occipital gyrus showed increase. When depression scores were included in a regression model as a covariate, apathetic participants showed decreased gray matter volume in the right precentral gyrus compared to the non-apathetic participants. These findings suggest that apathy is associated with the gray matter volume in the prefrontal-basal-ganglia network, and may have a neuroanatomical basis distinct from depression in healthy elderly.

  14. Gray Matter Volume Changes in the Apathetic Elderly

    PubMed Central

    Yan, Hongjie; Onoda, Keiichi; Yamaguchi, Shuhei

    2015-01-01

    This study is to test the hypothesis that apathy in healthy participants is closely related to the prefrontal-basal-ganglia circuit and associated structural changes. We selected 36 healthy aged participants with (n = 18) or without apathy (n = 18) from our database. Participants underwent structural MRI scanning, providing data for voxel-based morphometric analysis to explore gray matter changes associated with apathy. Compared to the non-apathy group, the apathy group showed reduced gray matter volume of the right putamen, whereas volumes of the bilateral inferior frontal gyri and left inferior occipital gyrus showed increase. When depression scores were included in a regression model as a covariate, apathetic participants showed decreased gray matter volume in the right precentral gyrus compared to the non-apathetic participants. These findings suggest that apathy is associated with the gray matter volume in the prefrontal-basal-ganglia network, and may have a neuroanatomical basis distinct from depression in healthy elderly. PMID:26082708

  15. Effective theory of Dirac dark matter

    SciTech Connect

    Harnik, Roni; Kribs, Graham D.

    2009-05-01

    A stable Dirac fermion with four-fermion interactions to leptons suppressed by a scale {lambda}{approx}1 TeV is shown to provide a viable candidate for dark matter. The thermal relic abundance matches cosmology, while nuclear recoil direct detection bounds are automatically avoided in the absence of (large) couplings to quarks. The annihilation cross section in the early Universe is the same as the annihilation in our Galactic neighborhood. This allows Dirac fermion dark matter to naturally explain the positron ratio excess observed by PAMELA with a minimal boost factor, given present astrophysical uncertainties. We use the Galprop program for propagation of signal and background; we discuss in detail the uncertainties resulting from the propagation parameters and, more importantly, the injected spectra. Fermi/GLAST has an opportunity to see a feature in the gamma-ray spectrum at the mass of the Dirac fermion. The excess observed by ATIC/PPB-BETS may also be explained with Dirac dark matter that is heavy. A supersymmetric model with a Dirac bino provides a viable UV model of the effective theory. The dominance of the leptonic operators, and thus the observation of an excess in positrons and not in antiprotons, is naturally explained by the large hypercharge and low mass of sleptons as compared with squarks. Minimizing the boost factor implies the right-handed selectron is the lightest slepton, which is characteristic of our model. Selectrons (or sleptons) with mass less than a few hundred GeV are an inescapable consequence awaiting discovery at the LHC.

  16. An Effective Theory of Dirac Dark Matter

    SciTech Connect

    Harnik, Roni; Kribs, Graham D.; /Oregon U.

    2010-06-11

    A stable Dirac fermion with four-fermion interactions to leptons suppressed by a scale {Lambda} {approx} 1 TeV is shown to provide a viable candidate for dark matter. The thermal relic abundance matches cosmology, while nuclear recoil direct detection bounds are automatically avoided in the absence of (large) couplings to quarks. The annihilation cross section in the early Universe is the same as the annihilation in our galactic neighborhood. This allows Dirac fermion dark matter to naturally explain the positron ratio excess observed by PAMELA with a minimal boost factor, given present astrophysical uncertainties. We use the Galprop program for propagation of signal and background; we discuss in detail the uncertainties resulting from the propagation parameters and, more importantly, the injected spectra. Fermi/GLAST has an opportunity to see a feature in the gamma-ray spectrum at the mass of the Dirac fermion. The excess observed by ATIC/PPB-BETS may also be explained with Dirac dark matter that is heavy. A supersymmetric model with a Dirac bino provides a viable UV model of the effective theory. The dominance of the leptonic operators, and thus the observation of an excess in positrons and not in anti-protons, is naturally explained by the large hypercharge and low mass of sleptons as compared with squarks. Minimizing the boost factor implies the right-handed selectron is the lightest slepton, which is characteristic of our model. Selectrons (or sleptons) with mass less than a few hundred GeV are an inescapable consequence awaiting discovery at the LHC.

  17. Matter, metaphors, and mechanisms: rethinking cell theories.

    PubMed

    Müller-Strahl, Gerhard

    2014-12-01

    This study analyzes the logical structure of classical cell theory (CCT) by pointing out that CCT conceives the properties of organic cellular matter as supervenient to successively emerging states of quasi-crystalline atoms. This concept supports the design of a metaphorical space the intelligible components of which display an explanatory structure in accordance with the contemporary complex-systems approach of mechanisms. These findings support the thesis of an explanatory turn within the life-sciences due to a conflict between anti-classificatory (Buffon), analogous (Wolff, Reil, Weber), and causal-mechanical (Kepler) strategies of explanation. The continuous process underlying these diverse discontinuities is taken to be the immanent process of objectifying scientific concepts for the need of explanation. This process repeatedly provides concepts which are identified as nomadic concepts. The meta-analysis of their interactions reveals that concepts of matter are obtained by idealizations which entertain one process with three dimensions: atomization originating from empirical classificatory regularities (classification) and aiming at an explanation of changing phenomena (dynamization). These dimensions are successfully incorporated into the explanatory scheme of CCT. The migrations of a second group of nomadic concepts beyond this historical point of transition are made responsible for blurring the explanatory turn.

  18. Matter, metaphors, and mechanisms: rethinking cell theories.

    PubMed

    Müller-Strahl, Gerhard

    2014-12-01

    This study analyzes the logical structure of classical cell theory (CCT) by pointing out that CCT conceives the properties of organic cellular matter as supervenient to successively emerging states of quasi-crystalline atoms. This concept supports the design of a metaphorical space the intelligible components of which display an explanatory structure in accordance with the contemporary complex-systems approach of mechanisms. These findings support the thesis of an explanatory turn within the life-sciences due to a conflict between anti-classificatory (Buffon), analogous (Wolff, Reil, Weber), and causal-mechanical (Kepler) strategies of explanation. The continuous process underlying these diverse discontinuities is taken to be the immanent process of objectifying scientific concepts for the need of explanation. This process repeatedly provides concepts which are identified as nomadic concepts. The meta-analysis of their interactions reveals that concepts of matter are obtained by idealizations which entertain one process with three dimensions: atomization originating from empirical classificatory regularities (classification) and aiming at an explanation of changing phenomena (dynamization). These dimensions are successfully incorporated into the explanatory scheme of CCT. The migrations of a second group of nomadic concepts beyond this historical point of transition are made responsible for blurring the explanatory turn. PMID:25156862

  19. Frontal White Matter Volume Is Associated with Brain Enlargement and Higher Structural Connectivity in Anthropoid Primates

    PubMed Central

    Smaers, Jeroen Bert; Schleicher, Axel; Zilles, Karl; Vinicius, Lucio

    2010-01-01

    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. PMID:20161758

  20. Theory Matters: Representation and Experimentation in Education

    ERIC Educational Resources Information Center

    Edwards, Richard

    2012-01-01

    This article provides a material enactment of educational theory to explore how we might do educational theory differently by defamiliarising the familiar. Theory is often assumed to be abstract, located solely in the realm of ideas and separate from practice. However, this view of theory emerges from a set of ontological and epistemological…

  1. White matter hyperintensity volume and impaired mobility among older adults

    PubMed Central

    Willey, Joshua Z.; Scarmeas, Nikolaos; Provenzano, Frank A.; Luchsinger, José A.; Mayeux, Richard; Brickman, Adam M.

    2012-01-01

    Gait speed is associated with multiple adverse outcomes of aging. White matter hyperintensities (WMH) on magnetic resonance imaging (MRI) have been associated with gait speed, though few studies have examined changes in gait speed over time in population-based studies comprising participants from diverse cultural backgrounds. The purpose of this study was to examine the association between a decline in gait speed and total and regional WMH volumes in a community-based study of aging. Participants (n=701) in a community-based study of older adults underwent gait speed measurement via a 4-meter walk test at the time of initial enrollment and MRI at a second time interval (mean 4.7[SD=0.5] years apart). Logistic regression was used to examine the association between large WMH volume and regional WMH volume with gait speed < 0.5 m/s (abnormal speed), and a transition to abnormal gait speed. Analyses were adjusted for demographic and clinical factors. Large WMH volume was associated with a transition to abnormal gait speed between the two visits, but not after adjustment for modifiable vascular disease risk factors. In adjusted models increased frontal lobe WMH volume was not associated with a transition to abnormal gait speed. WMH are associated with slowing of gait over time. Prevention of WMH presents a potential strategy for the prevention of gait speed decline. PMID:23128969

  2. Alterations in gray matter volume due to unilateral hearing loss

    PubMed Central

    Wang, Xingchao; Xu, Pengfei; Li, Peng; Wang, Zhenmin; Zhao, Fu; Gao, Zhixian; Xu, Lei; Luo, Yue-jia; Fan, Jin; Liu, Pinan

    2016-01-01

    Although extensive research on neural plasticity resulting from hearing deprivation has been conducted, the direct influence of compromised audition on the auditory cortex and the potential impact of long durations of incomplete sensory stimulation on the adult cortex are still not fully understood. In this study, using voxel-based morphometry, we evaluated gray matter (GM) volume changes that may be associated with reduced hearing ability and the duration of hearing impairment in 42 unilateral hearing loss (UHL) patients with acoustic neuromas compared to 24 normal controls. We found significant GM volume increases in the somatosensory and motor systems and GM volume decreases in the auditory (i.e., Heschl’s gyrus) and visual systems (i.e., the calcarine cortex) in UHL patients. The GM volume decreases in the primary auditory cortex (i.e., superior temporal gyrus and Heschl’s gyrus) correlated with reduced hearing ability. Meanwhile, the GM volume decreases in structures involving high-level cognitive control functions (i.e., dorsolateral prefrontal cortex and anterior cingulate cortex) correlated positively with hearing loss duration. Our findings demonstrated that the severity and duration of UHL may contribute to the dissociated morphology of auditory and high-level neural structures, providing insight into the brain’s plasticity related to chronic, persistent partial sensory loss. PMID:27174521

  3. New phase transitions in Chern-Simons matter theory

    NASA Astrophysics Data System (ADS)

    Zahabi, Ali

    2016-02-01

    Applying the machinery of random matrix theory and Toeplitz determinants we study the level k, U (N) Chern-Simons theory coupled with fundamental matter on S2 ×S1 at finite temperature T. This theory admits a discrete matrix integral representation, i.e. a unitary discrete matrix model of two-dimensional Yang-Mills theory. In this study, the effective partition function and phase structure of the Chern-Simons matter theory, in a special case with an effective potential namely the Gross-Witten-Wadia potential, are investigated. We obtain an exact expression for the partition function of the Chern-Simons matter theory as a function of k, N, T, for finite values and in the asymptotic regime. In the Gross-Witten-Wadia case, we show that ratio of the Chern-Simons matter partition function and the continuous two-dimensional Yang-Mills partition function, in the asymptotic regime, is the Tracy-Widom distribution. Consequently, using the explicit results for free energy of the theory, new second-order and third-order phase transitions are observed. Depending on the phase, in the asymptotic regime, Chern-Simons matter theory is represented either by a continuous or discrete two-dimensional Yang-Mills theory, separated by a third-order domain wall.

  4. White Matter Volume Abnormalities and Associations with Symptomatology in Schizophrenia

    PubMed Central

    Makris, N.; Seidman, L. J.; Ahern, T.; Kennedy, D. N.; Caviness, V. S.; Tsuang, M. T.; Goldstein, J. M.

    2010-01-01

    The cerebral white matter (WM) is critically involved in many bio-behavioral functions impaired in schizophrenia. However, the specific neural systems underlying symptomatology in schizophrenia are not well known. By comparing the volume of all brain fiber systems between chronic patients with DSM-III-R schizophrenia (n = 88) and matched healthy community controls (n = 40), we found that a set of a priori WM regions of local and distal associative fiber systems were significantly different in patients with schizophrenia. There were significant positive correlations between volumes (larger) in anterior callosal, cingulate and temporal deep WM regions (related to distal connections) with positive symptoms, such as hallucinations, delusions and bizarre behavior, and significant negative correlation between volumes (smaller) in occipital and paralimbic superficial WM (related to local connections) and posterior callosal fiber systems with higher negative symptoms, such as alogia. Furthermore, the temporal sagittal system showed significant rightward asymmetry between patients and controls. These observations suggest a pattern of volume WM alterations associated with symptomatology in schizophrenia that may be related in part to predisposition to schizophrenia. PMID:20538438

  5. Indirect Detection of Dark Matter: Theory Perspective

    SciTech Connect

    Profumo, Stefano

    2009-12-17

    Can we learn about New Physics with astronomical and astro-particle data? Understanding how this is possible is key to unraveling one of the most pressing mysteries at the interface of cosmology and particle physics: the fundamental nature of dark matter. Rapid progress may be within grasp in the context of an approach which combines information from high-energy particle physics with cosmic-ray and traditional astronomical data. I discuss recent puzzling data on cosmic-ray electrons and positrons and their interpretation. I show how the Fermi Space Telescope will soon shed light on those data as well as potentially on several dark matter particle properties. I also discuss a novel approach to particle dark matter searches based on the complementarity of astronomical observations across the electromagnetic spectrum, from radio to X-ray and to gamma-ray frequencies.

  6. Heavy dark matter annihilation from effective field theory.

    PubMed

    Ovanesyan, Grigory; Slatyer, Tracy R; Stewart, Iain W

    2015-05-29

    We formulate an effective field theory description for SU(2)_{L} triplet fermionic dark matter by combining nonrelativistic dark matter with gauge bosons in the soft-collinear effective theory. For a given dark matter mass, the annihilation cross section to line photons is obtained with 5% precision by simultaneously including Sommerfeld enhancement and the resummation of electroweak Sudakov logarithms at next-to-leading logarithmic order. Using these results, we present more accurate and precise predictions for the gamma-ray line signal from annihilation, updating both existing constraints and the reach of future experiments.

  7. Quantum theory and Aquinas's doctrine on matter

    NASA Astrophysics Data System (ADS)

    Grove, Stanley F.

    The Aristotelian conception of the material principle, deepened by Aquinas, is today widely misunderstood and largely alien to modern mathematical physics, despite the latter's preoccupation with matter and the spatiotemporal. The present dissertation seeks to develop a coherent understanding of matter in the Aristotelian-Thomistic sense, and to apply it to some key interpretive issues in quantum physics. I begin with a brief historical analysis of the Aristotelian, Newtonian ("classical"), and modern (quantum) approaches to physics, in order to highlight their commonality as well as their differences. Next, matter---especially prime matter---is investigated, in an Aristotelian-Thomistic perspective, under several rationes: as principle of individuation, as principle of extension or spatiality, as principle of corruptibility, as related to essence and existence, and as ground of intelligibility. An attempt is made to order these different rationes according to primordiality. A number of topics concerning the formal structure of hylomorphic being are then addressed: elementarity, virtual presence, the "dispositions of matter," entia vialia, natural minima, atomism, the nature of local motion, the plenum and instantaneous action at a distance---all with a view to their incorporation in a unified account of formed matter at or near the elementary level. Finally I take up several interpretive problems in quantum physics which were introduced early in the dissertation, and show how the material and formal principles expounded in the central chapters can render these problems intelligible. Thus I propose that wave and particle aspects in the quantum realm are related substantially rather than accidentally, and that characteristics of substantial (prime) matter and substantial form are therefore being evidenced directly at this level---in the reversibility of the wave-particle transition, in the spatial and temporal instantaneity of quantum events, and in the probabilism

  8. 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.

    PubMed

    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.

  9. 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.

    PubMed

    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. PMID:25595222

  10. Gravitational lenses and dark matter - Theory

    NASA Technical Reports Server (NTRS)

    Gott, J. Richard, III

    1987-01-01

    Theoretical models are presented for guiding the application of gravitational lenses to probe the characteristics of dark matter in the universe. Analytical techniques are defined for quantifying the mass associated with lensing galaxies (in terms of the image separation), determining the quantity of dark mass of the lensing bodies, and estimating the mass density of the lenses. The possibility that heavy halos are made of low mass stars is considered, along with the swallowing of central images of black holes or cusps in galactic nuclei and the effects produced on a lensed quasar image by nonbaryonic halos. The observable effects of dense groups and clusters and the characteristics of dark matter strings are discussed, and various types of images which are possible due to lensing phenomena and position are described.

  11. Stability in higher-derivative matter fields theories

    NASA Astrophysics Data System (ADS)

    Tretyakov, Petr V.

    2016-09-01

    We discuss possible instabilities in higher-derivative matter field theories. These theories have two free parameters β _1 and β _4. By using a dynamical system approach we explicitly demonstrate that for the stability of Minkowski space in an expanding universe we need the condition β _4<0. By using the quantum field theory approach we also find an additional restriction for the parameters, β _1>-1/3β _4, which is needed to avoid a tachyon-like instability.

  12. Correlations among brain gray matter volumes, age, gender, and hemisphere in healthy individuals.

    PubMed

    Taki, Yasuyuki; Thyreau, Benjamin; Kinomura, Shigeo; Sato, Kazunori; Goto, Ryoi; Kawashima, Ryuta; Fukuda, Hiroshi

    2011-01-01

    To determine the relationship between age and gray matter structure and how interactions between gender and hemisphere impact this relationship, we examined correlations between global or regional gray matter volume and age, including interactions of gender and hemisphere, using a general linear model with voxel-based and region-of-interest analyses. Brain magnetic resonance images were collected from 1460 healthy individuals aged 20-69 years; the images were linearly normalized and segmented and restored to native space for analysis of global gray matter volume. Linearly normalized images were then non-linearly normalized and smoothed for analysis of regional gray matter volume. Analysis of global gray matter volume revealed a significant negative correlation between gray matter ratio (gray matter volume divided by intracranial volume) and age in both genders, and a significant interaction effect of age × gender on the gray matter ratio. In analyzing regional gray matter volume, the gray matter volume of all regions showed significant main effects of age, and most regions, with the exception of several including the inferior parietal lobule, showed a significant age × gender interaction. Additionally, the inferior temporal gyrus showed a significant age × gender × hemisphere interaction. No regional volumes showed significant age × hemisphere interactions. Our study may contribute to clarifying the mechanism(s) of normal brain aging in each brain region.

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

    PubMed

    Delnooz, Cathérine C S; Pasman, Jaco W; van de Warrenburg, Bart P C

    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 sought to determine whether BoNT influences gray matter volume in a group of cervical dystonia (CD) patients. We analyzed whole brain gray matter volume in a sample of CD patients with VBM analysis. In patients, scans were repeated immediately before and some weeks after BoNT injections; controls were only scanned once. We analyzed 1) BoNT-related gray matter volume changes within patients; 2) gray matter volume differences between patients and controls; and 3) correlations between gray matter volume and disease duration and disease severity. The pre- and post-BoNT treatment analysis revealed an increase of gray matter volume within the right precentral sulcus, at the lateral border of the premotor cortex. In comparison to healthy controls, CD patients had reduced gray matter volume in area 45 functionally corresponding to the left ventral premotor cortex. No gray matter volume increase was found for CD patients in comparison to controls. Gray matter volume of the left supramarginal gyrus and left premotor cortex correlated positively with disease duration, and that of the right inferior parietal lobule correlated negatively with disease severity. We have identified structural, yet dynamic gray matter volume changes in CD. There were specific gray matter volume changes related to BoNT injections, illustrating indirect central consequences of modified peripheral sensory input. As differences were exclusively seen in higher order motor areas relevant to motor planning and spatial cognition, these observations support the hypothesis that deficits in these cognitive processes are crucial in the pathophysiology of CD.

  14. MAIL LOG, program theory, volume 2

    NASA Technical Reports Server (NTRS)

    Harris, D. K.

    1979-01-01

    Information relevant to the MAIL LOG program theory is documented. The L-files for mail correspondence, design information release/report, and the drawing/engineering order are given. In addition, sources for miscellaneous external routines and special support routines are documented along with a glossary of terms.

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

    PubMed

    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 < 0.001), but not with episodic memory, semantic memory, working memory, or visuospatial abilities (all 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 < 0.001). In a model with both MRI-derived measures included, the relation of WMH to perceptual speed remained significant (p < 0.001), while gray matter volumes were no longer related (p = 0.14). This study of older community-dwelling individuals without overt 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

  16. Effective field theory of dark matter: a global analysis

    NASA Astrophysics Data System (ADS)

    Liem, Sebastian; Bertone, Gianfranco; Calore, Francesca; de Austri, Roberto Ruiz; Tait, Tim M. P.; Trotta, Roberto; Weniger, Christoph

    2016-09-01

    We present global fits of an effective field theory description of real, and complex scalar dark matter candidates. We simultaneously take into account all possible dimension 6 operators consisting of dark matter bilinears and gauge invariant combinations of quark and gluon fields. We derive constraints on the free model parameters for both the real (five parameters) and complex (seven) scalar dark matter models obtained by combining Planck data on the cosmic microwave background, direct detection limits from LUX, and indirect detection limits from the Fermi Large Area Telescope. We find that for real scalars indirect dark matter searches disfavour a dark matter particle mass below 100 GeV. For the complex scalar dark matter particle current data have a limited impact due to the presence of operators that lead to p-wave annihilation, and also do not contribute to the spin-independent scattering cross-section. Although current data are not informative enough to strongly constrain the theory parameter space, we demonstrate the power of our formalism to reconstruct the theoretical parameters compatible with an actual dark matter detection, by assuming that the excess of gamma rays observed by the Fermi Large Area Telescope towards the Galactic centre is entirely due to dark matter annihilations. Please note that the excess can very well be due to astrophysical sources such as millisecond pulsars. We find that scalar dark matter interacting via effective field theory operators can in principle explain the Galactic centre excess, but that such interpretation is in strong tension with the non-detection of gamma rays from dwarf galaxies in the real scalar case. In the complex scalar case there is enough freedom to relieve the tension.

  17. Dark matter signals at neutrino telescopes in effective theories

    SciTech Connect

    Catena, Riccardo

    2015-04-29

    We constrain the effective theory of one-body dark matter-nucleon interactions using neutrino telescope observations. We derive exclusion limits on the 28 coupling constants of the theory, exploring interaction operators previously considered in dark matter direct detection only, and using new nuclear response functions recently derived through nuclear structure calculations. We determine for what interactions neutrino telescopes are superior to current direct detection experiments, and show that Hydrogen is not the most important element in the exclusion limit calculation for the majority of the spin-dependent operators.

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

    PubMed Central

    Ventura-Antunes, Lissa; Mota, Bruno; Herculano-Houzel, Suzana

    2013-01-01

    Expansion of the cortical gray matter in evolution has been accompanied by an even faster expansion of the subcortical white matter volume and by folding of the gray 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 gray 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 gray 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 gray 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. PMID:23576961

  19. Functional volumes modeling: theory and preliminary assessment.

    PubMed

    Fox, P T; Lancaster, J L; Parsons, L M; Xiong, J H; Zamarripa, F

    1997-01-01

    A construct for metanalytic modeling of the functional organization of the human brain, termed functional volumes modeling (FVM), is presented and preliminarily tested. FVM uses the published literature to model brain functional areas as spatial probability distributions. The FVM statistical model estimates population variance (i.e., among individuals) from the variance observed among group-mean studies, these being the most prevalent type of study in the functional imaging literature. The FVM modeling strategy is tested by: (1) constructing an FVM of the mouth region of primary motor cortex using published, group-mean, functional imaging reports as input, and (2) comparing the confidence bounds predicted by that FVM with those observed in 10 normal subjects performing overt-speech tasks. The FVM model correctly predicted the mean location and spatial distribution of per-subject functional responses. FVM has a wide range of applications, including hypothesis testing for statistical parametric images.

  20. Thermal density functional theory, ensemble density functional theory, and potential functional theory for warm dense matter

    NASA Astrophysics Data System (ADS)

    Pribram-Jones, Aurora

    Warm dense matter (WDM) is a high energy phase between solids and plasmas, with characteristics of both. It is present in the centers of giant planets, within the earth's core, and on the path to ignition of inertial confinement fusion. The high temperatures and pressures of warm dense matter lead to complications in its simulation, as both classical and quantum effects must be included. One of the most successful simulation methods is density functional theory-molecular dynamics (DFT-MD). Despite great success in a diverse array of applications, DFT-MD remains computationally expensive and it neglects the explicit temperature dependence of electron-electron interactions known to exist within exact DFT. Finite-temperature density functional theory (FT DFT) is an extension of the wildly successful ground-state DFT formalism via thermal ensembles, broadening its quantum mechanical treatment of electrons to include systems at non-zero temperatures. Exact mathematical conditions have been used to predict the behavior of approximations in limiting conditions and to connect FT DFT to the ground-state theory. An introduction to FT DFT is given within the context of ensemble DFT and the larger field of DFT is discussed for context. Ensemble DFT is used to describe ensembles of ground-state and excited systems. Exact conditions in ensemble DFT and the performance of approximations depend on ensemble weights. Using an inversion method, exact Kohn-Sham ensemble potentials are found and compared to approximations. The symmetry eigenstate Hartree-exchange approximation is in good agreement with exact calculations because of its inclusion of an ensemble derivative discontinuity. Since ensemble weights in FT DFT are temperature-dependent Fermi weights, this insight may help develop approximations well-suited to both ground-state and FT DFT. A novel, highly efficient approach to free energy calculations, finite-temperature potential functional theory, is derived, which has the

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

    ERIC Educational Resources Information Center

    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.

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

    ERIC Educational Resources Information Center

    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…

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

    PubMed Central

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

    2015-01-01

    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. PMID:22277302

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

    PubMed

    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.

  5. Bimetric gravity doubly coupled to matter: theory and cosmological implications

    SciTech Connect

    Akrami, Yashar; Koivisto, Tomi S.; Mota, David F.; Sandstad, Marit E-mail: t.s.koivisto@astro.uio.no E-mail: marit.sandstad@astro.uio.no

    2013-10-01

    A ghost-free theory of gravity with two dynamical metrics both coupled to matter is shown to be consistent and viable. Its cosmological implications are studied, and the models, in particular in the context of partially massless gravity, are found to explain the cosmic acceleration without resorting to dark energy.

  6. Black holes with surrounding matter in scalar-tensor theories.

    PubMed

    Cardoso, Vitor; Carucci, Isabella P; Pani, Paolo; Sotiriou, Thomas P

    2013-09-13

    We uncover two mechanisms that can render Kerr black holes unstable in scalar-tensor gravity, both associated with the presence of matter in the vicinity of the black hole and the fact that this introduces an effective mass for the scalar. Our results highlight the importance of understanding the structure of spacetime in realistic, astrophysical black holes in scalar-tensor theories.

  7. Why Theory Matters: An Examination of Contemporary Learning Time Reforms

    ERIC Educational Resources Information Center

    DiGiacomo, Daniela K.; Prudhomme, Joshua J.; Jones, Hannah R.; Welner, Kevin G.; Kishner, Ben

    2016-01-01

    This article explores the contemporary policy reform push to extend and expand learning time in schools. In light of the potential and continued prominence of learning time reforms in today's national educational landscape, this article makes visible the ways in which theory matters for the near- and long-term success of equity-focused educational…

  8. Regional volumes and spatial volumetric distribution of gray matter in the gender dysphoric brain.

    PubMed

    Hoekzema, Elseline; Schagen, Sebastian E E; Kreukels, Baudewijntje P C; Veltman, Dick J; Cohen-Kettenis, Peggy T; Delemarre-van de Waal, Henriette; Bakker, Julie

    2015-05-01

    The sexual differentiation of the brain is primarily driven by gonadal hormones during fetal development. Leading theories on the etiology of gender dysphoria (GD) involve deviations herein. To examine whether there are signs of a sex-atypical brain development in GD, we quantified regional neural gray matter (GM) volumes in 55 female-to-male and 38 male-to-female adolescents, 44 boys and 52 girls without GD and applied both univariate and multivariate analyses. In girls, more GM volume was observed in the left superior medial frontal cortex, while boys had more volume in the bilateral superior posterior hemispheres of the cerebellum and the hypothalamus. Regarding the GD groups, at whole-brain level they differed only from individuals sharing their gender identity but not from their natal sex. Accordingly, using multivariate pattern recognition analyses, the GD groups could more accurately be automatically discriminated from individuals sharing their gender identity than those sharing their natal sex based on spatially distributed GM patterns. However, region of interest analyses indicated less GM volume in the right cerebellum and more volume in the medial frontal cortex in female-to-males in comparison to girls without GD, while male-to-females had less volume in the bilateral cerebellum and hypothalamus than natal boys. Deviations from the natal sex within sexually dimorphic structures were also observed in the untreated subsamples. Our findings thus indicate that GM distribution and regional volumes in GD adolescents are largely in accordance with their respective natal sex. However, there are subtle deviations from the natal sex in sexually dimorphic structures, which can represent signs of a partial sex-atypical differentiation of the brain. PMID:25720349

  9. Statistical field theory description of inhomogeneous polarizable soft matter

    NASA Astrophysics Data System (ADS)

    Martin, Jonathan M.; Li, Wei; Delaney, Kris T.; Fredrickson, Glenn H.

    2016-10-01

    We present a new molecularly informed statistical field theory model of inhomogeneous polarizable soft matter. The model is based on fluid elements, referred to as beads, that can carry a net monopole of charge at their center of mass and a fixed or induced dipole through a Drude-type distributed charge approach. The beads are thus polarizable and naturally manifest attractive van der Waals interactions. Beyond electrostatic interactions, beads can be given soft repulsions to sustain fluid phases at arbitrary densities. Beads of different types can be mixed or linked into polymers with arbitrary chain models and sequences of charged and uncharged beads. By such an approach, it is possible to construct models suitable for describing a vast range of soft-matter systems including electrolyte and polyelectrolyte solutions, ionic liquids, polymerized ionic liquids, polymer blends, ionomers, and block copolymers, among others. These bead models can be constructed in virtually any ensemble and converted to complex-valued statistical field theories by Hubbard-Stratonovich transforms. One of the fields entering the resulting theories is a fluctuating electrostatic potential; other fields are necessary to decouple non-electrostatic interactions. We elucidate the structure of these field theories, their consistency with macroscopic electrostatic theory in the absence and presence of external electric fields, and the way in which they embed van der Waals interactions and non-uniform dielectric properties. Their suitability as a framework for computational studies of heterogeneous soft matter systems using field-theoretic simulation techniques is discussed.

  10. Millicharged dark matter in quantum gravity and string theory.

    PubMed

    Shiu, Gary; Soler, Pablo; Ye, Fang

    2013-06-14

    We examine the millicharged dark matter scenario from a string theory perspective. In this scenario, kinetic and mass mixings of the photon with extra U(1) bosons are claimed to give rise to small electric charges, carried by dark matter particles, whose values are determined by continuous parameters of the theory. This seems to contradict folk theorems of quantum gravity that forbid the existence of irrational charges in theories with a single massless gauge field. By considering the underlying structure of the U(1) mass matrix that appears in type II string compactifications, we show that millicharges arise exclusively through kinetic mixing, and require the existence of at least two exactly massless gauge bosons.

  11. Large-N volume independence in conformal and confining gauge theories

    SciTech Connect

    Unsal, Mithat; Yaffe, Laurence G.; /Washington U., Seattle

    2010-08-26

    Consequences of large N volume independence are examined in conformal and confining gauge theories. In the large N limit, gauge theories compactified on R{sup d-k} x (S{sup 1}){sup k} are independent of the S{sup 1} radii, provided the theory has unbroken center symmetry. In particular, this implies that a large N gauge theory which, on R{sup d}, flows to an IR fixed point, retains the infinite correlation length and other scale invariant properties of the decompactified theory even when compactified on R{sup d-k} x (S{sup 1}){sup k}. In other words, finite volume effects are 1/N suppressed. In lattice formulations of vector-like theories, this implies that numerical studies to determine the boundary between confined and conformal phases may be performed on one-site lattice models. In N = 4 supersymmetric Yang-Mills theory, the center symmetry realization is a matter of choice: the theory on R{sup 4-k} x (S{sup 1}){sup k} has a moduli space which contains points with all possible realizations of center symmetry. Large N QCD with massive adjoint fermions and one or two compactified dimensions has a rich phase structure with an infinite number of phase transitions coalescing in the zero radius limit.

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

    PubMed Central

    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; L, Reed; S, Williams; A, Lourdusamy; S, Costafreda; A, Cattrell; C, Nymberg; L, Topper; L, Smith; S, Havatzias; K, Stueber; C, Mallik; TK, Clarke; D, Stacey; Wong C, Peng; H, Werts; S, Williams; C, Andrew; S, Desrivieres; S, Zewdie; I, Häke; N, Ivanov; A, Klär; J, Reuter; C, Palafox; C, Hohmann; C, Schilling; K, Lüdemann; A, Romanowski; A, Ströhle; E, Wolff; M, Rapp; R, Brühl; A, Ihlenfeld; B, Walaszek; F, Schubert; C, Connolly; J, Jones; E, Lalor; E, McCabe; A, Ní Shiothcháin; R, Whelan; R, Spanagel; F, Leonardi-Essmann; W, Sommer; S, Vollstaedt-Klein; F, Nees; S, Steiner; M, Buehler; E, Stolzenburg; C, Schmal; F, Schirmbeck; P, Gowland; N, Heym; C, Newman; T, Huebner; S, Ripke; E, Mennigen; K, Muller; V, Ziesch; C, Büchel; U, Bromberg; L, Lueken; J, Yacubian; J, Finsterbusch; N, Bordas; S, de Bournonville; Z, Bricaud; Briand F, Gollier; J, Massicotte; JB, Poline; H, Vulser; Y, Schwartz; C, Lalanne; V, Frouin; B, Thyreau; J, Dalley; A, Mar; N, Subramaniam; D, Theobald; N, Richmond; M, de Rover; A, Molander; E, Jordan; E, Robinson; L, Hipolata; M, Moreno; M, Arroyo; D, Stephens; T, Ripley; H, Crombag; Y, Pena; M, Lathrop; D, Zelenika; S, Heath; D, Lanzerath; B, Heinrichs; T, Spranger; B, Fuchs; C, Speiser; F, Resch; J, Haffner; P, Parzer; R, Brunner; A, Klaassen; I, Klaassen; P, Constant; X, Mignon; T, Thomsen; S, Zysset; A, Vestboe; J, Ireland; J, Rogers

    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 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. PMID:23628983

  13. Seesaw theories at LHC and warm dark matter

    NASA Astrophysics Data System (ADS)

    Zhang, Yue

    2014-06-01

    Explaining the origin of neutrino masses clearly requires new physics beyond the Standard Model. I focus on the Seesaw paradigm and discuss a few simplest extensions of the SM that give Majorana masses to the active neutrinos. If realized at TeV scale, seesaw theories could manifest themselves in lepton number violating signatures at both low-energy processes and high-energy collider experiments. I summarize the constraints on the seesaw scales using the current LHC data. The left-right symmetric model connects the seesaw mechanism with the origin of parity symmetry breaking, and provides a unified framework for the simplest seesaw types. With new right-handed charged-current interactions, a TeV such model offers a plethora of new particles and exotic signatures at the LHC, and also accommodates a dark matter candidate, the lightest right-handed neutrino. A challenging question is the dark matter relic density which is typically over-produced in the early universe. The late decays of two heavier right-handed neutrinos can produce entropy and dilute the dark matter number. The key observation for this picture to work is the interplay between the freeze temperature of TeV right-handed gauge interaction and the QCD phase transition. The resulting dark matter mass is predicted to be around keV which makes the left-right model also a theory of warm dark matter. I will also comment on the fate of cosmic baryon asymmetry in this scenario.

  14. Mass eigenstates in bimetric theory with matter coupling

    SciTech Connect

    Schmidt-May, Angnis

    2015-01-01

    In this paper we study the ghost-free bimetric action extended by a recently proposed coupling to matter through a composite metric. The equations of motion for this theory are derived using a method which avoids varying the square-root matrix that appears in the matter coupling. We make an ansatz for which the metrics are proportional to each other and find that it can solve the equations provided that one parameter in the action is fixed. In this case, the proportional metrics as well as the effective metric that couples to matter solve Einstein's equations of general relativity including a matter source. Around these backgrounds we derive the quadratic action for perturbations and diagonalize it into generalized mass eigenstates. It turns out that matter only interacts with the massless spin-2 mode whose equation of motion has exactly the form of the linearized Einstein equations, while the field with Fierz-Pauli mass term is completely decoupled. Hence, bimetric theory, with one parameter fixed such that proportional solutions exist, is degenerate with general relativity up to linear order around these backgrounds.

  15. Parametric Finite-Volume Theory for Functionally Graded Materials

    NASA Astrophysics Data System (ADS)

    Cavalcante, Marcio A. A.; Marques, Severino P. C.; Pindera, M.-J.

    2008-02-01

    A parametric formulation of the finite-volume theory for functionally graded materials is presented based on a mapping of a square reference subcell onto a quadrilateral subcell in the actual discretized microstructure. This formulation significantly advances the capability and utility of the theory, enabling modeling of curved boundaries of functionally graded structural components, as well as inclusions employed for grading purposes, without the disadvantage of stress concentrations at the corners of rectangular subcells used in the standard version.

  16. Volume change theory for syringomyelia: A new perspective

    PubMed Central

    Rai, Survendra Kumar Rajdeo; Rai, Pooja Survendra Kumar

    2015-01-01

    Background: The etiopathogenesis of syringomyelia is still an enigma. The authors present a novel theory based on fluid dynamics at the craniovertebral (CV) junction to explain the genesis of syringomyelia (SM). The changes in volume of spinal canal, spinal cord, central canal and spinal subarachnoid space (SSS) in relation to the posterior fossa have been analysed, specifically during postural movements of flexion and extension. The effect of fluctuations in volume of spinal canal and its contents associated with cerebrospinal fluid (CSF) flow dynamics at the CV junction have been postulated to cause the origin and propagation of the syringomyelia. The relevant literature on the subject has been reviewed and the author's theory has been discussed. Conclusion: Volume of spinal canal in flexion is always greater than that in extension. Flexion of spine causes narrowing of the ventral subarachnoid space (SAS) and widening of dorsal SAS while extension causes reverse changes leading to fluid movement in dorsal spinal SAS in flexion and ventral spinal SAS in extension. Cervical and lumbar spinal region with maximum bulk hence maximum area and volume undergo maximum deformation during postural changes. SSS CSF is the difference between the volume of spinal canal and spinal cord, varies in flexion and extension which is compensated by changes in posterior fossa (CSF) volume in normal circumstances. Blocked SAS at foramen magnum donot permit spinal SAS CSF exchange which during postural changes is compensated by cavitatory/cystic (syrinx) change at locations in cervical and lumbar spine with propensity for maximum deformation. Augmentation of posterior fossa volume by decompression helps by normalization of this CSF exchange dynamics but immobilizing the spinal movement theoretically will cease any dynamic volume changes thereby minimizing the destructive influence of the fluid exchange on the cord. Thus, this theory strengthens the rational of treating patients by either

  17. Higher Education: Handbook of Theory and Research, Volume XVI.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    This volume contains essays related to various aspects of higher education, focusing on both educational theory and research. The chapters are: (1) "Apologia pro Vita Mia" (Robert Berdahl); (2) "Varieties of Validity: Quality in Qualitative Research" (Yvonna S. Lincoln); (3) "Academic Freedom and Federal Courts in the 1990s: The Legitimation of…

  18. Reading Research: Advances in Theory and Practice. Volume 4.

    ERIC Educational Resources Information Center

    MacKinnon, G. E., Ed.; Waller, T. Gary, Ed.

    Intended to provide an outlet for systematic and substantive reviews, both empirical and theoretical, and for extended integrative reports of programatic research, this volume focuses on the nature of reading and reading disabilities, with implications for both theory and practice. The first chapter of the book reports on a long-term study of the…

  19. Structure of matter, radioactivity, and nuclear fission. Volume 3

    SciTech Connect

    Not Available

    1986-01-01

    Subject matter includes structure of matter (what is matter, forces holding atoms together, visualizing the atom, the chemical elements, atomic symbols, isotopes, radiation from the atom), radioactivity (what holds the nucleus together, can one element change into another element, radiation from the nucleus, half-life, chart of the nuclides), and nuclear fission (nuclear energy release, the fission process, where does fission energy go, radiation and radioactivity resulting from fission).

  20. Dark matter effective field theory scattering in direct detection experiments

    NASA Astrophysics Data System (ADS)

    Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.; SuperCDMS Collaboration

    2015-05-01

    We examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  1. Dark matter effective field theory scattering in direct detection experiments

    SciTech Connect

    Schneck, K.; Cabrera, B.; Cerdeno, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, Priscilla B.; Daal, M.; Di Stefano, P. C.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, Jeter C.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, W.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

    2015-05-01

    We examine the consequences of the effective eld theory (EFT) of dark matter-nucleon scattering or current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral di*erences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  2. Dark matter effective field theory scattering in direct detection experiments

    SciTech Connect

    Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

    2015-05-18

    We examine the consequences of the effective field theory (EFT) of dark matter-nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. Here. we demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. In conclusion, we discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  3. The tunneling universe in scalar tensor theory with matter: II

    NASA Astrophysics Data System (ADS)

    Lee, Sunggeun

    2008-03-01

    In this paper, the wavefunction of the universe with a tunneling boundary condition is considered in the context of the Brans Dicke-type theory with matter. In the \\gamma=0 (matter) case, the action is invariant under the field redefinition which is a sort of generalization of the scale factor duality. The universe undergoes quantum transition from a super-inflationary (pre-big bang) to a deflationary (post-big bang) phase. We calculate the transition rate from the wavefunction by solving the Wheeler DeWitt equation and obtain a non-vanishing value. We learn that for a special value of the Brans Dicke parameter the transition rate grows heavily. From the ten-dimensional string theory point of view this happens when three-dimensional branes (D3-brane) become dominant.

  4. Finite volume Kolmogorov-Johnson-Mehl-Avrami theory.

    PubMed

    Berg, Bernd A; Dubey, Santosh

    2008-04-25

    We study the Kolmogorov-Johnson-Mehl-Avrami theory of phase conversion in finite volumes. For the conversion time we find the relationship tau(con)=tau(nu)[1+f(d)(q)]. Here d is the space dimension, tau(nu) the nucleation time in the volume V, and f(d)(q) a scaling function. Its dimensionless argument is q=tau(ex)/tau(nu), where tau(ex) is an expansion time, defined to be proportional to the diameter of the volume divided by expansion speed. We calculate f(d)(q) in one, two, and three dimensions. The often considered limits of phase conversion via either nucleation or spinodal decomposition are found to be volume-size dependent concepts, governed by simple power laws for f(d)(q).

  5. From superstrings theory to the dark matter in galaxies

    SciTech Connect

    Matos, Tonatiuh

    1999-10-25

    Starting from the effective action of the low energy limit of superstrings theory, I find an exact solution of the field equations which geodesics behavie exactly as the trajectories of stars arround of a spiral galaxy. Here dark matter is of dilatonic origin. It is remarkable that the energy density of this space-time is the same as the used by astronomers to model galaxy stability. Some remarks about a universe dominated by dilatons are pointed out.

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

    PubMed Central

    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. PMID:27199831

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

    PubMed

    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. PMID:27199831

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

    PubMed

    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.

  9. Depressive symptoms in adolescents: associations with white matter volume and marijuana use

    PubMed Central

    Medina, Krista Lisdahl; Nagel, Bonnie J.; Park, Ann; McQueeny, Tim; Tapert, Susan F.

    2008-01-01

    Background Depressed mood has been associated with decreased white matter and reduced hippocampal volumes. However, the relationship between brain structure and mood may be unique among adolescents who use marijuana heavily. The goal of this study was to examine the relationship between white matter and hippocampal volumes and depressive symptoms among adolescent marijuana users and controls. Methods Data were collected from marijuana users (n = 16) and demographically similar controls (n = 16) aged 16–18. Extensive exclusionary criteria included psychiatric and neurologic disorders, including major depression. Substance use, mood, and anatomical measures were collected after 28 days of monitored abstinence. Results Marijuana (MJ) users demonstrated more depressive symptoms than controls (p < .05). MJ use (β = .42, p < .005) and smaller white matter volume (β = −.34, p < .03) each predicted higher levels of depressive symptoms on the Hamilton Depression Rating Scale. MJ use interacted with white matter volume (β = −.55, p < .03) in predicting depression scores on the Beck Depression Inventory: among MJ users, but not controls, white matter volume was negatively associated with depressive symptoms. Conclusions Marijuana use and white matter volume were additive and interactive in predicting depressive symptoms among adolescents. Subtle neurodevelopmental white matter abnormalities may disrupt the connections between areas involved in mood regulation. PMID:17537075

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

    PubMed

    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.

  11. Effective field theory of dark matter from membrane inflationary paradigm

    NASA Astrophysics Data System (ADS)

    Choudhury, Sayantan; Dasgupta, Arnab

    2016-09-01

    In this article, we have studied the cosmological and particle physics constraints on dark matter relic abundance from effective field theory of inflation from tensor-to-scalar ratio (r), in case of Randall-Sundrum single membrane (RSII) paradigm. Using semi-analytical approach we establish a direct connection between the dark matter relic abundance (ΩDMh2) and primordial gravity waves (r), which establishes a precise connection between inflation and generation of dark matter within the framework of effective field theory in RSII membrane. Further assuming the UV completeness of the effective field theory perfectly holds good in the prescribed framework, we have explicitly shown that the membrane tension, σ ≤ O(10-9) Mp4, bulk mass scale M5 ≤ O(0.04 - 0.05) Mp, and cosmological constant Λ˜5 ≥ - O(10-15) Mp5, in RSII membrane plays the most significant role to establish the connection between dark matter and inflation, using which we have studied the features of various mediator mass scale suppressed effective field theory "relevant operators" induced from the localized s, t and u channel interactions in RSII membrane. Taking a completely model independent approach, we have studied an exhaustive list of tree-level Feynman diagrams for dark matter annihilation within the prescribed setup and to check the consistency of the obtained results, further we apply the constraints as obtained from recently observed Planck 2015 data and Planck + BICEP2 + Keck Array joint data sets. Using all of these derived results we have shown that to satisfy the bound on, ΩDMh2 = 0.1199 ± 0.0027, as from Planck 2015 data, it is possible to put further stringent constraint on r within, 0.01 ≤ r ≤ 0.12, for thermally averaged annihilation cross-section of dark matter, < σv > ≈ O(10-28 - 10-27) cm3 / s, which are very useful to constrain various membrane inflationary models.

  12. Yang-Mills theories with chiral matter at strong coupling

    SciTech Connect

    Shifman, M.; Uensal, Mithat

    2009-05-15

    Strong coupling dynamics of Yang-Mills theories with chiral fermion content remained largely elusive despite much effort over the years. In this work, we propose a dynamical framework in which we can address nonperturbative properties of chiral, nonsupersymmetric gauge theories, in particular, chiral quiver theories on S{sub 1}xR{sub 3}. Double-trace deformations are used to stabilize the center-symmetric vacuum. This allows one to smoothly connect small-r(S{sub 1}) to large-r(S{sub 1}) physics (R{sub 4} is the limiting case) where the double-trace deformations are switched off. In particular, the occurrence of the mass gap in the gauge sector and linear confinement due to bions are analytically demonstrated. We find the pattern of the chiral symmetry realization which depends on the structure of the monopole-ring operators, a novel class of topological excitations. The deformed chiral theory, unlike the undeformed one, satisfies volume independence down to arbitrarily small volumes (a working Eguchi-Kawai reduction) in the large N limit. This equivalence may open new perspectives on strong coupling chiral gauge theories on R{sub 4}.

  13. [Guidance of volume transmission theory on treatment of "bipolar lesions"].

    PubMed

    Shao, Xuanming; Han, Jie; Sun, Dayong; Ji, Xiaofei

    2015-10-01

    As the key organ of human, the brain has projection area corresponding to every part of the body, indicating that the damage on human body will locate a corresponding projection area in the brain. The primary injury on the distal end will produce secondary lesion in the projection area of brain, featuring as "bipolar lesions". The volume transmission (VT) theory and propagated sensation along meridians (PSAM) in TCM provide core guidance for the treatment of "bipolar lesions". The tendency to lesion of PSAM is achieved through volume transmission, which is also called "propagated sensation tendency to lesion of VT". From three aspects, VT can treat bipolar lesions, formatting a ring closed path. With VT as main treatment and wiring transmission as supplemented treatment, it has a more comprehensive guidance for treatment, and this theory may play an essential guiding role in the future treatment development for diseases. PMID:26790226

  14. [Guidance of volume transmission theory on treatment of "bipolar lesions"].

    PubMed

    Shao, Xuanming; Han, Jie; Sun, Dayong; Ji, Xiaofei

    2015-10-01

    As the key organ of human, the brain has projection area corresponding to every part of the body, indicating that the damage on human body will locate a corresponding projection area in the brain. The primary injury on the distal end will produce secondary lesion in the projection area of brain, featuring as "bipolar lesions". The volume transmission (VT) theory and propagated sensation along meridians (PSAM) in TCM provide core guidance for the treatment of "bipolar lesions". The tendency to lesion of PSAM is achieved through volume transmission, which is also called "propagated sensation tendency to lesion of VT". From three aspects, VT can treat bipolar lesions, formatting a ring closed path. With VT as main treatment and wiring transmission as supplemented treatment, it has a more comprehensive guidance for treatment, and this theory may play an essential guiding role in the future treatment development for diseases.

  15. Voxel-based morphometry reveals reduced grey matter volume in the temporal cortex of developmental prosopagnosics

    PubMed Central

    Furl, Nicholas; Draganski, Bogdan; Weiskopf, Nikolaus; Stevens, John; Tan, Geoffrey Chern-Yee; Driver, Jon; Dolan, Ray J.; Duchaine, Bradley

    2009-01-01

    Individuals with developmental prosopagnosia exhibit severe and lasting difficulties in recognizing faces despite the absence of apparent brain abnormalities. We used voxel-based morphometry to investigate whether developmental prosopagnosics show subtle neuroanatomical differences from controls. An analysis based on segmentation of T1-weighted images from 17 developmental prosopagnosics and 18 matched controls revealed that they had reduced grey matter volume in the right anterior inferior temporal lobe and in the superior temporal sulcus/middle temporal gyrus bilaterally. In addition, a voxel-based morphometry analysis based on the segmentation of magnetization transfer parameter maps showed that developmental prosopagnosics also had reduced grey matter volume in the right middle fusiform gyrus and the inferior temporal gyrus. Multiple regression analyses relating three distinct behavioural component scores, derived from a principal component analysis, to grey matter volume revealed an association between a component related to facial identity and grey matter volume in the left superior temporal sulcus/middle temporal gyrus plus the right middle fusiform gyrus/inferior temporal gyrus. Grey matter volume in the lateral occipital cortex was associated with component scores related to object recognition tasks. Our results demonstrate that developmental prosopagnosics have reduced grey matter volume in several regions known to respond selectively to faces and provide new evidence that integrity of these areas relates to face recognition ability. PMID:19887506

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

    PubMed Central

    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

  17. Quantum electrodynamics in finite volume and nonrelativistic effective field theories

    NASA Astrophysics Data System (ADS)

    Fodor, Z.; Hoelbling, C.; Katz, S. D.; Lellouch, L.; Portelli, A.; Szabo, K. K.; Toth, B. C.

    2016-04-01

    Electromagnetic effects are increasingly being accounted for in lattice quantum chromodynamics computations. Because of their long-range nature, they lead to large finite-size effects over which it is important to gain analytical control. Nonrelativistic effective field theories provide an efficient tool to describe these effects. Here we argue that some care has to be taken when applying these methods to quantum electrodynamics in a finite volume.

  18. Dark matter effective field theory scattering in direct detection experiments

    SciTech Connect

    Schneck, K.

    2015-05-01

    We examine the consequences of the effective field theory (EFT) of dark matter–nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  19. Dark matter effective field theory scattering in direct detection experiments

    DOE PAGES

    Schneck, K.

    2015-05-01

    We examine the consequences of the effective field theory (EFT) of dark matter–nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implicationsmore » of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.« less

  20. The effective field theory of dark matter direct detection

    SciTech Connect

    Fitzpatrick, A. Liam; Katz, Emanuel; Haxton, Wick; Lubbers, Nicholas; Xu, Yiming E-mail: haxton@berkeley.edu E-mail: nlubbers@bu.edu

    2013-02-01

    We extend and explore the general non-relativistic effective theory of dark matter (DM) direct detection. We describe the basic non-relativistic building blocks of operators and discuss their symmetry properties, writing down all Galilean-invariant operators up to quadratic order in momentum transfer arising from exchange of particles of spin 1 or less. Any DM particle theory can be translated into the coefficients of an effective operator and any effective operator can be simply related to most general description of the nuclear response. We find several operators which lead to novel nuclear responses. These responses differ significantly from the standard minimal WIMP cases in their relative coupling strengths to various elements, changing how the results from different experiments should be compared against each other. Response functions are evaluated for common DM targets — F, Na, Ge, I, and Xe — using standard shell model techniques. We point out that each of the nuclear responses is familiar from past studies of semi-leptonic electroweak interactions, and thus potentially testable in weak interaction studies. We provide tables of the full set of required matrix elements at finite momentum transfer for a range of common elements, making a careful and fully model-independent analysis possible. Finally, we discuss embedding non-relativistic effective theory operators into UV models of dark matter.

  1. Volume changes and brain-behavior relationships in white matter and subcortical gray matter in children with prenatal alcohol exposure.

    PubMed

    Gautam, Prapti; Lebel, Catherine; Narr, Katherine L; Mattson, Sarah N; May, Philip A; Adnams, Colleen M; Riley, Edward P; Jones, Kenneth L; Kan, Eric C; Sowell, Elizabeth R

    2015-06-01

    Children with prenatal alcohol exposure (PAE) may have cognitive, behavioral and brain abnormalities. Here, we compare rates of white matter and subcortical gray matter volume change in PAE and control children, and examine relationships between annual volume change and arithmetic ability, behavior, and executive function. Participants (n = 75 PAE/64 control; age: 7.1-15.9 years) each received two structural magnetic resonance scans, ~2 years apart. Assessments included Wechsler Intelligence Scale for Children (WISC-IV), the Child Behavior Checklist and the Behavior Rating Inventory of Executive Function. Subcortical white and gray volumes were extracted for each hemisphere. Group volume differences were tested using false discovery rate (q < 0.05). Analyses examined group-by-age interactions and group-score interactions for correlations between change in volume and raw behavioral scores. Results showed that subjects with PAE had smaller volumes than control subjects across the brain. Significant group-score interactions were found in temporal and parietal regions for WISC arithmetic scores and in frontal and parietal regions for behavioral measures. Poorer cognitive/ behavioral outcomes were associated with larger volume increases in PAE, while control subjects generally showed no significant correlations. In contrast with previous results demonstrating different trajectories of cortical volume change in PAE, our results show similar rates of subcortical volume growth in subjects with PAE and control subjects. We also demonstrate abnormal brain-behavior relationships in subjects with PAE, suggesting different use of brain resources. Our results are encouraging in that, due to the stable volume differences, there may be an extended window of opportunity for intervention in children with PAE.

  2. Volume changes and brain-behavior relationships in white matter and subcortical gray matter in children with prenatal alcohol exposure.

    PubMed

    Gautam, Prapti; Lebel, Catherine; Narr, Katherine L; Mattson, Sarah N; May, Philip A; Adnams, Colleen M; Riley, Edward P; Jones, Kenneth L; Kan, Eric C; Sowell, Elizabeth R

    2015-06-01

    Children with prenatal alcohol exposure (PAE) may have cognitive, behavioral and brain abnormalities. Here, we compare rates of white matter and subcortical gray matter volume change in PAE and control children, and examine relationships between annual volume change and arithmetic ability, behavior, and executive function. Participants (n = 75 PAE/64 control; age: 7.1-15.9 years) each received two structural magnetic resonance scans, ~2 years apart. Assessments included Wechsler Intelligence Scale for Children (WISC-IV), the Child Behavior Checklist and the Behavior Rating Inventory of Executive Function. Subcortical white and gray volumes were extracted for each hemisphere. Group volume differences were tested using false discovery rate (q < 0.05). Analyses examined group-by-age interactions and group-score interactions for correlations between change in volume and raw behavioral scores. Results showed that subjects with PAE had smaller volumes than control subjects across the brain. Significant group-score interactions were found in temporal and parietal regions for WISC arithmetic scores and in frontal and parietal regions for behavioral measures. Poorer cognitive/ behavioral outcomes were associated with larger volume increases in PAE, while control subjects generally showed no significant correlations. In contrast with previous results demonstrating different trajectories of cortical volume change in PAE, our results show similar rates of subcortical volume growth in subjects with PAE and control subjects. We also demonstrate abnormal brain-behavior relationships in subjects with PAE, suggesting different use of brain resources. Our results are encouraging in that, due to the stable volume differences, there may be an extended window of opportunity for intervention in children with PAE. PMID:25711175

  3. Alterations in white matter volume and integrity in obesity and type 2 diabetes.

    PubMed

    van Bloemendaal, Liselotte; Ijzerman, Richard G; Ten Kulve, Jennifer S; Barkhof, Frederik; Diamant, Michaela; Veltman, Dick J; van Duinkerken, Eelco

    2016-06-01

    Type 2 diabetes mellitus (T2DM) is characterized by obesity, hyperglycemia and insulin resistance. Both T2DM and obesity are associated with cerebral complications, including an increased risk of cognitive impairment and dementia, however the underlying mechanisms are largely unknown. In the current study, we aimed to determine the relative contributions of obesity and the presence of T2DM to altered white matter structure. We used diffusion tensor imaging (DTI) and voxel-based morphometry (VBM) to measure white matter integrity and volume in obese T2DM patients without micro- or macrovascular complications, age- gender- and BMI-matched normoglycemic obese subjects and age- and gender-matched normoglycemic lean subjects. We found that obese T2DM patients compared with lean subjects had lower axial diffusivity (in the right corticospinal tract, right inferior fronto-occipital tract, right superior longitudinal fasciculus and right forceps major) and reduced white matter volume (in the right inferior parietal lobe and the left external capsule region). In normoglycemic obese compared with lean subjects axial diffusivity as well as white matter volume tended to be reduced, whereas there were no significant differences between normoglycemic obese subjects and T2DM patients. Decreased white matter integrity and volume were univariately related to higher age, being male, higher BMI, HbA1C and fasting glucose and insulin levels. However, multivariate analyses demonstrated that only BMI was independently related to white matter integrity, and age, gender and BMI to white matter volume loss. Our data indicate that obese T2DM patients have reduced white matter integrity and volume, but that this is largely explained by BMI, rather than T2DM per se.

  4. Elasticity of microscale volumes of viscoelastic soft matter by cavitation rheometry

    PubMed Central

    Pavlovsky, Leonid; Ganesan, Mahesh; Younger, John G.; Solomon, Michael J.

    2014-01-01

    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. PMID:25316925

  5. Female Adolescents with Severe Substance and Conduct Problems Have Substantially Less Brain Gray Matter Volume

    PubMed Central

    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

    Objective 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. Hypotheses: 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). Methods 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. Results 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. Conclusions 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

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

    PubMed

    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 < 0.05, cluster size k > 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.

  7. Aging and large-scale functional networks: white matter integrity, gray matter volume, and functional connectivity in the resting state.

    PubMed

    Marstaller, L; Williams, M; Rich, A; Savage, G; Burianová, H

    2015-04-01

    Healthy aging is accompanied by neurobiological changes that affect the brain's functional organization and the individual's cognitive abilities. The aim of this study was to investigate the effect of global age-related differences in the cortical white and gray matter on neural activity in three key large-scale networks. We used functional-structural covariance network analysis to assess resting state activity in the default mode network (DMN), the fronto-parietal network (FPN), and the salience network (SN) of young and older adults. We further related this functional activity to measures of cortical thickness and volume derived from structural MRI, as well as to measures of white matter integrity (fractional anisotropy [FA], mean diffusivity [MD], and radial diffusivity [RD]) derived from diffusion-weighted imaging. First, our results show that, in the direct comparison of resting state activity, young but not older adults reliably engage the SN and FPN in addition to the DMN, suggesting that older adults recruit these networks less consistently. Second, our results demonstrate that age-related decline in white matter integrity and gray matter volume is associated with activity in prefrontal nodes of the SN and FPN, possibly reflecting compensatory mechanisms. We suggest that age-related differences in gray and white matter properties differentially affect the ability of the brain to engage and coordinate large-scale functional networks that are central to efficient cognitive functioning.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Gray Matter Volumes of Pain Related Brain Areas are Decreased in Fibromyalgia Syndrome

    PubMed Central

    Robinson, Michael E.; Craggs, Jason G.; Price, Donald D.; Perlstein, William M.; Staud, Roland

    2010-01-01

    Fibromyalgia (FM) is a chronic widespread musculoskeletal pain disorder that is very prevalent in the general population (approx. 5%). Accumulating evidence suggests that FM is associated with central pain processing abnormalities, i.e. central sensitization. Several previous studies of chronic pain patients, including FM, have shown gray matter atrophy of brain areas associated with sensory and affective pain processing. These findings, however, have not been confirmed in all FM studies. In this study, we investigated gray matter volumes of brain areas associated with pain-related areas of FM patients identified by functional brain imaging. Using voxel-based morphometric (VBM) analysis of magnetic resonance brain images, we compared 19 pain related brain areas of 14 female FM patients and 11 healthy controls (NC). We found that FM patients had significantly less gray matter volumes than NC in three of these brain regions, including the anterior and mid-cingulate, as well as mid-insular cortices. Importantly, FM patients neither demonstrated global gray matter atrophy nor gray matter changes associated with depression, as shown in some studies. Using a more stringent analysis than other VBM studies, we provide evidence for decreased gray matter volumes in a number of pain related brain areas in FM. Although the mechanisms for these gray matter changes are presently unclear, they may contribute to some of the core features of this chronic disorder including affective disturbances and chronic widespread pain PMID:21146463

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

    PubMed

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

    2010-01-01

    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. PMID:21170334

  11. Hot and dense matter beyond relativistic mean field theory

    NASA Astrophysics Data System (ADS)

    Zhang, Xilin; Prakash, Madappa

    2016-05-01

    Properties of hot and dense matter are calculated in the framework of quantum hadrodynamics by including contributions from two-loop (TL) diagrams arising from the exchange of isoscalar and isovector mesons between nucleons. Our extension of mean field theory (MFT) employs the same five density-independent coupling strengths which are calibrated using the empirical properties at the equilibrium density of isospin-symmetric matter. Results of calculations from the MFT and TL approximations are compared for conditions of density, temperature, and proton fraction encountered in the study of core-collapse supernovae, young and old neutron stars, and mergers of compact binary stars. The TL results for the equation of state (EOS) of cold pure neutron matter at sub- and near-nuclear densities agree well with those of modern quantum Monte Carlo and effective field-theoretical approaches. Although the high-density EOS in the TL approximation for cold and β -equilibrated neutron-star matter is substantially softer than its MFT counterpart, it is able to support a 2 M⊙ neutron star required by recent precise determinations. In addition, radii of 1.4 M⊙ stars are smaller by ˜1 km than those obtained in MFT and lie in the range indicated by analysis of astronomical data. In contrast to MFT, the TL results also give a better account of the single-particle or optical potentials extracted from analyses of medium-energy proton-nucleus and heavy-ion experiments. In degenerate conditions, the thermal variables are well reproduced by results of Landau's Fermi-liquid theory in which density-dependent effective masses feature prominently. The ratio of the thermal components of pressure and energy density expressed as Γth=1 +(Pth/ɛth) , often used in astrophysical simulations, exhibits a stronger dependence on density than on proton fraction and temperature in both MFT and TL calculations. The prominent peak of Γth at supranuclear density found in MFT is, however, suppressed in

  12. Theory of volume transition in polyelectrolyte gels with charge regularization.

    PubMed

    Hua, Jing; Mitra, Mithun K; Muthukumar, M

    2012-04-01

    We present a theory for polyelectrolyte gels that allow the effective charge of the polymer backbone to self-regulate. Using a variational approach, we obtain an expression for the free energy of gels that accounts for the gel elasticity, free energy of mixing, counterion adsorption, local dielectric constant, electrostatic interaction among polymer segments, electrolyte ion correlations, and self-consistent charge regularization on the polymer strands. This free energy is then minimized to predict the behavior of the system as characterized by the gel volume fraction as a function of external variables such as temperature and salt concentration. We present results for the volume transition of polyelectrolyte gels in salt-free solvents, solvents with monovalent salts, and solvents with divalent salts. The results of our theoretical analysis capture the essential features of existing experimental results and also provide predictions for further experimentation. Our analysis highlights the importance of the self-regularization of the effective charge for the volume transition of gels in particular, and for charged polymer systems in general. Our analysis also enables us to identify the dominant free energy contributions for charged polymer networks and provides a framework for further investigation of specific experimental systems.

  13. Precision Higgs Physics, Effective Field Theory, and Dark Matter

    NASA Astrophysics Data System (ADS)

    Henning, Brian Quinn

    The recent discovery of the Higgs boson calls for detailed studies of its properties. As precision measurements are indirect probes of new physics, the appropriate theoretical framework is effective field theory. In the first part of this thesis, we present a practical three-step procedure of using the Standard Model effective field theory (SM EFT) to connect ultraviolet (UV) models of new physics with weak scale precision observables. With this procedure, one can interpret precision measurements as constraints on the UV model concerned. We give a detailed explanation for calculating the effective action up to one-loop order in a manifestly gauge covariant fashion. The covariant derivative expansion dramatically simplifies the process of matching a UV model with the SM EFT, and also makes available a universal formalism that is easy to use for a variety of UV models. A few general aspects of renormalization group running effects and choosing operator bases are discussed. Finally, we provide mapping results between the bosonic sector of the SM EFT and a complete set of precision electroweak and Higgs observables to which present and near future experiments are sensitive. With a detailed understanding of how to use the SM EFT, we then turn to applications and study in detail two well-motivated test cases. The first is singlet scalar field that enables the first-order electroweak phase transition for baryogenesis; the second example is due to scalar tops in the MSSM. We find both Higgs and electroweak measurements are sensitive probes of these cases. The second part of this thesis centers around dark matter, and consists of two studies. In the first, we examine the effects of relic dark matter annihilations on big bang nucleosynthesis (BBN). The magnitude of these effects scale simply with the dark matter mass and annihilation cross-section, which we derive. Estimates based on these scaling behaviors indicate that BBN severely constrains hadronic and radiative dark

  14. Effective Field Theories for Hot and Dense Matter

    NASA Astrophysics Data System (ADS)

    Blaschke, D.

    2010-10-01

    The lecture is divided in two parts. The first one deals with an introduction to the physics of hot, dense many-particle systems in quantum field theory [1, 2]. The basics of the path integral approach to the partition function are explained for the example of chiral quark models. The QCD phase diagram is discussed in the meanfield approximation while QCD bound states in the medium are treated in the rainbow-ladder approximation (Gaussian fluctuations). Special emphasis is devoted to the discussion of the Mott effect, i.e. the transition of bound states to unbound, but resonant scattering states in the continnum under the influence of compression and heating of the system. Three examples are given: (1) the QCD model phase diagram with chiral symmetry ¨ restoration and color superconductivity [3], (2) the Schrodinger equation for heavy-quarkonia [4], and (2) Pions [5] as well as Kaons and D-mesons in the finite-temperature Bethe-Salpeter equation [6]. We discuss recent applications of this quantum field theoretical approach to hot and dense quark matter for a description of anomalous J/ψ supression in heavy-ion collisions [7] and for the structure and cooling of compact stars with quark matter interiors [8]. The second part provides a detailed introduction to the Polyakov-loop Nambu-Jona-Lasinio model [9] for thermodynamics and mesonic correlations [10] in the phase diagram of quark matter. Important relationships of low-energy QCD like the Gell-Mann-Oakes-Renner relation are generalized to finite temperatures. The effect of including the coupling to the Polyakov-loop potential on the phase diagram and mesonic correlations is discussed. An outlook is given to effects of nonlocality of the interactions [11] and of mesonic correlations in the medium [12] which go beyond the meanfield description.

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

    PubMed

    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 (pFWE<0.05, family-wise whole-brain corrected) of gmPVE correlated with EMP/LASB in dorsolateral and medial prefrontal regions, and in occipital cortex. BS/IMP did not correlate with gmPVE, but one scale of impulsivity (Eysenck I7) correlated positively with bilateral inferior frontal/orbitofrontal, and anterior insula gmPVE. In this large sample of community-dwelling young 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.

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

    PubMed

    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 (pFWE<0.05, family-wise whole-brain corrected) of gmPVE correlated with EMP/LASB in dorsolateral and medial prefrontal regions, and in occipital cortex. BS/IMP did not correlate with gmPVE, but one scale of impulsivity (Eysenck I7) correlated positively with bilateral inferior frontal/orbitofrontal, and anterior insula gmPVE. In this large sample of community-dwelling young 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. PMID:26778367

  17. Projective and volume-preserving bundle structures involved in the formulation of A(4) gauge theories.

    NASA Astrophysics Data System (ADS)

    Fulp, R. O.; Davis, W. R.; Norris, L. K.

    1986-01-01

    The bundle structures required by volume-preserving and related projective properties are developed and discussed in the context ofA(4) gauge theories which may be taken as the proper framework for Poincaré gauge theories. The results of this paper include methods for extending both tensors and connections to a principal fiber bundle havingG1(4,R)xG1(4,R) as its structure group. This bundle structure is shown to be a natural arena for the generalized (±) covariant differentiation utilized by Einstein for his extended gravitational theories involving nonsymmetric connections. In particular, it is shown that this generalized (±) covariant differentiation is actually a special case of ordinary covariant differentiation with respect to a connection on theG1(4,R) xG1(4,R) bundle. These results are discussed in relation to certain properties of generalized gravitational theories based on a nonsymmetric connection which include the metric affine theories of Hehl et al. and the general requirement that it should be possible to formulate well-defined local conservation laws. In terms of the extended bundle structure considered in this paper, it is found that physically distinct particle number type conservation expressions could exist for certain given types of matter currents.

  18. Cognitive subtypes of dyslexia are characterized by distinct patterns of grey matter volume.

    PubMed

    Jednoróg, Katarzyna; Gawron, Natalia; Marchewka, Artur; Heim, Stefan; Grabowska, Anna

    2014-09-01

    The variety of different causal theories together with inconsistencies about the anatomical brain markers emphasize the heterogeneity of developmental dyslexia. Attempts were made to test on a behavioral level the existence of subtypes of dyslexia showing distinguishable cognitive deficits. Importantly, no research was directly devoted to the investigation of structural brain correlates of these subtypes. Here, for the first time, we applied voxel-based morphometry (VBM) to study grey matter volume (GMV) differences in a relatively large sample (n = 46) of dyslexic children split into three subtypes based on the cognitive deficits: phonological, rapid naming, magnocellular/dorsal, and auditory attention shifting. VBM revealed GMV clusters specific for each studied group including areas of left inferior frontal gyrus, cerebellum, right putamen, and bilateral parietal cortex. In addition, using discriminant analysis on these clusters 79% of cross-validated cases were correctly re-classified into four groups (controls vs. three subtypes). Current results indicate that dyslexia may result from distinct cognitive impairments characterized by distinguishable anatomical markers.

  19. Kinetic theory molecular dynamics and hot dense matter: theoretical foundations.

    PubMed

    Graziani, F R; Bauer, J D; Murillo, M S

    2014-09-01

    Electrons are weakly coupled in hot, dense matter that is created in high-energy-density experiments. They are also mildly quantum mechanical and the ions associated with them are classical and may be strongly coupled. In addition, the dynamical evolution of plasmas under these hot, dense matter conditions involve a variety of transport and energy exchange processes. Quantum kinetic theory is an ideal tool for treating the electrons but it is not adequate for treating the ions. Molecular dynamics is perfectly suited to describe the classical, strongly coupled ions but not the electrons. We develop a method that combines a Wigner kinetic treatment of the electrons with classical molecular dynamics for the ions. We refer to this hybrid method as "kinetic theory molecular dynamics," or KTMD. The purpose of this paper is to derive KTMD from first principles and place it on a firm theoretical foundation. The framework that KTMD provides for simulating plasmas in the hot, dense regime is particularly useful since current computational methods are generally limited by their inability to treat the dynamical quantum evolution of the electronic component. Using the N-body von Neumann equation for the electron-proton plasma, three variations of KTMD are obtained. Each variant is determined by the physical state of the plasma (e.g., collisional versus collisionless). The first variant of KTMD yields a closed set of equations consisting of a mean-field quantum kinetic equation for the electron one-particle distribution function coupled to a classical Liouville equation for the protons. The latter equation includes both proton-proton Coulombic interactions and an effective electron-proton interaction that involves the convolution of the electron density with the electron-proton Coulomb potential. The mean-field approach is then extended to incorporate equilibrium electron-proton correlations through the Singwi-Tosi-Land-Sjolander (STLS) ansatz. This is the second variant of KTMD

  20. Kinetic theory molecular dynamics and hot dense matter: theoretical foundations.

    PubMed

    Graziani, F R; Bauer, J D; Murillo, M S

    2014-09-01

    Electrons are weakly coupled in hot, dense matter that is created in high-energy-density experiments. They are also mildly quantum mechanical and the ions associated with them are classical and may be strongly coupled. In addition, the dynamical evolution of plasmas under these hot, dense matter conditions involve a variety of transport and energy exchange processes. Quantum kinetic theory is an ideal tool for treating the electrons but it is not adequate for treating the ions. Molecular dynamics is perfectly suited to describe the classical, strongly coupled ions but not the electrons. We develop a method that combines a Wigner kinetic treatment of the electrons with classical molecular dynamics for the ions. We refer to this hybrid method as "kinetic theory molecular dynamics," or KTMD. The purpose of this paper is to derive KTMD from first principles and place it on a firm theoretical foundation. The framework that KTMD provides for simulating plasmas in the hot, dense regime is particularly useful since current computational methods are generally limited by their inability to treat the dynamical quantum evolution of the electronic component. Using the N-body von Neumann equation for the electron-proton plasma, three variations of KTMD are obtained. Each variant is determined by the physical state of the plasma (e.g., collisional versus collisionless). The first variant of KTMD yields a closed set of equations consisting of a mean-field quantum kinetic equation for the electron one-particle distribution function coupled to a classical Liouville equation for the protons. The latter equation includes both proton-proton Coulombic interactions and an effective electron-proton interaction that involves the convolution of the electron density with the electron-proton Coulomb potential. The mean-field approach is then extended to incorporate equilibrium electron-proton correlations through the Singwi-Tosi-Land-Sjolander (STLS) ansatz. This is the second variant of KTMD

  1. Current smoking and reduced gray matter volume-a voxel-based morphometry study.

    PubMed

    Fritz, Hans-Christian; Wittfeld, Katrin; Schmidt, Carsten O; Domin, Martin; Grabe, Hans J; Hegenscheid, Katrin; Hosten, Norbert; Lotze, Martin

    2014-10-01

    Nicotine modulates prefrontal processing when tested with functional imaging. Previous studies on changes in regional brain volumes in small samples, reporting different life-time exposure to nicotine, identified reduced volume in smokers in prefrontal areas but reported controversial results for other areas. We investigated the association of cigarette smoking and regional gray and white matter volume by using voxel-based morphometry (VBM) for T1-weighted high-resolution magnetic resonance imaging in 315 current-smokers and 659 never-smokers from the representative Study of Health in Pomerania (SHIP). Our study showed that in current-smokers smoking is significantly associated with gray matter volume loss in the prefrontal cortex, the anterior cingulate cortex, the insula, and the olfactory gyrus. White matter volumes were not relevantly reduced in current-smokers. In current-smokers, we found associations of gray matter loss and smoking exposure (pack-years) in the prefrontal cortex, the anterior and middle cingulate cortex, and the superior temporal and angular gyrus, which however did not stand corrections for multiple testing. We confirmed associations between smoking and gray matter differences in the prefrontal cortex, the anterior cingulate cortex and the insula in the general population of Pomerania (Germany). For the first time, we identified differences in brain volumes in the olfactory gyrus. Other cerebral regions did not show significant differences when correcting for multiple comparisons within the whole brain. The regions of structural deficits might be involved in addictive behavior and withdrawal symptoms, whereas further investigations have to show if the observed atrophies were caused by smoking itself or are preexisting differences between smoking and non-smoking individuals.

  2. Abnormal gray matter and white matter volume in 'Internet gaming addicts'.

    PubMed

    Lin, Xiao; Dong, Guangheng; Wang, Qiandong; Du, Xiaoxia

    2015-01-01

    Internet gaming addiction (IGA) is usually defined as the inability of an individual to control his/her use of the Internet with serious negative consequences. It is becoming a prevalent mental health concern around the world. To understand whether Internet gaming addiction contributes to cerebral structural changes, the present study examined the brain gray matter density and white matter density changes in participants suffering IGA using voxel-based morphometric analysis. Compared with the healthy controls (N=36, 22.2 ± 3.13 years), IGA participants (N=35, 22.28 ± 2.54 years) showed significant lower gray matter density in the bilateral inferior frontal gyrus, left cingulate gyrus, insula, right precuneus, and right hippocampus (all p<0.05). IGA participants also showed significant lower white matter density in the inferior frontal gyrus, insula, amygdala, and anterior cingulate than healthy controls (all p<0.05). Previous studies suggest that these brain regions are involved in decision-making, behavioral inhibition and emotional regulation. Current findings might provide insight in understanding the biological underpinnings of IGA.

  3. Dark matter directional detection in non-relativistic effective theories

    SciTech Connect

    Catena, Riccardo

    2015-07-20

    We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF{sub 4}, CS{sub 2} and {sup 3}He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments.

  4. Dark matter directional detection in non-relativistic effective theories

    SciTech Connect

    Catena, Riccardo

    2015-07-01

    We extend the formalism of dark matter directional detection to arbitrary one-body dark matter-nucleon interactions. The new theoretical framework generalizes the one currently used, which is based on 2 types of dark matter-nucleon interaction only. It includes 14 dark matter-nucleon interaction operators, 8 isotope-dependent nuclear response functions, and the Radon transform of the first 2 moments of the dark matter velocity distribution. We calculate the recoil energy spectra at dark matter directional detectors made of CF{sub 4}, CS{sub 2} and {sup 3}He for the 14 dark matter-nucleon interactions, using nuclear response functions recently obtained through numerical nuclear structure calculations. We highlight the new features of the proposed theoretical framework, and present our results for a spherical dark matter halo and for a stream of dark matter particles. This study lays the foundations for model independent analyses of dark matter directional detection experiments.

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

    PubMed

    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.

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

    ERIC Educational Resources Information Center

    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…

  7. Impact of Interacting Functional Variants in COMT on Regional Gray Matter Volume in Human Brain

    PubMed Central

    Honea, Robyn; Verchinski, Beth A.; Pezawas, Lukas; Kolachana, Bhaskar S.; Callicott, Joseph H.; Mattay, Venkata S.; Weinberger, Daniel R.; Meyer-Lindenberg, Andreas

    2009-01-01

    Background Functional variants in the catechol-O-methyltransferase (COMT) gene have been shown to impact cognitive function, cortical physiology and risk for schizophrenia. A recent study showed that previously reported effects of the functional val158met SNP (rs4680) on brain function are modified by other functional SNPs and haplotypes in the gene, though it was unknown if these effects are also seen in brain structure. Methods We used voxel-based morphometry to investigate the impact of multiple functional variants in COMT on gray matter volume in a large group of 151 healthy volunteers from the CBDB/NIMH Genetic Study of Schizophrenia. Results We found that the previously described rs4680 val risk variant affects hippocampal and dorsolateral prefrontal (DLPFC) gray matter volume. In addition, we found that this SNP interacts with a variant in the P2 promoter region (rs2097603) in predicting changes in hippocampal gray matter volume consistent with a nonlinear effect of extracellular dopamine. Conclusions We report evidence that interacting functional variants in COMT affect gray matter regional volume in hippocampus and DLPFC, providing further in vivo validation of the biological impact of complex genetic variation in COMT on neural systems relevant for the pathophysiology of schizophrenia and extending observations of nonlinear dependence of prefrontal neurons on extracellular dopamine to the domain of human brain structure. PMID:19071221

  8. Quantum Field Theory and Gravity: Black Holes and Dark Matter

    NASA Astrophysics Data System (ADS)

    Heo, Junseong

    1998-11-01

    This thesis examines the various field theory related issues motivated by the gravitational phenomena. Black Holes with quantum degrees of freedom, non-abelian generalization of vortex solutions, and WIMP detection rates for the ongoing experimental search for dark matter are explored. We derive a close relation between the Minkowski signature approach and the Euclidean formalism in the construction of quantum degrees of freedom on a Black hole solution. We demonstrate the benefit of a physically transparent energy momentum consideration and extend the previous analysis on Hawking temperature shifts. Specifically we clear up the issue of thick string limit behavior that obscures the direct intuition and draw an analogy that brings the instanton solutions in flat two dimensional planes to Euclidean vortex solutions in the black hole background. These considerations lead to the question on the various possibilities of non-abelian solutions which supply the seed for the source of quantum hair in general context. We construct an explicit non-abelian vortex solution with a remnant Z3 discrete symmetry and consider its new interaction properties distinct from the known abelian solution behavior. Dark Matter direct search experiments are now in operation yet the expected event rate is very low and the previously available theoretical formalism could not tell the differences among different halo models. We present a derivation of angle dependent differential event rates which allows this possibility, and enables the confirmation of detection of a galactic halo WIMP signal with a smaller number of experimental signals. It may open up realistic methods to distinguish one halo model from another.

  9. Identifying the theory of dark matter with direct detection

    SciTech Connect

    Gluscevic, Vera; Gresham, Moira I.; McDermott, Samuel D.; Peter, Annika H.G.; Zurek, Kathryn M.

    2015-12-29

    Identifying the true theory of dark matter depends crucially on accurately characterizing interactions of dark matter (DM) with other species. In the context of DM direct detection, we present a study of the prospects for correctly identifying the low-energy effective DM-nucleus scattering operators connected to UV-complete models of DM-quark interactions. We take a census of plausible UV-complete interaction models with different low-energy leading-order DM-nuclear responses. For each model (corresponding to different spin–, momentum–, and velocity-dependent responses), we create a large number of realizations of recoil-energy spectra, and use Bayesian methods to investigate the probability that experiments will be able to select the correct scattering model within a broad set of competing scattering hypotheses. We conclude that agnostic analysis of a strong signal (such as Generation-2 would see if cross sections are just below the current limits) seen on xenon and germanium experiments is likely to correctly identify momentum dependence of the dominant response, ruling out models with either “heavy” or “light” mediators, and enabling downselection of allowed models. However, a unique determination of the correct UV completion will critically depend on the availability of measurements from a wider variety of nuclear targets, including iodine or fluorine. We investigate how model-selection prospects depend on the energy window available for the analysis. In addition, we discuss accuracy of the DM particle mass determination under a wide variety of scattering models, and investigate impact of the specific types of particle-physics uncertainties on prospects for model selection.

  10. Identifying the theory of dark matter with direct detection

    SciTech Connect

    Gluscevic, Vera; Gresham, Moira I.; McDermott, Samuel D.; Peter, Annika H.G.; Zurek, Kathryn M. E-mail: gresham@whitman.edu E-mail: apeter@physics.osu.edu

    2015-12-01

    Identifying the true theory of dark matter depends crucially on accurately characterizing interactions of dark matter (DM) with other species. In the context of DM direct detection, we present a study of the prospects for correctly identifying the low-energy effective DM-nucleus scattering operators connected to UV-complete models of DM-quark interactions. We take a census of plausible UV-complete interaction models with different low-energy leading-order DM-nuclear responses. For each model (corresponding to different spin–, momentum–, and velocity-dependent responses), we create a large number of realizations of recoil-energy spectra, and use Bayesian methods to investigate the probability that experiments will be able to select the correct scattering model within a broad set of competing scattering hypotheses. We conclude that agnostic analysis of a strong signal (such as Generation-2 would see if cross sections are just below the current limits) seen on xenon and germanium experiments is likely to correctly identify momentum dependence of the dominant response, ruling out models with either 'heavy' or 'light' mediators, and enabling downselection of allowed models. However, a unique determination of the correct UV completion will critically depend on the availability of measurements from a wider variety of nuclear targets, including iodine or fluorine. We investigate how model-selection prospects depend on the energy window available for the analysis. In addition, we discuss accuracy of the DM particle mass determination under a wide variety of scattering models, and investigate impact of the specific types of particle-physics uncertainties on prospects for model selection.

  11. Identifying the theory of dark matter with direct detection

    NASA Astrophysics Data System (ADS)

    Gluscevic, Vera; Gresham, Moira I.; McDermott, Samuel D.; Peter, Annika H. G.; Zurek, Kathryn M.

    2015-12-01

    Identifying the true theory of dark matter depends crucially on accurately characterizing interactions of dark matter (DM) with other species. In the context of DM direct detection, we present a study of the prospects for correctly identifying the low-energy effective DM-nucleus scattering operators connected to UV-complete models of DM-quark interactions. We take a census of plausible UV-complete interaction models with different low-energy leading-order DM-nuclear responses. For each model (corresponding to different spin-, momentum-, and velocity-dependent responses), we create a large number of realizations of recoil-energy spectra, and use Bayesian methods to investigate the probability that experiments will be able to select the correct scattering model within a broad set of competing scattering hypotheses. We conclude that agnostic analysis of a strong signal (such as Generation-2 would see if cross sections are just below the current limits) seen on xenon and germanium experiments is likely to correctly identify momentum dependence of the dominant response, ruling out models with either "heavy" or "light" mediators, and enabling downselection of allowed models. However, a unique determination of the correct UV completion will critically depend on the availability of measurements from a wider variety of nuclear targets, including iodine or fluorine. We investigate how model-selection prospects depend on the energy window available for the analysis. In addition, we discuss accuracy of the DM particle mass determination under a wide variety of scattering models, and investigate impact of the specific types of particle-physics uncertainties on prospects for model selection.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed Central

    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

  16. Regional brain volumes and cognition in childhood epilepsy: Does size really matter?

    PubMed Central

    Zelko, Frank A.; Pardoe, Heath R.; Blackstone, Sarah R.; Jackson, Graeme D.; Berg, Anne T.

    2014-01-01

    Purpose Recent studies have correlated neurocognitive function and regional brain volumes in children with epilepsy. We tested whether brain volume differences between children with and without epilepsy explained differences in neurocognitive function. Methods The study sample included 108 individuals with uncomplicated nonsyndromic epilepsy (NSE) and 36 healthy age- and gender-matched controls. Participants received a standardized cognitive battery. Whole brain T1-weighted MRI was obtained and volumes analyzed with FreeSurfer (TM). Key Findings Total brain volume (TBV) was significantly smaller in cases. After adjustment for TBV, cases had significantly larger regional grey matter volumes for total, frontal, parietal, and precentral cortex. Cases had poorer performance on neurocognitive indices of intelligence and variability of sustained attention. In cases, TBV showed small associations with intellectual indices of verbal and perceptual ability, working memory, and overall IQ. In controls, TBV showed medium associations with working memory and variability of sustained attention. In both groups, small associations were seen between some TBV-adjusted regional brain volumes and neurocognitive indices, but not in a consistent pattern. Brain volume differences did not account for cognitive differences between the groups. Significance Patients with uncomplicated NSE have smaller brains than controls but areas of relative grey matter enlargement. That this relative regional enlargement occurs in the context of poorer overall neurocognitive functioning suggests that it is not adaptive. However, the lack of consistent associations between case-control differences in brain volumes and cognitive functioning suggests that brain volumes have limited explanatory value for cognitive functioning in childhood epilepsy. PMID:24630049

  17. A comprehensive assessment of gray and white matter volumes and their relationship to outcome and severity in schizophrenia

    PubMed Central

    Mitelman, Serge A.; Brickman, Adam M.; Shihabuddin, Lina; Newmark, Randall E.; Hazlett, Erin A.; Haznedar, M. Mehmet; Buchsbaum, Monte S.

    2007-01-01

    Preliminary data suggest an association of posterior cortical gray matter reduction with poor outcome in schizophrenia. We made a systematic MRI assessment of regional gray and white matter volumes, parcellated into 40 Brodmann’s areas, in 104 patients with schizophrenia (51 with good outcomes, 53 with poor outcomes) and 41 normal comparison subjects, and investigated correlations of regional morphometry with outcome and severity of the illness. Schizophrenia patients displayed differential reductions in frontal and to a lesser degree temporal gray matter volumes in both hemispheres, most pronounced in the frontal pole and lateral temporal cortex. White matter volumes in schizophrenia patients were bilaterally increased, primarily in the frontal, parietal, and isolated temporal regions, with volume reductions confined to anterior cingulate gyrus. In patients with schizophrenia as a group, higher illness severity was associated with reduced temporal gray matter volumes and expanded frontal white matter volumes in both hemispheres. In comparison to good-outcome group, patients with poor outcomes had lower temporal, occipital, and to a lesser degree parietal gray matter volumes in both hemispheres and temporal, parietal, occipital, and posterior cingulate white matter volumes in the right hemisphere. While gray matter deficits in the granular cortex were observed in all schizophrenia patients, agranular cortical deficits in the left hemisphere were peculiar to patients with poor outcomes. These results provide support for frontotemporal gray matter reduction and frontoparietal white matter expansion in schizophrenia. Poor outcome is associated with more posterior distribution (posteriorization) of both gray and white matter changes, and with preferential impairment in the unimodal visual and paralimbic cortical regions. PMID:17587598

  18. Directional volume growing for the extraction of white matter tracts from diffusion tensor data

    NASA Astrophysics Data System (ADS)

    Merhof, D.; Hastreiter, P.; Nimsky, C.; Fahlbusch, R.; Greiner, G.

    2005-04-01

    Diffusion tensor imaging measures diffusion of water in tissue. Within structured tissue, such as neural fiber tracts of the human brain, anisotropic diffusion is observed since the cell membranes of the long cylindric nerves restrict diffusion. Diffusion tensor imaging thus provides information about neural fiber tracts within the human brain which is of major interest for neurosurgery. However, the visualization is a challenging task due to noise and limited resolution of the data. A common visualization strategy of white matter is fiber tracking which utilizes techniques known from flow visualization. The resulting streamlines provide a good impression of the spatial relation of fibers and anatomy. Therefore, they are a valuable supplement for neurosurgical planning. As a drawback, fibers may diverge from the exact path due to numerical inaccuracies during streamline propagation even if higher order integration is used. To overcome this problem, a novel strategy for directional volume growing is presented which enables the extraction of separate tract systems and thus allows to compare and estimate the quality of fiber tracking algorithms. Furthermore, the presented approach is suited to get a more precise representation of the volume encompassing white matter tracts. Thereby, the entire volume potentially containing fibers is provided in contrast to fiber tracking which only shows a more restricted representation of the actual volume of interest. This is of major importance in brain tumor cases where white matter tracts are in the close vicinity of brain tumors. Overall, the presented strategy contributes to make surgical planning safer and more reliable.

  19. Reheating-volume measure in the string theory landscape

    SciTech Connect

    Winitzki, Sergei

    2008-12-15

    I recently proposed the ''reheating-volume'' (RV) prescription as a possible solution to the measure problem in ''multiverse'' cosmology. The goal of this work is to extend the RV measure to scenarios involving bubble nucleation, such as the string theory landscape. In the spirit of the RV prescription, I propose to calculate the distribution of observable quantities in a landscape that is conditioned in probability to nucleate a finite total number of bubbles to the future of an initial bubble. A general formula for the relative number of bubbles of different types can be derived. I show that the RV measure is well defined and independent of the choice of the initial bubble type, as long as that type supports further bubble nucleation. Applying the RV measure to a generic landscape, I find that the abundance of Boltzmann brains is always negligibly small compared with the abundance of ordinary observers in the bubbles of the same type. As an illustration, I present explicit results for a toy landscape containing four vacuum states, and for landscapes with a single high-energy vacuum and a large number of low-energy vacua.

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

    PubMed

    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.

  1. Correlating Gray Matter Volume with Individual Difference in the Flanker Interference Effect

    PubMed Central

    Chen, Changming; Yang, Jiemin; Lai, Jiayu; Li, Hong; Yuan, Jiajin; Abbasi, Najam ul Hasan

    2015-01-01

    The Eriksen Flanker task has been widely used as a measurement of cognitive control, however till now information is still scarce about how the neuroanatomical properties are related to performance in this task. Using voxel-based morphometry technique (VBM), the current study identified a set of distributed areas where the gray matter volume (GM) correlated positively with participants’ efficiency in interference inhibition. These areas included the bilateral prefrontal gyri, left insula and inferior temporal gyrus, the left inferior parietal lobule. Further analysis using a novel machine learning algorithm with balanced cross-validation procedure confirmed that in these areas the GM-behavioral association was unlikely a byproduct of outlier values, instead, the gray matter volume could predict reliably participants’ interference inhibition efficiency. These results underscore the importance of the fronto-parietal and insula systems to the brain functioning of interference inhibition from the neuroanatomical perspective. PMID:26322974

  2. Physical activity and memory functions: are neurotrophins and cerebral gray matter volume the missing link?

    PubMed

    Flöel, A; Ruscheweyh, R; Krüger, K; Willemer, C; Winter, B; Völker, K; Lohmann, H; Zitzmann, M; Mooren, F; Breitenstein, C; Knecht, S

    2010-02-01

    Epidemiological studies reveal better cognitive function in physically active individuals. Possible mediators for this effect are neurotrophins, which are up-regulated through physical exercise and induce neuronal growth and synaptogenesis in the animal model. Here we cross-sectionally assessed 75 healthy older individuals for levels of physical activity, aerobic fitness, and memory encoding, as well as neurotrophin levels and cerebral gray matter volume. We found that physical activity, but not cardiovascular fitness, was associated with better memory encoding after controlling for age, sex, education, depression, alcohol consumption, and smoking. Higher levels of physical activity were associated with higher levels of the neurotrophin granulocyte colony stimulating factor (G-CSF) and increased cerebral gray matter volume in prefrontal and cingulate cortex as assessed by magnetic resonance voxel-based morphometry. While mediating factors will need to be further elucidated, these findings indicate that even low-level physical activity exerts beneficial effects on memory functions in older individuals.

  3. Synergistic Effects of Age on Patterns of White and Gray Matter Volume across Childhood and Adolescence1,2,3

    PubMed Central

    Krongold, Mark; Cooper, Cassandra; Lebel, Catherine

    2015-01-01

    Abstract The human brain develops with a nonlinear contraction of gray matter across late childhood and adolescence with a concomitant increase in white matter volume. Across the adult population, properties of cortical gray matter covary within networks that may represent organizational units for development and degeneration. Although gray matter covariance may be strongest within structurally connected networks, the relationship to volume changes in white matter remains poorly characterized. In the present study we examined age-related trends in white and gray matter volume using T1-weighted MR images from 360 human participants from the NIH MRI study of Normal Brain Development. Images were processed through a voxel-based morphometry pipeline. Linear effects of age on white and gray matter volume were modeled within four age bins, spanning 4-18 years, each including 90 participants (45 male). White and gray matter age-slope maps were separately entered into k-means clustering to identify regions with similar age-related variability across the four age bins. Four white matter clusters were identified, each with a dominant direction of underlying fibers: anterior–posterior, left–right, and two clusters with superior–inferior directions. Corresponding, spatially proximal, gray matter clusters encompassed largely cerebellar, fronto-insular, posterior, and sensorimotor regions, respectively. Pairs of gray and white matter clusters followed parallel slope trajectories, with white matter changes generally positive from 8 years onward (indicating volume increases) and gray matter negative (decreases). As developmental disorders likely target networks rather than individual regions, characterizing typical coordination of white and gray matter development can provide a normative benchmark for understanding atypical development. PMID:26464999

  4. Synergistic Effects of Age on Patterns of White and Gray Matter Volume across Childhood and Adolescence(1,2,3).

    PubMed

    Bray, Signe; Krongold, Mark; Cooper, Cassandra; Lebel, Catherine

    2015-01-01

    The human brain develops with a nonlinear contraction of gray matter across late childhood and adolescence with a concomitant increase in white matter volume. Across the adult population, properties of cortical gray matter covary within networks that may represent organizational units for development and degeneration. Although gray matter covariance may be strongest within structurally connected networks, the relationship to volume changes in white matter remains poorly characterized. In the present study we examined age-related trends in white and gray matter volume using T1-weighted MR images from 360 human participants from the NIH MRI study of Normal Brain Development. Images were processed through a voxel-based morphometry pipeline. Linear effects of age on white and gray matter volume were modeled within four age bins, spanning 4-18 years, each including 90 participants (45 male). White and gray matter age-slope maps were separately entered into k-means clustering to identify regions with similar age-related variability across the four age bins. Four white matter clusters were identified, each with a dominant direction of underlying fibers: anterior-posterior, left-right, and two clusters with superior-inferior directions. Corresponding, spatially proximal, gray matter clusters encompassed largely cerebellar, fronto-insular, posterior, and sensorimotor regions, respectively. Pairs of gray and white matter clusters followed parallel slope trajectories, with white matter changes generally positive from 8 years onward (indicating volume increases) and gray matter negative (decreases). As developmental disorders likely target networks rather than individual regions, characterizing typical coordination of white and gray matter development can provide a normative benchmark for understanding atypical development.

  5. Synergistic Effects of Age on Patterns of White and Gray Matter Volume across Childhood and Adolescence(1,2,3).

    PubMed

    Bray, Signe; Krongold, Mark; Cooper, Cassandra; Lebel, Catherine

    2015-01-01

    The human brain develops with a nonlinear contraction of gray matter across late childhood and adolescence with a concomitant increase in white matter volume. Across the adult population, properties of cortical gray matter covary within networks that may represent organizational units for development and degeneration. Although gray matter covariance may be strongest within structurally connected networks, the relationship to volume changes in white matter remains poorly characterized. In the present study we examined age-related trends in white and gray matter volume using T1-weighted MR images from 360 human participants from the NIH MRI study of Normal Brain Development. Images were processed through a voxel-based morphometry pipeline. Linear effects of age on white and gray matter volume were modeled within four age bins, spanning 4-18 years, each including 90 participants (45 male). White and gray matter age-slope maps were separately entered into k-means clustering to identify regions with similar age-related variability across the four age bins. Four white matter clusters were identified, each with a dominant direction of underlying fibers: anterior-posterior, left-right, and two clusters with superior-inferior directions. Corresponding, spatially proximal, gray matter clusters encompassed largely cerebellar, fronto-insular, posterior, and sensorimotor regions, respectively. Pairs of gray and white matter clusters followed parallel slope trajectories, with white matter changes generally positive from 8 years onward (indicating volume increases) and gray matter negative (decreases). As developmental disorders likely target networks rather than individual regions, characterizing typical coordination of white and gray matter development can provide a normative benchmark for understanding atypical development. PMID:26464999

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

    PubMed

    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. PMID:27159568

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

    PubMed

    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 < 0.001). Subcortical gray matter regions that were significantly different between groups after correcting for overall gray matter volume included left hippocampus, bilateral amygdala and left thalamus (p < 0.01). These findings persisted even when correcting for infant age, gender, ethnicity and maternal 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. PMID:26616173

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

    PubMed

    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 < 0.001). Subcortical gray matter regions that were significantly different between groups after correcting for overall gray matter volume included left hippocampus, bilateral amygdala and left thalamus (p < 0.01). These findings persisted even when correcting for infant age, gender, ethnicity and maternal 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.

  9. Exercise boosts hippocampal volume by preventing early age-related gray matter loss.

    PubMed

    Fuss, Johannes; Biedermann, Sarah V; Falfán-Melgoza, Claudia; Auer, Matthias K; Zheng, Lei; Steinle, Jörg; Hörner, Felix; Sartorius, Alexander; Ende, Gabriele; Weber-Fahr, Wolfgang; Gass, Peter

    2014-02-01

    Recently, a larger hippocampus was found in exercising mice and men. Here we studied the morphological underpinnings in wheel running mice by longitudinal magnetic resonance imaging. Voxel-based morphometry revealed that running increases hippocampal volume by inhibiting an early age-related gray matter loss. Disruption of neurogenesis-related neuroplasticity by focalized irradiation is sufficient to block positive effects of exercise on macroscopic brain morphology. PMID:24178895

  10. The Particulate Theory of Matter for Preservice Elementary Teachers.

    ERIC Educational Resources Information Center

    Roth, Wolff-Michael

    1992-01-01

    Compared the effects of participation in six extra credit activities for teaching the concept of matter on female preservice elementary school teachers (n=9) to a control group (n=8). Pre- and posttests to assess changes in the students' understanding of phenomena associated with matter indicated significant changes in experimental students'…

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

    PubMed

    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. PMID:27639213

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

    PubMed

    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. PMID:26334946

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  16. Latent-variable modeling of brain gray-matter volume and psychopathy in incarcerated offenders.

    PubMed

    Baskin-Sommers, Arielle R; Neumann, Craig S; Cope, Lora M; Kiehl, Kent A

    2016-08-01

    Advanced statistical modeling has become a prominent feature in psychological science and can be a useful approach for representing the neural architecture linked to psychopathology. Psychopathy, a disorder characterized by dysfunction in interpersonal-affective and impulsive-antisocial domains, is associated with widespread neural abnormalities. Several imaging studies suggest that underlying structural deficits in paralimbic regions are associated with psychopathy. Although these studies are useful, they make assumptions about the organization of the brain and its relevance to individuals displaying psychopathic features. Capitalizing on statistical modeling, in the present study (N = 254), we used latent-variable methods to examine the structure of gray-matter volume in male offenders, and assessed the latent relations between psychopathy and gray-matter factors reflecting paralimbic and nonparalimbic regions. Results revealed good fit for a 4-factor gray-matter paralimbic model and these first-order factors were accounted for by a superordinate paralimbic "system" factor. Moreover, a superordinate psychopathy factor significantly predicted the paralimbic, but not the nonparalimbic factor. The latent-variable paralimbic model, specifically linked with psychopathy, goes beyond understanding single brain regions within the system and provides evidence for psychopathy-related gray-matter volume reductions in the paralimbic system as a whole. (PsycINFO Database Record PMID:27269123

  17. Multi-Dimensional Effective Field Theory Analysis for Direct Detection of Dark Matter

    NASA Astrophysics Data System (ADS)

    Rogers, Hannah; SuperCDMS Collaboration

    2016-03-01

    Experiments like the Cryogenic Dark Matter Search (CDMS) attempt to find dark matter (non-luminous matter that makes up approximately 80% of the matter in the universe) through direct detection of interactions between dark matter and a target material. The Effective Field Theory (EFT) approach increases the number of considered interactions between dark matter and the normal, target matter from two (spin independent and spin dependent interactions) to eleven operators with four possible interference terms. These additional operators allow for a more complete analysis of complimentary direct dark matter searches; however, the higher dimensional likelihoods necessary to span an increase in operators requires a clever computational tool such as MultiNest. I present here analyses of published and projected data from CDMS (Si and Ge targets) and LUX (liquid Xe target) assuming operator parameter spaces ranging from 3 - 5 dimensions and folding in information on energy-dependent backgrounds when possible.

  18. Can dark matter be an artifact of extended theories of gravity?

    NASA Astrophysics Data System (ADS)

    Choudhury, Sayantan; Sen, Manibrata; Sadhukhan, Soumya

    2016-09-01

    In this article, we propose different background models of extended theories of gravity, which are minimally coupled to the SM fields, to explain the possibility of genesis of dark matter without affecting the SM particle sector. We modify the gravity sector by allowing quantum corrections motivated from (1) local f( R) gravity and (2) non-minimally coupled gravity with SM sector and dilaton field. Next we apply a conformal transformation on the metric to transform the action back to the Einstein frame. We also show that an effective theory constructed from these extended theories of gravity and SM sector looks exactly the same. Using the relic constraint observed by Planck 2015, we constrain the scale of the effective field theory (Λ _{UV}) as well as the dark matter mass ( M). We consider two cases: (1) light dark matter (LDM) and (2) heavy dark matter (HDM), and we deduce upper bounds on thermally averaged cross section of dark matter annihilating to SM particles. Further we show that our model naturally incorporates self-interactions of dark matter. Using these self-interactions, we derive the constraints on the parameters of (1) local f( R) gravity and (2) non-minimally coupled gravity from a dark matter self-interaction. Finally, we propose some different UV complete models from a particle physics point of view, which can give rise to the same effective theory that we have deduced from extended theories of gravity.

  19. PION CONDENSATION IN A RELATIVISTIC FIELD THEORY CONSISTENT WITH BULK PROPERTIES OF NUCLEAR MATTER

    SciTech Connect

    Banerjee, B.; Glendenning, N.K.; Gyulassy, M.

    1980-07-01

    Pion condensation has not previously been investigated in a theory that accounts for the known bulk properties of nuclear matter, its saturation energy and density and compressibility. We have formulated and solved self-consistently, in the mean field approximation, a relativistic field theory that possesses a condensate solution and reproduces the correct bulk properties of nuclear matter, The theory is solved in its relativistically covariant form for a general class of space-time dependent pion condensates. Self-consistency and compatibility with bulk properties of nuclear matter turn out to be very stringent conditions on the existence and energy of the condensate, but they do allow a weak condensate energy to develop. The spin-isospin density oscillations, on the other hand, can be large. It is encouraging, as concerns the possible existence of new phases of nuclear matter, that this is so, unlike the Lee-Wick density isomer, that appears to be incompatible with nuclear matter properties.

  20. Regional white matter hyperintensity volume, not hippocampal atrophy, predicts incident Alzheimer disease in the community.

    PubMed

    Brickman, Adam M; Provenzano, Frank A; Muraskin, Jordan; Manly, Jennifer J; Blum, Sonja; Apa, Zoltan; Stern, Yaakov; Brown, Truman R; Luchsinger, José A; Mayeux, Richard

    2012-12-01

    BACKGROUND New-onset Alzheimer disease (AD) is often attributed to degenerative changes in the hippocampus. However, the contribution of regionally distributed small vessel cerebrovascular disease, visualized as white matter hyperintensities (WMHs) on magnetic resonance imaging, remains unclear. OBJECTIVE To determine whether regional WMHs and hippocampal volume predict incident AD in an epidemiological study. DESIGN A longitudinal community-based epidemiological study of older adults from northern Manhattan, New York. SETTING The Washington Heights/Inwood Columbia Aging Project. PARTICIPANTS Between 2005 and 2007, 717 participants without dementia received magnetic resonance imaging scans. A mean (SD) of 40.28 (9.77) months later, 503 returned for follow-up clinical examination and 46 met criteria for incident dementia (45 with AD). Regional WMHs and relative hippocampal volumes were derived. Three Cox proportional hazards models were run to predict incident dementia, controlling for relevant variables. The first included all WMH measurements; the second included relative hippocampal volume; and the third combined the 2 measurements. MAIN OUTCOME MEASURE Incident AD. RESULTS White matter hyperintensity volume in the parietal lobe predicted time to incident dementia (hazard ratio [HR] = 1.194; P = .03). Relative hippocampal volume did not predict incident dementia when considered alone (HR = 0.419; P = .77) or with the WMH measures included in the model (HR = 0.302; P = .70). Including hippocampal volume in the model did not notably alter the predictive utility of parietal lobe WMHs (HR = 1.197; P = .049). CONCLUSIONS The findings highlight the regional specificity of the association of WMHs with AD. It is not clear whether parietal WMHs solely represent a marker for cerebrovascular burden or point to distinct injury compared with other regions. Future work should elucidate pathogenic mechanisms linking WMHs and AD pathology.

  1. Dark matter as a ghost free conformal extension of Einstein theory

    SciTech Connect

    Barvinsky, A.O.

    2014-01-01

    We discuss ghost free models of the recently suggested mimetic dark matter theory. This theory is shown to be a conformal extension of Einstein general relativity. Dark matter originates from gauging out its local Weyl invariance as an extra degree of freedom which describes a potential flow of the pressureless perfect fluid. For a positive energy density of this fluid the theory is free of ghost instabilities, which gives strong preference to stable configurations with a positive scalar curvature and trace of the matter stress tensor. Instabilities caused by caustics of the geodesic flow, inherent in this model, serve as a motivation for an alternative conformal extension of Einstein theory, based on the generalized Proca vector field. A potential part of this field modifies the inflationary stage in cosmology, whereas its rotational part at the post inflationary epoch might simulate rotating flows of dark matter.

  2. BOOK REVIEW: Gravitational Waves, Volume 1: Theory and Experiments

    NASA Astrophysics Data System (ADS)

    Poisson, Eric

    2008-10-01

    A superficial introduction to gravitational waves can be found in most textbooks on general relativity, but typically, the treatment hardly does justice to a field that has grown tremendously, both in its theoretical and experimental aspects, in the course of the last twenty years. Other than the technical literature, few other sources have been available to the interested reader; exceptions include edited volumes such as [1] and [2], Weber's little book [3] which happily is still in print, and Peter Saulson's text [4] which appears, unfortunately, to be out of print. In addition to these technical references, the story of gravitational waves was famously told by a sociologist of scientific knowledge [5] (focusing mostly on the experimental aspects) and a historian of science [6] (focusing mostly on the theoretical aspects). The book Gravitational Waves, Volume 1, by Michele Maggiore, is a welcome point of departure. This is, as far as I know, the first comprehensive textbook on gravitational waves. It describes the theoretical foundations of the subject, the known (and anticipated) sources, and the principles of detection by resonant masses and laser interferometers. This book is a major accomplishment, and with the promised volume 2 on astrophysical and cosmological aspects of gravitational waves, the community of all scientists interested in this topic will be well served. Part I of the book is devoted to the theoretical aspects of gravitational waves. In chapter 1 the waves are introduced in usual relativist's fashion, in the context of an approximation to general relativity in which they are treated as a small perturbation of the Minkowski metric of flat spacetime. This is an adequate foundation to study how the waves propagate, and how they interact with freely moving masses making up a detector. The waves are presented in the usual traceless-transverse gauge, but the detection aspects are also worked out in the detector's proper rest frame; this dual

  3. Differential age-dependent associations of gray matter volume and white matter integrity with processing speed in healthy older adults.

    PubMed

    Hong, Zhaoping; Ng, Kwun Kei; Sim, Sam K Y; Ngeow, Mei Yi; Zheng, Hui; Lo, June C; Chee, Michael W L; Zhou, Juan

    2015-12-01

    Slower processing speed (PS), a highly robust feature of cognitive aging, is associated with white matter (WM) deterioration and gray matter volume (GMV) loss. Traditional linear regression models assume a constant relationship between brain structure and cognition over time. To probe for variation in the association between WM and GMV and PS over time, we used a novel sparse varying coefficient model on data collected from 126 relatively healthy older adults (67 females, aged 58-85years) evaluated with MRI and a standardized neuropsychological test-battery. We found that WM microstructural differences indexed by fractional anisotropy values in the fronto-striatal tracts (internal and external capsule) showed a stronger association with PS before the age of 70years. Contrastingly, GMV values of the left putamen and middle occipital gyrus were more strongly correlated with PS after 70years. Additionally, within GM and WM compartments, there was heterogeneity in the temporal sequence in which different cortical and subcortical elements were most strongly associated with PS. Together, these observations provide a more nuanced account of the relationships between different structural components of the aging brain and processing speed, a key cognitive domain affected in relatively healthy older adults. PMID:26302672

  4. Higher Education: Handbook of Theory and Research. Volume I.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Theory and research on a variety of topics in higher education are addressed in 13 articles. Titles and authors are as follows: "College Environmental Influences on Learning and Cognitive Development: A Critical Review and Synthesis" (Ernest T. Pascarella); "Learning Theory and Research" (Cameron Fincher); "Methods and Theories of Instruction"…

  5. The Layzer-Irvine equation in theories with non-minimal coupling between matter and curvature

    SciTech Connect

    Bertolami, O.; Gomes, C. E-mail: claudio.gomes@fc.up.pt

    2014-09-01

    We derive the Layzer-Irvine equation for alternative gravitational theories with non-minimal coupling between curvature and matter for an homogeneous and isotropic Universe. As an application, we study the case of Abell 586, a relaxed and spherically symmetric galaxy cluster, assuming some matter density profiles.

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

    PubMed

    Parvaz, Muhammad A; Maloney, Thomas; Moeller, Scott J; Malaker, Pias; Konova, Anna B; Alia-Klein, Nelly; Goldstein, Rita Z

    2014-01-01

    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.

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

    PubMed

    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

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

    PubMed

    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

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

    PubMed

    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. PMID:26544607

  10. Handbook of Learning and Cognitive Processes. Volume 6: Linguistic Functions in Cognitive Theory.

    ERIC Educational Resources Information Center

    Estes, W. K., Ed.

    This book concludes a six-volume review of research and theory on learning and cognition. Its six chapters cover the following topics: theories of semantic memory, comprehension and memory of text, coding processes in memory, perceptual learning from reading, speech perception, and the organization and core concepts of learning theory and…

  11. Theory and Simulation of Warm Dense Matter Targets

    SciTech Connect

    Barnard, J J; Armijo, J; More, R M; Friedman, A; Kaganovich, I; Logan, B G; Marinak, M M; Penn, G E; Sefkow, A B; Santhanam, P; Wurtele, J S

    2006-07-13

    We present simulations and analysis of the heating of warm dense matter foils by ion beams with ion energy less than one MeV per nucleon to target temperatures of order one eV. Simulations were carried out using the multi-physics radiation hydrodynamics code HYDRA and comparisons are made with analysis and the code DPC. We simulate possible targets for a proposed experiment at LBNL (the so-called Neutralized Drift Compression Experiment, NDCXII) for studies of warm dense matter. We compare the dynamics of ideally heated targets, under several assumed equation of states, exploring dynamics in the two-phase (fluid-vapor) regime.

  12. Impulsivity relates to striatal gray matter volumes in humans: evidence from a delay discounting paradigm.

    PubMed

    Tschernegg, Melanie; Pletzer, Belinda; Schwartenbeck, Philipp; Ludersdorfer, Philipp; Hoffmann, Uta; Kronbichler, Martin

    2015-01-01

    Time-stable personality traits, such as impulsivity and its relationship with functional and structural brain alterations, have gained much attention in the recent literature. Evidence from functional neuroimaging data implies an association between impulsivity and cortical as well as subcortical areas of the reward system. Discounting future rewards during impulsive decisions can be related to activation in the orbitofrontal cortex and striatum. Cortical structural changes in prefrontal regions have been found for introspective impulsivity measures. The present study focuses on brain regions associated with delay discounting to investigate structural manifestations of trait impulsivity. To test this, seventy subjects underwent structural magnetic resonance imaging (MRI) followed by a behavioral delay discounting task outside of the scanner to measure impulsivity with questions like: "Would you like to have 3€ immediately or 10€ in 5 days?". The amount of smaller-but-sooner decisions was calculated and used as a measure of behavioral impulsivity. Furthermore, we estimated subject's individual delay discounting parameter K reflecting the tendency to discount future rewards. Behaviorally, we found strong evidence in favor of a discounting utility model compared to a standard hyperbolic model of choice valuation. Neuronally, we focused on cortical and subcortical brain structure and investigated the association of behavioral impulsivity with delay discounting tendencies and gray matter volume. Voxel-based morphometric analyses showed positive correlations between delay discounting and gray matter volume in the striatum. Additional analyses using Freesurfer provided evidence for a positive correlation between delay discounting and gray matter volume of the caudate. Taken together, our study provides strong evidence for a structural manifestation of time-stable trait impulsivity in the human brain.

  13. Phase transitions of nuclear matter beyond mean field theory

    SciTech Connect

    Tran Huu Phat; Nguyen Tuan Anh; Nguyen Van Long; Le Viet Hoa

    2007-10-15

    The Cornwall-Jackiw-Tomboulis (CJT) effective action approach is applied to study the phase transition of nuclear matter modeled by the four-nucleon interaction. It is shown that in the Hartree-Fock approximation (HFA) a first-order phase transition takes place at low temperature, whereas the phase transition is of second order at higher temperature.

  14. Higher Education: Handbook of Theory and Research. Volume XIV.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.; Tierney, William G., Ed.

    The 11 papers in this collection address research and theory in higher education. The papers are: (1) "Teaching, Learning, and Thinking about Teaching and Learning" (W.J. McKeachie); (2) "Costs and Productivity in Higher Education: Theory, Evidence, and Policy Implications" (Darrell R. Lewis and Halil Dunbar); (3) "Institutional Adaptation:…

  15. Higher Education: Handbook of Theory and Research. Volume X.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    This collection of nine papers addresses theory and research in higher education. The papers include: (1) "Student Learning at Metropolitan Universities" (George D. Kuh and others); (2) "Applications of Generalizability Theory in Higher Education Assessment Research" (Gary R. Pike); (3) Policy Models and Policy Instruments in Higher Education: The…

  16. Prospects for direct detection of dark matter in an effective theory approach

    SciTech Connect

    Catena, Riccardo

    2014-07-01

    We perform the first comprehensive analysis of the prospects for direct detection of dark matter with future ton-scale detectors in the general 11-dimensional effective theory of isoscalar dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle. The theory includes 8 momentum and velocity dependent dark matter-nucleon interaction operators, besides the familiar spin-independent and spin-dependent operators. From a variegated sample of 27 benchmark points selected in the parameter space of the theory, we simulate independent sets of synthetic data for ton-scale Germanium and Xenon detectors. From the synthetic data, we then extract the marginal posterior probability density functions and the profile likelihoods of the model parameters. The associated Bayesian credible regions and frequentist confidence intervals allow us to assess the prospects for direct detection of dark matter at the 27 benchmark points. First, we analyze the data assuming the knowledge of the correct dark matter nucleon-interaction type, as it is commonly done for the familiar spin-independent and spin-dependent interactions. Then, we analyze the simulations extracting the dark matter-nucleon interaction type from the data directly, in contrast to standard analyses. This second approach requires an extensive exploration of the full 11-dimensional parameter space of the dark matter-nucleon effective theory. Interestingly, we identify 5 scenarios where the dark matter mass and the dark matter-nucleon interaction type can be reconstructed from the data simultaneously. We stress the importance of extracting the dark matter nucleon-interaction type from the data directly, discussing the main challenges found addressing this complex 11-dimensional problem.

  17. Searches for Dark Matter with IceCube and DeepCore : New constraints on theories predicting dark matter particles

    NASA Astrophysics Data System (ADS)

    Danninger, Matthias

    The cubic-kilometer sized IceCube neutrino observatory, constructed in the glacial ice at the South Pole, searches indirectly for dark matter via neutrinos from dark matter self-annihilations. It has a high discovery potential through striking signatures. This thesis presents searches for dark matter annihilations in the center of the Sun using experimental data collected with IceCube. The main physics analysis described here was performed for dark matter in the form of weakly interacting massive particles (WIMPs) with the 79-string configuration of the IceCube neutrino telescope. For the first time, the DeepCore sub-array was included in the analysis, lowering the energy threshold and extending the search to the austral summer. Data from 317 days live-time are consistent with the expected background from atmospheric muons and neutrinos. Upper limits were set on the dark matter annihilation rate, with conversions to limits on the WIMP-proton scattering cross section, which initiates the WIMP capture process in the Sun.These are the most stringent spin-dependent WIMP-proton cross-sections limits to date above 35 GeV for most WIMP models. In addition, a formalism for quickly and directly comparing event-level IceCube data with arbitrary annihilation spectra in detailed model scans, considering not only total event counts but also event directions and energy estimators, is presented. Two analyses were made that show an application of this formalism to both model exclusion and parameter estimation in models of supersymmetry. An analysis was also conducted that extended for the first time indirect dark matter searches with neutrinos using IceCube data, to an alternative dark matter candidate, Kaluza-Klein particles, arising from theories with extra space-time dimensions. The methods developed for the solar dark matter search were applied to look for neutrino emission during a flare of the Crab Nebula in 2010.

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

    PubMed Central

    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.

    2015-01-01

    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, p < .05) were partially mediated by both WM structural measures, but not hippocampal volume. Cortisol-WM relationships were modest, as was the degree to which WM structure attenuated cortisol–cognition associations (<15%). These data support the hypothesis that GCs contribute to cognitive ageing differences from childhood to the early 70s, partly via brain WM structure. PMID:26298692

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

    PubMed

    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. PMID:26490569

  20. A Voxel Based Morphometry Study of Brain Gray Matter Volumes in Juvenile Obsessive Compulsive Disorder

    PubMed Central

    Jayarajan, Rajan Nishanth; Agarwal, Sri Mahavir; Viswanath, Biju; Kalmady, Sunil V.; Venkatasubramanian, Ganesan; Srinath, Shoba; Chandrashekar, C.R.; Janardhan Reddy, Y.C.

    2015-01-01

    Introduction: Adult patients with Obsessive Compulsive Disorder (OCD) have been shown to have gray matter (GM) volume differences from healthy controls in multiple regions – the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), medial frontal gyri (MFG), striatum, thalamus, and superior parietal lobule. However, there is paucity of data with regard to juvenile OCD. Hence, we examined GM volume differences between juvenile OCD patients and matched healthy controls using voxel based morphometry (VBM) with the above apriori regions of interest. Method: Fifteen right handed juvenile patients with OCD and age- sex- handedness- matched healthy controls were recruited after administering the Mini International Neuropsychiatric Interview-KID and the Children’s Yale-Brown Obsessive Compulsive Scale, and scanned using a 3 Tesla magnetic resonance imaging scanner. VBM methodology was followed. Results: In comparison with healthy controls, patients had significantly smaller GM volumes in left ACC. YBOCS total score (current) showed significant negative correlation with GM volumes in bilateral OFC, and left superior parietal lobule. Conclusion: These findings while reiterating the important role of the orbito-fronto-striatal circuitry, also implicate in the parietal lobe – especially the superior parietal lobule as an important structure involved in the pathogenesis of OCD. PMID:26379719

  1. The relationship between inflammatory markers and voxel-based gray matter volumes in nondemented older adults.

    PubMed

    Zhang, Haobo; Sachdev, Perminder S; Wen, Wei; Crawford, John D; Brodaty, Henry; Baune, Bernard T; Kochan, Nicole A; Slavin, Melissa J; Reppermund, Simone; Kang, Kristan; Trollor, Julian N

    2016-01-01

    Ageing is characterized by chronically elevated inflammatory markers (IMs). Peripheral IM levels have been found in negative correlations with brain structural measures including global and lobar volumes and the hippocampus. This study investigated the relationship between 10 peripheral IMs and voxel-based gray matter (GM) volumes in nondemented older adults (n = 463). Two proinflammatory cytokines (tumor necrosis factor-α [TNF-α] and interleukin-1β) and 2 vascular IMs (vascular cellular adhesion molecule-1 and plasminogen activator inhibitor-1) were negatively correlated with regional GM volumes. TNF-α and interleukin-1β were both significantly correlated with GM volumes in the left occipitotemporal area, left superior occipital gyrus, and left inferior parietal lobule; TNF-α was also significantly correlated with the bilateral medial prefrontal cortices and approached significance for the correlations with the bilateral hippocampi. Significant GM correlations with vascular cellular adhesion molecule-1 were located in the bilateral anterior cingulate cortices, and with plasminogen activator inhibitor-1 in the cerebellum and right hippocampus. The neuroanatomical correlation patterns of 2 proinflammatory cytokines and 2 vascular IMs might be reflective of the effects of neurodegenerative and vascular pathological processes in the ageing brain.

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

    PubMed

    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, p<.05) were partially mediated by both WM structural measures, but not hippocampal volume. Cortisol-WM relationships were modest, as was the degree to which WM structure attenuated cortisol-cognition associations (<15%). These data support the hypothesis that GCs contribute to cognitive ageing differences from childhood to the early 70s, partly via brain WM structure. PMID:26298692

  3. Dynamic Theory: a new view of space, time, and matter

    SciTech Connect

    Williams, P.E.

    1980-12-01

    The theory presented represents a different approach toward unification of the various branches of physics. The foundation of the theory rests upon generalizations of the classical laws of thermodynamics, particularly Caratheodory's abstract statement of the second law. These adopted laws are shown to produce, as special cases, current theories such as Einstein's General and Special Relativity, Maxwell's electromagnetism, classical thermodynamics, and quantum principles. In addition to this unification, the theory provides predictions that may be experimentally investigated. Some of the predictions are a limiting rate of mass conversion, reduced pressures in electromagnetically contained plasmas, increased viscous effects in shocked materials, a finite self-energy for a charged particle, and the possible creation of particles with velocities greater than the speed of light. 8 figures.

  4. Atomic volumes and polarizabilities in density-functional theory.

    PubMed

    Kannemann, Felix O; Becke, Axel D

    2012-01-21

    Becke and Johnson introduced an ad hoc definition of atomic volume [J. Chem. Phys. 124, 014204 (2006)] in order to obtain atom-in-molecule polarizabilities from free-atom polarizabilities in their nonempirical exchange-hole dipole moment model of dispersion interactions. Here we explore the dependence of Becke-Johnson atomic volumes on basis sets and density-functional approximations and provide reference data for all atoms H-Lr. A persuasive theoretical foundation for the Becke-Johnson definition is also provided.

  5. Direct and Indirect Dark Matter Detection in Gauge Theories

    SciTech Connect

    Queiroz, Farinaldo

    2013-01-01

    The Dark matter (DM) problem constitutes a key question at the interface among Particle Physics, Astrophysics and Cosmology. The observational data which have been accumulated in the last years point to an existence of non baryonic amount of DM. Since the Standard Model (SM) does not provide any candidate for such non-baryonic DM, the evidence of DM is a major indication for new physics beyond the SM. We will study in this work one of the most popular DM candidates, the so called WIMPs (Weakly Interacting Massive Particles) from a direct and indirect detection perspective. In order to approach the direct and indirect dection of DM in the context of Particle Physics in a more pedagogic way, we will begin our discussion talking about a minimal extension of the SM. Later we will work on the subject in a 3-3-1 model. Next, we will study the role of WIMPs in the Big Bang Nucleosynthesis. Lastly, we will look for indirect DM signals in the center of our galaxy using the NASA Satellite, called Fermi-LAT. Through a comprehensive analysis of the data events observed by Fermi-LAT and some background models, we will constrain the dark matter annihilation cross section for several annihilation channels and dark matter halo profiles.

  6. New extended standard model, dark matters and relativity theory

    NASA Astrophysics Data System (ADS)

    Hwang, Jae-Kwang

    2016-03-01

    Three-dimensional quantized space model is newly introduced as the extended standard model. Four three-dimensional quantized spaces with total 12 dimensions are used to explain the universes including ours. Electric (EC), lepton (LC) and color (CC) charges are defined to be the charges of the x1x2x3, x4x5x6 and x7x8x9 warped spaces, respectively. Then, the lepton is the xi(EC) - xj(LC) correlated state which makes 3x3 = 9 leptons and the quark is the xi(EC) - xj(LC) - xk(CC) correlated state which makes 3x3x3 = 27 quarks. The new three bastons with the xi(EC) state are proposed as the dark matters seen in the x1x2x3 space, too. The matter universe question, three generations of the leptons and quarks, dark matter and dark energy, hadronization, the big bang, quantum entanglement, quantum mechanics and general relativity are briefly discussed in terms of this new model. The details can be found in the article titled as ``journey into the universe; three-dimensional quantized spaces, elementary particles and quantum mechanics at https://www.researchgate.net/profile/J_Hwang2''.

  7. Reading Research: Advances in Theory and Practice. Volume 1.

    ERIC Educational Resources Information Center

    Waller, T. Gary, Ed.; MacKinnon, G. E., Ed.

    The first of a series providing reviews, syntheses (empirical and rhetorical), and reports of reading research, the chapters in this volume treat the question, "What does a child have to know (or be able to do) in order to learn to read?" The book begins with an in-depth logical analysis in historical perspective of the concept of reading…

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

    PubMed Central

    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

  9. The Relationship between Processing Speed and Regional White Matter Volume in Healthy Young People

    PubMed Central

    Magistro, Daniele; Takeuchi, Hikaru; Nejad, Keyvan Kashkouli; Taki, Yasuyuki; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos Makoto; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Hashizume, Hiroshi; Sassa, Yuko; Kawashima, Ryuta

    2015-01-01

    Processing speed is considered a key cognitive resource and it has a crucial role in all types of cognitive performance. Some researchers have hypothesised the importance of white matter integrity in the brain for processing speed; however, the relationship at the whole-brain level between white matter volume (WMV) and processing speed relevant to the modality or problem used in the task has never been clearly evaluated in healthy people. In this study, we used various tests of processing speed and Voxel-Based Morphometry (VBM) analyses, it is involves a voxel-wise comparison of the local volume of gray and white, to assess the relationship between processing speed and regional WMV (rWMV). We examined the association between processing speed and WMV in 887 healthy young adults (504 men and 383 women; mean age, 20.7 years, SD, 1.85). We performed three different multiple regression analyses: we evaluated rWMV associated with individual differences in the simple processing speed task, word–colour and colour–word tasks (processing speed tasks with words) and the simple arithmetic task, after adjusting for age and sex. The results showed a positive relationship at the whole-brain level between rWMV and processing speed performance. In contrast, the processing speed performance did not correlate with rWMV in any of the regions examined. Our results support the idea that WMV is associated globally with processing speed performance regardless of the type of processing speed task. PMID:26397946

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

    PubMed Central

    De Giglio, L.; Marinelli, F.; Prosperini, L.; Contessa, G. M.; Gurreri, F.; Piattella, M. C.; De Angelis, F.; Barletta, V. T.; Tomassini, V.; Pantano, P.; Pozzilli, C.

    2015-01-01

    Background. The role of prolactin (PRL) on tissue injury and repair mechanisms in multiple sclerosis (MS) remains unclear. The aim of this work was to investigate the relationship between PRL plasma levels and brain damage as measured by magnetic resonance imaging (MRI). Methods. We employed a chemiluminescence immunoassay for measuring plasma levels of PRL. We used a 1.5 T scanner to acquire images and Jim 4.0 and SIENAX software to analyse them. Results. We included 106 women with relapsing remitting (RR) MS and stable disease in the last 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. PMID:26236110

  11. The Relationship between Processing Speed and Regional White Matter Volume in Healthy Young People.

    PubMed

    Magistro, Daniele; Takeuchi, Hikaru; Nejad, Keyvan Kashkouli; Taki, Yasuyuki; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos Makoto; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Hashizume, Hiroshi; Sassa, Yuko; Kawashima, Ryuta

    2015-01-01

    Processing speed is considered a key cognitive resource and it has a crucial role in all types of cognitive performance. Some researchers have hypothesised the importance of white matter integrity in the brain for processing speed; however, the relationship at the whole-brain level between white matter volume (WMV) and processing speed relevant to the modality or problem used in the task has never been clearly evaluated in healthy people. In this study, we used various tests of processing speed and Voxel-Based Morphometry (VBM) analyses, it is involves a voxel-wise comparison of the local volume of gray and white, to assess the relationship between processing speed and regional WMV (rWMV). We examined the association between processing speed and WMV in 887 healthy young adults (504 men and 383 women; mean age, 20.7 years, SD, 1.85). We performed three different multiple regression analyses: we evaluated rWMV associated with individual differences in the simple processing speed task, word-colour and colour-word tasks (processing speed tasks with words) and the simple arithmetic task, after adjusting for age and sex. The results showed a positive relationship at the whole-brain level between rWMV and processing speed performance. In contrast, the processing speed performance did not correlate with rWMV in any of the regions examined. Our results support the idea that WMV is associated globally with processing speed performance regardless of the type of processing speed task. PMID:26397946

  12. The correlation between gray matter volume and perceived social support: a voxel-based morphometry study.

    PubMed

    Che, XianWei; Wei, DongTao; Li, WenFu; Li, HaiJiang; Qiao, Lei; Qiu, Jiang; Zhang, QingLin; Liu, YiJun

    2014-01-01

    Social support refers to interpersonal exchanges that include the combinations of aid, affirmation and affection. Perceived social support is a kind of subjective judgment of one's availability of social support. In spite of the importance of perceived social support to health, however, its neural substrate remains unknown. To address this question, voxel-based morphometry was employed to investigate the neural bases of individual differences in responses to the Perceived Social Support Scale (PSSS) in healthy volunteers (144 men and 203 women; mean age = 19.9; SD = 1.33, age range : 17-27). As a result, multiple regression analysis revealed that the PSSS scores were significantly and positively correlated with gray matter volume in a cluster that mainly included areas in posterior parts of posterior cingulate cortex, bilateral lingual cortex, left occipital lobe and cuneus. Highly-supported individuals had larger gray matter volume in these brain regions, implying a relatively high level of ability to engage in self-referential processes and social cognition. Our results provide a biological basis for exploring perceived social support particularly in relationship to various health parameters and outcomes.

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

    SciTech Connect

    Berger, Joshua; Cui, Yanou; 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.

  14. Higher Education: Handbook of Theory and Research. Volumes III [and] IV.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Two volumes of a handbook on theory and research in higher education are presented. The 11 papers included in Volume III are as follows: "Qualitative Research Methods in Higher Education" (R. Crowson); "Bricks and Mortar: Architecture and the Study of Higher Education" (J. Thelin and J. Yankovich); "Enrollment Demand Models and Their Policy Uses…

  15. Theory in Bilingual Education: Ethnoperspectives in Bilingual Education Research, Volume II.

    ERIC Educational Resources Information Center

    Padilla, Raymond V., Ed.

    The second of three volumes that present the three basic factors of the bilingual education equation--public policy, theory, and technology--this volume focuses on the theoretical aspects of bilingual education. Papers from the areas of language, culture, neurolinguistics, and pedagogy include: (1) "Ethnic and Linguistic Processes: The Future of…

  16. Eshelby inclusions in granular matter: Theory and simulations.

    PubMed

    McNamara, Sean; Crassous, Jérôme; Amon, Axelle

    2016-08-01

    We present a numerical implementation of an active inclusion in a granular material submitted to a biaxial test. We discuss the dependence of the response to this perturbation on two parameters: the intragranular friction coefficient on one hand, and the degree of the loading on the other hand. We compare the numerical results to theoretical predictions taking into account the change of volume of the inclusion as well as the anisotropy of the elastic matrix. PMID:27627380

  17. Eshelby inclusions in granular matter: Theory and simulations

    NASA Astrophysics Data System (ADS)

    McNamara, Sean; Crassous, Jérôme; Amon, Axelle

    2016-08-01

    We present a numerical implementation of an active inclusion in a granular material submitted to a biaxial test. We discuss the dependence of the response to this perturbation on two parameters: the intragranular friction coefficient on one hand, and the degree of the loading on the other hand. We compare the numerical results to theoretical predictions taking into account the change of volume of the inclusion as well as the anisotropy of the elastic matrix.

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

    PubMed

    Liu, Mu-En; Huang, Chu-Chung; Yang, Albert C; Tu, Pei-Chi; Yeh, Heng-Liang; Hong, Chen-Jee; Chen, Jin-Fan; Liou, Ying-Jay; Lin, Ching-Po; Tsai, Shih-Jen

    2013-01-01

    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. PMID:23437205

  19. Astronomical constraints on quantum theories of cold dark matter - II. Supermassive black holes and luminous matter

    NASA Astrophysics Data System (ADS)

    Spivey, S. C.; Musielak, Z. E.; Fry, J. L.

    2015-04-01

    Our previous model of quantum cold dark matter (QCDM) is expanded to include the influence of supermassive black holes located at centres of different galaxies and galactic luminous (baryonic) matter distributions. The inclusion of a black hole to the galactic potential is shown to produce a more concentrated halo with a cuspier core. The addition of a small-scale galactic luminous matter distribution also concentrates the halo, while a large-scale distribution diffuses it; nevertheless, in either case the smooth core of the halo is preserved. Effects caused by including a non-linear scattering term are investigated by solving the Gross-Pitaevskii equation. The obtained results demonstrate that the scattering term produces a rounder and more diffuse density profile. Moreover, adding a sufficiently large black hole in combination with this term results in an even cuspier profile than the black hole alone. As a result of all these additions, our extended QCDM model can be applied to a much larger range of dark matter halo shapes and sizes.

  20. Transonic Symposium: Theory, Application, and Experiment, volume 1, part 2

    NASA Technical Reports Server (NTRS)

    Foughner, Jerome T., Jr. (Compiler)

    1989-01-01

    In order to assess the state of the art in transonic flow disciplines and to glimpse at future directions, NASA-Langley held a Transonic Symposium. Emphasis was placed on steady, three dimensional external, transonic flow and its simulation, both numerically and experimentally. The symposium included technical sessions on wind tunnel and flight experiments; computational fluid dynamic applications; inviscid methods and grid generation; viscous methods and boundary layer stability; and wind tunnel techniques and wall interference. This, being volume 1, is unclassified.

  1. DAMA confronts null searches in the effective theory of dark matter-nucleon interactions

    NASA Astrophysics Data System (ADS)

    Catena, Riccardo; Ibarra, Alejandro; Wild, Sebastian

    2016-05-01

    We examine the dark matter interpretation of the modulation signal reported by the DAMA experiment from the perspective of effective field theories displaying Galilean invariance. We consider the most general effective coupling leading to the elastic scattering of a dark matter particle with spin 0 or 1/2 off a nucleon, and we analyze the compatibility of the DAMA signal with the null results from other direct detection experiments, as well as with the non-observation of a high energy neutrino flux in the direction of the Sun from dark matter annihilation. To this end, we develop a novel semi-analytical approach for comparing experimental results in the high-dimensional parameter space of the non-relativistic effective theory. Assuming the standard halo model, we find a strong tension between the dark matter interpretation of the DAMA modulation signal and the null result experiments. We also list possible ways-out of this conclusion.

  2. Higher Education: Handbook of Theory and Research. Volume V.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Eleven papers on theory and research in higher education have the following titles and authors: "Strategy and Effectiveness in Systems of Higher Education" (Ellen Earle Chaffee); "Responsibilty Without Authority: The Impossible Job of the College President" (Robert Birnbaum); "Trouble in the Land: The Paradigm Revolution in the Academic…

  3. Theories on Criminality and Mental Retardation Project CAMIO, Volume 2.

    ERIC Educational Resources Information Center

    Haskins, Jimmy R.; Friel, Charles M.

    This historical review of theories on criminality and mental retardation is part of Project CAMIO (Correctional Administration and the Mentally Incompetent Offender), a Texas study to determine the incidence of criminal incarceration of the mentally retarded (MR) and to identify laws, procedures, and practices which affect the prosecution and…

  4. Higher Education: Handbook of Theory and Research. Volume VIII.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Ten papers on theory and research in higher education have the following titles and authors: "Collegiality: Toward a Clarification of Meaning and Function" (James L. Bess); "Quality by Design: Toward a Framework for Academic Quality Management" (David D. Dill); "Beyond 'the State': Interorganizational Relations and State Apparatuses in…

  5. Higher Education: Handbook of Theory and Research. Volume VI.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Eleven papers on theory and research in higher education have the following titles and authors: "A Paradigm for Research on Higher Education" (William F. Massy); "Minority Student Access to, and Persistence and Performance in College: A Review of the Trends and Research Literature" (Shirley L. Mow and Michael T. Nettles); "Master's Degree Programs…

  6. Higher Education: Handbook of Theory and Research. Volume XIII.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    The 10 papers in this handbook consider higher education theory and research. Following an opening essay, "Recollections and Reflections," by C. Robert Pace, which offers reflections on higher education as a field, on its evolution, and it future research needs, papers include: "Reflections on the Study of Effective College Teaching and Student…

  7. Higher Education: Handbook of Theory and Research. Volume II.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Theory and research on the effectiveness of college operations are covered in 12 chapters. Current research on each topic is reviewed, with attention to conceptual and methodological issues, and an agenda for future research is offered. Chapter titles and authors are as follows: "Transformational Leadership in Colleges and Universities" (Kim S.…

  8. Higher Education: Handbook of Theory and Research. Volume VII.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Eleven papers on theory and research in higher education have the following titles and authors: "Perceived Control in College Students: Implications for Instruction in Higher Education" (Raymond P. Perry); "The Changing Locus of Control Over Faculty Research: From Self-Regulation to Dispersed Influence" (Melissa S. Anderson and Karen Seashore…

  9. Sleep duration is associated with white matter hyperintensity volume in older adults: the Northern Manhattan Study.

    PubMed

    Ramos, Alberto R; Dong, Chuanhui; Rundek, Tatjana; Elkind, Mitchell S V; Boden-Albala, Bernadette; Sacco, Ralph L; Wright, Clinton B

    2014-10-01

    Self-reports of long or short sleep durations have indicated an association with cardiovascular morbidity and mortality, but there are limited data evaluating their association with white matter hyperintensity volume (WMHV), a marker of cerebral small vessel disease. We conducted a cross-sectional analysis of self-reported sleep duration to test for a correlation with white matter hyperintensities, measured by quantitative magnetic resonance imaging (MRI), in the Northern Manhattan Study. We used multivariable linear regression models to assess associations between both short (<6 h) and long (≥9 h) sleep durations and log-transformed WMHV, adjusting for demographic, behavioural and vascular risk factors. A total of 1244 participants, mean age 70 ± 9 years, 61% women and 68% Hispanics were analysed with magnetic resonance brain imaging and self-reported sleep duration. Short sleep was reported by 23% (n = 293) and long sleep by 10% (n = 121) of the sample. Long sleep (β = 0.178; P = 0.035), but not short sleep (β = -0.053; P = 0.357), was associated with greater log-WMHV in fully adjusted models. We observed an interaction between sleep duration, diabetes mellitus and log-WMHV (P = 0.07). In fully adjusted models, stratified analysis showed that long sleep duration was associated with greater WMHV only in those with diabetes (β = 0.78; P = 0.0314), but not in those without diabetes (β = 0.022; P = 0.2), whereas short sleep was not associated with white matter hyperintensities in those with or without diabetes. In conclusion, long sleep duration was associated with a greater burden of white matter lesions in this stroke-free urban sample. The association was seen mainly among those with diabetes mellitus.

  10. Many-particle theory of nuclear systems with application to neutron star matter

    NASA Technical Reports Server (NTRS)

    Chakkalakal, D. A.; Yang, C.

    1973-01-01

    The research is reported concerning energy-density relation for the normal state of neutron star matter, and the effects of superfluidity and polarization on neutron star matter. Considering constraints on variation, and the theory of quantum fluids, three methods for calculating the energy-density range are presented. The effects of polarization on neutron star structure, and polarization effects on condensation and superfluid-state energy are discussed.

  11. Witten index in N=1 and N=2 SYMCS theories with matter

    NASA Astrophysics Data System (ADS)

    Smilga, A. V.

    2014-06-01

    We calculate the Witten index for 3d supersymmetric Yang-Mills-Chern-Simons theories with matter. For N=2 theories, our results coincide with the results of recent [1]. We compare the situation in 3d to that in 4d N=1 theories with massive matter. In both cases, extra Higgs vacuum states may appear when the Lagrangian involves nontrivial Yukawa interactions between the matter superfields. In addition, in 3d theories, massive fermion loops affect the index via renormalization of the Chern-Simons level k. Put the theory in the large spatial box, g2L≫1. The problem of counting the vacuum states in the theory (1) can then be reduced to the problem of counting the states in the pure CS theory with the level renormalized by the fermion loop [2], krenN=1=ktree-sgn(ktree). Put the theory in small box, g2L≪1 and count carefully the vacuum states in the effective Born-Oppenheimer (BO) Hamiltonian [4,5]. In Section 4, we will describe this method in more details. A similar result for the N=2 theory involving, compared to (1), an extra adjoint matter multiplet is [3] IN=2SYMCS=|k|-1. In recent [1], the index for N=2 theories involving extra matter multiplets was calculated. In the present note, we explain how to do it for generic N=1 theories with matter, when working in the language of N=1 3d superfields. For N=2 theories, we reproduce the results of [1]. We give detailed pedagogical explanations concerning their accurate derivation (our method is based on the deformation N=2→N=1 and is somewhat different from that in Ref. [1]) and compare the vacuum dynamics of 3d theories with the more familiar 4d situation.In Section 2, we make a brief review of the vacuum dynamics of 4d SYM theories with matter and explain why the index may differ from its value in the pure SYM theory even if the matter is nonchiral and massive. In Section 3, we describe the 3d SYMCS theories in interest in the N=1 superspace approach. Section 4 is devoted to index calculations.Before going further

  12. Mixing subattolitre volumes in a quantitative and highly parallel manner with soft matter nanofluidics

    NASA Astrophysics Data System (ADS)

    Christensen, Sune M.; Bolinger, Pierre-Yves; Hatzakis, Nikos S.; Mortensen, Michael W.; Stamou, Dimitrios

    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 smaller than ~1 × 10-12 l. Self-assembled soft matter nanocontainers can in principle significantly improve miniaturization and biocompatibility, but exploiting their full potential is a challenge due to their small dimensions. Here, we show that small unilamellar lipid vesicles can be used to mix volumes as small as 1 × 10-19 l in a reproducible and highly parallelized fashion. The self-enclosed nanoreactors are functionalized with lipids of opposite charge to achieve reliable fusion. Single vesicles encapsulating one set of reactants are immobilized on a glass surface and then fused with diffusing vesicles of opposite charge that carry a complementary set of reactants. We find that ~85% of the ~1 × 106 cm-2 surface-tethered nanoreactors undergo non-deterministic fusion, which is leakage-free in all cases, and the system allows up to three to four consecutive mixing events per nanoreactor.

  13. Cognitive impairment and gray matter volume abnormalities in silent cerebral infarction.

    PubMed

    Yang, Tao; Zhang, Lan; Xiang, Mingqing; Luo, Wei; Huang, Jinbai; Li, Maokun; Xiong, Xunbo; Wang, Hua

    2015-10-21

    To investigate the association between cognitive impairment and gray matter volume (GMV) abnormalities in silent cerebral infarction (SCI) patients, the GMV of 62 pairs of patients and well-matched healthy controls was calculated. All participants underwent a P300 test, a Montreal Cognitive Assessment (MoCA) test. Compared with controls, the patients showed decreased GMV in the left superior frontal gyrus, left inferior frontal gyrus, left superior temporal gyrus, right middle temporal gyrus, and bilateral parahippocampal gyrus; no significantly increasing GMV was found. The volumes of the frontal and temporal lobes were positively correlated with the score of the MoCA scale and P300 amplitudes (r≥0.62, P<0.01). The P300 latency was negatively correlated with the volumes of the frontal lobe, the temporal lobe, and the hippocampus (r≤-0.71, P<0.05). No significant correlations between the GMV of the abnormal brain regions and four clinical characteristics in SCI patients were found, suggesting that cognitive deficiency existed in SCI patients and the reduced GMV might contribute to the pathology of cognitive deficiency in SCI patients. PMID:26313037

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

    PubMed

    Gautam, P; Nuñez, S C; Narr, K L; Kan, E C; Sowell, E R

    2014-01-01

    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. PMID:24918069

  15. How Theory Matters: Formative Assessment Theory and Practices and Their Different Relations to Education

    ERIC Educational Resources Information Center

    Crossouard, Barbara; Pryor, John

    2012-01-01

    The positioning of theory in relation to educational practice has provoked much recent debate, with some arguing that educational theory constrains thinking in education, while others dismiss "theory" out of hand as belonging to the world of the "academic," abstracted from the "realities" of the classroom. This paper views theory as necessarily…

  16. Why formal learning theory matters for cognitive science.

    PubMed

    Fulop, Sean; Chater, Nick

    2013-01-01

    This article reviews a number of different areas in the foundations of formal learning theory. After outlining the general framework for formal models of learning, the Bayesian approach to learning is summarized. This leads to a discussion of Solomonoff's Universal Prior Distribution for Bayesian learning. Gold's model of identification in the limit is also outlined. We next discuss a number of aspects of learning theory raised in contributed papers, related to both computational and representational complexity. The article concludes with a description of how semi-supervised learning can be applied to the study of cognitive learning models. Throughout this overview, the specific points raised by our contributing authors are connected to the models and methods under review.

  17. Testing spontaneous localization theories with matter-wave interferometry

    SciTech Connect

    Nimmrichter, Stefan; Haslinger, Philipp; Arndt, Markus; Hornberger, Klaus

    2011-04-15

    We propose to test the theory of continuous spontaneous localization (CSL) in an all-optical time-domain Talbot-Lau interferometer for clusters with masses exceeding 10{sup 6} amu. By assessing the relevant environmental decoherence mechanisms, as well as the growing size of the particles relative to the grating fringes, we argue that it will be feasible to test the quantum superposition principle in a mass range excluded by recent estimates of the CSL effect.

  18. Chiral gauge theories and a dirac neutrino - Dark matter connection

    NASA Astrophysics Data System (ADS)

    Hernandez, Daniel

    2016-06-01

    It is proposed that all light fermionic degrees of freedom, including the Standard Model (SM) fermions and all possible light beyond-the-standard model fields, are chiral with respect to some spontaneously broken abelian gauge symmetry. A new gauge symmetry U(1)ν is required if light fermionic new states are to exist. Anomaly cancellations mandate the existence of several new fields with nontrivial U(1)ν charges. A general technique to write down chiral-fermions-only models that are at least anomaly-free under a U(1) gauge symmetry is described. A concrete example that provides a Dark Matter candidate and leads to parametrically small Dirac neutrino masses is further developed.

  19. Simultaneous changes in gray matter volume and white matter fractional anisotropy in Alzheimer's disease revealed by multimodal CCA and joint ICA.

    PubMed

    Ouyang, X; Chen, K; Yao, L; Hu, B; Wu, X; Ye, Q; Guo, X

    2015-08-20

    The prominent morphometric alterations of Alzheimer's disease (AD) occur both in gray matter and in white matter. Multimodal fusion can examine joint information by combining multiple neuroimaging datasets to identify the covariant morphometric alterations in AD in greater detail. In the current study, we conducted a multimodal canonical correlation analysis and joint independent component analysis to identify the covariance patterns of the gray and white matter by fusing structural magnetic resonance imaging and diffusion tensor imaging data of 39 AD patients (23 males and 16 females, mean age: 74.91±8.13years) and 41 normal controls (NCs) (20 males and 21 females, mean age: 73.97±6.34years) derived from the Alzheimer's Disease Neuroimaging Initiative database. The results revealed 25 joint independent components (ICs), of which three joint ICs exhibited strong links between the gray matter volume and the white matter fractional anisotropy (FA) and significant differences between the AD and NC group. The joint IC maps revealed that the simultaneous changes in the gray matter and FA values primarily involved the following areas: (1) the temporal lobe/hippocampus-cingulum, (2) the frontal/cingulate gyrus-corpus callosum, and (3) the temporal/occipital/parietal lobe-corpus callosum/corona radiata. Our findings suggest that gray matter atrophy is associated with reduced white matter fiber integrity in AD and possibly expand the understanding of the neuropathological mechanisms in AD.

  20. Sketches of an Elephant: A Topos Theory Compendium - Volume 2

    NASA Astrophysics Data System (ADS)

    Johnstone, Peter T.

    2002-11-01

    Topos Theory is a subject that stands at the junction of geometry, mathematical logic and theoretical computer science, and it derives much of its power from the interplay of ideas drawn from these different areas. Because of this, an account of topos theory which approaches the subject from one particular direction can only hope to give a partial picture; the aim of this compendium is to present as comprehensive an account as possible of all the main approaches and to thereby demonstrate the overall unity of the subject. The material is organized in such a way that readers interested in following a particular line of approach may do so by starting at an appropriate point in the text.

  1. The Association of Type 2 Diabetes Mellitus with Cerebral Gray Matter Volume Is Independent of Retinal Vascular Architecture and Retinopathy

    PubMed Central

    Moran, C.; Tapp, R. J.; Hughes, A. D.; Magnussen, C. G.; Blizzard, L.; Phan, T. G.; Beare, R.; Witt, N.; Venn, A.; Münch, G.; Amaratunge, B. C.; Srikanth, V.

    2016-01-01

    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. PMID:27314049

  2. The Association of Type 2 Diabetes Mellitus with Cerebral Gray Matter Volume Is Independent of Retinal Vascular Architecture and Retinopathy.

    PubMed

    Moran, C; Tapp, R J; Hughes, A D; Magnussen, C G; Blizzard, L; Phan, T G; Beare, R; Witt, N; Venn, A; Münch, G; Amaratunge, B C; Srikanth, V

    2016-01-01

    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. PMID:27314049

  3. SIRU utilization. Volume 1: Theory, development and test evaluation

    NASA Technical Reports Server (NTRS)

    Musoff, H.

    1974-01-01

    The theory, development, and test evaluations of the Strapdown Inertial Reference Unit (SIRU) are discussed. The statistical failure detection and isolation, single position calibration, and self alignment techniques are emphasized. Circuit diagrams of the system components are provided. Mathematical models are developed to show the performance characteristics of the subsystems. Specific areas of the utilization program are identified as: (1) error source propagation characteristics and (2) local level navigation performance demonstrations.

  4. Gray matter volume abnormalities in type 2 diabetes mellitus with and without mild cognitive impairment.

    PubMed

    Zhang, Yanwei; Zhang, Xiao; Zhang, Jiuquan; Liu, Chen; Yuan, Qiaoying; Yin, Xuntao; Wei, Luqing; Cui, Jinguo; Tao, Ran; Wei, Ping; Wang, Jian

    2014-03-01

    This study sought to evaluate the potential brain gray matter (GM) volume changes that occur with the transition from normal cognition to mild cognitive impairment (MCI) in patients with type 2 diabetes mellitus (T2DM) using voxel-based morphometry (VBM). VBM analyses of brain GM based on magnetic resonance imaging (MRI) data were performed on 28 T2DM patients with MCI, 25 T2DM patients without MCI, 28 MCI patients and 29 healthy controls (HC). Compared with the HC, the T2DM patients both with and without MCI showed significantly decreased total GM volume. Furthermore, the VBM results indicated that the T2DM patients without MCI exhibited extensively decreased GM volume compared with the HC in certain brain regions, including the superior and middle temporal gyrus (MTG), the superior and medial frontal gyrus and the middle occipital gyrus. In addition to more extensive GM atrophy in the aforementioned brain regions, the medial temporal lobe also exhibited GM loss in the T2DM patients with MCI. Furthermore, relative to the patients without MCI, only the left MTG exhibited a lower GM volume in the T2DM patients with MCI, which was positively correlated with the total MoCA score (r=0.699, P<0.01). Finally, relative to MCI, the left MTG atrophy was also found in the T2DM patients with MCI. Our findings suggest that MTG atrophy was associated with an increased risk for MCI in T2DM patients. The brain structural changes in many brain regions may underlie the transition from normal cognition to MCI in T2DM patients.

  5. White matter atlas of the human spinal cord with estimation of partial volume effect.

    PubMed

    Lévy, S; Benhamou, M; Naaman, C; Rainville, P; Callot, V; Cohen-Adad, J

    2015-10-01

    Template-based analysis has proven to be an efficient, objective and reproducible way of extracting relevant information from multi-parametric MRI data. Using common atlases, it is possible to quantify MRI metrics within specific regions without the need for manual segmentation. This method is therefore free from user-bias and amenable to group studies. While template-based analysis is common procedure for the brain, there is currently no atlas of the white matter (WM) spinal pathways. The goals of this study were: (i) to create an atlas of the white matter tracts compatible with the MNI-Poly-AMU template and (ii) to propose methods to quantify metrics within the atlas that account for partial volume effect. The WM atlas was generated by: (i) digitalizing an existing WM atlas from a well-known source (Gray's Anatomy), (ii) registering this atlas to the MNI-Poly-AMU template at the corresponding slice (C4 vertebral level), (iii) propagating the atlas throughout all slices of the template (C1 to T6) using regularized diffeomorphic transformations and (iv) computing partial volume values for each voxel and each tract. Several approaches were implemented and validated to quantify metrics within the atlas, including weighted-average and Gaussian mixture models. Proof-of-concept application was done in five subjects for quantifying magnetization transfer ratio (MTR) in each tract of the atlas. The resulting WM atlas showed consistent topological organization and smooth transitions along the rostro-caudal axis. The median MTR across tracts was 26.2. Significant differences were detected across tracts, vertebral levels and subjects, but not across laterality (right-left). Among the different tested approaches to extract metrics, the maximum a posteriori showed highest performance with respect to noise, inter-tract variability, tract size and partial volume effect. This new WM atlas of the human spinal cord overcomes the biases associated with manual delineation and partial

  6. Fermentation, phlogiston and matter theory: chemistry and natural philosophy in Georg Ernst Stahl's Zymotechnia Fundamentalis.

    PubMed

    Chang, Ku-Ming Kevin

    2002-01-01

    This paper examines Georg Ernst Stahl's first book, the Zymotechnia Fundamentalis, in the context of contemporary natural philosophy and the author's career. I argue that the Zymotechnia was a mechanical theory of fermentation written consciously against the influential "fermentational program" of Joan Baptista van Helmont and especially Thomas Willis, Stahl's theory of fermentation introduced his first conception of phlogiston, which was in part a corpuscular transformation of the Paracelsian sulphur principle. Meanwhile some assumptions underlying this theory, such as the composition of matter, the absolute passivity of matter and the "passions" of sulphur, reveal the combined scholastic and mechanistic character of Stahl's natural philosophy. In the conclusion I show that Stahl's theory of fermentation undermined the old fermentational program and paved the way for his dualist vitalism. PMID:12049065

  7. Gray Matter Volume of the Lingual Gyrus Mediates the Relationship between Inhibition Function and Divergent Thinking

    PubMed Central

    Zhang, Lijie; Qiao, Lei; Chen, Qunlin; Yang, Wenjing; Xu, Mengsi; Yao, Xiaonan; Qiu, Jiang; Yang, Dong

    2016-01-01

    Although previous research provides converging evidence for the role of posterior regions of the brain (including temporal, occipital, and parietal regions) involved in inhibition on creative thinking, it remains unclear as to how these regions influence individual differences in creative thinking. Thus, we explored the relationship between posterior regions (i.e., hippocampal, parahippocampal, lingual gyrus, precuneus, and cuneus), inhibition function, and divergent thinking (DT) in 128 healthy college students. The results revealed that lower inhibition was associated with larger gray matter volume (GMV) in the lingual gyrus, which in turn was associated with higher DT. In addition, GMV in the lingual gyrus mediated the association between inhibition and DT. These results provide new evidence for the role of inhibition in creative thinking. Inhibition may affect the amount of information stored in long-term memory, which, in turn influences DT. PMID:27752250

  8. Association of television violence exposure with executive functioning and white matter volume in young adult males.

    PubMed

    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. PMID:24836970

  9. Association of television violence exposure with executive functioning and white matter volume in young adult males.

    PubMed

    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.

  10. Viscous wing theory development. Volume 1: Analysis, method and results

    NASA Technical Reports Server (NTRS)

    Chow, R. R.; Melnik, R. E.; Marconi, F.; Steinhoff, J.

    1986-01-01

    Viscous transonic flows at large Reynolds numbers over 3-D wings were analyzed using a zonal viscid-inviscid interaction approach. A new numerical AFZ scheme was developed in conjunction with the finite volume formulation for the solution of the inviscid full-potential equation. A special far-field asymptotic boundary condition was developed and a second-order artificial viscosity included for an improved inviscid solution methodology. The integral method was used for the laminar/turbulent boundary layer and 3-D viscous wake calculation. The interaction calculation included the coupling conditions of the source flux due to the wing surface boundary layer, the flux jump due to the viscous wake, and the wake curvature effect. A method was also devised incorporating the 2-D trailing edge strong interaction solution for the normal pressure correction near the trailing edge region. A fully automated computer program was developed to perform the proposed method with one scalar version to be used on an IBM-3081 and two vectorized versions on Cray-1 and Cyber-205 computers.

  11. The correlation between emotional intelligence and gray matter volume in university students.

    PubMed

    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.

  12. Gray Matter Volume Decreases in Elderly Patients with Schizophrenia: A Voxel-based Morphometry Study

    PubMed Central

    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

  13. The correlation between emotional intelligence and gray matter volume in university students.

    PubMed

    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. PMID:25282329

  14. Testing the Dark Matter Caustic Theory against Observations in the Milky Way

    NASA Astrophysics Data System (ADS)

    Dumas, Julie; Newberg, Heidi J.; Niedzielski, Bethany; Susser, Adam; Thompson, Jeffery M.; Weiss, Jake; Lewis, Kim M.

    2015-09-01

    We test a particular theory of dark matter in which dark matter axions form ring “caustics” in the plane of the Milky Way against actual observations of Milky Way stars. According to this theory, cold, collisionless dark matter particles with angular momentum flow in and out of the Milky Way on sheets. These flows form caustic rings (at the positions of the rings, the density of the flow is formally infinite) at the locations of closest approach to the Galactic center. We show that the caustic ring dark matter theory reproduces a roughly logarithmic halo, with large perturbations near the rings. We show that the theory can reasonably match the observed rotation curve of the Milky Way. We explore the effects of the caustic rings on dwarf galaxy tidal disruption using N-body simulations. In particular, simulations of the Sagittarius dwarf galaxy tidal disruption in a caustic ring halo potential match observations of the trailing tidal tail as far as 90 kpc from the Galactic center; they do not, however, match the leading tidal tail. None of the caustic ring, Navarro-Frenk-White, or triaxial logarithmic halos fit all of the data. The source code for calculating the acceleration due to a caustic ring halo has been made publicly available in the NEMO Stellar Dynamics Toolbox and the Milkyway@home client repository.

  15. Testing the Dark Matter Caustic Theory against Observations in the Milky Way

    NASA Astrophysics Data System (ADS)

    Dumas, Julie; Newberg, Heidi J.; Niedzielski, Bethany; Susser, Adam; Thompson, Jeffery M.; Weiss, Jake; Lewis, Kim M.

    2015-09-01

    We test a particular theory of dark matter in which dark matter axions form ring “caustics” in the plane of the Milky Way against actual observations of Milky Way stars. According to this theory, cold, collisionless dark matter particles with angular momentum flow in and out of the Milky Way on sheets. These flows form caustic rings (at the positions of the rings, the density of the flow is formally infinite) at the locations of closest approach to the Galactic center. We show that the caustic ring dark matter theory reproduces a roughly logarithmic halo, with large perturbations near the rings. We show that the theory can reasonably match the observed rotation curve of the Milky Way. We explore the effects of the caustic rings on dwarf galaxy tidal disruption using N-body simulations. In particular, simulations of the Sagittarius dwarf galaxy tidal disruption in a caustic ring halo potential match observations of the trailing tidal tail as far as 90 kpc from the Galactic center; they do not, however, match the leading tidal tail. None of the caustic ring, Navarro–Frenk–White, or triaxial logarithmic halos fit all of the data. The source code for calculating the acceleration due to a caustic ring halo has been made publicly available in the NEMO Stellar Dynamics Toolbox and the Milkyway@home client repository.

  16. Dynamic properties of interfaces in soft matter: Experiments and theory

    NASA Astrophysics Data System (ADS)

    Sagis, Leonard M. C.

    2011-10-01

    The dynamic properties of interfaces often play a crucial role in the macroscopic dynamics of multiphase soft condensed matter systems. These properties affect the dynamics of emulsions, of dispersions of vesicles, of biological fluids, of coatings, of free surface flows, of immiscible polymer blends, and of many other complex systems. The study of interfacial dynamic properties, surface rheology, is therefore a relevant discipline for many branches of physics, chemistry, engineering, and life sciences. In the past three to four decades a vast amount of literature has been produced dealing with the rheological properties of interfaces stabilized by low molecular weight surfactants, proteins, (bio)polymers, lipids, colloidal particles, and various mixtures of these surface active components. In this paper recent experiments are reviewed in the field of surface rheology, with particular emphasis on the models used to analyze surface rheological data. Most of the models currently used are straightforward generalizations of models developed for the analysis of rheological data of bulk phases. In general the limits on the validity of these generalizations are not discussed. Not much use is being made of recent advances in nonequilibrium thermodynamic formalisms for multiphase systems, to construct admissible models for the stress-deformation behavior of interfaces. These formalisms are ideally suited to construct thermodynamically admissible constitutive equations for rheological behavior that include the often relevant couplings to other fluxes in the interface (heat and mass), and couplings to the transfer of mass from the bulk phase to the interface. In this review recent advances in the application of classical irreversible thermodynamics, extended irreversible thermodynamics, rational thermodynamics, extended rational thermodynamics, and the general equation for the nonequilibrium reversible-irreversible coupling formalism to multiphase systems are also discussed

  17. Isotropic non-white matter partial volume effects in constrained spherical deconvolution.

    PubMed

    Roine, Timo; Jeurissen, Ben; Perrone, Daniele; Aelterman, Jan; Leemans, Alexander; Philips, Wilfried; Sijbers, Jan

    2014-01-01

    Diffusion-weighted (DW) magnetic resonance imaging (MRI) is a non-invasive imaging method, which can be used to investigate neural tracts in the white matter (WM) of the brain. Significant partial volume effects (PVEs) are present in the DW signal due to relatively large voxel sizes. These PVEs can be caused by both non-WM tissue, such as gray matter (GM) and cerebrospinal fluid (CSF), and by multiple non-parallel WM fiber populations. High angular resolution diffusion imaging (HARDI) methods have been developed to correctly characterize complex WM fiber configurations, but to date, many of the HARDI methods do not account for non-WM PVEs. In this work, we investigated the isotropic PVEs caused by non-WM tissue in WM voxels on fiber orientations extracted with constrained spherical deconvolution (CSD). Experiments were performed on simulated and real DW-MRI data. In particular, simulations were performed to demonstrate the effects of varying the diffusion weightings, signal-to-noise ratios (SNRs), fiber configurations, and tissue fractions. Our results show that the presence of non-WM tissue signal causes a decrease in the precision of the detected fiber orientations and an increase in the detection of false peaks in CSD. We estimated 35-50% of WM voxels to be affected by non-WM PVEs. For HARDI sequences, which typically have a relatively high degree of diffusion weighting, these adverse effects are most pronounced in voxels with GM PVEs. The non-WM PVEs become severe with 50% GM volume for maximum spherical harmonics orders of 8 and below, and already with 25% GM volume for higher orders. In addition, a low diffusion weighting or SNR increases the effects. The non-WM PVEs may cause problems in connectomics, where reliable fiber tracking at the WM-GM interface is especially important. We suggest acquiring data with high diffusion-weighting 2500-3000 s/mm(2), reasonable SNR (~30) and using lower SH orders in GM contaminated regions to minimize the non-WM PVEs in CSD

  18. Gray matter volume and executive functioning correlate with time since injury following mild traumatic brain injury.

    PubMed

    Killgore, William D S; Singh, Prabhjyot; Kipman, Maia; Pisner, Derek; Fridman, Andrew; Weber, Mareen

    2016-01-26

    Most people who sustain a mild traumatic brain injury (mTBI) will recover to baseline functioning within a period of several days to weeks. A substantial minority of patients, however, will show persistent symptoms and mild cognitive complaints for much longer. To more clearly delineate how the duration of time since injury (TSI) is associated with neuroplastic cortical volume changes and cognitive recovery, we employed voxel-based morphometry (VBM) and select neuropsychological measures in a cross-sectional sample of 26 patients with mTBI assessed at either two-weeks, one-month, three-months, six-months, or one-year post injury, and a sample of 12 healthy controls. Longer duration of TSI was associated with larger gray matter volume (GMV) within the ventromedial prefrontal cortex (vmPFC) and right fusiform gyrus, and better neurocognitive performance on measures of visuospatial design fluency and emotional functioning. In particular, volume within the vmPFC was positively correlated with design fluency and negatively correlated with symptoms of anxiety, whereas GMV of the fusiform gyrus was associated with greater design fluency and sustained visual psychomotor vigilance performance. Moreover, the larger GMV seen among the more chronic individuals was significantly greater than healthy controls, suggesting possible enlargement of these regions with time since injury. These findings are interpreted in light of burgeoning evidence suggesting that cortical regions often exhibit structural changes following experience or practice, and suggest that with greater time since an mTBI, the brain displays compensatory remodeling of cortical regions involved in emotional regulation, which may reduce distractibility during attention demanding visuo-motor tasks. PMID:26711488

  19. Octanol-Water Partition Coefficient from 3D-RISM-KH Molecular Theory of Solvation with Partial Molar Volume Correction.

    PubMed

    Huang, WenJuan; Blinov, Nikolay; Kovalenko, Andriy

    2015-04-30

    The octanol-water partition coefficient is an important physical-chemical characteristic widely used to describe hydrophobic/hydrophilic properties of chemical compounds. The partition coefficient is related to the transfer free energy of a compound from water to octanol. Here, we introduce a new protocol for prediction of the partition coefficient based on the statistical-mechanical, 3D-RISM-KH molecular theory of solvation. It was shown recently that with the compound-solvent correlation functions obtained from the 3D-RISM-KH molecular theory of solvation, the free energy functional supplemented with the correction linearly related to the partial molar volume obtained from the Kirkwood-Buff/3D-RISM theory, also called the "universal correction" (UC), provides accurate prediction of the hydration free energy of small compounds, compared to explicit solvent molecular dynamics [ Palmer , D. S. ; J. Phys.: Condens. Matter 2010 , 22 , 492101 ]. Here we report that with the UC reparametrized accordingly this theory also provides an excellent agreement with the experimental data for the solvation free energy in nonpolar solvent (1-octanol) and so accurately predicts the octanol-water partition coefficient. The performance of the Kovalenko-Hirata (KH) and Gaussian fluctuation (GF) functionals of the solvation free energy, with and without UC, is tested on a large library of small compounds with diverse functional groups. The best agreement with the experimental data for octanol-water partition coefficients is obtained with the KH-UC solvation free energy functional.

  20. Reheating-volume measure in the string theory landscape

    NASA Astrophysics Data System (ADS)

    Winitzki, Sergei

    2008-12-01

    I recently proposed the “reheating-volume” (RV) prescription as a possible solution to the measure problem in “multiverse” cosmology. The goal of this work is to extend the RV measure to scenarios involving bubble nucleation, such as the string theory landscape. In the spirit of the RV prescription, I propose to calculate the distribution of observable quantities in a landscape that is conditioned in probability to nucleate a finite total number of bubbles to the future of an initial bubble. A general formula for the relative number of bubbles of different types can be derived. I show that the RV measure is well defined and independent of the choice of the initial bubble type, as long as that type supports further bubble nucleation. Applying the RV measure to a generic landscape, I find that the abundance of Boltzmann brains is always negligibly small compared with the abundance of ordinary observers in the bubbles of the same type. As an illustration, I present explicit results for a toy landscape containing four vacuum states, and for landscapes with a single high-energy vacuum and a large number of low-energy vacua.

  1. Effective field theory treatment of the neutrino background in direct dark matter detection experiments

    NASA Astrophysics Data System (ADS)

    Dent, James B.; Dutta, Bhaskar; Newstead, Jayden L.; Strigari, Louis E.

    2016-04-01

    Distinguishing a dark matter interaction from an astrophysical neutrino-induced interaction will be major challenge for future direct dark matter searches. In this paper, we consider this issue within nonrelativistic effective field theory (EFT), which provides a well-motivated theoretical framework for determining nuclear responses to dark matter scattering events. We analyze the nuclear energy recoil spectra from the different dark matter-nucleon EFT operators, and compare them to the nuclear recoil energy spectra that are predicted to be induced by astrophysical neutrino sources. We determine that for 11 of the 14 possible operators, the dark matter-induced recoil spectra can be cleanly distinguished from the corresponding neutrino-induced recoil spectra with moderate-size detector technologies that are now being pursued, e.g., these operators would require 0.5 tonne years to be distinguished from the neutrino background for low mass dark matter. Our results imply that in most models detectors with good energy resolution will be able to distinguish a dark matter signal from a neutrino signal, without the need for much larger detectors that must rely on additional information from timing or direction. In addition we calculate up-to-date exclusion limits in the EFT model space using data from the LUX experiment.

  2. Gray-matter volume, midbrain dopamine D2/D3 receptors and drug craving in methamphetamine users.

    PubMed

    Morales, A M; Kohno, M; Robertson, C L; Dean, A C; Mandelkern, M A; London, E D

    2015-06-01

    Dysfunction of the mesocorticolimbic system has a critical role in clinical features of addiction. Despite evidence suggesting that midbrain dopamine receptors influence amphetamine-induced dopamine release and that dopamine is involved in methamphetamine-induced neurotoxicity, associations between dopamine receptors and gray-matter volume have been unexplored in methamphetamine users. Here we used magnetic resonance imaging and [(18)F]fallypride positron emission tomography, respectively, to measure gray-matter volume (in 58 methamphetamine users) and dopamine D2/D3 receptor availability (binding potential relative to nondisplaceable uptake of the radiotracer, BPnd) (in 31 methamphetamine users and 37 control participants). Relationships between these measures and self-reported drug craving were examined. Although no difference in midbrain D2/D3 BPnd was detected between methamphetamine and control groups, midbrain D2/D3 BPnd was positively correlated with gray-matter volume in the striatum, prefrontal cortex, insula, hippocampus and temporal cortex in methamphetamine users, but not in control participants (group-by-midbrain D2/D3 BPnd interaction, P<0.05 corrected for multiple comparisons). Craving for methamphetamine was negatively associated with gray-matter volume in the insula, prefrontal cortex, amygdala, temporal cortex, occipital cortex, cerebellum and thalamus (P<0.05 corrected for multiple comparisons). A relationship between midbrain D2/D3 BPnd and methamphetamine craving was not detected. Lower midbrain D2/D3 BPnd may increase vulnerability to deficits in gray-matter volume in mesocorticolimbic circuitry in methamphetamine users, possibly reflecting greater dopamine-induced toxicity. Identifying factors that influence prefrontal and limbic volume, such as midbrain BPnd, may be important for understanding the basis of drug craving, a key factor in the maintenance of substance-use disorders.

  3. Topology of genetic associations between regional gray matter volume and intellectual ability: Evidence for a high capacity network.

    PubMed

    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.

  4. KICKSTARTING REIONIZATION WITH THE FIRST BLACK HOLES: THE EFFECTS OF SECOND-ORDER PERTURBATION THEORY IN PRE-REIONIZATION VOLUMES

    SciTech Connect

    Holley-Bockelmann, Kelly; Sinha, Manodeep; Wise, John H. E-mail: manodeep.sinha@vanderbilt.edu

    2012-12-10

    We explore structure formation in the dark ages (z {approx} 30-6) using two well-known methods for initializing cosmological N-body simulations. Overall, both the Zel'dovich approximation and second-order Lagrangian perturbation theory (2LPT) are known to produce accurate present-day dark matter halo mass functions. However, since the 2LPT method drives more rapid evolution of dense regions, it increases the occurrence of rare massive objects-an effect that is most pronounced at high redshift. We find that 2LPT produces more halos that could harbor Population III stars and their black hole remnants, and they produce them earlier. Although the differences between the 2LPT and Zel'dovich approximation mass functions are nearly erased by z = 6, this small boost to the number and mass of black holes more than doubles the reionized volume of the early universe. We discuss the implications for reionization and massive black hole growth.

  5. Use of dynamic theory to describe experimental results from volume holography

    NASA Technical Reports Server (NTRS)

    Magnusson, R.; Gaylord, T. K.

    1976-01-01

    The general applicability of dynamic theory to the description of the recording and readout characteristics of volume (thick) hologram gratings is indicated. In dynamic theory (as opposed to static theory), the volume nature of the thick holographic grating allows the interference of an incident light beam with its own diffracted beam inside the recording medium. This effect causes the continuous recording of another grating that alters the initial one, producing a resultant grating that is not uniform through the thickness of the recording material and a grating whose writing and reading characteristics may vary dramatically, depending on the recording material and the experimental conditions. A large number of diverse types of writing, reading, and angular-selectivity behavior have been reported. The dynamic theory of thick-hologram writing and reading is shown to predict qualitatively all of these various types of experimental behavior.

  6. Surface area accounts for the relation of gray matter volume to reading-related skills and history of dyslexia.

    PubMed

    Frye, Richard E; Liederman, Jacqueline; Malmberg, Benjamin; McLean, John; Strickland, David; Beauchamp, Michael S

    2010-11-01

    It is unknown whether the abnormalities in brain structure and function observed in dyslexic readers are congenital or arise later in development. Analyzing the 2 components of gray matter volume separately may help in differentiating these possibilities. Gray matter volume is the product of cortical surface area, determined during prenatal brain development, and cortical thickness, determined during postnatal development. For this study, 16 adults with a history of phonological dyslexia and 16 age- and gender-matched controls underwent magnetic resonance imaging and an extensive battery of tests of reading-related skills. Cortical surface area and gray matter volume measures of the whole brain, the inferior frontal gyrus, and the fusiform gyrus were similarly related to phonological skills and a history of dyslexia. There was no relationship between cortical thickness and phonological skills or history of dyslexia. Because cortical surface area reflects cortical folding patterns determined prenatally, this suggests that brain differences in dyslexia are rooted in early cortical development and are not due to compensatory changes that occur during postnatal development and would be expected to influence cortical thickness. This study demonstrates the importance of examining the separate components of gray matter volume when studying developmental abnormalities. PMID:20154011

  7. Set-Shifting Ability Is Associated with Gray Matter Volume in Older People with Mild Cognitive Impairment

    PubMed Central

    Tsutsumimoto, Kota; Makizako, Hyuma; Shimada, Hiroyuki; Doi, Takehiko; Suzuki, Takao

    2015-01-01

    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. PMID:26628898

  8. An arbitrary grid CFD algorithm for configuration aerodynamics analysis. Volume 1: Theory and validations

    NASA Technical Reports Server (NTRS)

    Baker, A. J.; Iannelli, G. S.; Manhardt, Paul D.; Orzechowski, J. A.

    1993-01-01

    This report documents the user input and output data requirements for the FEMNAS finite element Navier-Stokes code for real-gas simulations of external aerodynamics flowfields. This code was developed for the configuration aerodynamics branch of NASA ARC, under SBIR Phase 2 contract NAS2-124568 by Computational Mechanics Corporation (COMCO). This report is in two volumes. Volume 1 contains the theory for the derived finite element algorithm and describes the test cases used to validate the computer program described in the Volume 2 user guide.

  9. Form factors for dark matter capture by the Sun in effective theories

    SciTech Connect

    Catena, Riccardo; Schwabe, Bodo

    2015-04-24

    In the effective theory of isoscalar and isovector dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle, 8 isotope-dependent nuclear response functions can be generated in the dark matter scattering by nuclei. We compute the 8 nuclear response functions for the 16 most abundant elements in the Sun, i.e. H, {sup 3}He, {sup 4}He, {sup 12}C, {sup 14}N, {sup 16}O, {sup 20}Ne, {sup 23}Na, {sup 24}Mg, {sup 27}Al, {sup 28}Si, {sup 32}S, {sup 40}Ar, {sup 40}Ca, {sup 56}Fe, and {sup 59}Ni, through numerical shell model calculations. We use our response functions to compute the rate of dark matter capture by the Sun for all isoscalar and isovector dark matter-nucleon effective interactions, including several operators previously considered for dark matter direct detection only. We study in detail the dependence of the capture rate on specific dark matter-nucleon interaction operators, and on the different elements in the Sun. We find that a so far neglected momentum dependent dark matter coupling to the nuclear vector charge gives a larger contribution to the capture rate than the constant spin-dependent interaction commonly included in dark matter searches at neutrino telescopes. Our investigation lays the foundations for model independent analyses of dark matter induced neutrino signals from the Sun. The nuclear response functions obtained in this study are listed in analytic form in an appendix, ready to be used in other projects.

  10. Form factors for dark matter capture by the Sun in effective theories

    SciTech Connect

    Catena, Riccardo; Schwabe, Bodo E-mail: bodo.schwabe@theorie.physik.uni-goettingen.de

    2015-04-01

    In the effective theory of isoscalar and isovector dark matter-nucleon interactions mediated by a heavy spin-1 or spin-0 particle, 8 isotope-dependent nuclear response functions can be generated in the dark matter scattering by nuclei. We compute the 8 nuclear response functions for the 16 most abundant elements in the Sun, i.e. H, {sup 3}He, {sup 4}He, {sup 12}C, {sup 14}N, {sup 16}O, {sup 20}Ne, {sup 23}Na, {sup 24}Mg, {sup 27}Al, {sup 28}Si, {sup 32}S, {sup 40}Ar, {sup 40}Ca, {sup 56}Fe, and {sup 59}Ni, through numerical shell model calculations. We use our response functions to compute the rate of dark matter capture by the Sun for all isoscalar and isovector dark matter-nucleon effective interactions, including several operators previously considered for dark matter direct detection only. We study in detail the dependence of the capture rate on specific dark matter-nucleon interaction operators, and on the different elements in the Sun. We find that a so far neglected momentum dependent dark matter coupling to the nuclear vector charge gives a larger contribution to the capture rate than the constant spin-dependent interaction commonly included in dark matter searches at neutrino telescopes. Our investigation lays the foundations for model independent analyses of dark matter induced neutrino signals from the Sun. The nuclear response functions obtained in this study are listed in analytic form in an appendix, ready to be used in other projects.

  11. Modularity and 4D-2D spectral equivalences for large- N gauge theories with adjoint matter

    NASA Astrophysics Data System (ADS)

    Basar, Gökçe; Cherman, Aleksey; Dienes, Keith R.; McGady, David A.

    2016-06-01

    In recent work, we demonstrated that the confined-phase spectrum of non-supersymmetric pure Yang-Mills theory coincides with the spectrum of the chiral sector of a two-dimensional conformal field theory in the large- N limit. This was done within the tractable setting in which the gauge theory is compactified on a three-sphere whose radius is small compared to the strong length scale. In this paper, we generalize these observations by demonstrating that similar results continue to hold even when massless adjoint matter fields are introduced. These results hold for both thermal and (-1) F -twisted partition functions, and collectively suggest that the spectra of large- N confining gauge theories are organized by the symmetries of two-dimensional conformal field theories.

  12. 3d N = 1 Chern-Simons-matter theory and localization

    NASA Astrophysics Data System (ADS)

    Tsimpis, Dimitrios; Zhu, Yaodong

    2016-10-01

    We consider the most general, classically-conformal, three-dimensional N = 1 Chern-Simons-matter theory with global symmetry Sp (2) and gauge group U (N) × U (N). We show that the Lagrangian in the on-shell formulation of the theory admits one more free parameter as compared to the theory formulated in off-shell N = 1 superspace. The theory on T3 can be formally localized. We partially carry out the localization procedure for the theory on T3 with periodic boundary conditions. In particular we show that restricting to the saddle points with vanishing gauge connection gives a trivial contribution to the partition function, i.e. the bosonic and fermionic contributions exactly cancel each other.

  13. Binary Mutual Diffusion Coefficients of Polymer/Solvent Systems Using Compressible Regular Solutions Theory and Free Volume Theory

    NASA Astrophysics Data System (ADS)

    Farajnezhad, Arsalan; Asef Afshar, Orang; Asgarpour Khansary, Milad; Shirazian, Saeed

    2016-07-01

    The free volume theory has found practical application for prediction of diffusional behavior of polymer/solvent systems. In this paper, reviewing free volume theory, binary mutual diffusion coefficients in some polymer/solvent systems have been systematically presented through chemical thermodynamic modeling in terms of both activity coefficients and fugacity coefficients models. Here chemical thermodynamic model of compressible regular solution (CRS) was used for evaluation of diffusion coefficients calculations as the pure component properties would be required only. Four binary polymeric solutions of cyclohexane/polyisobutylene, n-pentane/polyisobutylene, toluene/polyisobutylene and chloroform/polyisobutylene were considered. The agreement between calculated data and the experimentally collected data was desirable and no considerable error propagation in approximating mutual diffusion coefficients has been observed.

  14. Simplified models vs. effective field theory approaches in dark matter searches

    NASA Astrophysics Data System (ADS)

    De Simone, Andrea; Jacques, Thomas

    2016-07-01

    In this review we discuss and compare the usage of simplified models and Effective Field Theory (EFT) approaches in dark matter searches. We provide a state of the art description on the subject of EFTs and simplified models, especially in the context of collider searches for dark matter, but also with implications for direct and indirect detection searches, with the aim of constituting a common language for future comparisons between different strategies. The material is presented in a form that is as self-contained as possible, so that it may serve as an introductory review for the newcomer as well as a reference guide for the practitioner.

  15. Reduced visual cortex grey matter volume in children and adolescents with reactive attachment disorder

    PubMed Central

    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. PMID:26288752

  16. Reduced visual cortex grey matter volume in children and adolescents with reactive attachment disorder.

    PubMed

    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. PMID:26288752

  17. CRC handbook of lubrication. Theory and practice of tribology: Volume II: Theory and design

    SciTech Connect

    Booser, E.R.

    1984-01-01

    This handbook covers the general area of lubrication and tribology in all its facets: friction, wear lubricants (liquid, solid, and gas), greases, lubrication principles, applications to various mechanisms, design principles of devices incorporating lubrication, maintenance, lubrication scheduling, and standardized tests; as well as environmental problems and conservation. The information contained in these two volumes will aid in achieving effective lubrication for control of friction and wear, and is another step to improve understanding of the complex factors involved in tribology. Both metric and English units are provided throughout both volumes.

  18. GSK3B and MAPT Polymorphisms Are Associated with Grey Matter and Intracranial Volume in Healthy Individuals

    PubMed Central

    Dobson-Stone, Carol; Polly, Patsie; Korgaonkar, Mayuresh S.; Williams, Leanne M.; Gordon, Evian; Schofield, Peter R.; Mather, Karen; Armstrong, Nicola J.; Wen, Wei; Sachdev, Perminder S.; Kwok, John B. J.

    2013-01-01

    The microtubule-associated protein tau gene (MAPT) codes for a protein that plays an integral role in stabilisation of microtubules and axonal transport in neurons. As well as its role in susceptibility to neurodegeneration, previous studies have found an association between the MAPT haplotype and intracranial volume and regional grey matter volumes in healthy adults. The glycogen synthase kinase-3β gene (GSK3B) codes for a serine/threonine kinase that phosphorylates various proteins, including tau, and has also been associated with risk for neurodegenerative disorders and schizophrenia. We examined the effects of MAPT and two functional promoter polymorphisms in GSK3B (rs3755557 and rs334558) on total grey matter and intracranial volume in three independent cohorts totaling 776 neurologically healthy individuals. In vitro analyses revealed a significant effect of rs3755557 on gene expression, and altered binding of at least two transcription factors, Octamer transcription factor 1 (Oct-1) and Pre-B-cell leukemia transcription factor 1 (Pbx-1), to the GSK3B promoter. Meta-analysis across the three cohorts revealed a significant effect of rs3755557 on total grey matter volume (summary B = 0.082, 95% confidence interval = 0.037–0.128) and intracranial volume (summary B = 0.113, 95% confidence interval = 0.082–0.144). No significant effect was observed for MAPT H1/H2 diplotype or GSK3B rs334558 on total grey matter or intracranial volume. Our genetic and biochemical analyses have identified a role for GSK3B in brain development, which could have important aetiological implications for neurodegenerative and neurodevelopmental disorders. PMID:23951236

  19. Theories of hydrophobic effects and the description of free volume in complex liquids

    SciTech Connect

    Pratt, L.R.; Garde, S.; Hummer, G.

    1998-12-31

    Recent progress on molecular theories of hydration of nonpolar solutes in liquid aqueous solution has lead to new ways to thinking about the old issue of free volume in liquids. This article surveys the principal new results with particular attention to the context of general issues of packing in liquids.

  20. The effect of a muscarinic receptor 1 gene variant on grey matter volume in schizophrenia.

    PubMed

    Cropley, Vanessa L; Scarr, Elizabeth; Fornito, Alex; Klauser, Paul; Bousman, Chad A; Scott, Rodney; Cairns, Murray J; Tooney, Paul A; Pantelis, Christos; Dean, Brian

    2015-11-30

    Previous research has demonstrated that individuals with schizophrenia who are homozygous at the c.267C>A single nucleotide polymorphism (rs2067477) within the cholinergic muscarinic M1 receptor (CHRM1) perform less well on the Wisconsin Card Sorting Test (WCST) than those who are heterozygous. This study sought to determine whether variation in the rs2067477 genotype was associated with differential changes in brain structure. Data from 227 patients with established schizophrenia or schizoaffective disorder were obtained from the Australian Schizophrenia Research Bank. Whole-brain voxel-based morphometry was performed to compare regional grey matter volume (GMV) between the 267C/C (N=191) and 267C/A (N=36) groups. Secondary analyses tested for an effect of genotype on cognition (the WCST was not available). Individuals who were homozygous (267C/C) demonstrated significantly reduced GMV in the right precentral gyrus compared to those who were heterozygous (267C/A). These preliminary results suggest that the rs2067477 genotype is associated with brain structure in the right precentral gyrus in individuals with schizophrenia/schizoaffective disorder. Future studies are required to replicate these results and directly link the volumetric reductions with specific cognitive processes.

  1. The alteration of gray matter volume and cognitive control in adolescents with internet gaming disorder

    PubMed Central

    Wang, Hongmei; Jin, Chenwang; Yuan, Kai; Shakir, Tahir Mehmood; Mao, Cuiping; Niu, Xuan; Niu, Chen; Guo, Liping; Zhang, Ming

    2015-01-01

    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. PMID:25852507

  2. Alterations of Regional Spontaneous Brain Activity and Gray Matter Volume in the Blind

    PubMed Central

    Jiang, Aili; Tian, Jing; Li, Rui; Liu, Yong; Jiang, Tianzi; Qin, Wen; Yu, Chunshui

    2015-01-01

    Visual deprivation can induce alterations of regional spontaneous brain activity (RSBA). However, the effects of onset age of blindness on the RSBA and the association between the alterations of RSBA and brain structure are still unclear in the blind. In this study, we performed resting-state functional and structural magnetic resonance imaging on 50 sighted controls and 91 blind subjects (20 congenitally blind, 27 early blind, and 44 late blind individuals). Compared with the sighted control, we identified increased RSBA in the blind in primary and high-level visual areas and decreased RSBA in brain regions which are ascribed to sensorimotor and salience networks. In contrast, blind subjects exhibited significantly decreased gray matter volume (GMV) in the visual areas, while they exhibited significantly increased GMV in the sensorimotor areas. Moreover, the onset age of blindness was negatively correlated with the GMV of visual areas in blind subjects, whereas it exerted complex influences on the RSBA. Finally, significant negative correlations were shown between RSBA and GMV values. Our results demonstrated system-dependent, inverse alterations in RSBA and GMV after visual deprivation. Furthermore, the onset age of blindness has different effects on the reorganizations in RSBA and GMV. PMID:26568891

  3. Alterations of Regional Spontaneous Brain Activity and Gray Matter Volume in the Blind.

    PubMed

    Jiang, Aili; Tian, Jing; Li, Rui; Liu, Yong; Jiang, Tianzi; Qin, Wen; Yu, Chunshui

    2015-01-01

    Visual deprivation can induce alterations of regional spontaneous brain activity (RSBA). However, the effects of onset age of blindness on the RSBA and the association between the alterations of RSBA and brain structure are still unclear in the blind. In this study, we performed resting-state functional and structural magnetic resonance imaging on 50 sighted controls and 91 blind subjects (20 congenitally blind, 27 early blind, and 44 late blind individuals). Compared with the sighted control, we identified increased RSBA in the blind in primary and high-level visual areas and decreased RSBA in brain regions which are ascribed to sensorimotor and salience networks. In contrast, blind subjects exhibited significantly decreased gray matter volume (GMV) in the visual areas, while they exhibited significantly increased GMV in the sensorimotor areas. Moreover, the onset age of blindness was negatively correlated with the GMV of visual areas in blind subjects, whereas it exerted complex influences on the RSBA. Finally, significant negative correlations were shown between RSBA and GMV values. Our results demonstrated system-dependent, inverse alterations in RSBA and GMV after visual deprivation. Furthermore, the onset age of blindness has different effects on the reorganizations in RSBA and GMV. PMID:26568891

  4. Interindividual differences in cognitive flexibility: influence of gray matter volume, functional connectivity and trait impulsivity

    PubMed Central

    Langner, Robert; Cieslik, Edna C.; Rottschy, Claudia; Eickhoff, Simon B.

    2016-01-01

    Cognitive flexibility, a core aspect of executive functioning, is required for the speeded shifting between different tasks and sets. Using an interindividual differences approach, we examined whether cognitive flexibility, as assessed by the Delis–Kaplan card-sorting test, is associated with gray matter volume (GMV) and functional connectivity (FC) of regions of a core network of multiple cognitive demands as well as with different facets of trait impulsivity. The core multiple-demand network was derived from three large-scale neuroimaging meta-analyses and only included regions that showed consistent associations with sustained attention, working memory as well as inhibitory control. We tested to what extent self-reported impulsivity as well as GMV and resting-state FC in this core network predicted cognitive flexibility independently and incrementally. Our analyses revealed that card-sorting performance correlated positively with GMV of the right anterior insula, FC between bilateral anterior insula and midcingulate cortex/supplementary motor area as well as the impulsivity dimension “Premeditation.” Importantly, GMV, FC and impulsivity together accounted for more variance of card-sorting performance than every parameter alone. Our results therefore indicate that various factors contribute individually to cognitive flexibility, underlining the need to search across multiple modalities when aiming to unveil the mechanisms behind executive functioning. PMID:24878823

  5. World-volume effective action of exotic five-brane in M-theory

    NASA Astrophysics Data System (ADS)

    Kimura, Tetsuji; Sasaki, Shin; Yata, Masaya

    2016-02-01

    We study the world-volume effective action of an exotic five-brane, known as the M-theory 53-brane (M53-brane) in eleven dimensions. The supermultiplet of the world-volume theory is the {N}=(2, 0) tensor multiplet in six dimensions. The world-volume action contains three Killing vectors {widehat{k}}_{widehat{I}}^M ( Ȋ = 1 , 2 , 3) associated with the U(1)3 isometry. We find the effective T-duality rule for the eleven-dimensional backgrounds that transforms the M5-brane effective action to that of the M53-brane. We also show that our action provides the source term for the M53-brane geometry in eleven-dimensional supergravity.

  6. Association of grey matter volume deviation with insight impairment in first-episode affective and non-affective psychosis.

    PubMed

    McFarland, John; Cannon, Dara M; Schmidt, Heike; Ahmed, Mohamed; Hehir, Sarah; Emsell, Louise; Barker, Gareth; McCarthy, Peter; Elliott, Mark A; McDonald, Colm

    2013-03-01

    The neurobiological correlates of impaired insight in psychotic illness remain uncertain and may be confounded by factors such as illness progression and medication use. Our study consisted of two separate experiments. In the first experiment, we examined the association between measures of insight and regional brain volume in thirty-two patients with first-episode psychosis. In the second experiment, we looked at similar associations in thirty individuals with chronic schizophrenia. Detailed measures of symptom awareness and symptom attribution were obtained using the Scale to assess Unawareness of Mental Disorder. MRI scans were acquired and analysed using Statistical Non-Parametric Mapping for voxel-based analyses of grey matter maps. Regression models were used to assess the relationship between insight and grey matter volume in both the first-episode psychosis and the chronic schizophrenia experiments whilst controlling for potential confounds. In first-episode psychosis patients, symptom misattribution was associated with increased grey matter in the right and left caudate, right thalamus, left insula, putamen and cerebellum. In the chronic schizophrenia study, there were no significant associations between regional grey matter volume and measures of insight. These findings suggest that neuroplastic changes within subcortical and frontotemporal regions are associated with impaired insight in individuals during their first episode of psychosis. PMID:22673767

  7. New constraints on dark matter effective theories from standard model loops.

    PubMed

    Crivellin, Andreas; D'Eramo, Francesco; Procura, Massimiliano

    2014-05-16

    We consider an effective field theory for a gauge singlet Dirac dark matter particle interacting with the standard model fields via effective operators suppressed by the scale Λ ≳ 1 TeV. We perform a systematic analysis of the leading loop contributions to spin-independent Dirac dark matter-nucleon scattering using renormalization group evolution between Λ and the low-energy scale probed by direct detection experiments. We find that electroweak interactions induce operator mixings such that operators that are naively velocity suppressed and spin dependent can actually contribute to spin-independent scattering. This allows us to put novel constraints on Wilson coefficients that were so far poorly bounded by direct detection. Constraints from current searches are already significantly stronger than LHC bounds, and will improve in the near future. Interestingly, the loop contribution we find is isospin violating even if the underlying theory is isospin conserving.

  8. Quantum field theory in curved spacetime and the dark matter problem

    SciTech Connect

    Grib, A. A.; Pavlov, Yu. V.

    2007-11-14

    Quantum field theory in nonstationary curved Friedmann spacetime leads to the phenomenon of creation of massive particles. The hypothesis that in the end of inflation gravitation creates from vacuum superheavy particles decaying on quarks and leptons leading to the observed baryon charge is investigated. Taking the complex scalar field for these particles in analogy with K{sup 0}-meson theory one obtains two components - the long living and short living ones, so that the long living component after breaking the Grand Unification symmetry has a long life time and is observed today as dark matter. The hypothesis that ultra high energy cosmic rays occur as manifestation of superheavy dark matter is considered and some experimental possibilities of the proposed scheme are analyzed.

  9. New constraints on dark matter effective theories from standard model loops.

    PubMed

    Crivellin, Andreas; D'Eramo, Francesco; Procura, Massimiliano

    2014-05-16

    We consider an effective field theory for a gauge singlet Dirac dark matter particle interacting with the standard model fields via effective operators suppressed by the scale Λ ≳ 1 TeV. We perform a systematic analysis of the leading loop contributions to spin-independent Dirac dark matter-nucleon scattering using renormalization group evolution between Λ and the low-energy scale probed by direct detection experiments. We find that electroweak interactions induce operator mixings such that operators that are naively velocity suppressed and spin dependent can actually contribute to spin-independent scattering. This allows us to put novel constraints on Wilson coefficients that were so far poorly bounded by direct detection. Constraints from current searches are already significantly stronger than LHC bounds, and will improve in the near future. Interestingly, the loop contribution we find is isospin violating even if the underlying theory is isospin conserving. PMID:24877928

  10. Quasiparticle theory of transport coefficients for hadronic matter at finite temperature and baryon density

    NASA Astrophysics Data System (ADS)

    Albright, M.; Kapusta, J. I.

    2016-01-01

    We develop a flexible quasiparticle theory of transport coefficients of hot hadronic matter at finite baryon density. We begin with a hadronic quasiparticle model which includes a scalar and a vector mean field. Quasiparticle energies and the mean fields depend on temperature and baryon chemical potential. Starting with the quasiparticle dispersion relation, we derive the Boltzmann equation and use the Chapman-Enskog expansion to derive formulas for the shear and bulk viscosities and thermal conductivity. We obtain both relaxation-time approximation formulas and more general integral equations. Throughout the work, we explicitly enforce the Landau-Lifshitz conditions of fit and ensure the theory is thermodynamically self-consistent. The derived formulas should be useful for predicting the transport coefficients of the hadronic phase of matter produced in heavy-ion collisions at the Relativistic Heavy Ion Collider and at other accelerators.

  11. On residual stresses and homeostasis: an elastic theory of functional adaptation in living matter

    NASA Astrophysics Data System (ADS)

    Ciarletta, P.; Destrade, M.; Gower, A. L.

    2016-04-01

    Living matter can functionally adapt to external physical factors by developing internal tensions, easily revealed by cutting experiments. Nonetheless, residual stresses intrinsically have a complex spatial distribution, and destructive techniques cannot be used to identify a natural stress-free configuration. This work proposes a novel elastic theory of pre-stressed materials. Imposing physical compatibility and symmetry arguments, we define a new class of free energies explicitly depending on the internal stresses. This theory is finally applied to the study of arterial remodelling, proving its potential for the non-destructive determination of the residual tensions within biological materials.

  12. On residual stresses and homeostasis: an elastic theory of functional adaptation in living matter

    PubMed Central

    Ciarletta, P.; Destrade, M.; Gower, A. L.

    2016-01-01

    Living matter can functionally adapt to external physical factors by developing internal tensions, easily revealed by cutting experiments. Nonetheless, residual stresses intrinsically have a complex spatial distribution, and destructive techniques cannot be used to identify a natural stress-free configuration. This work proposes a novel elastic theory of pre-stressed materials. Imposing physical compatibility and symmetry arguments, we define a new class of free energies explicitly depending on the internal stresses. This theory is finally applied to the study of arterial remodelling, proving its potential for the non-destructive determination of the residual tensions within biological materials. PMID:27113413

  13. The properties of nuclear matter with lattice NN potential in relativistic Brueckner-Hartree-Fock theory

    PubMed Central

    Hu, Jinniu; Toki, Hiroshi; Shen, Hong

    2016-01-01

    We study the properties of nuclear matter with lattice nucleon-nucleon (NN) potential in the relativistic Brueckner-Hartree-Fock (RBHF) theory. To use this potential in such a microscopic many-body theory, we firstly have to construct a one-boson-exchange potential (OBEP) based on the latest lattice NN potential. Three mesons, pion, σ meson, and ω meson, are considered. Their coupling constants and cut-off momenta are determined by fitting the on-shell behaviors and phase shifts of the lattice force, respectively. Therefore, we obtain two parameter sets of the OBEP potential (named as LOBEP1 and LOBEP2) with these two fitting ways. We calculate the properties of symmetric and pure neutron matter with LOBEP1 and LOBEP2. In non-relativistic Brueckner-Hartree-Fock case, the binding energies of symmetric nuclear matter are around −3 and −5 MeV at saturation density, while it becomes −8 and −12 MeV in relativistic framework with 1S0, 3S1, and 3D1 channels using our two parameter sets. For the pure neutron matter, the equations of state in non-relativistic and relativistic cases are very similar due to only consideration 1S0 channel with isospin T = 1 case. PMID:27752124

  14. Enriched environment increases myelinated fiber volume and length in brain white matter of 18-month female rats.

    PubMed

    Yang, Shu; Lu, Wei; Zhou, De-shan; Tang, Yong

    2015-04-23

    Cognition and memory decline with normal aging, which could be partly attributed to the degeneration of brain white matter. Previous studies demonstrated that exposure to an enriched environment (EE) could protect cognition and memory from aging. However, if or how EE might affect the brain white matter has not been thoroughly investigated. In the current study, 24 middle-aged (14-month-old) female Sprague -Dawley (SD) rats were randomly assigned to EE or standard environment (SE) for 4 months. At the end of the environment intervention, the Morris water maze tests were performed. Then, 5 rats were randomly selected from each group for stereological assessment of the brain white matter and its myelinated fibers. The results revealed that middle-aged rats living in EE displayed better spatial learning than SE controls. The white matter volume was 124.6 ± 7.8mm(3) in EE rats, which was significantly enlarged compared with 84.8 ± 3.4mm(3) in SE rats. Likewise, the myelinated fiber volume was markedly increased from 56.6 ± 1.7 mm(3) in SE rats to 87.2 ± 9.0mm(3) in EE rats; so was the myelinated fiber length from 83.5 ± 6.6 km in SE rats to 119.0 ± 10.0 km in EE rats. Our data suggested that EE could protect brain white matter and its myelinated fibers of female rats at middle age.

  15. Neutron-star matter within the energy-density functional theory and neutron-star structure

    SciTech Connect

    Fantina, A. F.; Chamel, N.; Goriely, S.; Pearson, J. M.

    2015-02-24

    In this lecture, we will present some nucleonic equations of state of neutron-star matter calculated within the nuclear energy-density functional theory using generalized Skyrme functionals developed by the Brussels-Montreal collaboration. These equations of state provide a consistent description of all regions of a neutron star. The global structure of neutron stars predicted by these equations of state will be discussed in connection with recent astrophysical observations.

  16. Decreased bilateral thalamic gray matter volume in first-episode schizophrenia with prominent hallucinatory symptoms: A volumetric MRI study.

    PubMed

    Huang, Peng; Xi, Yibin; Lu, Zhong-Lin; Chen, Yunchun; Li, Xiangrui; Li, Weiguo; Zhu, Xia; Cui, Long-Biao; Tan, Qingrong; Liu, Wenming; Li, Chen; Miao, Danmin; Yin, Hong

    2015-01-01

    Studies comparing gray matter (GM) volume of schizophrenic patients with or without auditory verbal hallucinations (AVHs) to that of normal controls remain controversial. This project aims to investigate changes of GM volumes of drug-naïve schizophrenic patients with and without AVHs. Eighteen first episode schizophrenic (FES) patients with AVHs, 18 FES patients without AVHs, and 18 healthy controls were scanned using structural MRI. Voxel-based morphometry (VBM) analysis was conducted to investigate changes of GM volume among the three groups. Patients with and without AVHs exhibited reduced GM volumes relative to normal controls in the left superior temporal gyrus, frontal regions, cerebellum and caudate. Further analysis of the GM of subcortical structures found that patients with AVHs had reduced thalamic volume than healthy controls. No significant difference was found between patients with and without AVHs. Significant correlation was found between the total scores of the Positive and Negative Syndrome Scale and bilateral thalamic volume. ROC analysis of thalamic volumes of the patients with AVHs and normal controls showed that the area under the curve was 0.698 (P = 0.043). The decreased thalamic volumes might serve as a biomarker for discriminating FES AVHs patients from normals. PMID:26403064

  17. A longitudinal study of age- and gender-related annual rate of volume changes in regional gray matter in healthy adults.

    PubMed

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

    2013-09-01

    The aim of this study was to analyze correlations among the annual rate of gray matter volume change, age, gender, and cerebrovascular risk factors in 381 healthy community-dwelling subjects with a large age range by applying a longitudinal design over 6 years using brain magnetic resonance images (MRIs). Brain MRI data were processed with voxel-based morphometry using a custom template by applying diffeomorphic anatomical registration using the exponentiated lie algebra procedure. The annual rate of regional gray matter volume change showed significant positive correlations with age in several regions, including the bilateral temporal pole, caudate nucleus, ventral and dorsolateral prefrontal cortices, insula, hippocampus, and temporoparietal cortex, whereas significant negative correlations with age were observed in several regions including the bilateral cingulate gyri and anterior lobe of the cerebellum. Additionally, a significant age-by-gender interaction was found for the annual rate of regional gray matter volume change in the bilateral hippocampus. No significant correlations were observed between the annual rate of regional gray matter volume change and body mass index or systolic blood pressure. A significant positive correlation between the annual rate of gray matter volume change and age indicates that the region shows not linear but accelerated gray matter loss with age. Therefore, evaluating the annual rate of the gray matter volume change with age in healthy subjects is important in understanding how gray matter volume changes with aging in each brain region and in anticipating what cognitive functions are likely to show accelerated decline with aging.

  18. The Indirect Effect of Age Group on Switch Costs via Gray Matter Volume and Task-Related Brain Activity.

    PubMed

    Steffener, Jason; Gazes, Yunglin; Habeck, Christian; Stern, Yaakov

    2016-01-01

    Healthy aging simultaneously affects brain structure, brain function, and cognition. These effects are often investigated in isolation ignoring any relationships between them. It is plausible that age related declines in cognitive performance are the result of age-related structural and functional changes. This straightforward idea is tested in within a conceptual research model of cognitive aging. The current study tested whether age-related declines in task-performance were explained by age-related differences in brain structure and brain function using a task-switching paradigm in 175 participants. Sixty-three young and 112 old participants underwent MRI scanning of brain structure and brain activation. The experimental task was an executive context dual task with switch costs in response time as the behavioral measure. A serial mediation model was applied voxel-wise throughout the brain testing all pathways between age group, gray matter volume, brain activation and increased switch costs, worsening performance. There were widespread age group differences in gray matter volume and brain activation. Switch costs also significantly differed by age group. There were brain regions demonstrating significant indirect effects of age group on switch costs via the pathway through gray matter volume and brain activation. These were in the bilateral precuneus, bilateral parietal cortex, the left precentral gyrus, cerebellum, fusiform, and occipital cortices. There were also significant indirect effects via the brain activation pathway after controlling for gray matter volume. These effects were in the cerebellum, occipital cortex, left precentral gyrus, bilateral supramarginal, bilateral parietal, precuneus, middle cingulate extending to medial superior frontal gyri and the left middle frontal gyri. There were no significant effects through the gray matter volume alone pathway. These results demonstrate that a large proportion of the age group effect on switch costs can

  19. The Indirect Effect of Age Group on Switch Costs via Gray Matter Volume and Task-Related Brain Activity

    PubMed Central

    Steffener, Jason; Gazes, Yunglin; Habeck, Christian; Stern, Yaakov

    2016-01-01

    Healthy aging simultaneously affects brain structure, brain function, and cognition. These effects are often investigated in isolation ignoring any relationships between them. It is plausible that age related declines in cognitive performance are the result of age-related structural and functional changes. This straightforward idea is tested in within a conceptual research model of cognitive aging. The current study tested whether age-related declines in task-performance were explained by age-related differences in brain structure and brain function using a task-switching paradigm in 175 participants. Sixty-three young and 112 old participants underwent MRI scanning of brain structure and brain activation. The experimental task was an executive context dual task with switch costs in response time as the behavioral measure. A serial mediation model was applied voxel-wise throughout the brain testing all pathways between age group, gray matter volume, brain activation and increased switch costs, worsening performance. There were widespread age group differences in gray matter volume and brain activation. Switch costs also significantly differed by age group. There were brain regions demonstrating significant indirect effects of age group on switch costs via the pathway through gray matter volume and brain activation. These were in the bilateral precuneus, bilateral parietal cortex, the left precentral gyrus, cerebellum, fusiform, and occipital cortices. There were also significant indirect effects via the brain activation pathway after controlling for gray matter volume. These effects were in the cerebellum, occipital cortex, left precentral gyrus, bilateral supramarginal, bilateral parietal, precuneus, middle cingulate extending to medial superior frontal gyri and the left middle frontal gyri. There were no significant effects through the gray matter volume alone pathway. These results demonstrate that a large proportion of the age group effect on switch costs can

  20. Loss of Fornix White Matter Volume as a Predictor of Cognitive Impairment in Cognitively Normal Elderly Individuals

    PubMed Central

    Fletcher, Evan; Raman, Mekala; Huebner, Philip; Liu, Amy; Mungas, Dan; Carmichael, Owen; DeCarli, Charles

    2014-01-01

    IMPORTANCE Magnetic resonance imaging markers of incipient cognitive decline among healthy elderly individuals have become important for both clarifying the biological underpinnings of dementia and clinically identifying healthy individuals at high risk of cognitive decline. Even though the role of hippocampal atrophy is well known in the later stages of decline, the ability of fornix-hippocampal markers to predict the earliest clinical deterioration is less clear. OBJECTIVES To examine the involvement of the hippocampus-fornix circuit in the very earliest stages of cognitive impairment and to determine whether the volumes of fornix white matter and hippocampal gray matter would be useful markers for understanding the onset of dementia and for clinical intervention. DESIGN A longitudinal cohort of cognitively normal elderly participants received clinical evaluations with T1-weighted magnetic resonance imaging and diffusivity scans during repeated visits over an average of 4 years. Regression and Cox proportional hazards models were used to analyze the relationships between fornix and hippocampal measures and their predictive power for incidence and time of conversion from normal to impaired cognition. SETTING A cohort of community-recruited elderly individuals at the Alzheimer Disease Center of the University of California, Davis. PARTICIPANTS A total of 102 cognitively normal elderly participants, with an average age of 73 years, recruited through community outreach using methods designed to enhance ethnic diversity. MAIN OUTCOMES AND MEASURES Our preliminary hypothesis was that fornix white matter volume should be a significant predictor of cognitive decline among normal elderly individuals and that fornix measures would be associated with gray matter changes in the hippocampus. RESULTS Fornix body volume and axial diffusivity were highly significant predictors (P = .02 and .005, respectively) of cognitive decline from normal cognition. Hippocampal volume was not

  1. Regional gray matter volume is associated with empathizing and systemizing in young adults.

    PubMed

    Takeuchi, Hikaru; Taki, Yasuyuki; Sassa, Yuko; Hashizume, Hiroshi; Sekiguchi, Atsushi; Fukushima, Ai; Kawashima, Ryuta

    2014-01-01

    Empathizing is defined as the drive to identify the mental states of others for predicting their behavior and responding with an appropriate emotion. Systemizing is defined as the drive to analyze a system in terms of the rules that govern the system in order to predict its behavior. Using voxel-based morphometry and questionnaires in a large sample of normal, right-handed young adults, we investigated the regional gray matter volume (rGMV) correlates of empathizing and systemizing and additionally those of the D score, which is the difference between systemizing and empathizing, to reveal the comprehensive picture of those correlates. Negative rGMV correlates of empathizing and positive rGMV correlates of the D score (formed by the negative correlation between rGMV and empathizing), were found primarily in nodes in the default mode network, mirror neuron system, dorsal anterior cingulate cortex, and the lateral part of the prefrontal cortex together with other areas. Positive rGMV correlates of systemizing and of the D score (formed by the positive correlation between rGMV and systemizing) were found primarily in nodes in the external attention system, middle cingulate cortex, and other regions. Negative rGMV correlates of systemizing were found in an area close to the left posterior insula and putamen. These findings reconcile some previously inconsistent findings, provide other new findings and suggest that these areas contribute to empathizing-systemizing. Furthermore, the negative/positive rGMV correlates of empathizing and positive/negative rGMV correlates of systemizing overlapped substantially. This may be in line with the notion that empathizing and systemizing compete neurally in the brain. PMID:24409308

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

    PubMed Central

    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

  3. Parcellation of the human orbitofrontal cortex based on gray matter volume covariance.

    PubMed

    Liu, Huaigui; Qin, Wen; Qi, Haotian; Jiang, Tianzi; Yu, Chunshui

    2015-02-01

    The human orbitofrontal cortex (OFC) is an enigmatic brain region that cannot be parcellated reliably using diffusional and functional magnetic resonance imaging (fMRI) because there is signal dropout that results from an inherent defect in imaging techniques. We hypothesise that the OFC can be reliably parcellated into subregions based on gray matter volume (GMV) covariance patterns that are derived from artefact-free structural images. A total of 321 healthy young subjects were examined by high-resolution structural MRI. The OFC was parcellated into subregions-based GMV covariance patterns; and then sex and laterality differences in GMV covariance pattern of each OFC subregion were compared. The human OFC was parcellated into the anterior (OFCa), medial (OFCm), posterior (OFCp), intermediate (OFCi), and lateral (OFCl) subregions. This parcellation scheme was validated by the same analyses of the left OFC and the bilateral OFCs in male and female subjects. Both visual observation and quantitative comparisons indicated a unique GMV covariance pattern for each OFC subregion. These OFC subregions mainly covaried with the prefrontal and temporal cortices, cingulate cortex and amygdala. In addition, GMV correlations of most OFC subregions were similar across sex and laterality except for significant laterality difference in the OFCl. The right OFCl had stronger GMV correlation with the right inferior frontal cortex. Using high-resolution structural images, we established a reliable parcellation scheme for the human OFC, which may provide an in vivo guide for subregion-level studies of this region and improve our understanding of the human OFC at subregional levels.

  4. Regional Gray Matter Volume Is Associated with Empathizing and Systemizing in Young Adults

    PubMed Central

    Takeuchi, Hikaru; Taki, Yasuyuki; Sassa, Yuko; Hashizume, Hiroshi; Sekiguchi, Atsushi; Fukushima, Ai; Kawashima, Ryuta

    2014-01-01

    Empathizing is defined as the drive to identify the mental states of others for predicting their behavior and responding with an appropriate emotion. Systemizing is defined as the drive to analyze a system in terms of the rules that govern the system in order to predict its behavior. Using voxel-based morphometry and questionnaires in a large sample of normal, right-handed young adults, we investigated the regional gray matter volume (rGMV) correlates of empathizing and systemizing and additionally those of the D score, which is the difference between systemizing and empathizing, to reveal the comprehensive picture of those correlates. Negative rGMV correlates of empathizing and positive rGMV correlates of the D score (formed by the negative correlation between rGMV and empathizing), were found primarily in nodes in the default mode network, mirror neuron system, dorsal anterior cingulate cortex, and the lateral part of the prefrontal cortex together with other areas. Positive rGMV correlates of systemizing and of the D score (formed by the positive correlation between rGMV and systemizing) were found primarily in nodes in the external attention system, middle cingulate cortex, and other regions. Negative rGMV correlates of systemizing were found in an area close to the left posterior insula and putamen. These findings reconcile some previously inconsistent findings, provide other new findings and suggest that these areas contribute to empathizing–systemizing. Furthermore, the negative/positive rGMV correlates of empathizing and positive/negative rGMV correlates of systemizing overlapped substantially. This may be in line with the notion that empathizing and systemizing compete neurally in the brain. PMID:24409308

  5. New N{>=}4 Superconformal Chern-Simons Theories

    SciTech Connect

    Lee, Sangmin

    2008-11-23

    We present a method of constructing the general N{>=}4 superconformal Chern-Simons matter theories and discuss how some of these theories can describe the world-volume theories of M2-branes probing conical singularities.

  6. PREFACE: Classical density functional theory methods in soft and hard matter Classical density functional theory methods in soft and hard matter

    NASA Astrophysics Data System (ADS)

    Haataja, Mikko; Gránásy, László; Löwen, Hartmut

    2010-08-01

    Herein we provide a brief summary of the background, events and results/outcome of the CECAM workshop 'Classical density functional theory methods in soft and hard matter held in Lausanne between October 21 and October 23 2009, which brought together two largely separately working communities, both of whom employ classical density functional techniques: the soft-matter community and the theoretical materials science community with interests in phase transformations and evolving microstructures in engineering materials. After outlining the motivation for the workshop, we first provide a brief overview of the articles submitted by the invited speakers for this special issue of Journal of Physics: Condensed Matter, followed by a collection of outstanding problems identified and discussed during the workshop. 1. Introduction Classical density functional theory (DFT) is a theoretical framework, which has been extensively employed in the past to study inhomogeneous complex fluids (CF) [1-4] and freezing transitions for simple fluids, amongst other things. Furthermore, classical DFT has been extended to include dynamics of the density field, thereby opening a new avenue to study phase transformation kinetics in colloidal systems via dynamical DFT (DDFT) [5]. While DDFT is highly accurate, the computations are numerically rather demanding, and cannot easily access the mesoscopic temporal and spatial scales where diffusional instabilities lead to complex solidification morphologies. Adaptation of more efficient numerical methods would extend the domain of DDFT towards this regime of particular interest to materials scientists. In recent years, DFT has re-emerged in the form of the so-called 'phase-field crystal' (PFC) method for solid-state systems [6, 7], and it has been successfully employed to study a broad variety of interesting materials phenomena in both atomic and colloidal systems, including elastic and plastic deformations, grain growth, thin film growth, solid

  7. On Yang--Mills Theories with Chiral Matter at Strong Coupling

    SciTech Connect

    Shifman, M.; Unsal, Mithat; /SLAC /Stanford U., Phys. Dept.

    2008-08-20

    Strong coupling dynamics of Yang-Mills theories with chiral fermion content remained largely elusive despite much effort over the years. In this work, we propose a dynamical framework in which we can address non-perturbative properties of chiral, non-supersymmetric gauge theories, in particular, chiral quiver theories on S{sub 1} x R{sub 3}. Double-trace deformations are used to stabilize the center-symmetric vacuum. This allows one to smoothly connect smaller(S{sub 1}) to larger(S{sub 1}) physics (R{sub 4} is the limiting case) where the double-trace deformations are switched off. In particular, occurrence of the mass gap in the gauge sector and linear confinement due to bions are analytically demonstrated. We find the pattern of the chiral symmetry realization which depends on the structure of the ring operators, a novel class of topological excitations. The deformed chiral theory, unlike the undeformed one, satisfies volume independence down to arbitrarily small volumes (a working Eguchi-Kawai reduction) in the large N limit. This equivalence, may open new perspectives on strong coupling chiral gauge theories on R{sub 4}.

  8. In vivo evaluation of gray and white matter volume loss in the parkinsonian variant of multiple system atrophy using SPM8 plus DARTEL for VBM.

    PubMed

    Shigemoto, Yoko; Matsuda, Hiroshi; Kamiya, Kouhei; Maikusa, Norihide; Nakata, Yasuhiro; Ito, Kimiteru; Ota, Miho; Matsunaga, Naofumi; Sato, Noriko

    2013-01-01

    In multiple system atrophy with predominant parkinsonism (MSA-P), several voxel-based morphometry (VBM) studies have revealed gray matter loss; however, the white matter volume changes have been rarely reported. We investigated the volume changes of white matter as well as gray matter by VBM. A retrospective MRI study was performed in 20 patients with MSA-P and 30 age-matched healthy controls. We applied VBM with statistical parametric mapping (SPM8) plus diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL) to explore the regional atrophy of gray and white matter in all of the MSA-P patients, 14 patients with left-side dominant and 6 patients with right-side dominant onset as compared to controls. In all of the MSA-P patients, VBM revealed a significant volume reduction of gray matter in the bilateral putamina, cerebellums and dorsal midbrain. White matter loss was located in bilateral globus pallidi, external capsules extending to the midbrain, right subcortical to precentral area through internal capsule, the pons, bilateral middle cerebellar peduncles and left cerebellum. In left-side dominant MSA-P patients, the gray and white matter volume loss was detected predominantly on the right side and vice versa in right-side dominant MSA-P patients. A correlation with disease duration and severity was not detected. VBM using SPM8 plus DARTEL detected significant volume loss not only in the gray but also in the white matter of the area affected by MSA-P.

  9. A Prospective Pilot Investigation of Brain Volume, White Matter Hyperintensities, and Hemorrhagic Lesions after Mild Traumatic Brain Injury

    PubMed Central

    Jarrett, Michael; Tam, Roger; Hernández-Torres, Enedino; Martin, Nancy; Perera, Warren; Zhao, Yinshan; Shahinfard, Elham; Dadachanji, Shiroy; Taunton, Jack; Li, David K. B.; Rauscher, Alexander

    2016-01-01

    Traumatic brain injury (TBI) is among the most common neurological disorders. Hemorrhagic lesions and white matter hyperintensities (WMH) are radiological features associated with moderate and severe TBI. Brain volume reductions have also been observed during the months following injury. In concussion, no signs of injury are observed on conventional magnetic resonance imaging (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 females) and 15 controls (9 females), 40 players underwent 3-T MRI for hemorrhages [multi-echo susceptibility-weighted imaging (SWI)], WMH (three-dimensional fluid-attenuated inversion recovery), and brain volume at the beginning and the end of the hockey season. Concussed athletes underwent additional imaging and neuropsychological testing at 3 days, 2 weeks, and 2 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 2 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 gray matter and white matter compared to controls. No significant changes in the number of WMH over the duration of the study were found in athletes. No microhemorrhages 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 2 weeks after concussion and persist until at least 2 months after concussion. Brain volume is reduced

  10. A Prospective Pilot Investigation of Brain Volume, White Matter Hyperintensities, and Hemorrhagic Lesions after Mild Traumatic Brain Injury.

    PubMed

    Jarrett, Michael; Tam, Roger; Hernández-Torres, Enedino; Martin, Nancy; Perera, Warren; Zhao, Yinshan; Shahinfard, Elham; Dadachanji, Shiroy; Taunton, Jack; Li, David K B; Rauscher, Alexander

    2016-01-01

    Traumatic brain injury (TBI) is among the most common neurological disorders. Hemorrhagic lesions and white matter hyperintensities (WMH) are radiological features associated with moderate and severe TBI. Brain volume reductions have also been observed during the months following injury. In concussion, no signs of injury are observed on conventional magnetic resonance imaging (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 females) and 15 controls (9 females), 40 players underwent 3-T MRI for hemorrhages [multi-echo susceptibility-weighted imaging (SWI)], WMH (three-dimensional fluid-attenuated inversion recovery), and brain volume at the beginning and the end of the hockey season. Concussed athletes underwent additional imaging and neuropsychological testing at 3 days, 2 weeks, and 2 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 2 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 gray matter and white matter compared to controls. No significant changes in the number of WMH over the duration of the study were found in athletes. No microhemorrhages 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 2 weeks after concussion and persist until at least 2 months after concussion. Brain volume is reduced between

  11. Dark energy and dark matter from hidden symmetry of gravity model with a non-Riemannian volume form

    NASA Astrophysics Data System (ADS)

    Guendelman, Eduardo; Nissimov, Emil; Pacheva, Svetlana

    2015-10-01

    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 √{-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.

  12. Is Gray Matter Volume an Intermediate Phenotype for Schizophrenia? A VBM Study of Patients with Schizophrenia and their Healthy Siblings

    PubMed Central

    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

  13. Effective meson masses in nuclear matter based on a cutoff field theory

    SciTech Connect

    Nakano, M.; Noda, N.; Mitsumori, T.; Koide, K.; Kouno, H.; Hasegawa, A.

    1997-02-01

    Effective masses of {sigma}, {omega}, {pi}, and {rho} mesons in nuclear matter are calculated based on a cutoff field theory. Instead of the traditional density-Feynman representation, we adopt the particle-hole-antiparticle representation for nuclear propagators so that unphysical components are not included in the meson self-energies. For an estimation of the contribution from the divergent particle-antiparticle excitations, i.e., vacuum polarization in nuclear matter, the idea of the renormalization group method is adopted. In this cutoff field theory, all the counterterms are finite and calculated numerically. It is shown that the predicted meson masses converge even if the cutoff {Lambda} is changed as long as {Lambda} is sufficiently large and that the prescription works well also for so-called nonrenormalized mesons such as {pi} and {rho}. According to this method, it is concluded that meson masses in nuclear matter have a weak dependence on the baryon density. {copyright} {ital 1997} {ital The American Physical Society}

  14. Three-index symmetric matter representations of SU(2) in F-theory from non-Tate form Weierstrass models

    NASA Astrophysics Data System (ADS)

    Klevers, Denis; Taylor, Washington

    2016-06-01

    We give an explicit construction of a class of F-theory models with matter in the three-index symmetric (4) representation of SU(2). This matter is realized at codimen-sion two loci in the F-theory base where the divisor carrying the gauge group is singular; the associated Weierstrass model does not have the form associated with a generic SU(2) Tate model. For 6D theories, the matter is localized at a triple point singularity of arithmetic genus g = 3 in the curve supporting the SU(2) group. This is the first explicit realization of matter in F-theory in a representation corresponding to a genus contribution greater than one. The construction is realized by "unHiggsing" a model with a U(1) gauge factor under which there is matter with charge q = 3. The resulting SU(2) models can be further unHiggsed to realize non-Abelian G 2 × SU(2) models with more conventional matter content or SU(2)3 models with trifundamental matter. The U(1) models used as the basis for this construction do not seem to have a Weierstrass realization in the general form found by Morrison-Park, suggesting that a generalization of that form may be needed to incorporate models with arbitrary matter representations and gauge groups localized on singular divisors.

  15. Neuroanatomical correlates of the sense of control: Gray and white matter volumes associated with an internal locus of control.

    PubMed

    Hashimoto, Teruo; Takeuchi, Hikaru; Taki, Yasuyuki; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos Makoto; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Hashizume, Hiroshi; Kunitoki, Keiko; Kawashima, Ryuta

    2015-10-01

    A belief that effort is rewarded can develop incentive, achievement motivation, and self-efficacy. Individuals with such a belief attribute causes of events to themselves, not to external, uncontrollable factors, and are thus said to have an internal locus of control. An internal locus of control is a positive personality trait and has been thoroughly studied in applied psychology, but has not been widely examined in neuroscience. In the present study, correlations between locus of control assessment scores and brain volumes were examined in 777 healthy young adults using magnetic resonance imaging. A whole-brain multiple regression analysis with corrections for the effects of age, gender, and intelligence was conducted. Voxel-based morphometry analyses revealed that gray matter volumes in the anterior cingulate cortex, striatum, and anterior insula positively correlated with higher scores, which indicate an internal LOC. In addition, white matter volumes in the striatum showed significant correlations with an internal locus of control. These results suggest that cognitive, socioemotional, self-regulatory, and reward systems might be associated with internal control orientation. The finding of greater volumes in several brain regions in individuals with a stronger internal locus of control indicates that there is a neuroanatomical basis for the belief that one's efforts are rewarded.

  16. Association between a longer duration of illness, age and lower frontal lobe grey matter volume in schizophrenia.

    PubMed

    Premkumar, Preethi; Fannon, Dominic; Kuipers, Elizabeth; Cooke, Michael A; Simmons, Andrew; Kumari, Veena

    2008-11-01

    The frontal lobe has an extended maturation period and may be vulnerable to the long-term effects of schizophrenia. We tested this hypothesis by studying the relationship between duration of illness (DoI), grey matter (GM) and cerebro-spinal fluid (CSF) volume across the whole brain. Sixty-four patients with schizophrenia and 25 healthy controls underwent structural MRI scanning and neuropsychological assessment. We performed regression analyses in patients to examine the relationship between DoI and GM and CSF volumes across the whole brain, and correlations in controls between age and GM or CSF volume of the regions where GM or CSF volumes were associated with DoI in patients. Correlations were also performed between GM volume in the regions associated with DoI and neuropsychological performance. A longer DoI was associated with lower GM volume in the left dorsomedial prefrontal cortex (PFC), right middle frontal cortex, left fusiform gyrus (FG) and left cerebellum (lobule III). Additionally, age was inversely associated with GM volume in the left dorsomedial PFC in patients, and in the left FG and CSF excess near the left cerebellum in healthy controls. Greater GM volume in the left dorsomedial PFC was associated with better working memory, attention and psychomotor speed in patients. Our findings suggest that the right middle frontal cortex is particularly vulnerable to the long-term effect of schizophrenia illness whereas the dorsomedial PFC, FG and cerebellum are affected by both a long DoI and aging. The effect of illness chronicity on GM volume in the left dorsomedial PFC may be extended to brain structure-neuropsychological function relationships. PMID:18586335

  17. The quantum 1/2 BPS Wilson loop in {N}=4 Chern-Simons-matter theories

    NASA Astrophysics Data System (ADS)

    Bianchi, Marco S.; Griguolo, Luca; Leoni, Matias; Mauri, Andrea; Penati, Silvia; Seminara, Domenico

    2016-09-01

    In three dimensional {N}=4 Chern-Simons-matter theories two independent fermionic Wilson loop operators can be defined, which preserve half of the supersymmetry charges and are cohomologically equivalent at classical level. We compute their three-loop expectation value in a convenient color sector and prove that the degeneracy is uplifted by quantum corrections. We expand the matrix model prediction in the same regime and by comparison we conclude that the quantum 1/2 BPS Wilson loop is the average of the two operators. We provide an all-loop argument to support this claim at any order. As a by-product, we identify the localization result at three loops as a correction to the framing factor induced by matter interactions. Finally, we comment on the quantum properties of the non-1/2 BPS Wilson loop operator defined as the difference of the two fermionic ones.

  18. The quantum 1/2 BPS Wilson loop in N=4 Chern-Simons-matter theories

    NASA Astrophysics Data System (ADS)

    Bianchi, Marco S.; Griguolo, Luca; Leoni, Matias; Mauri, Andrea; Penati, Silvia; Seminara, Domenico

    2016-09-01

    In three dimensional N=4 Chern-Simons-matter theories two independent fermionic Wilson loop operators can be defined, which preserve half of the supersymmetry charges and are cohomologically equivalent at classical level. We compute their three-loop expectation value in a convenient color sector and prove that the degeneracy is uplifted by quantum corrections. We expand the matrix model prediction in the same regime and by comparison we conclude that the quantum 1/2 BPS Wilson loop is the average of the two operators. We provide an all-loop argument to support this claim at any order. As a by-product, we identify the localization result at three loops as a correction to the framing factor induced by matter interactions. Finally, we comment on the quantum properties of the non-1/2 BPS Wilson loop operator defined as the difference of the two fermionic ones.

  19. Optimism and the brain: trait optimism mediates the protective role of the orbitofrontal cortex gray matter volume against anxiety.

    PubMed

    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.

  20. White matter volume change and its correlation with symptom severity in patients with schizophrenia: a VBM-DARTEL study.

    PubMed

    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. PMID:26485094

  1. Interplay of the sign problem and the infinite volume limit: Gauge theories with a theta term

    NASA Astrophysics Data System (ADS)

    Cai, Yiming; Cohen, Thomas; Goldbloom-Helzner, Ari; McPeak, Brian

    2016-06-01

    QCD and related gauge theories have a sign problem when a θ term is included; this complicates the extraction of physical information from Euclidean-space calculations as one would do in lattice studies. The sign problem arises in this system because the partition function for configurations with fixed topological charge Q , ZQ, are summed weighted by exp (i Q θ ) to obtain the partition function for fixed θ , Z (θ ). The sign problem gets exponentially worse numerically as the space-time volume is increased. Here it is shown that, apart from the practical numerical issues associated with large volumes, there are some interesting issues of principle. A key quantity is the energy density as a function of θ , ɛ (θ )=-log (Z (θ ) )/V . This is expected to be well defined in the large four-volume limit. Similarly, one expects the energy density for a fixed topological density ɛ ˜(Q /V )=-log (ZQ )/V to be well defined in the limit of large four volumes. Intuitively, one might expect that if one had the infinite volume expression for ɛ ˜(Q /V ) to arbitrary accuracy, then one could reconstruct ɛ (θ ) by directly summing over the topological sectors of the partition function. We show here that there are circumstances where this is not the case. In particular, this occurs in regions where the curvature of ɛ (θ ) is negative.

  2. G-flux, chiral matter and singularity resolution in F-theory compactifications

    NASA Astrophysics Data System (ADS)

    Krause, Sven; Mayrhofer, Christoph; Weigand, Timo

    2012-05-01

    We construct a set of chirality inducing G-fluxes in global F-theory compactifications on Calabi-Yau four-folds. Special emphasis is put on models with gauge group SU(5)×U(1 relevant in the context of F-theory GUT model building, which are described in terms of a U(1)-restricted Tate model. A G-flux arises in a manner completely analogous to the U(1 gauge potential. We describe in detail the resolution by blow-up of the various singularities responsible for the U(1 factor and the standard SU(5) gauge group and match the result with techniques applied in the context of toric geometry. This provides an explicit identification of the structure of the resolved fibre over the matter curves and over the enhancement points relevant for Yukawa couplings. We compute the flux-induced chiral index both of SU(5) charged matter and of SU(5) singlets charged only under U(1 localised on curves which are not contained in the SU(5) locus. We furthermore discuss global consistency conditions such as D3-tadpole cancellation, D-term supersymmetry and Freed-Witten quantisation. The U(1 gauge flux is a global extension of a class of split spectral cover bundles. It constitutes an essential ingredient in the construction of globally defined F-theory compactifications with chiral matter. We exemplify this in a three-generation SU(5)×U(1 model whose flux satisfies all of the above global consistency conditions. We also extend our results to chiral fluxes in models without U(1) restriction.

  3. Construction and classification of novel BPS Wilson loops in quiver Chern-Simons-matter theories

    NASA Astrophysics Data System (ADS)

    Ouyang, Hao; Wu, Jun-Bao; Zhang, Jia-ju

    2016-09-01

    In this paper we construct and classify novel Drukker-Trancanelli (DT) type BPS Wilson loops along infinite straight lines and circles in N = 2 , 3 quiver superconformal Chern-Simons-matter theories, Aharony-Bergman-Jafferis-Maldacena (ABJM) theory, and N = 4 orbifold ABJM theory. Generally we have four classes of Wilson loops, and all of them preserve the same supersymmetries as the BPS Gaiotto-Yin (GY) type Wilson loops. There are several free complex parameters in the DT type BPS Wilson loops, and for two classes of Wilson loops in ABJM theory and N = 4 orbifold ABJM theory there are supersymmetry enhancements at special values of the parameters. We check that the differences of the DT type and GY type Wilson loops are Q-exact with Q being some supercharges preserved by both the DT type and GY type Wilson loops. The results would be useful to calculate vacuum expectation values of the DT type Wilson loops in matrix models if they are still BPS quantum mechanically.

  4. Light states in Chern-Simons theory coupled to fundamental matter

    NASA Astrophysics Data System (ADS)

    Banerjee, Shamik; Hellerman, Simeon; Maltz, Jonathan; Shenker, Stephen H.

    2013-03-01

    Motivated by developments in vectorlike holography, we study SU(N) Chern-Simons theory coupled to matter fields in the fundamental representation on various spatial manifolds. On the spatial torus T 2, we find light states at small `t Hooft coupling λ = N/k, where k is the Chern-Simons level, taken to be large. In the free scalar theory the gaps are of order sqrt{λ }/N and in the critical scalar theory and the free fermion theory they are of order λ /N. The entropy of these states grows like N log( k). We briefly consider spatial surfaces of higher genus. Based on results from pure Chern-Simons theory, it appears that there are light states with entropy that grows even faster, like N 2 log( k). This is consistent with the log of the partition function on the three sphere S 3, which also behaves like N 2 log( k). These light states require bulk dynamics beyond standard Vasiliev higher spin gravity to explain them.

  5. The viscosity to entropy ratio: From string theory motivated bounds to warm dense matter

    SciTech Connect

    Faussurier, G.; Libby, S. B.; Silvestrelli, P. L.

    2014-07-04

    Here, we study the ratio of viscosity to entropy density in Yukawa one-component plasmas as a function of coupling parameter at fixed screening, and in realistic warm dense matter models as a function of temperature at fixed density. In these two situations, the ratio is minimized for values of the coupling parameters that depend on screening, and for temperatures that in turn depend on density and material. In this context, we also examine Rosenfeld arguments relating transport coefficients to excess reduced entropy for Yukawa one-component plasmas. For these cases we show that this ratio is always above the lower-bound conjecture derived from string theory ideas.

  6. Theory of magnetohydrodynamic accretion of matter with an ultrahard equation of state onto a black hole

    SciTech Connect

    Chernov, S. V.

    2015-06-15

    We consider the magnetohydrodynamic theory of spherically symmetric accretion of a perfect fluid onto a Schwarzschild black hole with an ultrahard equation of state, p = μ ∼ ρ{sup 2}, where p is the pressure, μ is the total energy density, and ρ is the fluid density. An approximate analytical solution is written out. We show that one critical sonic surface that coincides with the black hole event horizon is formed instead of two critical surfaces (fast and slow magnetosonic surfaces) for a degenerate ultrahard equation of state of matter.

  7. From dilute matter to the equilibrium point in the energy-density-functional theory

    NASA Astrophysics Data System (ADS)

    Yang, C. J.; Grasso, M.; Lacroix, D.

    2016-09-01

    Due to the large value of the scattering length in nuclear systems, standard density-functional theories based on effective interactions usually fail to reproduce the nuclear Fermi-liquid behavior both at very low densities and close to equilibrium. Guided on one side by the success of the Skyrme density functional and, on the other side, by resummation techniques used in effective field theories for systems with large scattering lengths, a new energy-density functional is proposed. This functional, adjusted on microscopic calculations, reproduces the nuclear equations of state of neutron and symmetric matter at various densities. Furthermore, it provides reasonable saturation properties as well as an appropriate density dependence for the symmetry energy.

  8. Field theory for zero sound and ion acoustic wave in astrophysical matter

    NASA Astrophysics Data System (ADS)

    Gabadadze, Gregory; Rosen, Rachel A.

    2016-02-01

    We set up a field theory model to describe the longitudinal low-energy modes in high density matter present in white dwarf stars. At the relevant scales, ions—the nuclei of oxygen, carbon, and helium—are treated as heavy pointlike spin-0 charged particles in an effective field theory approach, while the electron dynamics is described by the Dirac Lagrangian at the one-loop level. We show that there always exists a longitudinal gapless mode in the system irrespective of whether the ions are in a plasma, crystal, or quantum liquid state. For certain values of the parameters, the gapless mode can be interpreted as a zero sound mode and, for other values, as an ion acoustic wave; we show that the zero sound and ion acoustic wave are complementary to each other. We discuss possible physical consequences of these modes for properties of white dwarfs.

  9. Cerebral gray matter volume variation in female-to-male transsexuals: a voxel-based morphometric study.

    PubMed

    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. PMID:26559725

  10. Voxel-based morphometry in opera singers: Increased gray-matter volume in right somatosensory and auditory cortices.

    PubMed

    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.

  11. PREFACE: Classical density functional theory methods in soft and hard matter Classical density functional theory methods in soft and hard matter

    NASA Astrophysics Data System (ADS)

    Haataja, Mikko; Gránásy, László; Löwen, Hartmut

    2010-08-01

    Herein we provide a brief summary of the background, events and results/outcome of the CECAM workshop 'Classical density functional theory methods in soft and hard matter held in Lausanne between October 21 and October 23 2009, which brought together two largely separately working communities, both of whom employ classical density functional techniques: the soft-matter community and the theoretical materials science community with interests in phase transformations and evolving microstructures in engineering materials. After outlining the motivation for the workshop, we first provide a brief overview of the articles submitted by the invited speakers for this special issue of Journal of Physics: Condensed Matter, followed by a collection of outstanding problems identified and discussed during the workshop. 1. Introduction Classical density functional theory (DFT) is a theoretical framework, which has been extensively employed in the past to study inhomogeneous complex fluids (CF) [1-4] and freezing transitions for simple fluids, amongst other things. Furthermore, classical DFT has been extended to include dynamics of the density field, thereby opening a new avenue to study phase transformation kinetics in colloidal systems via dynamical DFT (DDFT) [5]. While DDFT is highly accurate, the computations are numerically rather demanding, and cannot easily access the mesoscopic temporal and spatial scales where diffusional instabilities lead to complex solidification morphologies. Adaptation of more efficient numerical methods would extend the domain of DDFT towards this regime of particular interest to materials scientists. In recent years, DFT has re-emerged in the form of the so-called 'phase-field crystal' (PFC) method for solid-state systems [6, 7], and it has been successfully employed to study a broad variety of interesting materials phenomena in both atomic and colloidal systems, including elastic and plastic deformations, grain growth, thin film growth, solid

  12. Bino variations: Effective field theory methods for dark matter direct detection

    NASA Astrophysics Data System (ADS)

    Berlin, Asher; Robertson, Denis S.; Solon, Mikhail P.; Zurek, Kathryn M.

    2016-05-01

    We apply effective field theory methods to compute bino-nucleon scattering, in the case where tree-level interactions are suppressed and the leading contribution is at loop order via heavy flavor squarks or sleptons. We find that leading log corrections to fixed-order calculations can increase the bino mass reach of direct detection experiments by a factor of 2 in some models. These effects are particularly large for the bino-sbottom coannihilation region, where bino dark matter as heavy as 5-10 TeV may be detected by near future experiments. For the case of stop- and selectron-loop mediated scattering, an experiment reaching the neutrino background will probe thermal binos as heavy as 500 and 300 GeV, respectively. We present three key examples that illustrate in detail the framework for determining weak scale coefficients, and for mapping onto a low-energy theory at hadronic scales, through a sequence of effective theories and renormalization group evolution. For the case of a squark degenerate with the bino, we extend the framework to include a squark degree of freedom at low energies using heavy particle effective theory, thus accounting for large logarithms through a "heavy-light current." Benchmark predictions for scattering cross sections are evaluated, including complete leading order matching onto quark and gluon operators, and a systematic treatment of perturbative and hadronic uncertainties.

  13. Active matter beyond mean-field: Ring-kinetic theory for self-propelled particles

    NASA Astrophysics Data System (ADS)

    Chou, Yen-Liang; Ihle, Thomas

    2015-02-01

    Recently, Hanke et al. [Phys. Rev. E 88, 052309 (2013), 10.1103/PhysRevE.88.052309] showed that mean-field kinetic theory fails to describe collective motion in soft active colloids and that correlations must not be neglected. Correlation effects are also expected to be essential in systems of biofilaments driven by molecular motors and in swarms of midges. To obtain correlations in an active matter system from first principles, we derive a ring-kinetic theory for Vicsek-style models of self-propelled agents from the exact N -particle evolution equation in phase space. The theory goes beyond mean-field and does not rely on Boltzmann's approximation of molecular chaos. It can handle precollisional correlations and cluster formation, which are both important to understand the phase transition to collective motion. We propose a diagrammatic technique to perform a small-density expansion of the collision operator and derive the first two equations of the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. An algorithm is presented that numerically solves the evolution equation for the two-particle correlations on a lattice. Agent-based simulations are performed and informative quantities such as orientational and density correlation functions are compared with those obtained by ring-kinetic theory. Excellent quantitative agreement between simulations and theory is found at not-too-small noises and mean free paths. This shows that there are parameter ranges in Vicsek-like models where the correlated closure of the BBGKY hierarchy gives correct and nontrivial results. We calculate the dependence of the orientational correlations on distance in the disordered phase and find that it seems to be consistent with a power law with an exponent around -1.8 , followed by an exponential decay. General limitations of the kinetic theory and its numerical solution are discussed.

  14. Active matter beyond mean-field: ring-kinetic theory for self-propelled particles.

    PubMed

    Chou, Yen-Liang; Ihle, Thomas

    2015-02-01

    Recently, Hanke et al. [Phys. Rev. E 88, 052309 (2013)] showed that mean-field kinetic theory fails to describe collective motion in soft active colloids and that correlations must not be neglected. Correlation effects are also expected to be essential in systems of biofilaments driven by molecular motors and in swarms of midges. To obtain correlations in an active matter system from first principles, we derive a ring-kinetic theory for Vicsek-style models of self-propelled agents from the exact N-particle evolution equation in phase space. The theory goes beyond mean-field and does not rely on Boltzmann's approximation of molecular chaos. It can handle precollisional correlations and cluster formation, which are both important to understand the phase transition to collective motion. We propose a diagrammatic technique to perform a small-density expansion of the collision operator and derive the first two equations of the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. An algorithm is presented that numerically solves the evolution equation for the two-particle correlations on a lattice. Agent-based simulations are performed and informative quantities such as orientational and density correlation functions are compared with those obtained by ring-kinetic theory. Excellent quantitative agreement between simulations and theory is found at not-too-small noises and mean free paths. This shows that there are parameter ranges in Vicsek-like models where the correlated closure of the BBGKY hierarchy gives correct and nontrivial results. We calculate the dependence of the orientational correlations on distance in the disordered phase and find that it seems to be consistent with a power law with an exponent around -1.8, followed by an exponential decay. General limitations of the kinetic theory and its numerical solution are discussed.

  15. Precise segmentation of multiple organs in CT volumes using learning-based approach and information theory.

    PubMed

    Lu, Chao; Zheng, Yefeng; Birkbeck, Neil; Zhang, Jingdan; Kohlberger, Timo; Tietjen, Christian; Boettger, Thomas; Duncan, James S; Zhou, S Kevin

    2012-01-01

    In this paper, we present a novel method by incorporating information theory into the learning-based approach for automatic and accurate pelvic organ segmentation (including the prostate, bladder and rectum). We target 3D CT volumes that are generated using different scanning protocols (e.g., contrast and non-contrast, with and without implant in the prostate, various resolution and position), and the volumes come from largely diverse sources (e.g., diseased in different organs). Three key ingredients are combined to solve this challenging segmentation problem. First, marginal space learning (MSL) is applied to efficiently and effectively localize the multiple organs in the largely diverse CT volumes. Second, learning techniques, steerable features, are applied for robust boundary detection. This enables handling of highly heterogeneous texture pattern. Third, a novel information theoretic scheme is incorporated into the boundary inference process. The incorporation of the Jensen-Shannon divergence further drives the mesh to the best fit of the image, thus improves the segmentation performance. The proposed approach is tested on a challenging dataset containing 188 volumes from diverse sources. Our approach not only produces excellent segmentation accuracy, but also runs about eighty times faster than previous state-of-the-art solutions. The proposed method can be applied to CT images to provide visual guidance to physicians during the computer-aided diagnosis, treatment planning and image-guided radiotherapy to treat cancers in pelvic region.

  16. Precise segmentation of multiple organs in CT volumes using learning-based approach and information theory.

    PubMed

    Lu, Chao; Zheng, Yefeng; Birkbeck, Neil; Zhang, Jingdan; Kohlberger, Timo; Tietjen, Christian; Boettger, Thomas; Duncan, James S; Zhou, S Kevin

    2012-01-01

    In this paper, we present a novel method by incorporating information theory into the learning-based approach for automatic and accurate pelvic organ segmentation (including the prostate, bladder and rectum). We target 3D CT volumes that are generated using different scanning protocols (e.g., contrast and non-contrast, with and without implant in the prostate, various resolution and position), and the volumes come from largely diverse sources (e.g., diseased in different organs). Three key ingredients are combined to solve this challenging segmentation problem. First, marginal space learning (MSL) is applied to efficiently and effectively localize the multiple organs in the largely diverse CT volumes. Second, learning techniques, steerable features, are applied for robust boundary detection. This enables handling of highly heterogeneous texture pattern. Third, a novel information theoretic scheme is incorporated into the boundary inference process. The incorporation of the Jensen-Shannon divergence further drives the mesh to the best fit of the image, thus improves the segmentation performance. The proposed approach is tested on a challenging dataset containing 188 volumes from diverse sources. Our approach not only produces excellent segmentation accuracy, but also runs about eighty times faster than previous state-of-the-art solutions. The proposed method can be applied to CT images to provide visual guidance to physicians during the computer-aided diagnosis, treatment planning and image-guided radiotherapy to treat cancers in pelvic region. PMID:23286081

  17. Milk and dairy consumption correlates with cerebral cortical as well as cerebral white matter volume in healthy young adults.

    PubMed

    Darnai, Gergely; Plózer, Enikő; Perlaki, Gábor; Orsi, Gergely; Nagy, Szilvia Anett; Horváth, Réka; Schwarcz, Attila; Kovács, Norbert; Altbäcker, Anna; Janszky, József; Clemens, Zsófia

    2015-01-01

    The objective of this study was to investigate the relation between habitual milk and dairy consumption and brain morphology as assessed by magnetic resonance imaging (MRI) investigations in 119 young healthy university students. MRI measurements were performed on a Siemens Magnetom Trio Tim (3T) system while FreeSurfer software suite was used for volumetric segmentation. Dietary habits related to milk and dairy consumption were assessed by a structured questionnaire. Total cerebral cortex, total cerebral white matter, and total cerebral parenchyma were significantly related with cottage cheese and total protein intake from milk and dairy also when controlled for age and gender in the multivariate model. Our results indicate that dietary habits related with milk and dairy are proportionally associated with volumes of both cerebral cortex and cerebral white matter. PMID:26436708

  18. Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors

    PubMed Central

    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. PMID:26915025

  19. World-volume effective theory for higher-dimensional black holes.

    PubMed

    Emparan, Roberto; Harmark, Troels; Niarchos, Vasilis; Obers, Niels A

    2009-05-15

    We argue that the main feature behind novel properties of higher-dimensional black holes, compared to four-dimensional ones, is that their horizons can have two characteristic lengths of very different size. We develop a long-distance world-volume effective theory that captures the black hole dynamics at scales much larger than the short scale. In this limit the black hole is regarded as a blackfold: a black brane (possibly boosted locally) whose world volume spans a curved submanifold of the spacetime. This approach reveals black objects with novel horizon geometries and topologies more complex than the black ring, but more generally it provides a new organizing framework for the dynamics of higher-dimensional black holes.

  20. World-volume effective theory for higher-dimensional black holes.

    PubMed

    Emparan, Roberto; Harmark, Troels; Niarchos, Vasilis; Obers, Niels A

    2009-05-15

    We argue that the main feature behind novel properties of higher-dimensional black holes, compared to four-dimensional ones, is that their horizons can have two characteristic lengths of very different size. We develop a long-distance world-volume effective theory that captures the black hole dynamics at scales much larger than the short scale. In this limit the black hole is regarded as a blackfold: a black brane (possibly boosted locally) whose world volume spans a curved submanifold of the spacetime. This approach reveals black objects with novel horizon geometries and topologies more complex than the black ring, but more generally it provides a new organizing framework for the dynamics of higher-dimensional black holes. PMID:19518938

  1. Associative memory in a volume holographic medium: a new approach based on operator theory

    NASA Astrophysics Data System (ADS)

    Pashaie, Ramin

    2014-07-01

    In this article, we present a new method for holographic implementation of associative memories. In the current approach, the memory capacity is implemented in the form of spatial perturbation of refractive index within the volume of a three dimensional holographic material. We use operator theory to solve the inverse problem and compute a closed-form solution for the spatial distribution of the perturbation considering any arbitrary set of input-output prototype vectors. Simplicity of the hardware is the major advantage of the current method.

  2. Superspace formulation in a three-algebra approach to D=3, N=4, 5 superconformal Chern-Simons matter theories

    SciTech Connect

    Chen Famin; Wu Yongshi

    2010-11-15

    We present a superspace formulation of the D=3, N=4, 5 superconformal Chern-Simons Matter theories, with matter supermultiplets valued in a symplectic 3-algebra. We first construct an N=1 superconformal action and then generalize a method used by Gaitto and Witten to enhance the supersymmetry from N=1 to N=5. By decomposing the N=5 supermultiplets and the symplectic 3-algebra properly and proposing a new superpotential term, we construct the N=4 superconformal Chern-Simons matter theories in terms of two sets of generators of a (quaternion) symplectic 3-algebra. The N=4 theories can also be derived by requiring that the supersymmetry transformations are closed on-shell. The relationship between the 3-algebras, Lie superalgebras, Lie algebras, and embedding tensors (proposed in [E. A. Bergshoeff, O. Hohm, D. Roest, H. Samtleben, and E. Sezgin, J. High Energy Phys. 09 (2008) 101.]) is also clarified. The general N=4, 5 superconformal Chern-Simons matter theories in terms of ordinary Lie algebras can be re-derived in our 3-algebra approach. All known N=4, 5 superconformal Chern-Simons matter theories can be recovered in the present superspace formulation for super-Lie algebra realization of symplectic 3-algebras.

  3. Superspace formulation in a three-algebra approach to D=3, N=4, 5 superconformal Chern-Simons matter theories

    NASA Astrophysics Data System (ADS)

    Chen, Fa-Min; Wu, Yong-Shi

    2010-11-01

    We present a superspace formulation of the D=3, N=4, 5 superconformal Chern-Simons Matter theories, with matter supermultiplets valued in a symplectic 3-algebra. We first construct an N=1 superconformal action and then generalize a method used by Gaitto and Witten to enhance the supersymmetry from N=1 to N=5. By decomposing the N=5 supermultiplets and the symplectic 3-algebra properly and proposing a new superpotential term, we construct the N=4 superconformal Chern-Simons matter theories in terms of two sets of generators of a (quaternion) symplectic 3-algebra. The N=4 theories can also be derived by requiring that the supersymmetry transformations are closed on-shell. The relationship between the 3-algebras, Lie superalgebras, Lie algebras, and embedding tensors (proposed in [E. A. Bergshoeff, O. Hohm, D. Roest, H. Samtleben, and E. Sezgin, J. High Energy Phys.JHEPFG1029-8479 09 (2008) 101.10.1088/1126-6708/2008/09/101]) is also clarified. The general N=4, 5 superconformal Chern-Simons matter theories in terms of ordinary Lie algebras can be re-derived in our 3-algebra approach. All known N=4, 5 superconformal Chern-Simons matter theories can be recovered in the present superspace formulation for super-Lie algebra realization of symplectic 3-algebras.

  4. Control theory based airfoil design for potential flow and a finite volume discretization

    NASA Technical Reports Server (NTRS)

    Reuther, J.; Jameson, A.

    1994-01-01

    This paper describes the implementation of optimization techniques based on control theory for airfoil design. In previous studies it was shown that control theory could be used to devise an effective optimization procedure for two-dimensional profiles in which the shape is determined by a conformal transformation from a unit circle, and the control is the mapping function. The goal of our present work is to develop a method which does not depend on conformal mapping, so that it can be extended to treat three-dimensional problems. Therefore, we have developed a method which can address arbitrary geometric shapes through the use of a finite volume method to discretize the potential flow equation. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented, where both target speed distributions and minimum drag are used as objective functions.

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

    SciTech Connect

    Silver, R.N.

    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)

  6. Specific regions display altered grey matter volume in μ-opioid receptor knockout mice: MRI voxel-based morphometry

    PubMed Central

    Sasaki, Kazumasu; Sumiyoshi, Akira; Nonaka, Hiroi; Kasahara, Yoshiyuki; Ikeda, Kazutaka; Hall, F Scott; Uhl, George R; Watanabe, Masahiko; Kawashima, Ryuta; Sora, Ichiro

    2015-01-01

    BACKGROUND AND PURPOSE μ Opioid receptor knockout (MOP-KO) mice display several behavioural differences from wild-type (WT) littermates including differential responses to nociceptive stimuli. Brain structural changes have been tied to behavioural alterations noted in transgenic mice with targeting of different genes. Hence, we assess the brain structure of MOP-KO mice. EXPERIMENTAL APPROACH Magnetic resonance imaging (MRI) voxel-based morphometry (VBM) and histological methods were used to identify structural differences between extensively backcrossed MOP-KO mice and WT mice. KEY RESULTS MOP-KO mice displayed robust increases in regional grey matter volume in olfactory bulb, several hypothalamic nuclei, periaqueductal grey (PAG) and several cerebellar areas, most confirmed by VBM analysis. The largest increases in grey matter volume were detected in the glomerular layer of the olfactory bulb, arcuate nucleus of hypothalamus, ventrolateral PAG (VLPAG) and cerebellar regions including paramedian and cerebellar lobules. Histological analyses confirm several of these results, with increased VLPAG cell numbers and increased thickness of the olfactory bulb granule cell layer and cerebellar molecular and granular cell layers. CONCLUSIONS AND IMPLICATIONS MOP deletion causes previously undescribed structural changes in specific brain regions, but not in all regions with high MOP receptor densities (e.g. thalamus, nucleus accumbens) or that exhibit adult neurogenesis (e.g. hippocampus). Volume differences in hypothalamus and PAG may reflect behavioural changes including hyperalgesia. Although the precise relationship between volume change and MOP receptor deletion was not determined from this study alone, these findings suggest that levels of MOP receptor expression may influence a broader range of neural structure and function in humans than previously supposed. LINKED ARTICLES This article is part of a themed section on Opioids: New Pathways to Functional Selectivity

  7. Final report of the independent counsel for Iran/Contra matters. Volume 2: Indictments, plea agreements, interim reports to the congress, and administrative matters

    SciTech Connect

    Walsh, L.E.

    1993-08-04

    In October and November 1986, two secret U.S. Government operations were publicly exposed, potentially implicating Reagan Administration officials in illegal activities. These operations were the provision of assistance to the military activities of the Nicaraguan contra rebels during an October 1984 to October 1986 prohibition on such aid, and the sale of U.S. arms to Iran in contravention of stated U.S. policy and in possible violation of arms-export controls. In late November 1986, Reagan Administration officials announced that some of the proceeds from the sale of U.S. arms to Iran had been diverted to the contras. As a result, Attorney General Edwin Meese III sought the appointment of an independent counsel to investigate and prosecute possible crimes. Volume II contains indictments, plea agreements, interim reports to Congress and administrative matters from that investigation.

  8. Gray matter volume is associated with rate of subsequent skill learning after a long term training intervention

    PubMed Central

    Sampaio-Baptista, Cassandra; Scholz, Jan; Jenkinson, Mark; Thomas, Adam G.; Filippini, Nicola; Smit, Gabrielle; Douaud, Gwenaëlle; Johansen-Berg, Heidi

    2014-01-01

    The ability to predict learning performance from brain imaging data has implications for selecting individuals for training or rehabilitation interventions. Here, we used structural MRI to test whether baseline variations in gray matter (GM) volume correlated with subsequent performance after a long-term training of a complex whole-body task. 44 naïve participants were scanned before undertaking daily juggling practice for 6 weeks, following either a high intensity or a low intensity training regime. To assess performance across the training period participants' practice sessions were filmed. Greater GM volume in medial occipito-parietal areas at baseline correlated with steeper learning slopes. We also tested whether practice time or performance outcomes modulated the degree of structural brain change detected between the baseline scan and additional scans performed immediately after training and following a further 4 weeks without training. Participants with better performance had higher increases in GM volume during the period following training (i.e., between scans 2 and 3) in dorsal parietal cortex and M1. When contrasting brain changes between the practice intensity groups, we did not find any straightforward effects of practice time though practice modulated the relationship between performance and GM volume change in dorsolateral prefrontal cortex. These results suggest that practice time and performance modulate the degree of structural brain change evoked by long-term training regimes. PMID:24680712

  9. Effects of the BDNF Val66Met Polymorphism on Gray Matter Volume in Typically Developing Children and Adolescents

    PubMed Central

    Hashimoto, Teruo; Fukui, Kento; Takeuchi, Hikaru; Yokota, Susumu; Kikuchi, Yoshie; Tomita, Hiroaki; Taki, Yasuyuki; Kawashima, Ryuta

    2016-01-01

    The Val66Met polymorphism of brain-derived neurotrophic factor (BDNF) is associated with psychiatric disorders and regional gray matter volume (rGMV) in adults. However, the relationship between BDNF and rGMV in children has not been clarified. In this 3-year cross-sectional/longitudinal (2 time points) study, we investigated the effects of BDNF genotypes on rGMV in 185 healthy Japanese children aged 5.7–18.4 using magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) analyses. We found that the volume of the right cuneus in Met homozygotes (Met/Met) was greater than in Val homozygotes (Val/Val) in both exams, and the left insula and left ventromedial prefrontal cortex volumes were greater in Val homozygotes versus Met homozygotes in Exam l. In addition, Met homozygous subjects exhibited higher processing speed in intelligence indices than Val homozygotes and Val/Met heterozygotes at both time points. Longitudinal analysis showed that the left temporoparietal junction volume of Val/Met heterozygotes increased more substantially over the 3-year study period than in Val homozygotes, and age-related changes were observed for the Val/Met genotype. Our findings suggest that the presence of 2 Met alleles may have a positive effect on rGMV at the developmental stages analyzed in this study. PMID:26830347

  10. Correlators of left charges and weak operators in finite volume chiral perturbation theory

    NASA Astrophysics Data System (ADS)

    Hernández, Pilar; Laine, Mikko

    2003-01-01

    We compute the two-point correlator between left-handed flavour charges, and the three-point correlator between two left-handed charges and one strangeness violating DeltaI = 3/2 weak operator, at next-to-leading order in finite volume SU(3)L × SU(3)R chiral perturbation theory, in the so-called epsilon-regime. Matching these results with the corresponding lattice measurements would in principle allow to extract the pion decay constant F, and the effective chiral theory parameter g27, which determines the Delta I = 3/2 amplitude of the weak decays K to pipi as well as the kaon mixing parameter BK in the chiral limit. We repeat the calculations in the replica formulation of quenched chiral perturbation theory, finding only mild modifications. In particular, a properly chosen ratio of the three-point and two-point functions is shown to be identical in the full and quenched theories at this order.

  11. Differential effects of androgenic and anti-androgenic progestins on fusiform and frontal gray matter volume and face recognition performance.

    PubMed

    Pletzer, Belinda; Kronbichler, Martin; Kerschbaum, Hubert

    2015-01-30

    Effects of oral hormonal contraceptives (OC) on human brain structure and behavior have only recently become a focus of research. Two explorative reports observed larger regional gray matter (GM) volumes in OC users within the prefrontal cortex, ACC and fusiform gyri, as well as parahippocampal gyri, hippocampus and cerebellum. These studies did however not control for the androgenicity of the progestin compound of OC, did not take into consideration how long OC users had been on their OC, and did not control for age differences between the OC group and the naturally cycling group. We compared 20 naturally cycling women during their early follicular cycle phase to 18 users of OC containing androgenic progestins and 22 users of OC containing anti-androgenic progestins. When controlling for age, we found that in users of anti-androgenic progestins relative GM volumes within the bilateral fusiform gyri, fusiform face area (FFA), parahippocampal place area (PPA) and cerebellum, were significantly larger than in naturally cycling women, while in users of androgenic progestins, relative as well as absolute volumes within the bilateral middle and superior frontal gyri were significantly smaller compared to naturally cycling women. These morphological changes were related to performance in a face recognition task. Face recognition performance was significantly better in users of anti-androgenic progestins compared to the other groups and significantly related to absolute as well as relative GM volumes in the FFA and PPA. Total GM volume, as well as absolute GM volumes within the bilateral fusiform gyri, FFA, hippocampus, parahippocampus, PPA, middle frontal gyri and ACC were significantly larger, the longer the duration of OC use, particularly in users of androgenic progestins. Morphological differences between active and inactive pill phase were observed in users of androgenic progestins. These findings suggest differential effects of androgenic and anti

  12. Does mode mixing matter in EMD-based highlight volume methods for hydrocarbon detection? Experimental evidence

    NASA Astrophysics Data System (ADS)

    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

  13. Testing universal relations of neutron stars with a nonlinear matter-gravity coupling theory

    SciTech Connect

    Sham, Y.-H.; Lin, L.-M.; Leung, P. T. E-mail: lmlin@phy.cuhk.edu.hk

    2014-02-01

    Due to our ignorance of the equation of state (EOS) beyond nuclear density, there is still no unique theoretical model for neutron stars (NSs). It is therefore surprising that universal EOS-independent relations connecting different physical quantities of NSs can exist. Lau et al. found that the frequency of the f-mode oscillation, the mass, and the moment of inertia are connected by universal relations. More recently, Yagi and Yunes discovered the I-Love-Q universal relations among the mass, the moment of inertia, the Love number, and the quadrupole moment. In this paper, we study these universal relations in the Eddington-inspired Born-Infeld (EiBI) gravity. This theory differs from general relativity (GR) significantly only at high densities due to the nonlinear coupling between matter and gravity. It thus provides us an ideal case to test how robust the universal relations of NSs are with respect to the change of the gravity theory. Due to the apparent EOS formulation of EiBI gravity developed recently by Delsate and Steinhoff, we are able to study the universal relations in EiBI gravity using the same techniques as those in GR. We find that the universal relations in EiBI gravity are essentially the same as those in GR. Our work shows that, within the currently viable coupling constant, there exists at least one modified gravity theory that is indistinguishable from GR in view of the unexpected universal relations.

  14. Grey matter volume abnormalities in patients with bipolar I depressive disorder and unipolar depressive disorder: a voxel-based morphometry study.

    PubMed

    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.

  15. Size Matters: Spleen and Lung Volumes Predict Performance in Human Apneic Divers

    PubMed Central

    Schagatay, Erika; Richardson, Matt X.; Lodin-Sundström, Angelica

    2012-01-01

    Humans share with seals the ability to contract the spleen and increase circulating hematocrit, which may improve apneic performance by enhancing gas storage. Seals have large spleens and while human spleen size is small in comparison, it shows great individual variation. Unlike many marine mammals, human divers rely to a great extent on lung oxygen stores, but the impact of lung volume on competitive apnea performance has never been determined. We studied if spleen- and lung size correlated with performance in elite apnea divers. Volunteers were 14 male apnea world championship participants, with a mean (SE) of 5.8 (1.2) years of previous apnea training. Spleen volume was calculated from spleen length, width, and thickness measured via ultrasound during rest, and vital capacity via spirometry. Accumulated competition scores from dives of maximal depth, time, and distance were compared to anthropometric measurements and training data. Mean (SE) diving performance was 75 (4) m for constant weight depth, 5 min 53 (39) s for static apnea and 139 (13) m for dynamic apnea distance. Subjects’ mean height was 184 (2) cm, weight 82 (3) kg, vital capacity (VC) 7.3 (0.3) L and spleen volume 336 (32) mL. Spleen volume did not correlate with subject height or weight, but was positively correlated with competition score (r = 0.57; P < 0.05). Total competition score was also positively correlated with VC (r = 0.54; P < 0.05). The three highest scoring divers had the greatest spleen volumes, averaging 538 (53) mL, while the three lowest-scoring divers had a volume of 270 (71) mL (P < 0.01). VC was also greater in the high-scorers, at 7.9 (0.36) L as compared to 6.7 (0.19) L in the low scorers (P < 0.01). Spleen volume was reduced to half after 2 min of apnea in the highest scoring divers, and the estimated resting apnea time gain from the difference between high and low scorers was 15 s for spleen volume and 60 s for VC

  16. The Impact of Comparative Education Research on Institutional Theory. International Perspectives on Education and Society. Volume 7

    ERIC Educational Resources Information Center

    Baker, David, Ed.; Wiseman, Alex, Ed.

    2006-01-01

    This volume of International Perspectives on Education and Society explores how educational research from a comparative perspective has been instrumental in broadening and testing hypotheses from institutional theory. Institutional theory has also played an increasingly influential role in developing an understanding of education in society. This…

  17. Age of second language acquisition in multilinguals has an impact on gray matter volume in language-associated brain areas.

    PubMed

    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. PMID:26106338

  18. Sex differences in socioemotional functioning, attentional bias, and gray matter volume in maltreated children: A multilevel investigation.

    PubMed

    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. PMID:26535946

  19. Age of second language acquisition in multilinguals has an impact on gray matter volume in language-associated brain areas.

    PubMed

    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.

  20. Age of second language acquisition in multilinguals has an impact on gray matter volume in language-associated brain areas

    PubMed Central

    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. PMID:26106338

  1. Individual differences in the Behavioral Inhibition System are associated with orbitofrontal cortex and precuneus gray matter volume.

    PubMed

    Fuentes, Paola; Barrós-Loscertales, Alfonso; Bustamante, Juan Carlos; Rosell, Patricia; Costumero, Víctor; Ávila, César

    2012-09-01

    The Behavioral Inhibition System (BIS) is described in Gray's Reinforcement Sensitivity Theory as a hypothetical construct that mediates anxiety in animals and humans. The neuroanatomical correlates of this system are not fully clear, although they are known to involve the amygdala, the septohippocampal system, and the prefrontal cortex. Previous neuroimaging research has related individual differences in BIS with regional volume and functional variations in the prefrontal cortex, amygdala, and hippocampal formation. The aim of the present work was to study BIS-related individual differences and their relationship with brain regional volume. BIS sensitivity was assessed through the BIS/BAS questionnaire in a sample of male participants (N = 114), and the scores were correlated with brain regional volume in a voxel-based morphometry analysis. The results show a negative correlation between the BIS and the volume of the right and medial orbitofrontal cortices and the precuneus. Our results and previous findings suggest that individual differences in anxiety-related personality traits and their related psychopathology may be associated with reduced brain volume in certain structures relating to emotional control (i.e., the orbitofrontal cortex) and self-consciousness (i.e., the precuneus), as shown by our results.

  2. The viscosity to entropy ratio: From string theory motivated bounds to warm dense matter

    DOE PAGES

    Faussurier, G.; Libby, S. B.; Silvestrelli, P. L.

    2014-07-04

    Here, we study the ratio of viscosity to entropy density in Yukawa one-component plasmas as a function of coupling parameter at fixed screening, and in realistic warm dense matter models as a function of temperature at fixed density. In these two situations, the ratio is minimized for values of the coupling parameters that depend on screening, and for temperatures that in turn depend on density and material. In this context, we also examine Rosenfeld arguments relating transport coefficients to excess reduced entropy for Yukawa one-component plasmas. For these cases we show that this ratio is always above the lower-bound conjecturemore » derived from string theory ideas.« less

  3. Density-functional theory for resonantly interacting fermions with effective range and neutron matter

    NASA Astrophysics Data System (ADS)

    Lacroix, Denis

    2016-10-01

    A density-functional theory is proposed for strongly interacting fermions with arbitrary large negative scattering length. The functional has only two parameters that are directly fixed to reproduce the universal properties of unitary gas: the so-called Bertsch parameter ξ0 and a parameter ηe related to the possible influence of the effective range re at infinite scattering length a . Using most recent quantum Monte Carlo (QMC) estimates of these two parameters, it is shown that the functional properly reproduces the experimental measurements of interacting Fermi systems not only at unitarity but also away from this limit over a wide range of (akF) -1 values. The functional is applied to obtain an expression of Tan's contact parameter including the effect of re. Application is finally made to neutron matter. It is shown that most recent QMC results are well reproduced.

  4. Differences in prefrontal, limbic, and white matter lesion volumes according to cognitive status in elderly patients with first-onset subsyndromal depression.

    PubMed

    Lee, Jun-Young; Park, Soowon; Mackin, Scott; Ewers, Michael; Chui, Helena; Jagust, William; Insel, Philip S; Weiner, Michael W

    2014-01-01

    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.

  5. No need for dark matter in galaxy clusters within Galileon theory

    NASA Astrophysics Data System (ADS)

    Salzano, Vincenzo; Mota, David F.; Dabrowski, Mariusz P.; Capozziello, Salvatore

    2016-10-01

    Modified gravity theories with a screening mechanism have acquired much interest recently in the quest for a viable alternative to General Relativity on cosmological scales, given their intrinsic property of being able to pass Solar System scale tests and, at the same time, to possibly drive universe acceleration on much larger scales. Here, we explore the possibility that the same screening mechanism, or its breaking at a certain astrophysical scale, might be responsible of those gravitational effects which, in the context of general relativity, are generally attributed to Dark Matter. We consider a recently proposed extension of covariant Galileon models in the so-called ``beyond Horndeski'' scenario, where a breaking of the Vainshtein mechanism is possible and, thus, some peculiar observational signatures should be detectable and make it distinguishable from general relativity. We apply this model to a sample of clusters of galaxies observed under the CLASH survey, using both new data from gravitational lensing events and archival data from X-ray intra-cluster hot gas observations. In particular, we use the latter to model the gas density, and then use it as the only ingredient in the matter clusters' budget to calculate the expected lensing convergence map. Results show that, in the context of this extended Galileon, the assumption of having only gas and no Dark Matter at all in the clusters is able to match observations. We also obtain narrow and very interesting bounds on the parameters which characterize this model. In particular, we find that, at least for one of them, the general relativity limit is excluded at 2σ confidence level, thus making this model clearly statistically different and competitive with respect to general relativity.

  6. The one-loop matter bispectrum in the Effective Field Theory of Large Scale Structures

    DOE PAGES

    Angulo, Raul E.; Foreman, Simon; Schmittfull, Marcel; Senatore, Leonardo

    2015-10-14

    With this study, given the importance of future large scale structure surveys for delivering new cosmological information, it is crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a manifestly convergent perturbative scheme to compute the clustering of dark matter in the weakly nonlinear regime in an expansion in k/kNL, where k is the wavenumber of interest and kNL is the wavenumber associated to the nonlinear scale. It has been recently shown that the EFTofLSS matches to 1% level the dark matter power spectrum at redshift zero up to k ≃ 0.3 hmore » Mpc–1 and k ≃ 0.6 h Mpc–1 at one and two loops respectively, using only one counterterm that is fit to data. Similar results have been obtained for the momentum power spectrum at one loop. This is a remarkable improvement with respect to former analytical techniques. Here we study the prediction for the equal-time dark matter bispectrum at one loop. We find that at this order it is sufficient to consider the same counterterm that was measured in the power spectrum. Without any remaining free parameter, and in a cosmology for which kNL is smaller than in the previously considered cases (σ8=0.9), we find that the prediction from the EFTofLSS agrees very well with N-body simulations up to k ≃ 0.25 h Mpc–1, given the accuracy of the measurements, which is of order a few percent at the highest k's of interest. While the fit is very good on average up to k ≃ 0.25 h Mpc–1, the fit performs slightly worse on equilateral configurations, in agreement with expectations that for a given maximum k, equilateral triangles are the most nonlinear.« less

  7. A further update on possible crises in nuclear-matter theory

    NASA Astrophysics Data System (ADS)

    Dickhoff, W. H.

    2016-03-01

    The ancient problem of the saturation of symmetric nuclear matter is reviewed with an update on the status of the crises that were identified at an early stage by John Clark. We discuss how the initial problem with variational calculations providing more binding than the two hole-line contribution for the same interaction was overcome by calculations including three hole-line contributions without however reproducing the empirical nuclear saturation properties. It is argued that this remaining problem is still open because many solutions have been proposed or ad hoc adjustments implemented without generating universal agreement on the proper interpretation of the physics. The problem of nuclear saturation therefore persists leading to the necessity of an analysis of the way the nuclear saturation properties are obtained from experimental data. We clarify the role of short-range correlations and review results for nuclear saturation when such ingredients are completely taken into account using the Green’s function method. The role of long-range correlations is then analyzed with special emphasis on the importance of attractive pion-dominated excitation modes which inevitably lead to higher saturation densities than observed. Because such modes have no counterpart in finite nuclear systems, it is therefore argued that they should not be considered when calculating nuclear matter properties. The remaining open question is then whether long-range correlations in finite nuclei which in turn have no counterpart in infinite matter, represent the remaining missing ingredient in this analysis. We also briefly comment on the role of three-body interactions in the context of the dispersive optical model description of experimental data. It is further noted that interactions based on chiral perturbation theory at present do not generate a sufficient number of high-momentum nucleons leading to radii that are too small and substantial overbinding in finite nuclei.

  8. The underlying anatomical correlates of long-term meditation: larger hippocampal and frontal volumes of gray matter.

    PubMed

    Luders, Eileen; Toga, Arthur W; Lepore, Natasha; Gaser, Christian

    2009-04-15

    Although the systematic study of meditation is still in its infancy, research has provided evidence for meditation-induced improvements in psychological and physiological well-being. Moreover, meditation practice has been shown not only to benefit higher-order cognitive functions but also to alter brain activity. Nevertheless, little is known about possible links to brain structure. Using high-resolution MRI data of 44 subjects, we set out to examine the underlying anatomical correlates of long-term meditation with different regional specificity (i.e., global, regional, and local). For this purpose, we applied voxel-based morphometry in association with a recently validated automated parcellation approach. We detected significantly larger gray matter volumes in meditators in the right orbito-frontal cortex (as well as in the right thalamus and left inferior temporal gyrus when co-varying for age and/or lowering applied statistical thresholds). In addition, meditators showed significantly larger volumes of the right hippocampus. Both orbito-frontal and hippocampal regions have been implicated in emotional regulation and response control. Thus, larger volumes in these regions might account for meditators' singular abilities and habits to cultivate positive emotions, retain emotional stability, and engage in mindful behavior. We further suggest that these regional alterations in brain structures constitute part of the underlying neurological correlate of long-term meditation independent of a specific style and practice. Future longitudinal analyses are necessary to establish the presence and direction of a causal link between meditation practice and brain anatomy.

  9. Normal age-related brain morphometric changes: nonuniformity across cortical thickness, surface area and gray matter volume?

    PubMed

    Lemaitre, Herve; Goldman, Aaron L; Sambataro, Fabio; Verchinski, Beth A; Meyer-Lindenberg, Andreas; Weinberger, Daniel R; Mattay, Venkata S

    2012-03-01

    Normal aging is accompanied by global as well as regional structural changes. While these age-related changes in gray matter volume have been extensively studied, less has been done using newer morphological indexes, such as cortical thickness and surface area. To this end, we analyzed structural images of 216 healthy volunteers, ranging from 18 to 87 years of age, using a surface-based automated parcellation approach. Linear regressions of age revealed a concomitant global age-related reduction in cortical thickness, surface area and volume. Cortical thickness and volume collectively confirmed the vulnerability of the prefrontal cortex, whereas in other cortical regions, such as in the parietal cortex, thickness was the only measure sensitive to the pronounced age-related atrophy. No cortical regions showed more surface area reduction than the global average. The distinction between these morphological measures may provide valuable information to dissect age-related structural changes of the brain, with each of these indexes probably reflecting specific histological changes occurring during aging. PMID:20739099

  10. Anterior cingulate cortex gray matter volume mediates an association between 2D:4D ratio and trait aggression in women but not men.

    PubMed

    Gorka, Adam X; Norman, Rachel E; Radtke, Spenser R; Carré, Justin M; Hariri, Ahmad R

    2015-06-01

    Previous research demonstrates that prenatal testosterone exposure increases aggression, possibly through its effects on the structure and function of neural circuits supporting threat detection and emotion regulation. Here we examined associations between regional gray matter volume, trait aggression, and the ratio of the second and fourth digit of the hand (2D:4D ratio) as a putative index of prenatal testosterone exposure in 464 healthy young adult volunteers. Our analyses revealed a significant positive correlation between 2D:4D ratio and gray matter volume of the dorsal anterior cingulate cortex (dACC), a brain region supporting emotion regulation, conflict monitoring, and behavioral inhibition. Subsequent analyses demonstrated that reduced (i.e., masculinized) gray matter volume in the dACC mediated the relationship between 2D:4D ratio and aggression in women, but not men. Expanding on this gender-specific mediation, additional analyses demonstrated that the shared variance between 2D:4D ratio, dACC gray matter volume, and aggression in women reflected the tendency to engage in cognitive reappraisal of emotionally provocative stimuli. Our results provide novel evidence that 2D:4D ratio is associated with masculinization of dACC gray matter volume, and that this neural phenotype mediates, in part, the expression of trait aggression in women.

  11. Effective field theory and keV lines from dark matter

    SciTech Connect

    Krall, Rebecca; Reece, Matthew; Roxlo, Thomas E-mail: mreece@physics.harvard.edu

    2014-09-01

    We survey operators that can lead to a keV photon line from dark matter decay or annihilation. We are motivated in part by recent claims of an unexplained 3.5 keV line in galaxy clusters and in Andromeda, but our results could apply to any hypothetical line observed in this energy range. We find that given the amount of flux that is observable, explanations in terms of decay are more plausible than annihilation, at least if the annihilation is directly to Standard Model states rather than intermediate particles. The decay case can be explained by a scalar or pseudoscalar field coupling to photons suppressed by a scale not far below the reduced Planck mass, which can be taken as a tantalizing hint of high-scale physics. The scalar case is particularly interesting from the effective field theory viewpoint, and we discuss it at some length. Because of a quartically divergent mass correction, naturalness strongly suggests the theory should be cut off at or below the 1000 TeV scale. The most plausible such natural UV completion would involve supersymmetry. These bottom-up arguments reproduce expectations from top-down considerations of the physics of moduli. A keV line could also arise from the decay of a sterile neutrino, in which case a renormalizable UV completion exists and no direct inference about high-scale physics is possible.

  12. Distribution function approach to redshift space distortions. Part V: perturbation theory applied to dark matter halos

    SciTech Connect

    Vlah, Zvonimir; Seljak, Uroš; Okumura, Teppei; Desjacques, Vincent E-mail: seljak@physik.uzh.ch E-mail: Vincent.Desjacques@unige.ch

    2013-10-01

    Numerical simulations show that redshift space distortions (RSD) introduce strong scale dependence in the power spectra of halos, with ten percent deviations relative to linear theory predictions even on relatively large scales (k < 0.1h/Mpc) and even in the absence of satellites (which induce Fingers-of-God, FoG, effects). If unmodeled these effects prevent one from extracting cosmological information from RSD surveys. In this paper we use Eulerian perturbation theory (PT) and Eulerian halo biasing model and apply it to the distribution function approach to RSD, in which RSD is decomposed into several correlators of density weighted velocity moments. We model each of these correlators using PT and compare the results to simulations over a wide range of halo masses and redshifts. We find that with an introduction of a physically motivated halo biasing, and using dark matter power spectra from simulations, we can reproduce the simulation results at a percent level on scales up to k ∼ 0.15h/Mpc at z = 0, without the need to have free FoG parameters in the model.

  13. Association of Superoxide Dismutase 2 (SOD2) Genotype with Gray Matter Volume Shrinkage in Chronic Alcohol Users: Replication and Further Evaluation of an Addiction Gene Panel

    PubMed Central

    Gitik, Miri; Srivastava, Vibhuti; Hodgkinson, Colin A.; Shen, Pei-Hong; Goldman, David

    2016-01-01

    Background: Reduction in brain volume, especially gray matter volume, has been shown to be one of the many deleterious effects of prolonged alcohol consumption. High variance in the degree of gray matter tissue shrinkage among alcohol-dependent individuals and a previous neuroimaging genetics report suggest the involvement of environmental and/or genetic factors, such as superoxide dismutase 2 (SOD2). Identification of such underlying factors will help in the clinical management of alcohol dependence. Methods: We analyzed quantitative magnetic resonance imaging and genotype data from 103 alcohol users, including both light drinkers and treatment-seeking alcohol-dependent individuals. Genotyping was performed using a custom gene array that included genes selected from 8 pathways relevant to chronic alcohol-related brain volume loss. Results: We replicated a significant association of a functional SOD2 single nucleotide polymorphism with normalized gray matter volume, which had been reported previously in an independent smaller sample of alcohol-dependent individuals. The SOD2-related genetic protection was observed only at the cohort’s lower drinking range. Additional associations between normalized gray matter volume and other candidate genes such as alcohol dehydrogenase gene cluster (ADH), GCLC, NOS3, and SYT1 were observed across the entire sample but did not survive corrections for multiple comparisons. Conclusion: Converging independent evidence for a SOD2 gene association with gray matter volume shrinkage in chronic alcohol users suggests that SOD2 genetic variants predict differential brain volume loss mediated by free radicals. This study also provides the first catalog of genetic variations relevant to gray matter loss in chronic alcohol users. The identified gene-brain structure relationships are functionally pertinent and merit replication. PMID:27207918

  14. A Deconstruction Lattice Description of the D1/D5 Brane World-Volume Gauge Theory

    DOE PAGES

    Giedt, Joel

    2011-01-01

    I genermore » alize the deconstruction lattice formulation of Endres and Kaplan to two-dimensional super-QCD with eight supercharges, denoted by (4,4), and bifundamental matter. I specialize to a particularly interesting (4,4) gauge theory, with gauge group U ( N c ) × U ( N f ) , and U ( N f ) being weakly gauged. It describes the infrared limit of the D1/D5 brane system, which has been studied extensively as an example of the AdS 3 /CFT 2 correspondence. The construction here preserves two supercharges exactly and has a lattice structure quite similar to that which has previously appeared in the deconstruction approach, that is, site, link, and diagonal fields with both the Bose and Fermi statistics. I remark on possible applications of the lattice theory that would test the AdS 3 /CFT 2 correspondence, particularly one that would exploit the recent worldsheet instanton analysis of Chen and Tong.« less

  15. The Etiology of Improved Outcomes at High Volume Centers Learning Theory and the Case of Implant Flashing.

    PubMed

    Bookman, Jared; Duffey, Romney; Hutzler, Lorraine; Slover, James; Iorio, Richard; Bosco, Joseph

    2016-06-01

    Increased volume has been shown to be associated with improved outcomes for many orthopaedic procedures. For individual surgeons, the concepts of learning curves and volume effects have been well established in the literature. For institutions, high-volume hospitals have also been shown to have better outcomes for orthopaedic procedures such as total joint replacements. However, exactly how hospital volume mediates this improvement is not well understood. Learning theory states that learning occurs as a result of accumulated experience, not based on time. We compared our institution's curve representing our implant flashing rates to other institutional data sets that exhibit learning and continuous quality improvement, including airline near misses, coal mining accidents, and others. Development of expertise is based on volume and rate of errors, and therefore higher volume is conducive to faster learning. PMID:27281321

  16. Nonlinear diffusion in two-dimensional ordered porous media based on a free volume theory

    NASA Astrophysics Data System (ADS)

    Godec, A.; Gaberscek, M.; Jamnik, J.; Merzel, F.

    2009-12-01

    A continuum nonlinear diffusion model is developed to describe molecular transport in ordered porous media. An existing generic van der Waals equation of state based free volume theory of binary diffusion coefficients is modified and introduced into the two-dimensional diffusion equation. The resulting diffusion equation is solved numerically with the alternating-direction fully implicit method under Neumann boundary conditions. Two types of pore structure symmetries are considered, hexagonal and cubic. The former is modeled as parallel channels while in case of the latter equal-sized channels are placed perpendicularly thus creating an interconnected network. First, general features of transport in both systems are explored, followed by the analysis of the impact of molecular properties on diffusion inside and out of the porous matrix. The influence of pore size on the diffusion-controlled release kinetics is assessed and the findings used to comment recent experimental studies of drug release profiles from ordered mesoporous silicates.

  17. Mimetic Theory for Cell-Centered Lagrangian Finite Volume Formulation on General Unstructured Grids

    SciTech Connect

    Sambasivan, Shiv Kumar; Shashkov, Mikhail J.; Burton, Donald E.; Christon, Mark A.

    2012-07-19

    A finite volume cell-centered Lagrangian scheme for solving large deformation problems is constructed based on the hypo-elastic model and using the mimetic theory. Rigorous analysis in the context of gas and solid dynamics, and arbitrary polygonal meshes, is presented to demonstrate the ability of cell-centered schemes in mimicking the continuum properties and principles at the discrete level. A new mimetic formulation based gradient evaluation technique and physics-based, frame independent and symmetry preserving slope limiters are proposed. Furthermore, a physically consistent dissipation model is employed which is both robust and inexpensive to implement. The cell-centered scheme along with these additional new features are applied to solve solids undergoing elasto-plastic deformation.

  18. Application of taxonomy theory, Volume 1: Computing a Hopf bifurcation-related segment of the feasibility boundary. Final report

    SciTech Connect

    Zaborszky, J.; Venkatasubramanian, V.

    1995-10-01

    Taxonomy Theory is the first precise comprehensive theory for large power system dynamics modeled in any detail. The motivation for this project is to show that it can be used, practically, for analyzing a disturbance that actually occurred on a large system, which affected a sizable portion of the Midwest with supercritical Hopf type oscillations. This event is well documented and studied. The report first summarizes Taxonomy Theory with an engineering flavor. Then various computational approaches are sighted and analyzed for desirability to use with Taxonomy Theory. Then working equations are developed for computing a segment of the feasibility boundary that bounds the region of (operating) parameters throughout which the operating point can be moved without losing stability. Then experimental software incorporating large EPRI software packages PSAPAC is developed. After a summary of the events during the subject disturbance, numerous large scale computations, up to 7600 buses, are reported. These results are reduced into graphical and tabular forms, which then are analyzed and discussed. The report is divided into two volumes. This volume illustrates the use of the Taxonomy Theory for computing the feasibility boundary and presents evidence that the event indeed led to a Hopf type oscillation on the system. Furthermore it proves that the Feasibility Theory can indeed be used for practical computation work with very large systems. Volume 2, a separate volume, will show that the disturbance has led to a supercritical (that is stable oscillation) Hopf bifurcation.

  19. Serial longitudinal magnetic resonance imaging data indicate non-linear regional gray matter volume recovery in abstinent alcohol-dependent individuals.

    PubMed

    Durazzo, Timothy C; Mon, Anderson; Gazdzinski, Stefan; Yeh, Ping-Hong; Meyerhoff, Dieter J

    2015-09-01

    The trajectory of regional volume changes during the first year of sustained abstinence in those recovering from an alcohol use disorder is unclear because previous research typically employed only two assessment points. To better understand the trajectory of regional brain volume recovery in treatment-seeking alcohol-dependent individuals (ALC), regional brain volumes were measured after 1 week, 1 month and 7.5 months of sustained abstinence via magnetic resonance imaging at 1.5 T. ALC showed significant volume increases in frontal, parietal and occipital gray matter (GM) and white matter (WM), total cortical GM and total lobar WM, thalamus and cerebellum, and decreased ventricular volume over 7.5 months of abstinence. Volume increases in regional GM were significantly greater over 1 week to 1 month than from 1 month to 7.5 months of abstinence, indicating a non-linear rate of change in regional GM over 7.5 months. Overall, regional lobar WM showed linear volume increases over 7.5 months. With increasing age, smoking ALC showed lower frontal and total cortical GM volume recovery than non-smoking ALC. Despite significant volume increases, ALC showed smaller GM volumes in all regions, except the frontal cortex, than controls after 7.5 months of abstinence. ALC and controls showed no regional WM volume differences at any assessment point. In non-smoking ALC only, increasing regional GM and WM volumes were related to improving processing speed. Findings may indicate a differential rate of recovery of cell types/cellular components contributing to GM and WM volume during early abstinence, and that GM volume deficits persist after 7.5 months of sustained sobriety in this ALC cohort.

  20. Nuclear matter properties in the relativistic mean-field theory at finite temperature with interaction between sigma-omega mesons

    SciTech Connect

    Costa, R. S.; Duarte, S. B.; Oliveira, J. C. T.; Chiapparini, M.

    2010-05-21

    We study the nuclear matter properties in the regime of high temperatures using a relativistic mean-field theory. Contrasting with the usual linear Walecka model, we include the sigma-omega meson coupling in order to investigate the role of this interaction in the nucleon effective mass behavior. Some numerical results are presented and discussed.

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

    DOE R&D Accomplishments Database

    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.

  2. Research in the theory of condensed matter and elementary particles: Final report, September 1, 1984-November 30, 1987

    SciTech Connect

    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.

  3. Permutation and parametric tests for effect sizes in voxel-based morphometry of gray matter volume in brain structural MRI.

    PubMed

    Dickie, David A; Mikhael, Shadia; Job, Dominic E; Wardlaw, Joanna M; Laidlaw, David H; Bastin, Mark E

    2015-12-01

    Permutation testing has been widely implemented in voxel-based morphometry (VBM) tools. However, this type of non-parametric inference has yet to be thoroughly compared with traditional parametric inference in VBM studies of brain structure. Here we compare both types of inference and investigate what influence the number of permutations in permutation testing has on results in an exemplar study of how gray matter proportion changes with age in a group of working age adults. High resolution T1-weighted volume scans were acquired from 80 healthy adults aged 25-64years. Using a validated VBM procedure and voxel-based permutation testing for Pearson product-moment coefficient, the effect sizes of changes in gray matter proportion with age were assessed using traditional parametric and permutation testing inference with 100, 500, 1000, 5000, 10000 and 20000 permutations. The statistical significance was set at P<0.05 and false discovery rate (FDR) was used to correct for multiple comparisons. Clusters of voxels with statistically significant (PFDR<0.05) declines in gray matter proportion with age identified with permutation testing inference (N≈6000) were approximately twice the size of those identified with parametric inference (N=3221voxels). Permutation testing with 10000 (N=6251voxels) and 20000 (N=6233voxels) permutations produced clusters that were generally consistent with each other. However, with 1000 permutations there were approximately 20% more statistically significant voxels (N=7117voxels) than with ≥10000 permutations. Permutation testing inference may provide a more sensitive method than traditional parametric inference for identifying age-related differences in gray matter proportion. Based on the results reported here, at least 10000 permutations should be used in future univariate VBM studies investigating age related changes in gray matter to avoid potential false findings. Additional studies using permutation testing in large imaging databanks

  4. Cerebellar gray matter and lobular volumes correlate with core autism symptoms

    PubMed Central

    D'Mello, Anila M.; Crocetti, Deana; Mostofsky, Stewart H.; Stoodley, Catherine J.

    2015-01-01

    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. PMID:25844317

  5. Dark matter and halo bispectrum in redshift space: theory and applications

    SciTech Connect

    Gil-Marín, Héctor; Percival, Will; Wagner, Christian; Noreña, Jorge; Verde, Licia E-mail: cwagner@mpa-garching.mpg.de E-mail: liciaverde@icc.ub.edu

    2014-12-01

    We present a phenomenological modification of the standard perturbation theory prediction for the bispectrum in redshift space that allows us to extend the model to mildly non-linear scales over a wide range of redshifts, z≤1.5. Our model require 18 free parameters that are fitted to N-body simulations using the shapes k{sub 2}/k{sub 1}=1, 1.5, 2.0, 2.5. We find that we can describe the bispectrum of dark matter particles with ∼5% accuracy for k{sub i}∼<0.10 h/Mpc at z=0, for k{sub i}∼<0.15 h/Mpc at z=0.5, for k{sub i}∼<0.17 h/Mpc at z=1.0 and for k{sub i}∼<0.20 h/Mpc at z=1.5. For very squeezed triangles with k{sub 1}=k{sub 2}∼>0.1 hMpc{sup -1} and k{sub 3}≤0.02 hMpc{sup -1}, however, neither SPT nor the proposed fitting formula are able to describe the measured dark matter bispectrum with this accuracy. We show that the fitting formula is sufficiently general that can be applied to other intermediate shapes such as k{sub 2}/k{sub 1}=1.25, 1.75, and 2.25. We also test that the fitting formula is able to describe with similar accuracy the bispectrum of cosmologies with different Ω{sub m}, in the range 0.2∼< Ω{sub m} ∼< 0.4, and consequently with different values of the logarithmic grow rate f at z=0, 0.4∼< f(z=0) ∼< 0.6. We apply this new formula to recover the bias parameters, f and σ{sub 8}, by combining the redshift space power spectrum monopole and quadrupole with the bispectrum monopole for both dark matter particles and haloes. We find that the combination of these three statistics can break the degeneracy between b{sub 1}, f and σ{sub 8}. For dark matter particles the new model can be used to recover f and σ{sub 8} with ∼1% accuracy. For dark matter haloes we find that f and σ{sub 8} present larger systematic shifts, ∼10%. The systematic offsets arise because of limitations in the modelling of the interplay between bias and redshift space distortions, and represent a limitation as the statistical errors of

  6. Dark matter and halo bispectrum in redshift space: theory and applications

    NASA Astrophysics Data System (ADS)

    Gil-Marín, Héctor; Wagner, Christian; Noreña, Jorge; Verde, Licia; Percival, Will

    2014-12-01

    We present a phenomenological modification of the standard perturbation theory prediction for the bispectrum in redshift space that allows us to extend the model to mildly non-linear scales over a wide range of redshifts, z<=1.5. Our model require 18 free parameters that are fitted to N-body simulations using the shapes k2/k1=1, 1.5, 2.0, 2.5. We find that we can describe the bispectrum of dark matter particles with ~5% accuracy for kilesssim0.10 h/Mpc at z=0, for kilesssim0.15 h/Mpc at z=0.5, for kilesssim0.17 h/Mpc at z=1.0 and for kilesssim0.20 h/Mpc at z=1.5. For very squeezed triangles with k1=k2gtrsim0.1 hMpc-1 and k3<=0.02 hMpc-1, however, neither SPT nor the proposed fitting formula are able to describe the measured dark matter bispectrum with this accuracy. We show that the fitting formula is sufficiently general that can be applied to other intermediate shapes such as k2/k1=1.25, 1.75, and 2.25. We also test that the fitting formula is able to describe with similar accuracy the bispectrum of cosmologies with different Ωm, in the range 0.2lesssim Ωm lesssim 0.4, and consequently with different values of the logarithmic grow rate f at z=0, 0.4lesssim f(z=0) lesssim 0.6. We apply this new formula to recover the bias parameters, f and σ8, by combining the redshift space power spectrum monopole and quadrupole with the bispectrum monopole for both dark matter particles and haloes. We find that the combination of these three statistics can break the degeneracy between b1, f and σ8. For dark matter particles the new model can be used to recover f and σ8 with ~1% accuracy. For dark matter haloes we find that f and σ8 present larger systematic shifts, ~10%. The systematic offsets arise because of limitations in the modelling of the interplay between bias and redshift space distortions, and represent a limitation as the statistical errors of forthcoming surveys reach this level. Conveniently, we find that these residual systematics are mitigated for

  7. The one-loop matter bispectrum in the Effective Field Theory of Large Scale Structures

    SciTech Connect

    Angulo, Raul E.; Foreman, Simon; Schmittfull, Marcel; Senatore, Leonardo

    2015-10-14

    With this study, given the importance of future large scale structure surveys for delivering new cosmological information, it is crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a manifestly convergent perturbative scheme to compute the clustering of dark matter in the weakly nonlinear regime in an expansion in k/kNL, where k is the wavenumber of interest and kNL is the wavenumber associated to the nonlinear scale. It has been recently shown that the EFTofLSS matches to 1% level the dark matter power spectrum at redshift zero up to k ≃ 0.3 h Mpc–1 and k ≃ 0.6 h Mpc–1 at one and two loops respectively, using only one counterterm that is fit to data. Similar results have been obtained for the momentum power spectrum at one loop. This is a remarkable improvement with respect to former analytical techniques. Here we study the prediction for the equal-time dark matter bispectrum at one loop. We find that at this order it is sufficient to consider the same counterterm that was measured in the power spectrum. Without any remaining free parameter, and in a cosmology for which kNL is smaller than in the previously considered cases (σ8=0.9), we find that the prediction from the EFTofLSS agrees very well with N-body simulations up to k ≃ 0.25 h Mpc–1, given the accuracy of the measurements, which is of order a few percent at the highest k's of interest. While the fit is very good on average up to k ≃ 0.25 h Mpc–1, the fit performs slightly worse on equilateral configurations, in agreement with expectations that for a given maximum k, equilateral triangles are the most nonlinear.

  8. Enhanced Recovery after Surgery in a Single High-Volume Surgical Oncology Unit: Details Matter

    PubMed Central

    Vohra, Nasreen A.; Edwards, Kimberly V.; Zervos, Emmanuel E.

    2016-01-01

    Benefits of ERAS protocol have been well documented; however, it is unclear whether the improvement stems from the protocol or shifts in expectations. Interdisciplinary educational seminars were conducted for all health professionals. However, one test surgeon adopted the protocol. 394 patients undergoing elective abdominal surgery from June 2013 to April 2015 with a median age of 63 years were included. The implementation of ERAS protocol resulted in a decrease in the length of stay (LOS) and mortality, whereas the difference in cost was found to be insignificant. For the test surgeon, ERAS was associated with decreased LOS, cost, and mortality. For the control providers, the LOS, cost, mortality, readmission rates, and complications remained similar both before and after the implementation of ERAS. An ERAS protocol on the single high-volume surgical unit decreased the cost, LOS, and mortality. PMID:27648469

  9. Enhanced Recovery after Surgery in a Single High-Volume Surgical Oncology Unit: Details Matter.

    PubMed

    Fitzgerald, Timothy L; Mosquera, Catalina; Koutlas, Nicholas J; Vohra, Nasreen A; Edwards, Kimberly V; Zervos, Emmanuel E

    2016-01-01

    Benefits of ERAS protocol have been well documented; however, it is unclear whether the improvement stems from the protocol or shifts in expectations. Interdisciplinary educational seminars were conducted for all health professionals. However, one test surgeon adopted the protocol. 394 patients undergoing elective abdominal surgery from June 2013 to April 2015 with a median age of 63 years were included. The implementation of ERAS protocol resulted in a decrease in the length of stay (LOS) and mortality, whereas the difference in cost was found to be insignificant. For the test surgeon, ERAS was associated with decreased LOS, cost, and mortality. For the control providers, the LOS, cost, mortality, readmission rates, and complications remained similar both before and after the implementation of ERAS. An ERAS protocol on the single high-volume surgical unit decreased the cost, LOS, and mortality. PMID:27648469

  10. Enhanced Recovery after Surgery in a Single High-Volume Surgical Oncology Unit: Details Matter

    PubMed Central

    Vohra, Nasreen A.; Edwards, Kimberly V.; Zervos, Emmanuel E.

    2016-01-01

    Benefits of ERAS protocol have been well documented; however, it is unclear whether the improvement stems from the protocol or shifts in expectations. Interdisciplinary educational seminars were conducted for all health professionals. However, one test surgeon adopted the protocol. 394 patients undergoing elective abdominal surgery from June 2013 to April 2015 with a median age of 63 years were included. The implementation of ERAS protocol resulted in a decrease in the length of stay (LOS) and mortality, whereas the difference in cost was found to be insignificant. For the test surgeon, ERAS was associated with decreased LOS, cost, and mortality. For the control providers, the LOS, cost, mortality, readmission rates, and complications remained similar both before and after the implementation of ERAS. An ERAS protocol on the single high-volume surgical unit decreased the cost, LOS, and mortality.

  11. Regional white matter volume and the relation with attentional functioning in survivors of malignant pediatric brain tumors

    NASA Astrophysics Data System (ADS)

    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.

  12. Individual differences in local gray and white matter volumes reflect differences in temperament and character: a voxel-based morphometry study in healthy young females.

    PubMed

    Van Schuerbeek, Peter; Baeken, Chris; De Raedt, Rudi; De Mey, Johan; Luypaert, Rob

    2011-01-31

    The psychobiological personality model of Cloninger distinguishes four heritable temperament traits (harm avoidance (HA), novelty seeking (NS), reward dependence (RD) and persistence (P)) and three character traits (self-directedness (SD), cooperativeness (CO) and self-transcendence (ST)) which develop during lifetime. Prior research already showed that individual differences in temperament are reflected in structural variances in specific brain areas. In this study, we used voxel-based morphometry (VBM) to correlate the different temperament and character traits with local gray and white matter volumes (GMV and WMV) in young healthy female volunteers. We found correlations between the temperament traits and GMV and WMV in the frontal, temporal and limbic regions involved in controlling and generating the corresponding behavior as proposed in Cloninger's theory: anxious for HA, impulsive for NS, reward-directed for RD and goal-directed for P. The character traits correlated with GMV and WMV in the frontal, temporal and limbic regions involved in the corresponding cognitive tasks: self-reflection for SD, mentalizing and empathizing with others for CO and religious belief for ST. This study shows that individual variations in brain morphology can be related to the temperament and character dimensions, and lends support to the hypothesis of a neurobiological basis of personality traits.

  13. Asymmetry of cerebral gray and white matter and structural volumes in relation to sex hormones and chromosomes

    PubMed Central

    Savic, Ivanka

    2014-01-01

    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 gray 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 GMV 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. PMID:25505869

  14. Altered activation of innate immunity associates with white matter volume and diffusion in first-episode psychosis.

    PubMed

    Mäntylä, Teemu; Mantere, Outi; Raij, Tuukka T; Kieseppä, Tuula; Laitinen, Hanna; Leiviskä, Jaana; Torniainen, Minna; Tuominen, Lauri; Vaarala, Outi; Suvisaari, Jaana

    2015-01-01

    First-episode psychosis (FEP) is associated with inflammatory and brain structural changes, but few studies have investigated whether systemic inflammation associates with brain structural changes in FEP. Thirty-seven FEP patients (median 27 days on antipsychotic medication), and 19 matched controls were recruited. Serum levels of 38 chemokines and cytokines, and cardiovascular risk markers were measured at baseline and 2 months later. We collected T1- and diffusion-weighted MRIs with a 3 T scanner from the patients at baseline. We analyzed the association of psychosis-related inflammatory markers with gray and white matter (WM) volume using voxel-based morphometry and WM diffusion using tract-based spatial statistics with whole-brain and region-of-interest (ROI) analyses. FEP patients had higher CCL22 and lower TGFα, CXCL1, CCL7, IFN-α2 and ApoA-I than controls. CCL22 decreased significantly between baseline and 2 months in patients but was still higher than in controls. The association between inflammatory markers and FEP remained significant after adjusting for age, sex, smoking and BMI. We did not observe a correlation of inflammatory markers with any symptoms or duration of antipsychotic treatment. Baseline CCL22 levels correlated negatively with WM volume and positively with mean diffusivity and radial diffusivity bilaterally in the frontal lobes in ROI analyses. Decreased serum level of ApoA-I was associated with smaller volume of the medial temporal WM. In whole-brain analyses, CCL22 correlated positively with mean diffusivity and radial diffusivity, and CXCL1 associated negatively with fractional anisotropy and positively with mean diffusivity and radial diffusivity in several brain regions. This is the first report to demonstrate an association between circulating chemokine levels and WM in FEP patients. Interestingly, CCL22 has been previously implicated in autoimmune diseases associated with WM pathology. The results suggest that an altered activation

  15. Altered Activation of Innate Immunity Associates with White Matter Volume and Diffusion in First-Episode Psychosis

    PubMed Central

    Raij, Tuukka T.; Kieseppä, Tuula; Laitinen, Hanna; Leiviskä, Jaana; Torniainen, Minna; Tuominen, Lauri; Vaarala, Outi; Suvisaari, Jaana

    2015-01-01

    First-episode psychosis (FEP) is associated with inflammatory and brain structural changes, but few studies have investigated whether systemic inflammation associates with brain structural changes in FEP. Thirty-seven FEP patients (median 27 days on antipsychotic medication), and 19 matched controls were recruited. Serum levels of 38 chemokines and cytokines, and cardiovascular risk markers were measured at baseline and 2 months later. We collected T1- and diffusion-weighted MRIs with a 3 T scanner from the patients at baseline. We analyzed the association of psychosis-related inflammatory markers with gray and white matter (WM) volume using voxel-based morphometry and WM diffusion using tract-based spatial statistics with whole-brain and region-of-interest (ROI) analyses. FEP patients had higher CCL22 and lower TGFα, CXCL1, CCL7, IFN-α2 and ApoA-I than controls. CCL22 decreased significantly between baseline and 2 months in patients but was still higher than in controls. The association between inflammatory markers and FEP remained significant after adjusting for age, sex, smoking and BMI. We did not observe a correlation of inflammatory markers with any symptoms or duration of antipsychotic treatment. Baseline CCL22 levels correlated negatively with WM volume and positively with mean diffusivity and radial diffusivity bilaterally in the frontal lobes in ROI analyses. Decreased serum level of ApoA-I was associated with smaller volume of the medial temporal WM. In whole-brain analyses, CCL22 correlated positively with mean diffusivity and radial diffusivity, and CXCL1 associated negatively with fractional anisotropy and positively with mean diffusivity and radial diffusivity in several brain regions. This is the first report to demonstrate an association between circulating chemokine levels and WM in FEP patients. Interestingly, CCL22 has been previously implicated in autoimmune diseases associated with WM pathology. The results suggest that an altered activation

  16. Relativistic and nonrelativistic annihilation of dark matter: a sanity check using an effective field theory approach

    NASA Astrophysics Data System (ADS)

    Cannoni, Mirco

    2016-03-01

    We find an exact formula for the thermally averaged cross section times the relative velocity < σ v_{text {rel}} rangle with relativistic Maxwell-Boltzmann statistics. The formula is valid in the effective field theory approach when the masses of the annihilation products can be neglected compared with the dark matter mass and cut-off scale. The expansion at x=m/T≫ 1 directly gives the nonrelativistic limit of < σ v_{text {rel}}rangle , which is usually used to compute the relic abundance for heavy particles that decouple when they are nonrelativistic. We compare this expansion with the one obtained by expanding the total cross section σ (s) in powers of the nonrelativistic relative velocity v_r. We show the correct invariant procedure that gives the nonrelativistic average < σ _{nr} v_r rangle _{nr} coinciding with the large x expansion of < σ v_{text {rel}}rangle in the comoving frame. We explicitly formulate flux, cross section, thermal average, collision integral of the Boltzmann equation in an invariant way using the true relativistic relative v_text {rel}, showing the uselessness of the Møller velocity and further elucidating the conceptual and numerical inconsistencies related with its use.

  17. Brain-derived neurotrophic factor genotype is associated with brain gray and white matter tissue volumes recovery in abstinent alcohol-dependent individuals

    PubMed Central

    Mon, A.; Durazzo, T. C.; Gazdzinski, S.; Hutchison, K. E.; Pennington, D.; Meyerhoff, D. J.

    2014-01-01

    Neuroimaging studies have linked the methionine (Met) allele of the brain-derived neurotrophic factor (BDNF ) gene to abnormal regional brain volumes in several psychiatric and neurodegenerative diseases. However, no neuroimaging studies assessed the effects of this allele on brain morphology in alcohol use disorders and its demonstrated change during abstinence from alcohol. Here we assessed the effects of the BDNF Val66Met (rs6265) polymorphism on regional brain tissue volumes and their recovery during short-term abstinence in treatment-seeking alcohol-dependent individuals. 3D T1 weighted magnetic resonance images from 62 individuals were acquired at 1.5 T at one week of abstinence from alcohol; 41 of the participants were rescanned at 5 weeks of abstinence. The images were segmented into gray matter (GM), white matter (WM) and cerebrospinal fluid and parcellated into regional volumes. The BDNF genotype was determined from blood samples using the TaqMan technique. Alcohol-dependent Val (Valine)/Met heterozygotes and Val homozygotes had similar regional brain volumes at either time point. However, Val homozygotes had significant GM volume increases, while Val/Met heterozygotes increased predominantly in WM volumes over the scan interval. Longitudinal increases in GM but not WM volumes were related to improvements in neurocognitive measures during abstinence. The findings suggest that functionally significant brain tissue volume recovery during abstinence from alcohol is influenced by BDNF genotype. PMID:22989210

  18. Higher Adolescent Body Mass Index Is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality

    PubMed Central

    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.

  19. Higher Adolescent Body Mass Index Is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality.

    PubMed

    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. PMID:27660604

  20. Higher Adolescent Body Mass Index Is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality

    PubMed Central

    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. PMID:27660604

  1. Translating Theory into Practice: Implications of Japanese Management Theory for Student Personnel Administrators. NASPA Monograph Series Volume 3. First Edition.

    ERIC Educational Resources Information Center

    Deegan, William L.; And Others

    Japanese management theory was studied to identify specific models for consideration by student personnel administrators. The report is organized into three sections: major components of Japanese management theory, potential implications for student personnel administration, and three models, based on components of Japanese management theory, for…

  2. High density matter in AGS, SPS and RHIC collisions: Proceedings. Volume 9

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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

  4. Gray matter myelination of 1555 human brains using partial volume corrected MRI images

    PubMed Central

    Shafee, Rebecca; Buckner, Randy L.; Fischl, Bruce

    2014-01-01

    The myelin content of the cortex changes over the human lifetime and aberrant cortical myelination is associated with diseases such as schizophrenia and multiple sclerosis. Recently magnetic resonance imaging (MRI) techniques have shown potential in differentiating between myeloarchitectonically distinct cortical regions in vivo. Here we introduce a new algorithm for correcting partial volume effects present in mm-scale MRI images which was used to investigate the myelination pattern of the cerebral cortex in 1555 clinically normal subjects using the ratio of T1-weighted (T1w) and T2-weighted (T2w) MRI images. A significant linear cross-sectional age increase in T1w/T2w estimated myelin was detected across an 18 to 35 year age span (highest value of ~ 1%/year compared to mean T1w/T2w myelin value at 18 years). The cortex was divided at mid-thickness and the value of T1w/T2w myelin calculated for the inner and the outer layers separately. The increase in T1w/T2w estimated myelin occurs predominantly in the inner layer for most cortical regions. The ratio of the inner and outer layer T1w/T12w myelin was further validated using high-resolution in vivo MRI scans and also a high-resolution MRI scan of a postmortem brain. Additionally, the relationships between cortical thickness, curvature and T1w/T2w estimated myelin were found to be significant, although the relationships varied across the cortex. We discuss these observations as well as limitations of using the T1w/T2w ratio as an estimate of cortical myelin. PMID:25449739

  5. Species, Diaspore Volume and Body Mass Matter in Gastropod Seed Feeding Behavior

    PubMed Central

    Türke, Manfred; Weisser, Wolfgang W.

    2013-01-01

    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. PMID:23844239

  6. Foundations of Education, Volume I: History and Theory of Teaching Children and Youths with Visual Impairments. Second Edition.

    ERIC Educational Resources Information Center

    Holbrook, M. Cay, Ed.; Koenig, Alan J., Ed.

    This text, one of two volumes on the instruction of students with visual impairments, focuses on the history and theory of teaching such students. The following chapters are included: (1) "Historical Perspectives" (Phil Hatlen) with emphasis on the last 50 years; (2) "Visual Impairment" (Kathleen M. Huebner) which provides general information…

  7. HPA-axis function and grey matter volume reductions: imaging the diathesis-stress model in individuals at ultra-high risk of psychosis.

    PubMed

    Valli, I; Crossley, N A; Day, F; Stone, J; Tognin, S; Mondelli, V; Howes, O; Valmaggia, L; Pariante, C; McGuire, P

    2016-01-01

    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.

  8. HPA-axis function and grey matter volume reductions: imaging the diathesis-stress model in individuals at ultra-high risk of psychosis.

    PubMed

    Valli, I; Crossley, N A; Day, F; Stone, J; Tognin, S; Mondelli, V; Howes, O; Valmaggia, L; Pariante, C; McGuire, P

    2016-01-01

    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. PMID:27138796

  9. HPA-axis function and grey matter volume reductions: imaging the diathesis-stress model in individuals at ultra-high risk of psychosis

    PubMed Central

    Valli, I; Crossley, N A; Day, F; Stone, J; Tognin, S; Mondelli, V; Howes, O; Valmaggia, L; Pariante, C; McGuire, P

    2016-01-01

    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. PMID:27138796

  10. Gray Matter Volume in Adolescent Anxiety: An Impact of the Brain-Derived Neurotrophic Factor Val[superscript 66]Met Polymorphism?

    ERIC Educational Resources Information Center

    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…

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

    NASA Astrophysics Data System (ADS)

    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

  12. Research in the theory of condensed matter and elementary particles. (Progress report)

    SciTech Connect

    Not Available

    1985-01-01

    The proposed research is concerned with problems occupying the common ground between quantum field theory and statistical mechanics. The topics under investigation include: superconformal field theory in two dimensions, its relationship to two dimensional critical phenomena and its applications in string theory; the covariant formulation of the superstring theory; formation of large-scale structures and spatial chaos in dynamical systems; fermion-boson mass relations in BCS type theories; and properties of quantum field theories defined over galois fields. 37 refs.

  13. Distribution function approach to redshift space distortions. Part IV: perturbation theory applied to dark matter

    SciTech Connect

    Vlah, Zvonimir; Seljak, Uroš; Baldauf, Tobias; McDonald, Patrick; Okumura, Teppei E-mail: seljak@physik.uzh.ch E-mail: teppei@ewha.ac.kr

    2012-11-01

    We develop a perturbative approach to redshift space distortions (RSD) using the phase space distribution function approach and apply it to the dark matter redshift space power spectrum and its moments. RSD can be written as a sum over density weighted velocity moments correlators, with the lowest order being density, momentum density and stress energy density. We use standard and extended perturbation theory (PT) to determine their auto and cross correlators, comparing them to N-body simulations. We show which of the terms can be modeled well with the standard PT and which need additional terms that include higher order corrections which cannot be modeled in PT. Most of these additional terms are related to the small scale velocity dispersion effects, the so called finger of god (FoG) effects, which affect some, but not all, of the terms in this expansion, and which can be approximately modeled using a simple physically motivated ansatz such as the halo model. We point out that there are several velocity dispersions that enter into the detailed RSD analysis with very different amplitudes, which can be approximately predicted by the halo model. In contrast to previous models our approach systematically includes all of the terms at a given order in PT and provides a physical interpretation for the small scale dispersion values. We investigate RSD power spectrum as a function of μ, the cosine of the angle between the Fourier mode and line of sight, focusing on the lowest order powers of μ and multipole moments which dominate the observable RSD power spectrum. Overall we find considerable success in modeling many, but not all, of the terms in this expansion. This is similar to the situation in real space, but predicting power spectrum in redshift space is more difficult because of the explicit influence of small scale dispersion type effects in RSD, which extend to very large scales.

  14. Contributions of organic and inorganic matter to sediment volume and accretion in tidal wetlands at steady state

    NASA Astrophysics Data System (ADS)

    Morris, James T.; Barber, Donald C.; Callaway, John C.; Chambers, Randy; Hagen, Scott C.; Hopkinson, Charles S.; Johnson, Beverly J.; Megonigal, Patrick; Neubauer, Scott C.; Troxler, Tiffany; Wigand, Cathleen

    2016-04-01

    A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 and k2 are the self-packing densities of the pure organic and inorganic components, respectively. The model explained 78% of the variability in total BD when fitted to 5075 measurements drawn from 33 wetlands distributed around the conterminous United States. The values of k1 and k2 were estimated to be 0.085 ± 0.0007 g cm-3 and 1.99 ± 0.028 g cm-3, respectively. Based on the fitted organic density (k1) and constrained by primary production, the model suggests that the maximum steady state accretion arising from the sequestration of refractory organic matter is ≤ 0.3 cm yr-1. Thus, tidal peatlands are unlikely to indefinitely survive a higher rate of sea-level rise in the absence of a significant source of mineral sediment. Application of k2 to a mineral sediment load typical of East and eastern Gulf Coast estuaries gives a vertical accretion rate from inorganic sediment of 0.2 cm yr-1. Total steady state accretion is the sum of the parts and therefore should not be greater than 0.5 cm yr-1 under the assumptions of the model. Accretion rates could deviate from this value depending on variation in plant productivity, root:shoot ratio, suspended sediment concentration, sediment-capture efficiency, and episodic events.

  15. Contributions of organic and inorganic matter to sediment volume and accretion in tidal wetlands at steady state

    PubMed Central

    Barber, Donald C.; Callaway, John C.; Chambers, Randy; Hagen, Scott C.; Hopkinson, Charles S.; Johnson, Beverly J.; Megonigal, Patrick; Neubauer, Scott C.; Troxler, Tiffany; Wigand, Cathleen

    2016-01-01

    Abstract A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self‐packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1‐LOI)/k2], where k1 and k2 are the self‐packing densities of the pure organic and inorganic components, respectively. The model explained 78% of the variability in total BD when fitted to 5075 measurements drawn from 33 wetlands distributed around the conterminous United States. The values of k1 and k2 were estimated to be 0.085 ± 0.0007 g cm−3 and 1.99 ± 0.028 g cm−3, respectively. Based on the fitted organic density (k1) and constrained by primary production, the model suggests that the maximum steady state accretion arising from the sequestration of refractory organic matter is ≤ 0.3 cm yr−1. Thus, tidal peatlands are unlikely to indefinitely survive a higher rate of sea‐level rise in the absence of a significant source of mineral sediment. Application of k2 to a mineral sediment load typical of East and eastern Gulf Coast estuaries gives a vertical accretion rate from inorganic sediment of 0.2 cm yr−1. Total steady state accretion is the sum of the parts and therefore should not be greater than 0.5 cm yr−1 under the assumptions of the model. Accretion rates could deviate from this value depending on variation in plant productivity, root:shoot ratio, suspended sediment concentration, sediment‐capture efficiency, and episodic events.

  16. The Impact of the in utero and Early Postnatal Environments on Grey and White Matter Volume: A Study with Adolescent Monozygotic Twins.

    PubMed

    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.

  17. Children's Theory of God's Mind: Theory-of-Mind Studies and Why They Matter to Religious Education

    ERIC Educational Resources Information Center

    Wigger, J. Bradley

    2016-01-01

    Theory-of-mind research has been carried out for over three decades, examining the ways children understand the minds of others--their perspectives, intentions, desires, and knowledge. Since the early 21st century, theory-of-mind studies have begun exploring the ways in which children think and reason about the minds--not only of ordinary, visible…

  18. Gray matter volume alterations in first-episode drug-naïve patients with deficit and nondeficit schizophrenia.

    PubMed

    Lei, Wei; Deng, Wei; Li, Mingli; He, Zongling; Han, Yuanyuan; Huang, Chaohua; Ma, Xiaohong; Wang, Qiang; Guo, Wanjun; Li, Yinfei; Jiang, Lijun; Gong, Qiyong; Hu, Xun; Zhang, Nanyin; Li, Tao

    2015-11-30

    Different patterns of gray matter volume (GMV) abnormalities have been reported between chronic patients with deficit schizophrenia (DS), relative to nondeficit schizophrenia (NDS) patients. However, it is not clear whether these differences are characteristic to the pathophysiology of DS or due to the effects of medications or illness durations. To address this issue, GMV in 88 first-episode, drug-naive patients with schizophrenia (44 DS and 44 NDS), 67 of their first-degree relatives and 84 healthy controls were assessed using voxel- based morphometry (VBM) and compared between groups. Correlations between GMV and clinical symptoms in patients were also assessed. Compared to controls, DS patients displayed more severe GMV reduction in the cerebellar culmen than NDS patients. GMV reduction in culmen was also observed in the first-degree relatives of DS (but not NDS) patients, suggesting possible different genetic risk in DS and NDS. The left insula was significantly smaller in DS patients than both NDS patients and controls, and smaller GMV of this region was associated with more severe negative symptoms in patients. Our results collectively indicate that DS might represent a distinct subtype of schizophrenia from NDS and the GMV change in left insula may be a morphological signature of DS. PMID:26409573

  19. Relationship between personality and gray matter volume in healthy young adults: a voxel-based morphometric study.

    PubMed

    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.

  20. Gray matter volume alterations in first-episode drug-naïve patients with deficit and nondeficit schizophrenia.

    PubMed

    Lei, Wei; Deng, Wei; Li, Mingli; He, Zongling; Han, Yuanyuan; Huang, Chaohua; Ma, Xiaohong; Wang, Qiang; Guo, Wanjun; Li, Yinfei; Jiang, Lijun; Gong, Qiyong; Hu, Xun; Zhang, Nanyin; Li, Tao

    2015-11-30

    Different patterns of gray matter volume (GMV) abnormalities have been reported between chronic patients with deficit schizophrenia (DS), relative to nondeficit schizophrenia (NDS) patients. However, it is not clear whether these differences are characteristic to the pathophysiology of DS or due to the effects of medications or illness durations. To address this issue, GMV in 88 first-episode, drug-naive patients with schizophrenia (44 DS and 44 NDS), 67 of their first-degree relatives and 84 healthy controls were assessed using voxel- based morphometry (VBM) and compared between groups. Correlations between GMV and clinical symptoms in patients were also assessed. Compared to controls, DS patients displayed more severe GMV reduction in the cerebellar culmen than NDS patients. GMV reduction in culmen was also observed in the first-degree relatives of DS (but not NDS) patients, suggesting possible different genetic risk in DS and NDS. The left insula was significantly smaller in DS patients than both NDS patients and controls, and smaller GMV of this region was associated with more severe negative symptoms in patients. Our results collectively indicate that DS might represent a distinct subtype of schizophrenia from NDS and the GMV change in left insula may be a morphological signature of DS.

  1. Free D-aspartate regulates neuronal dendritic morphology, synaptic plasticity, gray matter volume and brain activity in mammals

    PubMed Central

    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. PMID:25072322

  2. Free D-aspartate regulates neuronal dendritic morphology, synaptic plasticity, gray matter volume and brain activity in mammals.

    PubMed

    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.

  3. Many-particle theory of nuclear systems with application to neutron star matter

    NASA Technical Reports Server (NTRS)

    Chakkalakal, D. A.; Yang, C. H.

    1974-01-01

    The energy-density relation was calculated for pure neutron matter in the density range relevant for neutron stars, using four different hard-core potentials. Calculations are also presented of the properties of the superfluid state of the neutron component, along with the superconducting state of the proton component and the effects of polarization in neutron star matter.

  4. Applicability of the theory of volume filling of micropores to adsorption of caprolactam from aqueous solutions with active carbons

    SciTech Connect

    Khodorov, E.I.; Kazakov, V.A.; Semerikova, V.V.; Surinova, S.I.

    1985-06-10

    The absence of a scientifically based method of selecting adsorbents in the extraction of organic substances from waste water and solution which would allow for their multicycle use in adsorption-desorption stages often prevents the introduction of adsorption technology into industrial practice. This paper demonstrates the possibility of calculating the adsorption equilibrium of highly soluble organic compounds with the theory of volume filling of micropores equations in consideration of the activities of the extracted component in the solution and the change in the partial affinity coefficient with the degree of filling of the adsorption volume on the example of extraction of caprolactam from aqueous solutions.

  5. Rotary-wing aerodynamics. Volume 1: Basic theories of rotor aerodynamics with application to helicopters. [momentum, vortices, and potential theory

    NASA Technical Reports Server (NTRS)

    Stepniewski, W. Z.

    1979-01-01

    The concept of rotary-wing aircraft in general is defined. The energy effectiveness of helicopters is compared with that of other static thrust generators in hover, as well as with various air and ground vehicles in forward translation. The most important aspects of rotor-blade dynamics and rotor control are reviewed. The simple physicomathematical model of the rotor offered by the momentum theory is introduced and its usefulness and limitations are assessed. The combined blade-element and momentum theory approach, which provides greater accuracy in performance predictions, is described as well as the vortex theory which models a rotor blade by means of a vortex filament or vorticity surface. The application of the velocity and acceleration potential theory to the determination of flow fields around three dimensional, non-rotating bodies as well as to rotor aerodynamic problems is described. Airfoil sections suitable for rotors are also considered.

  6. Toward accurate modelling of the non-linear matter bispectrum: standard perturbation theory and transients from initial conditions

    NASA Astrophysics Data System (ADS)

    McCullagh, Nuala; Jeong, Donghui; Szalay, Alexander S.

    2016-01-01

    Accurate modelling of non-linearities in the galaxy bispectrum, the Fourier transform of the galaxy three-point correlation function, is essential to fully exploit it as a cosmological probe. In this paper, we present numerical and theoretical challenges in modelling the non-linear bispectrum. First, we test the robustness of the matter bispectrum measured from N-body simulations using different initial conditions generators. We run a suite of N-body simulations using the Zel'dovich approximation and second-order Lagrangian perturbation theory (2LPT) at different starting redshifts, and find that transients from initial decaying modes systematically reduce the non-linearities in the matter bispectrum. To achieve 1 per cent accuracy in the matter bispectrum at z ≤ 3 on scales k < 1 h Mpc-1, 2LPT initial conditions generator with initial redshift z ≳ 100 is required. We then compare various analytical formulas and empirical fitting functions for modelling the non-linear matter bispectrum, and discuss the regimes for which each is valid. We find that the next-to-leading order (one-loop) correction from standard perturbation theory matches with N-body results on quasi-linear scales for z ≥ 1. We find that the fitting formula in Gil-Marín et al. accurately predicts the matter bispectrum for z ≤ 1 on a wide range of scales, but at higher redshifts, the fitting formula given in Scoccimarro & Couchman gives the best agreement with measurements from N-body simulations.

  7. SPAR thermal analysis processors reference manual, system level 16. Volume 1: Program executive. Volume 2: Theory. Volume 3: Demonstration problems. Volume 4: Experimental thermal element capability. Volume 5: Programmer reference

    NASA Technical Reports Server (NTRS)

    Marlowe, M. B.; Moore, R. A.; Whetstone, W. D.

    1979-01-01

    User instructions are given for performing linear and nonlinear steady state and transient thermal analyses with SPAR thermal analysis processors TGEO, SSTA, and TRTA. It is assumed that the user is familiar with basic SPAR operations and basic heat transfer theory.

  8. Nuclear charge and neutron radii and nuclear matter: Trend analysis in Skyrme density-functional-theory approach

    NASA Astrophysics Data System (ADS)

    Reinhard, P.-G.; Nazarewicz, W.

    2016-05-01

    Background: Radii of charge and neutron distributions are fundamental nuclear properties. They depend on both nuclear interaction parameters related to the equation of state of infinite nuclear matter and on quantal shell effects, which are strongly impacted by the presence of nuclear surface. Purpose: In this work, by studying the correlation of charge and neutron radii, and neutron skin, with nuclear matter parameters, we assess different mechanisms that drive nuclear sizes. Method: We apply nuclear density functional theory using a family of Skyrme functionals obtained by means of optimization protocols, which do not include any radius information. By performing the Monte Carlo sampling of reasonable functionals around the optimal parametrization, we scan all correlations between nuclear matter properties and observables characterizing charge and neutron distributions of spherical closed-shell nuclei 48Ca,208Pb, and 298Fl. Results: By considering the influence of various nuclear matter properties on charge and neutron radii in a multidimensional parameter space of Skyrme functionals, we demonstrate the existence of two strong relationships: (i) between the nuclear charge radii and the saturation density of symmetric nuclear matter ρ0, and (ii) between the neutron skins and the slope of the symmetry energy L . The impact of other nuclear matter properties on nuclear radii is weak or nonexistent. For functionals optimized to experimental binding energies only, proton and neutron radii are found to be weakly correlated due to canceling trends from different nuclear matter characteristics. Conclusion: The existence of only two strong relations connecting nuclear radii with nuclear matter properties has important consequences. First, by requiring that the nuclear functional reproduces the empirical saturation point of symmetric nuclear matter practically fixes the charge (or proton) radii, and vice versa. This explains the recent results of ab initio calculations

  9. Bootstrapping Processes in the Development of Students' Commonsense Matter Theories: Using Analogical Mappings, Thought Experiments, and Learning to Measure to Promote Conceptual Restructuring

    ERIC Educational Resources Information Center

    Smith, Carol L.

    2007-01-01

    This study explores whether the development of students' understanding of matter as something that occupies space and has weight involves conceptual change and restructuring rather than only simple belief revision. Based on an analysis of how the concepts in students' initial matter theory (henceforth MT1) may differ from the concepts in the…

  10. Burning odor-elicited anxiety in OEF/OIF combat veterans: Inverse relationship to gray matter volume in olfactory cortex.

    PubMed

    Cortese, Bernadette M; McConnell, Patrick A; Froeliger, Brett; Leslie, Kimberly; Uhde, Thomas W

    2015-11-01

    Despite the anatomical overlap between the brain's fear/threat and olfactory systems, a very limited number of investigations have considered the role of odors and the central olfactory system in the pathophysiology of PTSD. The goal of the present study was to assess structural differences in primary and secondary olfactory cortex between combat veterans with and without PTSD (CV + PTSD, CV-PTSD, respectively). An additional goal was to determine the relationship between gray matter volume (GMV) in olfactory cortex and the distressing properties of burning-related odors. A region of interest voxel-based morphometric (VBM) approach was used to measure GMV in olfactory cortex in a well-characterized group of CV + PTSD (n = 20) and CV-PTSD (n = 25). Prior to the MRI exam, combat-related (i.e., burning rubber) and control odors were systematically sampled and rated according to their potential for eliciting PTSD symptoms. Results showed that CV + PTSD exhibited significantly reduced GMV in anterior piriform (primary olfactory) and orbitofrontal (secondary olfactory) cortices compared to CV-PTSD (both p < .01). For the entire group, GMV in bilateral anterior piriform cortex was inversely related to burning rubber odor-elicited memories of trauma (p < .05). GMV in orbitofrontal cortex was inversely related to both clinical and laboratory measures of PTSD symptoms (all p < .05). In addition to replicating an established inverse relationship between GMV in anxiety-associated brain structures and PTSD symptomatology, the present study extends those findings by being the first report of volumetric decreases in olfactory cortex that are inversely related to odor-elicited PTSD symptoms. Potential mechanisms underlying these findings are discussed. PMID:26424424

  11. Reduced visual cortex gray matter volume and thickness in young adults who witnessed domestic violence during childhood.

    PubMed

    Tomoda, Akemi; Polcari, Ann; Anderson, Carl M; Teicher, Martin H

    2012-01-01

    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. PMID:23300699

  12. Reduced Visual Cortex Gray Matter Volume and Thickness in Young Adults Who Witnessed Domestic Violence during Childhood

    PubMed Central

    Tomoda, Akemi; Polcari, Ann; Anderson, Carl M.; Teicher, Martin H.

    2012-01-01

    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. PMID:23300699

  13. Reduced visual cortex gray matter volume and thickness in young adults who witnessed domestic violence during childhood.

    PubMed

    Tomoda, Akemi; Polcari, Ann; Anderson, Carl M; Teicher, Martin H

    2012-01-01

    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.

  14. Voxel-based meta-analysis of gray matter volume reductions associated with cognitive impairment in Parkinson's disease.

    PubMed

    Xu, Yaqian; Yang, Jing; Hu, Xinyu; Shang, Huifang

    2016-06-01

    Brain gray matter volume (GMV) reduction has been reported in Parkinson's disease (PD) with mild cognitive impairment (PD-MCI) and in PD patients with dementia (PDD) with cumulative evidence using voxel-based morphometry (VBM). However, the findings of these studies have not been entirely concordant. Whole-brain VBM studies comparing PD-MCI with PD patients without cognitive impairment (PD-NCI) and comparing PDD with PD patients without dementia (PDND) were systematically searched in PubMed and EMBASE databases from January 1995 to December 2015. Coordinates with significant differences were extracted from each cluster. Meta-analysis was performed using AES-SDM to quantitatively evaluate the GMV changes. Five studies comparing 92 PD-MCI with 192 PD-NCI patients were included in the PD-MCI vs. PD-NCI meta-analysis. Ten studies with 168 PDD and 233 PDND patients were included in the PDD vs. PDND meta-analysis. Compared with PD-NCI, GMV reductions were observed in left superior temporal lobe, left insula and left superior frontal lobe in PD-MCI patients. Significant GMV reduction were found in bilateral superior temporal lobe extending to hippocampus, and left superior frontal lobe in PDD patients comparing with PDND. Meta-regression of PDD studies showed that disease duration was negatively correlated with GMV in the left superior frontal lobe. GMV reductions in the frontal-limbic-temporal regions were main features of cognitive decline in PD. Unilateral-to-bilateral development of GMV reduction in the frontal-limbic-temporal regions is a possible indicator for PD-MCI to PDD progression, whereas significant hippocampal GMV reduction may not be a marker for early cognitive decline in PD. PMID:27113603

  15. White matter integrity, hippocampal volume, and cognitive performance of a world-famous nonagenarian track-and-field athlete.

    PubMed

    Burzynska, A Z; Wong, C N; Chaddock-Heyman, L; Olson, E A; Gothe, N P; Knecht, A; Voss, M W; McAuley, E; Kramer, A F

    2016-01-01

    Physical activity (PA) and cardiorespiratory fitness (CRF) are associated with successful brain and cognitive aging. However, little is known about the effects of PA, CRF, and exercise on the brain in the oldest-old. Here we examined white matter (WM) integrity, measured as fractional anisotropy (FA) and WM hyperintensity (WMH) burden, and hippocampal (HIPP) volume of Olga Kotelko (1919-2014). Olga began training for competitions at age of 77 and as of June 2014 held over 30 world records in her age category in track-and-field. We found that Olga's WMH burden was larger and the HIPP was smaller than in the reference sample (58 healthy low-active women 60-78 years old), and her FA was consistently lower in the regions overlapping with WMH. Olga's FA in many normal-appearing WM regions, however, did not differ or was greater than in the reference sample. In particular, FA in her genu corpus callosum was higher than any FA value observed in the reference sample. We speculate that her relatively high FA may be related to both successful aging and the beneficial effects of exercise in old age. In addition, Olga had lower scores on memory, reasoning and speed tasks than the younger reference sample, but outperformed typical adults of age 90-95 on speed and memory. Together, our findings open the possibility of old-age benefits of increasing PA on WM microstructure and cognition despite age-related increase in WMH burden and HIPP shrinkage, and add to the still scarce neuroimaging data of the healthy oldest-old (>90 years) adults.

  16. Alabama Children: A Matter of Commitment and Priority. Special Report to Governor Fob James and the Alabama Legislature. Volume I and Volume II.

    ERIC Educational Resources Information Center

    Ames, Bobbie H.

    This report in two volumes is the product of a year-long needs assessment undertaken by the Governor of Alabama's Commission for the Alabama Year of the Child. Volume I, which contains an overview and recommendations to the governor and the legislature, includes position papers and letters from the commission and interested citizens. These…

  17. Self-consistent field theory of tethered polymers: One dimensional, three dimensional, strong stretching theories and the effects of excluded-volume-only interactions

    SciTech Connect

    Suo, Tongchuan Whitmore, Mark D.

    2014-11-28

    We examine end-tethered polymers in good solvents, using one- and three-dimensional self-consistent field theory, and strong stretching theories. We also discuss different tethering scenarios, namely, mobile tethers, fixed but random ones, and fixed but ordered ones, and the effects and important limitations of including only binary interactions (excluded volume terms). We find that there is a “mushroom” regime in which the layer thickness is independent of the tethering density, σ, for systems with ordered tethers, but we argue that there is no such plateau for mobile or disordered anchors, nor is there one in the 1D theory. In the other limit of brushes, all approaches predict that the layer thickness scales linearly with N. However, the σ{sup 1/3} scaling is a result of keeping only excluded volume interactions: when the full potential is included, the dependence is faster and more complicated than σ{sup 1/3}. In fact, there does not appear to be any regime in which the layer thickness scales in the combination Nσ{sup 1/3}. We also compare the results for two different solvents with each other, and with earlier Θ solvent results.

  18. Effective theory of WIMP dark matter supplemented by simplified models: Singlet-like Majorana fermion case

    NASA Astrophysics Data System (ADS)

    Matsumoto, Shigeki; Mukhopadhyay, Satyanarayan; Tsai, Yue-Lin Sming

    2016-09-01

    We enumerate the set of simplified models which match onto the complete set of gauge invariant effective operators up to dimension six describing interactions of a singlet-like Majorana fermion dark matter with the standard model. Tree-level matching conditions for each case are worked out in the large mediator mass limit, defining a one-to-one correspondence between the effective operator coefficients and the simplified model parameters for weakly interacting models. Utilizing such a mapping, we compute the dark matter annihilation rate in the early universe, as well as other low-energy observables like nuclear recoil rates using the effective operators, while the simplified models are used to compute the dark matter production rates at high-energy colliders like LEP, LHC and future lepton colliders. Combining all relevant constraints with a profile-likelihood analysis, we then discuss the currently allowed parameter regions and prospects for future searches in terms of the effective operator parameters, reducing the model dependence to a minimal level. In the parameter region where such a model-independent analysis is applicable, and leaving aside the special dark matter mass regions where the annihilation proceeds through an s -channel Z or Higgs boson pole, the current constraints allow effective operator suppression scales (Λ ) of the order of a few hundred GeV for dark matter masses mχ>20 GeV at 95% C.L., while the maximum allowed scale is around 3 TeV for mχ˜O (1 TeV ) . An estimate of the future reach of ton-scale direct detection experiments and planned electron-positron colliders show that most of the remaining regions can be probed, apart from dark matter masses near half of the Z -boson mass (with 500 GeV <Λ <2 TeV ) and those beyond the kinematic reach of the future lepton colliders.

  19. Mind-sets matter: a meta-analytic review of implicit theories and self-regulation.

    PubMed

    Burnette, Jeni L; O'Boyle, Ernest H; VanEpps, Eric M; Pollack, Jeffrey M; Finkel, Eli J

    2013-05-01

    This review builds on self-control theory (Carver & Scheier, 1998) to develop a theoretical framework for investigating associations of implicit theories with self-regulation. This framework conceptualizes self-regulation in terms of 3 crucial processes: goal setting, goal operating, and goal monitoring. In this meta-analysis, we included articles that reported a quantifiable assessment of implicit theories and at least 1 self-regulatory process or outcome. With a random effects approach used, meta-analytic results (total unique N = 28,217; k = 113) across diverse achievement domains (68% academic) and populations (age range = 5-42; 10 different nationalities; 58% from United States; 44% female) demonstrated that implicit theories predict distinct self-regulatory processes, which, in turn, predict goal achievement. Incremental theories, which, in contrast to entity theories, are characterized by the belief that human attributes are malleable rather than fixed, significantly predicted goal setting (performance goals, r = -.151; learning goals, r = .187), goal operating (helpless-oriented strategies, r = -.238; mastery-oriented strategies, r = .227), and goal monitoring (negative emotions, r = -.233; expectations, r = .157). The effects for goal setting and goal operating were stronger in the presence (vs. absence) of ego threats such as failure feedback. Discussion emphasizes how the present theoretical analysis merges an implicit theory perspective with self-control theory to advance scholarship and unlock major new directions for basic and applied research.

  20. Mind-Sets Matter: A Meta-Analytic Review of Implicit Theories and Self-Regulation

    ERIC Educational Resources Information Center

    Burnette, Jeni L.; O'Boyle, Ernest H.; VanEpps, Eric M.; Pollack, Jeffrey M.; Finkel, Eli J.

    2013-01-01

    This review builds on self-control theory (Carver & Scheier, 1998) to develop a theoretical framework for investigating associations of implicit theories with self-regulation. This framework conceptualizes self-regulation in terms of 3 crucial processes: goal setting, goal operating, and goal monitoring. In this meta-analysis, we included articles…

  1. Mind-sets matter: a meta-analytic review of implicit theories and self-regulation.

    PubMed

    Burnette, Jeni L; O'Boyle, Ernest H; VanEpps, Eric M; Pollack, Jeffrey M; Finkel, Eli J

    2013-05-01

    This review builds on self-control theory (Carver & Scheier, 1998) to develop a theoretical framework for investigating associations of implicit theories with self-regulation. This framework conceptualizes self-regulation in terms of 3 crucial processes: goal setting, goal operating, and goal monitoring. In this meta-analysis, we included articles that reported a quantifiable assessment of implicit theories and at least 1 self-regulatory process or outcome. With a random effects approach used, meta-analytic results (total unique N = 28,217; k = 113) across diverse achievement domains (68% academic) and populations (age range = 5-42; 10 different nationalities; 58% from United States; 44% female) demonstrated that implicit theories predict distinct self-regulatory processes, which, in turn, predict goal achievement. Incremental theories, which, in contrast to entity theories, are characterized by the belief that human attributes are malleable rather than fixed, significantly predicted goal setting (performance goals, r = -.151; learning goals, r = .187), goal operating (helpless-oriented strategies, r = -.238; mastery-oriented strategies, r = .227), and goal monitoring (negative emotions, r = -.233; expectations, r = .157). The effects for goal setting and goal operating were stronger in the presence (vs. absence) of ego threats such as failure feedback. Discussion emphasizes how the present theoretical analysis merges an implicit theory perspective with self-control theory to advance scholarship and unlock major new directions for basic and applied research. PMID:22866678

  2. Life Goals Matter to Happiness: A Revision of Set-Point Theory

    ERIC Educational Resources Information Center

    Headey, Bruce

    2008-01-01

    Using data from the long-running German Socio-Economic Panel Survey (SOEP), this paper provides evidence that life goals matter substantially to subjective well-being (SWB). Non-zero sum goals, which include commitment to family, friends and social and political involvement, promote life satisfaction. Zero sum goals, including commitment to career…

  3. Grey matter volumes in treatment naïve vs. chronically treated children with attention deficit/hyperactivity disorder: a combined approach.

    PubMed

    Villemonteix, Thomas; De Brito, Stéphane A; Kavec, Martin; Balériaux, Danielle; Metens, Thierry; Slama, Hichem; Baijot, Simon; Mary, Alison; Peigneux, Philippe; Massat, Isabelle

    2015-08-01

    Psychostimulants are the first-line treatment in attention deficit/hyperactivity disorder (ADHD), but their effects on brain development remain poorly understood. In particular, previous structural magnetic resonance imaging (sMRI) studies only investigated treatment effects on grey matter (GM) volumes in selected regions of interest (ROIs). In this study, voxel-based morphometry (VBM) was used to assess medication-related GM volume differences across the entire brain. Automated tracing measurements of selected ROIs were also obtained. Three groups (77 participants aged 7-to-13 year old) underwent MRI scans and were compared: never-medicated children with ADHD (n=33), medicated (methylphenidate) children with ADHD (n=20) and typically developing children (TD; n=24). Optimised VBM was used to investigate regional GM volumes, controlling for age and gender. Automated tracing procedures were also used to assess the average volume of the caudate nucleus, the amygdala and the nucleus accumbens. When compared to both medicated children with ADHD and TD children, never-medicated children with ADHD exhibited decreased GM volume in the insula and in the middle temporal gyrus. When compared to TD children, medicated children with ADHD had decreased GM volume in the middle frontal gyrus and in the precentral gyrus. Finally, ROI analyses revealed a significant association between duration of treatment and GM volume of the left nucleus accumbens in medicated children with ADHD. In conclusion, this study documents potential methylphenidate-related GM volume normalization and deviation in previously unexplored brain structures, and reports a positive association between treatment history and GM volume in the nucleus accumbens, a key region for reward-processing.

  4. Finding Freedom in the Classroom: A Practical Introduction to Critical Theory. Counterpoints, Volume 24.

    ERIC Educational Resources Information Center

    Hinchey, Patricia H.

    This book introduces critical theory, providing a practical starting point for teachers interested in exploring alternatives for creating a new kind of classroom experience, both for themselves and their students. Critical theory offers most educators an approach to education that is radically different from the norm. This book provides the…

  5. Grey matter volume differences associated with gender in children with attention-deficit/hyperactivity disorder: A voxel-based morphometry study.

    PubMed

    Villemonteix, Thomas; De Brito, Stéphane A; Slama, Hichem; Kavec, Martin; Balériaux, Danielle; Metens, Thierry; Baijot, Simon; Mary, Alison; Peigneux, Philippe; Massat, Isabelle

    2015-08-01

    Female participants have been underrepresented in previous structural magnetic resonance imaging reports on attention-deficit/hyperactivity disorder (ADHD). In this study, we used optimized voxel-based morphometry to examine grey matter volumes in a sample of 33 never-medicated children with combined-type ADHD and 27 typically developing (TD) children. We found a gender-by-diagnosis interaction effect in the ventral anterior cingulate cortex (ACC), whereby boys with ADHD exhibited reduced volumes compared with TD boys, while girls with ADHD showed increased volumes when compared with TD girls. Considering the key role played by the ventral ACC in emotional regulation, we discuss the potential contribution of these alterations to gender-specific symptoms' profiles in ADHD.

  6. The QCD vacuum, hadrons and superdense matter

    SciTech Connect

    Shuryak, E.

    1986-01-01

    This is probably the only textbook available that gathers QCD, many-body theory and phase transitions in one volume. The presentation is pedagogical and readable. Contents: The QCD Vacuum: Introduction; QCD on the Lattice Topological Effects in Gauges Theories. Correlation Functions and Microscopic Excitations: Introduction; Operator Product Expansion; The Sum Rules beyond OPE; Nonpower Contributions to Correlators and Instantons; Hadronic Spectroscopy on the Lattice. Dense Matter: Hadronic Matter; Asymptotically Dense Quark-Gluon Plasma; Instantons in Matter; Lattice Calculations at Finite Temperature; Phase Transitions; Macroscopic Excitations and Experiments: General Properties of High Energy Collisions; ''Barometers'', ''Thermometers'', Interferometric ''Microscope''; Experimental Perspectives.

  7. Improved longitudinal [(18)F]-AV45 amyloid PET by white matter reference and VOI-based partial volume effect correction.

    PubMed

    Brendel, Matthias; Högenauer, Marcus; Delker, Andreas; Sauerbeck, Julia; Bartenstein, Peter; Seibyl, John; Rominger, Axel

    2015-03-01

    Amyloid positron-emission-tomography (PET) offers an important research and diagnostic tool for investigating Alzheimer's disease (AD). The majority of amyloid PET studies have used the cerebellum as a reference region, and clinical studies have not accounted for atrophy-based partial volume effects (PVE). Longitudinal studies using cerebellum as reference tissue have revealed only small mean increases and high inter-subject variability in amyloid binding. We aimed to test the effects of different reference regions and PVE-correction (PVEC) on the discriminatory power and longitudinal performance of amyloid PET. We analyzed [(18)F]-AV45 PET and T1-weighted MRI data of 962 subjects at baseline and two-year follow-up data of 258 subjects. Cortical composite volume-of-interest (VOI) values (COMP) for tracer uptake were generated using either full brain atlas VOIs, gray matter segmented VOIs or gray matter segmented VOIs after VOI-based PVEC. Standard-uptake-value ratios (SUVR) were calculated by scaling the COMP values to uptake in cerebellum (SUVRCBL), brainstem (SUVRBST) or white matter (SUVRWM). Mean SUV, SUVR, and changes after PVEC were compared at baseline between diagnostic groups of healthy controls (HC; N=316), mild cognitive impairment (MCI; N=483) and AD (N=163). Receiver operating characteristics (ROC) were calculated for the discriminations between HC, MCI and AD, and expressed as area under the curve (AUC). Finally, the longitudinal [(18)F]-AV45-PET data were used to analyze the impact of quantitation procedures on apparent changes in amyloid load over time. Reference region SUV was most constant between diagnosis groups for the white matter. PVEC led to decreases of COMP-SUV in HC (-18%) and MCI (-10%), but increases in AD (+7%). Highest AUCs were found when using PVEC with white matter scaling for the contrast between HC/AD (0.907) or with brainstem scaling for the contrast between HC/MCI (0.658). Longitudinal increases were greatest in all diagnosis

  8. Habitual 'sleep credit' is associated with greater grey matter volume of the medial prefrontal cortex, higher emotional intelligence and better mental health.

    PubMed

    Weber, Mareen; Webb, Christian A; Deldonno, Sophie R; Kipman, Maia; Schwab, Zachary J; Weiner, Melissa R; Killgore, William D S

    2013-10-01

    In modern society, people often fail to obtain the amount of sleep that experts recommend for good health and performance. Insufficient sleep can lead to degraded cognitive performance and alterations in emotional functioning. However, most people also acknowledge that on a regular basis they obtain more sleep than they subjectively perceive they need at a minimum to stave off performance decrements, a construct we describe as subjective 'sleep credit'. Few people would contest the notion that getting more sleep is better, but data on both behavioural and neuroanatomical correlates of 'sleep credit' are surprisingly limited. We conducted a voxel-based morphometric study to assess cerebral grey matter correlates of habitually sleeping more than one's subjective requirements. We further tested whether these structural correlates are associated with perceived emotional intelligence and indices of psychopathology while controlling for age, gender, and total intracranial volume. In a sample of 55 healthy adults aged 18-45 years (28 males, 27 females), whole-brain multiple regression showed that habitual subjective 'sleep credit' was correlated positively with grey matter volume within regions of the left medial prefrontal cortex and right orbitofrontal gyrus. Volumes were extracted and regressed against self-report emotion and psychopathology indices. Only grey matter volume of the medial prefrontal cortex cluster correlated with greater emotional intelligence and lower scores on several indices of psychopathology. Findings converge with previous evidence of the role of the medial prefrontal cortex in the relationship between sleep and emotional functioning, and suggest that behaviour and brain structure vary with habitual 'sleep credit'.

  9. Chiral symmetry and effective field theories for hadronic, nuclear and stellar matter

    NASA Astrophysics Data System (ADS)

    Holt, Jeremy W.; Rho, Mannque; Weise, Wolfram

    2016-03-01

    Chiral symmetry, first entering in nuclear physics in the 1970s for which Gerry Brown played a seminal role, has led to a stunningly successful framework for describing strongly-correlated nuclear dynamics both in finite and infinite systems. We review how the early, germinal idea conceived with the soft-pion theorems in the pre-QCD era has evolved into a highly predictive theoretical framework for nuclear physics, aptly assessed by Steven Weinberg: "it (chiral effective field theory) allows one to show in a fairly convincing way that what they (nuclear physicists) have been doing all along... is the correct first step in a consistent approximation scheme". Our review recounts both how the theory presently fares in confronting Nature and how one can understand its extremely intricate workings in terms of the multifaceted aspects of chiral symmetry, namely, chiral perturbation theory, skyrmions, Landau Fermi-liquid theory, the Cheshire cat phenomenon, and hidden local and mended symmetries.

  10. Dark matter in galaxies according to the tensor-four-scalars theory

    SciTech Connect

    Scharf, Guenter

    2011-10-15

    Massive gravity previously constructed as the spin-2 quantum gauge theory leads in the mass-zero limit to a modification of general relativity. As a relic from the massive theory, a vector field v{sup {lambda}} survives which couples to the metric only. However, the coupling does not involve covariant derivatives so that v{sup {lambda}} must be considered as four scalar fields. We analyze the static, spherically symmetric solutions of this theory. From the corresponding geodesics, we find the circular velocity profile. By interpreting this as coming from a dark density profile, the theory predicts a flat density core for r{yields}0. But the circular velocity profile is not universal.

  11. Indirect detection constraints on the model space of dark matter effective theories

    NASA Astrophysics Data System (ADS)

    Carpenter, Linda M.; Colburn, Russell; Goodman, Jessica

    2015-11-01

    Using limits on photon flux from dwarf spheroidal galaxies, we place bounds on the parameter space of models in which dark matter annihilates into multiple final state particle pair channels. We derive constraints on effective operator models with dark matter couplings to third generation fermions and to pairs of standard model vector bosons. We present limits in various slices of model parameter space along with estimations of the region of maximal validity of the effective operator approach for indirect detection. We visualize our bounds for models with multiple final state annihilations by projecting parameter space constraints onto triangles, a technique familiar from collider physics; and we compare our bounds to collider limits on equivalent models.

  12. John Dewey on theory of learning and inquiry: The scientific method and subject matter

    NASA Astrophysics Data System (ADS)

    Chen, Po-Nien

    This study examines the educational debate between Dewey and some of his critics on the merits of learning the scientific method. Four of Dewey's critics---Hutchins, Hirsch, Hirst, and Scheffler criticize Dewey for over-emphasizing the importance of the scientific method and under-emphasizing the importance of subject matter in education. This dissertation argues that these critics misunderstand Dewey's use of the scientific method and its importance in education. It argues that Dewey conceives of the scientific method in two different ways: first as an attitude and second as a tool. It also argues that, by failing to understand this critical distinction, these critics misunderstand the role of the scientific method in education. The dissertation concludes by showing that, educationally, Dewey's ideas of the scientific method have different meanings in different context. It analyzes the scientific method as empirical method, critical thinking, cooperative learning, and creative thinking, and shows the place of subject matter in each of them.

  13. A Matter of Principle: The Principles of Quantum Theory, Dirac's Equation, and Quantum Information

    NASA Astrophysics Data System (ADS)

    Plotnitsky, Arkady

    2015-10-01

    This article is concerned with the role of fundamental principles in theoretical physics, especially quantum theory. The fundamental principles of relativity will be addressed as well, in view of their role in quantum electrodynamics and quantum field theory, specifically Dirac's work, which, in particular Dirac's derivation of his relativistic equation of the electron from the principles of relativity and quantum theory, is the main focus of this article. I shall also consider Heisenberg's earlier work leading him to the discovery of quantum mechanics, which inspired Dirac's work. I argue that Heisenberg's and Dirac's work was guided by their adherence to and their confidence in the fundamental principles of quantum theory. The final section of the article discusses the recent work by D'Ariano and coworkers on the principles of quantum information theory, which extend quantum theory and its principles in a new direction. This extension enabled them to offer a new derivation of Dirac's equations from these principles alone, without using the principles of relativity.

  14. Fast Computation of Solvation Free Energies with Molecular Density Functional Theory: Thermodynamic-Ensemble Partial Molar Volume Corrections.

    PubMed

    Sergiievskyi, Volodymyr P; Jeanmairet, Guillaume; Levesque, Maximilien; Borgis, Daniel

    2014-06-01

    Molecular density functional theory (MDFT) offers an efficient implicit-solvent method to estimate molecule solvation free-energies, whereas conserving a fully molecular representation of the solvent. Even within a second-order approximation for the free-energy functional, the so-called homogeneous reference fluid approximation, we show that the hydration free-energies computed for a data set of 500 organic compounds are of similar quality as those obtained from molecular dynamics free-energy perturbation simulations, with a computer cost reduced by 2-3 orders of magnitude. This requires to introduce the proper partial volume correction to transform the results from the grand canonical to the isobaric-isotherm ensemble that is pertinent to experiments. We show that this correction can be extended to 3D-RISM calculations, giving a sound theoretical justification to empirical partial molar volume corrections that have been proposed recently.

  15. Understanding College and University Organization: Theories for Effective Policy and Practice. Two Volume Set

    ERIC Educational Resources Information Center

    Bess, James L.; Dee, Jay R.

    2007-01-01

    This two-volume work is intended to help readers develop powerful new ways of thinking about organizational principles, and apply them to policy-making and management in colleges and universities. The book is written with two audiences in mind: administrative and faculty leaders in institutions of higher learning, and students (both doctoral and…

  16. Writing as a Learning Tool: Integrating Theory and Practice. Studies in Writing, Volume 7.

    ERIC Educational Resources Information Center

    Tynjala, Paivi, Ed.; Mason, Lucia, Ed.; Lonka, Kirsti, Ed.

    This book, the seventh volume in the Studies in Writing International Series on the Research of Learning and Instruction of Writing, is an account of the current state of using writing as a tool for learning. The book presents psychological and educational foundations of the writing across the curriculum movement and describes writing-to-learn…

  17. Health Occupations Curriculum. Skills and Theory for Health Assistant. Volume 2, Units 5-7.

    ERIC Educational Resources Information Center

    Arizona State Dept. of Education, Phoenix.

    This volume consists of three units of a basic core curriculum that is intended for all health workers. Covered in the units are the following topics: (1) the body's need for food, the effect of food on the body, the five food groups, the six nutrients, and therapeutic diets; (2) general principles of asepsis, specific methods of maintaining…

  18. Health Occupations Curriculum. Skills and Theory for Health Assistant. Volume I, Units 1-4.

    ERIC Educational Resources Information Center

    Arizona State Dept. of Education, Phoenix.

    This volume consists of the first four units of a basic core curriculum that is intended for all health workers. The units deal with the following topics: (1) the health care facility, the long-term care facility, the health team, and the nursing team; (2) verbal and nonverbal communication, written communication, human behavior, ethical behavior,…

  19. Note: Perturbation theory of polymer chains revisited. I. Corrected C1 and C2 parameters for excluded volume chains

    NASA Astrophysics Data System (ADS)

    Zifferer, Gerhard; Olaj, Oskar Friedrich

    2011-06-01

    Random walks (RWs) and self-avoiding random walks (SAWs) embedded in the cubic lattice are evaluated with respect to the number of i-tuples of overlaps within incompatible pairs leading to the parameters Ck of the perturbation theory of the excluded volume u. These parameters are strongly dependent on chain length N never before realized by theory. Extrapolated to infinite chain length C1 and C2 are fairly well recovered for RWs while markedly larger values appear for SAWs. The Kurata-Yamakawa approach recovers the simulation results with high accuracy if self-consistent C1 and C2 values are applied thus representing an easy to use well-performing method for the prediction of u in athermal solution.

  20. Exact results in Chern-Simons-matter theories and quantum geometry

    NASA Astrophysics Data System (ADS)

    Codesido, Santiago; Grassi, Alba; Mariño, Marcos

    2015-07-01

    We show that, in ABJ(M) theories with supersymmetry, the non-perturbative sector of the partition function on the three-sphere simplifies drastically. Due to this simplification, we are able to write closed form expressions for the grand potential of these theories, which determines the full large N asymptotics. Moreover, we find explicit formulae for the generating functionals of their partition functions, for all values of the rank N of the gauge group: they involve Jacobi theta functions on the spectral curve associated to the planar limit. Exact quantization conditions for the spectral problem of the Fermi gas are then obtained from the vanishing of the theta function. We also show that the partition function, as a function of N , can be extended in a natural way to an entire function on the full complex plane, and we explore some possible consequences of this fact for the quantum geometry of M-theory and for putative de Sitter extensions.

  1. Contributions of organic and inorganic matter to sediment volume and accretion in tidal wetlands at steady state

    EPA Science Inventory

    A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD =...

  2. Higgs mass scales and matter-antimatter oscillations in grand unified theories

    SciTech Connect

    Senjanovic, G.

    1982-01-01

    A general discussion of mass scales in grand unified theories is presented, with special emphasis on Higgs scalars which mediate neutron-antineutron (n-anti n) and hydrogen-antihydrogen (H-anti H) oscillations. It is shown that the analogue of survival hypothesis for fermions naturally makes such particles superheavy, thus leading to unobservable lifetimes. If this hypothesis is relaxed, an interesting possibility of potentially observable n-anti n and H-anti H transitions, mutually related arises in the context of SU(5) theory with spontaneously broken B-L symmetry.

  3. Gauge groups and matter fields on some models of F-theory without section

    NASA Astrophysics Data System (ADS)

    Kimura, Yusuke

    2016-03-01

    We investigate F-theory on an elliptic Calabi-Yau 4-fold without a section to the fibration. To construct an elliptic Calabi-Yau 4-fold without a section, we introduce families of elliptic K3 surfaces which do not admit a section. A product K3 × K3, with one of the K3's chosen from these families of elliptic K3 surfaces without a section, realises an elliptic Calabi-Yau 4-fold without a section. We then compactify F-theory on such K3 × K3's.

  4. Theory of neutrino emission from nucleon-hyperon matter in neutron stars: angular integrals

    NASA Astrophysics Data System (ADS)

    Kaminker, A. D.; Yakovlev, D. G.; Haensel, P.

    2016-08-01

    Investigations of thermal evolution of neutron stars with hyperon cores require neutrino emissivities for many neutrino reactions involving strongly degenerate particles (nucleons, hyperons, electrons, muons). We calculate the angular integrals In (over orientations of momenta of n degenerate particles) for major neutrino reactions with n=3, 4, 5 at all possible combinations of particle Fermi momenta. The integrals In are necessary ingredients for constructing a uniform database of neutrino emissivities in dense nucleon-hyperon matter. The results can also be used in many problems of physical kinetics of strongly degenerate systems.

  5. Continuous Theory of Active Matter Systems with Metric-Free Interactions

    NASA Astrophysics Data System (ADS)

    Peshkov, Anton; Ngo, Sandrine; Bertin, Eric; Chaté, Hugues; Ginelli, Francesco

    2012-08-01

    We derive a hydrodynamic description of metric-free active matter: starting from self-propelled particles aligning with neighbors defined by “topological” rules, not metric zones—a situation advocated recently to be relevant for bird flocks, fish schools, and crowds—we use a kinetic approach to obtain well-controlled nonlinear field equations. We show that the density-independent collision rate per particle characteristic of topological interactions suppresses the linear instability of the homogeneous ordered phase and the nonlinear density segregation generically present near threshold in metric models, in agreement with microscopic simulations.

  6. Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 1: Noise Sources

    NASA Technical Reports Server (NTRS)

    Hubbard, Harvey H. (Editor)

    1991-01-01

    Methodology recommended to evaluate aeroacoustic related problems is provided, and approaches to their solutions are suggested without extensive tables, nomographs, and derivations. Orientation is toward flight vehicles and emphasis is on underlying physical concepts. Theoretical, experimental, and applied aspects are covered, including the main formulations and comparisons of theory and experiment. The topics covered include: propeller and propfan noise, rotor noise, turbomachinery noise, jet noise classical theory and experiments, noise from turbulent shear flows, jet noise generated by large-scale coherent motion, airframe noise, propulsive lift noise, combustion and core noise, and sonic booms.

  7. A review on the relativistic effective field theory with parameterized couplings for nuclear matter and neutron stars

    SciTech Connect

    Vasconcellos, C. A. Zen

    2015-12-17

    Nuclear science has developed many excellent theoretical models for many-body systems in the domain of the baryon-meson strong interaction for the nucleus and nuclear matter at low, medium and high densities. However, a full microscopic understanding of nuclear systems in the extreme density domain of compact stars is still lacking. The aim of this contribution is to shed some light on open questions facing the nuclear many-body problem at the very high density domain. Here we focus our attention on the conceptual issue of naturalness and its role in shaping the baryon-meson phase space dynamics in the description of the equation of state (EoS) of nuclear matter and neutrons stars. In particular, in order to stimulate possible new directions of research, we discuss relevant aspects of a recently developed relativistic effective theory for nuclear matter within Quantum Hadrodynamics (QHD) with genuine many-body forces and derivative natural parametric couplings. Among other topics we discuss in this work the connection of this theory with other known effective QHD models of the literature and its potentiality in describing a new physics for dense matter. The model with parameterized couplings exhausts the whole fundamental baryon octet (n, p, Σ{sup −}, Σ{sup 0}, Σ{sup +}, Λ, Ξ{sup −}, Ξ{sup 0}) and simulates n-order corrections to the minimal Yukawa baryon couplings by considering nonlinear self-couplings of meson fields and meson-meson interaction terms coupled to the baryon fields involving scalar-isoscalar (σ, σ∗), vector-isoscalar (ω, Φ), vector-isovector (ϱ) and scalar-isovector (δ) virtual sectors. Following recent experimental results, we consider in our calculations the extreme case where the Σ{sup −} experiences such a strong repulsion that its influence in the nuclear structure of a neutron star is excluded at all. A few examples of calculations of properties of neutron stars are shown and prospects for the future are discussed.

  8. Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 2: Noise Control

    NASA Technical Reports Server (NTRS)

    Hubbard, Harvey H. (Editor)

    1991-01-01

    Flight vehicles and the underlying concepts of noise generation, noise propagation, noise prediction, and noise control are studied. This volume includes those chapters that relate to flight vehicle noise control and operations: human response to aircraft noise; atmospheric propagation; theoretical models for duct acoustic propagation and radiation; design and performance of duct acoustic treatment; jet noise suppression; interior noise; flyover noise measurement and prediction; and quiet aircraft design and operational characteristics.

  9. Holographic renormalization group flows in N =3 Chern-Simons-Matter theory from N =3 4D gauged supergravity

    NASA Astrophysics Data System (ADS)

    Karndumri, Parinya

    2016-08-01

    We study various supersymmetric renormalization group (RG) flows of N =3 Chern-Simons-Matter theory in three dimensions by using four-dimensional N =3 gauged supergravity coupled to eight vector multiplets with S O (3 )×S U (3 ) gauge group. The AdS4 critical point preserving the full S O (3 )×S U (3 ) provides a gravity dual of N =3 superconformal field theory with flavor symmetry S U (3 ). We study the scalar potential and identify a new supersymmetric AdS4 critical point preserving the full N =3 supersymmetry and unbroken S O (3 )×U (1 ) symmetry. An analytic RG flow solution interpolating between S O (3 )×S U (3 ) and S O (3 )×U (1 ) critical points is explicitly given. We then investigate possible RG flows from these AdS4 critical points to nonconformal field theories in the IR. All of the singularities appearing in the IR turn out to be physically acceptable. Furthermore, we look for supersymmetric solutions of the form AdS2×Σ2 with Σ2 being a two-sphere or a two-dimensional hyperbolic space and find a number of AdS2 geometries preserving four supercharges with S O (2 )×S O (2 )×S O (2 ) and S O (2 )×S O (2 ) symmetries.

  10. Non-Gaussian covariance of the matter power spectrum in the effective field theory of large scale structure

    NASA Astrophysics Data System (ADS)

    Bertolini, Daniele; Schutz, Katelin; Solon, Mikhail P.; Walsh, Jonathan R.; Zurek, Kathryn M.

    2016-06-01

    We compute the non-Gaussian contribution to the covariance of the matter power spectrum at one-loop order in standard perturbation theory (SPT), using the framework of the effective field theory (EFT) of large scale structure (LSS). The complete one-loop contributions are evaluated for the first time, including the leading EFT corrections that involve seven independent operators, of which four appear in the power spectrum and bispectrum. We compare the non-Gaussian part of the one-loop covariance computed with both SPT and EFT of LSS to two separate simulations. In one simulation, we find that the one-loop prediction from SPT reproduces the simulation well to ki+kj˜0.25 h /Mpc , while in the other simulation we find a substantial improvement of EFT of LSS (with one free parameter) over SPT, more than doubling the range of k where the theory accurately reproduces the simulation. The disagreement between these two simulations points to unaccounted for systematics, highlighting the need for improved numerical and analytic understanding of the covariance.

  11. The Theory of Multiple Intelligences: A Case of Missing Cognitive Matter.

    ERIC Educational Resources Information Center

    Allix, Nicholas M.

    2000-01-01

    Argues that although Gardner's conception of human cognition, characterized by a set of multiple and distinct cognitive capabilities, is an advance over the narrow conception of IQ, it runs into fundamental difficulties of a methodological kind and is based on a discredited empiricist theory of knowledge which work with artificial neural networks…

  12. A Test and Extension of Objectification Theory as It Predicts Disordered Eating: Does Women's Age Matter?

    ERIC Educational Resources Information Center

    Augustus-Horvath, Casey L.; Tylka, Tracy L.

    2009-01-01

    When predicting disordered eating, models incorporating several of objectification theory's (B. L. Fredrickson & T. A. Roberts, 1997) core constructs (i.e., sexual objectification, self-objectification, body shame, poor interoceptive awareness) have been empirically supported with women of traditional undergraduate age who are consistent in age…

  13. Approaches to Teaching the Particulate Theory of Matter. Children's Learning in Science Project.

    ERIC Educational Resources Information Center

    Leeds Univ. (England). Centre for Studies in Science and Mathematics Education.

    During the period 1984-1986, over 30 teachers from the Yorkshire (England) region have worked in collaboration with the Children's Learning in Science Project (CLIS) developing and testing teaching schemes in the areas of energy, particle theory, and plant nutrition. The project is based upon the constructivist approach to teaching. This guide…

  14. Using Multiple Representations to Promote Grade 11 Students' Scientific Understanding of the Particle Theory of Matter

    ERIC Educational Resources Information Center

    Adadan, Emine

    2013-01-01

    This study explored two groups of Grade 11 (age 16-17) students' conceptual understandings about aspects of particle theory before, immediately after, and 3 months after instruction with multiple representations (IMR) and instruction with verbal representations (IVR). Data sources included open-ended questionnaires, interviews, and student…

  15. Auxiliary-field quantum Monte Carlo simulations of neutron matter in chiral effective field theory.

    PubMed

    Wlazłowski, G; Holt, J W; Moroz, S; Bulgac, A; Roche, K J

    2014-10-31

    We present variational Monte Carlo calculations of the neutron matter equation of state using chiral nuclear forces. The ground-state wave function of neutron matter, containing nonperturbative many-body correlations, is obtained from auxiliary-field quantum Monte Carlo simulations of up to about 340 neutrons interacting on a 10(3) discretized lattice. The evolution Hamiltonian is chosen to be attractive and spin independent in order to avoid the fermion sign problem and is constructed to best reproduce broad features of the chiral nuclear force. This is facilitated by choosing a lattice spacing of 1.5 fm, corresponding to a momentum-space cutoff of Λ=414  MeV/c, a resolution scale at which strongly repulsive features of nuclear two-body forces are suppressed. Differences between the evolution potential and the full chiral nuclear interaction (Entem and Machleidt Λ=414  MeV [L. Coraggio et al., Phys. Rev. C 87, 014322 (2013).

  16. Transformative Leadership: A Reader. Counterpoints: Studies in the Postmodern Theory of Education. Volume 409

    ERIC Educational Resources Information Center

    Shields, Carolyn M., Ed.

    2011-01-01

    This important, timely, and thought-provoking reader is a collection of original chapters by authors from five different countries, each of whom explores a facet of transformative leadership. Transformative leadership is fundamentally a critical approach to leadership that goes well beyond the tenets of most current leadership theories to focus on…

  17. Teaching Together, Learning Together. Counterpoints, Studies in the Postmodern Theory of Education Volume 294

    ERIC Educational Resources Information Center

    Roth, Wolff-Michael, Ed.; Tobin, Kenneth, Ed.

    2005-01-01

    Coteaching and cogenerative dialoguing are ways of learning to teach that truly bridge the gap between theory and praxis, as new teachers learn to teach alongside peers and more experienced teachers. These practices are also means of overcoming teacher isolation and burnout. Through cogenerative dialogue sessions, new and experienced teachers,…

  18. RIKEN BNL RESEARCH CENTER WORKSHOP ON GAUGE-INVARIANT VARIABLES IN GAUGE THEORIES, VOLUME 20

    SciTech Connect

    VAN BAAL,P.; ORLAND,P.; PISARSKI,R.

    2000-06-01

    This four-day workshop focused on the wide variety of approaches to the non-perturbative physics of QCD. The main topic was the formulation of non-Abelian gauge theory in orbit space, but some other ideas were discussed, in particular the possible extension of the Maldacena conjecture to nonsupersymmetric gauge theories. The idea was to involve most of the participants in general discussions on the problem. Panel discussions were organized to further encourage debate and understanding. Most of the talks roughly fell into three categories: (1) Variational methods in field theory; (2) Anti-de Sitter space ideas; (3) The fundamental domain, gauge fixing, Gribov copies and topological objects (both in the continuum and on a lattice). In particular some remarkable progress in three-dimensional gauge theories was presented, from the analytic side by V.P. Nair and mostly from the numerical side by O. Philipsen. This work may ultimately have important implications for RHIC experiments on the high-temperature quark-gluon plasma.

  19. Reduced gray matter volume in the anterior cingulate, orbitofrontal cortex and thalamus as a function of mild depressive symptoms: a voxel-based morphometric analysis

    PubMed Central

    Webb, C. A.; Weber, M.; Mundy, E. A.; Killgore, W. D. S.

    2014-01-01

    Background Studies investigating structural brain abnormalities in depression have typically employed a categorical rather than dimensional approach to depression [i.e. comparing subjects with Diagnostic and Statistical Manual of Mental Disorders (DSM)-defined major depressive disorder (MDD) v. healthy controls]. The National Institute of Mental Health, through their Research Domain Criteria initiative, has encouraged a dimensional approach to the study of psychopathology as opposed to an over-reliance on categorical (e.g. DSM-based) diagnostic approaches. Moreover, subthreshold levels of depressive symptoms (i.e. severity levels below DSM criteria) have been found to be associated with a range of negative outcomes, yet have been relatively neglected in neuroimaging research. Method To examine the extent to which depressive symptoms – even at subclinical levels – are linearly related to gray matter volume reductions in theoretically important brain regions, we employed whole-brain voxel-based morphometry in a sample of 54 participants. Results The severity of mild depressive symptoms, even in a subclinical population, was associated with reduced gray matter volume in the orbitofrontal cortex, anterior cingulate, thalamus, superior temporal gyrus/temporal pole and superior frontal gyrus. A conjunction analysis revealed concordance across two separate measures of depression. Conclusions Reduced gray matter volume in theoretically important brain regions can be observed even in a sample that does not meet DSM criteria for MDD, but who nevertheless report relatively elevated levels of depressive symptoms. Overall, these findings highlight the need for additional research using dimensional conceptual and analytic approaches, as well as further investigation of subclinical populations. PMID:25066703

  20. On the validity of the effective field theory for dark matter searches at the LHC part III: analysis for the t-channel

    SciTech Connect

    Busoni, Giorgio; Simone, Andrea De; Jacques, Thomas; Morgante, Enrico; Riotto, Antonio E-mail: andrea.desimone@sissa.it E-mail: enrico.morgante@unige.ch

    2014-09-01

    We extend our recent analysis of the limitations of the effective field theory approach to studying dark matter at the LHC, by investigating the case in which Dirac dark matter couples to standard model quarks via t-channel exchange of a heavy scalar mediator. We provide analytical results for the validity of the effective field theory description, for both √s = 8 TeV and 14 TeV. We make use of a MonteCarlo event generator to assess the validity of our analytical conclusions. We also point out the general trend that in the regions where the effective field theory is valid, the dark matter relic abundance is typically large.

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

    PubMed

    Mohammed, Asadig; Murugan, Jeff; Nastase, Horatiu

    2012-11-01

    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.

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

    PubMed

    Mohammed, Asadig; Murugan, Jeff; Nastase, Horatiu

    2012-11-01

    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. PMID:23215268

  3. The association of white matter volume in psychotic disorders with genotypic variation in NRG1, MOG and CNP: a voxel-based analysis in affected individuals and their unaffected relatives.

    PubMed

    Cannon, D M; Walshe, M; Dempster, E; Collier, D A; Marshall, N; Bramon, E; Murray, R M; McDonald, C

    2012-01-01

    We investigated the role of variation in putative psychosis genes coding for elements of the white matter system by examining the contribution of genotypic variation in three single-nucleotide polymorphisms (SNPs) neuregulin 1 (NRG1) SNP8NRG221533, myelin oligodendrocytes glycoprotein (MOG) rs2857766 and CNP (rs2070106) and one haplotype HAP(ICE) (deCODE) to white matter volume in patients with psychotic disorder and their unaffected relatives. Structural magnetic resonance imaging and blood samples for genotyping were collected on 189 participants including patients with schizophrenia (SZ) or bipolar I disorder (BDI), unaffected first-degree relatives of these patients and healthy volunteers. The association of genotypic variation with white matter volume was assessed using voxel-based morphometry in SPM5. The NRG1 SNP and the HAP(ICE) haplotype were associated with abnormal white matter volume in the BDI group in the fornix, cingulum and parahippocampal gyrus circuit. In SZ the NRG1 SNP risk allele was associated with lower white matter volume in the uncinate fasciculus (UF), right inferior longitudinal fasciculus and the anterior limb of the internal capsule. Healthy G-homozygotes of the MOG SNP had greater white matter volume in areas of the brainstem and cerebellum; this relationship was absent in those with a psychotic disorder and the unaffected relatives groups. The CNP SNP did not contribute to white matter volume variation in the diagnostic groups studied. Variation in the genes coding for structural and protective components of myelin are implicated in abnormal white matter volume in the emotion circuitry of the cingulum, fornix, parahippocampal gyrus and UF in psychotic disorders. PMID:23032943

  4. Grey matter volume in the cerebellum is related to the processing of grammatical rules in a second language: a structural voxel-based morphometry study.

    PubMed

    Pliatsikas, Christos; Johnstone, Tom; Marinis, Theodoros

    2014-02-01

    The experience of learning and using a second language (L2) has been shown to affect the grey matter (GM) structure of the brain. Importantly, GM density in several cortical and subcortical areas has been shown to be related to performance in L2 tasks. Here, we show that bilingualism can lead to increased GM volume in the cerebellum, a structure that has been related to the processing of grammatical rules. Additionally, the cerebellar GM volume of highly proficient L2 speakers is correlated to their performance in a task tapping on grammatical processing in an L2, demonstrating the importance of the cerebellum for the establishment and use of grammatical rules in an L2.

  5. Oxidative mitochondrial DNA damage in peripheral blood mononuclear cells is associated with reduced volumes of hippocampus and subcortical gray matter in chronically HIV-infected patients

    PubMed Central

    Kallianpur, Kalpana J.; Gerschenson, Mariana; Mitchell, Brooks I.; LiButti, Daniel E.; Umaki, Tracie M.; Ndhlovu, Lishomwa C.; Nakamoto, Beau K.; Chow, Dominic C.; Shikuma, Cecilia M.

    2016-01-01

    Cross-sectional relationships were examined between regional brain volumes and mitochondrial DNA (mtDNA) 8-hydroxy-2-deoxyguanosine (8-oxo-dG) in peripheral blood mononuclear cells (PBMCs) of 47 HIV patients [mean age 51 years; 81% with HIV RNA ≤50 copies/mL] on combination antiretroviral therapy. The gene-specific DNA damage and repair assay measured mtDNA 8-oxo-dG break frequency. Magnetic resonance imaging was performed at 3 T. Higher mtDNA 8-oxo-dG was associated with lateral ventricular enlargement and with decreased volumes of hippocampus, pallidum, and total subcortical gray matter, suggesting the involvement of systemic mitochondrial-specific oxidative stress in chronic HIV-related structural brain changes and cognitive difficulties. Clarification of the mechanism may provide potential therapeutic targets. PMID:26923169

  6. Density functional theory approach for calculation of dielectric properties of warm dense matter

    NASA Astrophysics Data System (ADS)

    Saitov, Ilnur

    2015-06-01

    The reflectivity of shocked xenon was measured in the experiments of Mintsev and Zaporoghets for wavelength 1064 nm. But there is no adequate theoretical explanation of these reflectivity results in the framework of the standard methods of nonideal plasma theory. The assumption of significant width to the shock front gives a good agreement with the experimental data. However, there are no evidences of this effect in the experiment. Reflectivity of shocked compressed xenon plasma is calculated in the framework of the density functional theory approach as in. Dependencies on the frequency of incident radiation and on the plasma density are analyzed. The Fresnel formula for the reflectivity is used. The longitudinal expression in the long wavelength limit is applied for the calculation of the imaginary part of the dielectric function. The real part of the dielectric function is calculated by means of the Kramers-Kronig transformation. The approach for the calculation of plasma frequency is developed.

  7. Nonlocal orbital-free density functional theory for warm dense matter

    NASA Astrophysics Data System (ADS)

    Sjostrom, Travis

    2014-03-01

    Accurate simulations of warm dense matter remain challenging in current research, while being motivated further as recent experiments probe more accurately into this regime. While the de facto standard is quantum molecular dynamics using Kohn-Sham DFT, this methods scales significantly with temperature due to the orbital dependence. From the other side, the orbital-free Thomas-Fermi approximation works well for hot dense systems, but loses accuracy at lower temperatures. Recently developed nonlocal orbital-free functionals for the noninteracting free energy [Phys. Rev. B 88, 195103], which show near Kohn-Sham accuracy for broad ranges of temperature and density are presented. The application of which are detailed in regards to pseudopotentials and molecular dynamics for various systems. Comparisons with local orbital-free methods as well as orbital-dependent Kohn-Sham calculations, including accuracy and computational cost are made. This research has been supported by the DOE Office of Fusion Sciences (FES).

  8. Muon flux limits for Majorana dark matter from strong coupling theories

    SciTech Connect

    Belotsky, Konstantin; Khlopov, Maxim; Kouvaris, Chris

    2009-04-15

    We analyze the effects of the capture of dark matter (DM) particles, with successive annihilations, predicted in the minimal walking technicolor model (MWT) by the Sun and the Earth. We show that the Super-Kamiokande upper limit on excessive muon flux disfavors the mass interval between 100 and 200 GeV for MWT DM with a suppressed standard model interaction (due to a mixing angle), and the mass interval between 0 and 1500 GeV for MWT DM without such suppression, upon making the standard assumption about the value of the local DM distribution. In the first case, the exclusion interval is found to be very sensitive to the DM distribution parameters and can vanish at the extreme of the acceptable values.

  9. MAIL LOG, program theory, volume 1. [Scout project automatic data system

    NASA Technical Reports Server (NTRS)

    Harris, D. K.

    1979-01-01

    The program theory used to obtain the software package, MAIL LOG, developed for the Scout Project Automatic Data System, SPADS, is described. The program is written in FORTRAN for the PRIME 300 computer system. The MAIL LOG data base consists of three main subfiles: (1) incoming and outgoing mail correspondence; (2) design information releases and reports; and (3) drawings and engineering orders. All subroutine descriptions, flowcharts, and MAIL LOG outputs are given and the data base design is described.

  10. Constraints on cold dark matter theories from observations of massive x-ray-luminous clusters of galaxies at high redshift

    NASA Technical Reports Server (NTRS)

    Luppino, G. A.; Gioia, I. M.

    1995-01-01

    During the course of a gravitational lensing survey of distant, X-ray selected Einstein Observatory Extended Medium Sensitivity Survey (EMSS) clusters of galaxies, we have studied six X-ray-luminous (L(sub x) greater than 5 x 10(exp 44)(h(sub 50)(exp -2))ergs/sec) clusters at redshifts exceeding z = 0.5. All of these clusters are apparently massive. In addition to their high X-ray luminosity, two of the clusters at z approximately 0.6 exhibit gravitationally lensed arcs. Furthermore, the highest redshift cluster in our sample, MS 1054-0321 at z = 0.826, is both extremely X-ray luminous (L(sub 0.3-3.5keV)=9.3 x 10(exp 44)(h(sub 50)(exp -2))ergs/sec) and exceedingly rich with an optical richness comparable to an Abell Richness Class 4 cluster. In this Letter, we discuss the cosmological implications of the very existence of these clusters for hierarchical structure formation theories such as standard Omega = 1 CDM (cold dark matter), hybrid Omega = 1 C + HDM (hot dark matter), and flat, low-density Lambda + CDM models.

  11. Transforming gravity: From derivative couplings to matter to second-order scalar-tensor theories beyond the Horndeski Lagrangian

    NASA Astrophysics Data System (ADS)

    Zumalacárregui, Miguel; García-Bellido, Juan

    2014-03-01

    We study the structure of scalar-tensor theories of gravity based on derivative couplings between the scalar and the matter degrees of freedom introduced through an effective metric. Such interactions are classified by their tensor structure into conformal (scalar), disformal (vector), and extended disformal (traceless tensor), as well as by the derivative order of the scalar field. Relations limited to first derivatives of the field ensure second-order equations of motion in the Einstein frame and hence the absence of Ostrogradski ghost degrees of freedom. The existence of a mapping to the Jordan frame is not trivial in the general case, and can be addressed using the Jacobian of the frame transformation through its eigenvalues and eigentensors. These objects also appear in the study of different aspects of such theories, including the metric and field redefinition transformation of the path integral in the quantum mechanical description. Although second-order in the Einstein frame, generic disformally coupled theories are described by higher-order equations of motion in the Jordan frame. This apparent contradiction is solved by the use of a hidden constraint: the contraction of the metric equations with a Jacobian eigentensor provides a constraint relation for the higher field derivatives, which allows one to express the dynamical equations in a second-order form. This signals a loophole in Horndeski's theorem and allows one to enlarge the set of scalar-tensor theories which are Ostrogradski stable. The transformed Gauss-Bonnet terms are also discussed for the simplest conformal and disformal relations.

  12. An installed nacelle design code using a multiblock Euler solver. Volume 1: Theory document

    NASA Technical Reports Server (NTRS)

    Chen, H. C.

    1992-01-01

    An efficient multiblock Euler design code was developed for designing a nacelle installed on geometrically complex airplane configurations. This approach employed a design driver based on a direct iterative surface curvature method developed at LaRC. A general multiblock Euler flow solver was used for computing flow around complex geometries. The flow solver used a finite-volume formulation with explicit time-stepping to solve the Euler Equations. It used a multiblock version of the multigrid method to accelerate the convergence of the calculations. The design driver successively updated the surface geometry to reduce the difference between the computed and target pressure distributions. In the flow solver, the change in surface geometry was simulated by applying surface transpiration boundary conditions to avoid repeated grid generation during design iterations. Smoothness of the designed surface was ensured by alternate application of streamwise and circumferential smoothings. The capability and efficiency of the code was demonstrated through the design of both an isolated nacelle and an installed nacelle at various flow conditions. Information on the execution of the computer program is provided in volume 2.

  13. Coupled 2-dimensional cascade theory for noise an d unsteady aerodynamics of blade row interaction in turbofans. Volume 2: Documentation for computer code CUP2D

    NASA Technical Reports Server (NTRS)

    Hanson, Donald B.

    1994-01-01

    A two dimensional linear aeroacoustic theory for rotor/stator interaction with unsteady coupling was derived and explored in Volume 1 of this report. Computer program CUP2D has been written in FORTRAN embodying the theoretical equations. This volume (Volume 2) describes the structure of the code, installation and running, preparation of the input file, and interpretation of the output. A sample case is provided with printouts of the input and output. The source code is included with comments linking it closely to the theoretical equations in Volume 1.

  14. SOURCE SAMPLING FINE PARTICULATE MATTER: A KRAFT PROCESS RECOVERY BOILER AT A PULP AND PAPER FACILITY, VOLUMES 1 AND 2

    EPA Science Inventory

    Fine particulate matter of aerodynamic diameter 2.5 m or less (PM-2.5) has been found harmful to human health, and a National Ambient Air Quality Standard for PM-2.5 was promulgated by the U.S. Environmental Protection Agency in July 1997. A national network of ambient monitorin...

  15. Middle School Matters: Improving the Life Course of Black Boys. Policy Notes. Volume 20, Number 4, Winter 2012

    ERIC Educational Resources Information Center

    Yaffe, Deborah

    2012-01-01

    This issue of ETS Policy Notes (Vol. 20, No. 4) provides highlights from the symposium, "Middle School Matters: Improving the Life Course of Black Boys" held on July 23-24, 2012. The second in a series of four symposia co-sponsored by ETS and the Children's Defense Fund (CDF), the seminar examined the education and status of…

  16. Radiation Therapy After Breast-Conserving Surgery: Does Hospital Surgical Volume Matter? A Population-Based Study in Taiwan

    SciTech Connect

    Chien, Chun-Ru; Pan, I-Wen; Tsai, Yi-Wen; Tsai, Teressa; Liang, Ji-An; Buchholz, Thomas A.; Shih, Ya-Chen Tina

    2012-01-01

    Purpose: To examine the association between hospital surgical volume and the use of radiation therapy (RT) after breast-conserving surgery (BCS) in Taiwan. Methods and Materials: We used claims data from the National Health Insurance program in Taiwan (1997-2005) in this retrospective population-based study. We identified patients with breast cancer, receipt of BCS, use of radiation, and the factors that could potentially associated with the use of RT from enrollment records, and the ICD-9 and billing codes in claims. We conducted logistic regression to examine factors associated with RT use after BCS, and performed subgroup analyses to examine whether the association differs by medical center status or hospital volumes. Results: Among 5,094 patients with newly diagnosed invasive breast cancer who underwent BCS, the rate of RT was significantly lower in low-volume hospitals (74% vs. 82%, p < 0.01). Patients treated in low-volume hospitals were less likely to receive RT after BCS (odds ratio = 0.72, 95% confidence interval = 0.62-0.83). In addition, patients treated after the implementation of the voluntary pay-for-performance policy in 2001 were more likely to receive RT (odds ratio = 1.23; 95% confidence interval = 1.05-1.45). Subgroup analyses indicated that the high-volume effect was limited to hospitals accredited as non-medical centers, and that the effect of the pay-for-performance policy was most pronounced among low-volume hospitals. Conclusions: Using population-based data from Taiwan, our study concluded that hospital surgical volume and pay-for-performance policy are positively associated with RT use after BCS.

  17. Constraints on dark matter particles from theory, galaxy observations, and N-body simulations

    SciTech Connect

    Boyanovsky, D.; Vega, H. J. de; Sanchez, N. G.

    2008-02-15

    Mass bounds on dark matter (DM) candidates are obtained for particles that decouple in or out of equilibrium while ultrarelativistic with arbitrary isotropic and homogeneous distribution functions. A coarse grained Liouville invariant primordial phase-space density D is introduced which depends solely on the distribution function at decoupling. The density D is explicitly computed and combined with recent photometric and kinematic data on dwarf spheroidal satellite galaxies in the Milky Way (dShps) and the observed DM density today yielding upper and lower bounds on the mass, primordial phase-space densities, and velocity dispersion of the DM candidates. Combining these constraints with recent results from N-body simulations yields estimates for the mass of the DM particles in the range of a few keV. We establish in this way a direct connection between the microphysics of decoupling in or out of equilibrium and the constraints that the particles must fulfill to be suitable DM candidates. If chemical freeze-out occurs before thermal decoupling, light bosonic particles can Bose condense. We study such Bose-Einstein condensate (BEC) as a dark matter candidate. It is shown that, depending on the relation between the critical (T{sub c}) and decoupling (T{sub d}) temperatures, a BEC light relic could act as cold DM but the decoupling scale must be higher than the electroweak scale. The condensate hastens the onset of the nonrelativistic regime and tightens the upper bound on the particle's mass. A nonequilibrium scenario which describes particle production and partial thermalization, sterile neutrinos produced out of equilibrium, and other DM models is analyzed in detail and the respective bounds on mass, primordial phase-space density, and velocity dispersion are obtained. Thermal relics with m{approx}few keV that decouple when ultrarelativistic and sterile neutrinos produced resonantly or nonresonantly lead to a primordial phase-space density compatible with cored d

  18. A voxel-based morphometry (VBM) analysis of regional grey and white matter volume abnormalities within the speech production network of children who stutter

    PubMed Central

    Beal, Deryk S.; Gracco, Vincent L.; Brettschneider, Jane; Kroll, Robert M.; De Nil, Luc F.

    2012-01-01

    It is well documented that neuroanatomical differences exist between adults who stutter and their fluently speaking peers. Specifically, adults who stutter have been found to have more grey matter volume (GMV) in speech relevant regions including inferior frontal gyrus, insula and superior temporal gyrus (Beal et al., 2007; Song et al., 2007). Despite stuttering having its onset in childhood only one study has investigated the neuroanatomical differences between children who do and do not stutter. Chang et al. (2008) reported children who stutter had less GMV in the bilateral inferior frontal gyri and middle temporal gyrus relative to fluently speaking children. Thus it appears that children who stutter present with unique neuroanatomical abnormalities as compared to those of adults who stutter. In order to better understand the neuroanatomical correlates of stuttering earlier in its development, near the time of onset, we used voxel-based morphometry to examine volumetric differences between 11 children who stutter and 11 fluent children. Children who stutter had less GMV in the bilateral inferior frontal gyri and left putamen but more GMV in right Rolandic operculum and superior temporal gyrus relative to fluent children. Children who stutter also had less white matter volume bilaterally in the forceps minor of the corpus callosum. We discuss our findings of widespread anatomic abnormalities throughout the cortical network for speech motor control within the context of the speech motor skill limitations identified in people who stutter (Namasivayam and van Lieshout, 2008; Smits-Bandstra et al., 2006). PMID:23140891

  19. Regional grey matter volume and concentration in at-risk adolescents: Untangling associations with callous-unemotional traits and conduct disorder symptoms.

    PubMed

    Cohn, Moran D; Viding, Essi; McCrory, Eamon; Pape, Louise; van den Brink, Wim; Doreleijers, Theo A H; Veltman, Dick J; Popma, Arne

    2016-08-30

    Structural Magnetic Resonance Imaging studies have reported volume reductions in several brain regions implicated in social cognition and emotion recognition in juvenile antisocial populations. However, it is unclear whether these structural abnormalities are specifically related to antisocial features, or to co-occurring callous-unemotional (CU) traits. The present study employed voxel-based morphometry to assess both grey matter volume (GMV) and grey matter concentration (GMC) in a large representative at-risk sample of adolescents (n=134; mean age 17.7yr), characterized by a broad range of CU trait and conduct disorder (CD) symptom scores. There was a significant interaction between CD symptom and CU trait scores in the prediction of GMV in the anterior insula, with a significant positive association between CU traits and GMV in youth low on CD symptoms only. In addition, we found a significant unique positive association between CD symptoms and GMC in the amygdala, and unique negative associations between CU traits and GMC in the amygdala and insula. These findings are in line with accumulating evidence of distinct associations of CD symptoms and CU traits with amygdala and insula GMC in juvenile antisocial populations. PMID:27479922

  20. Nonlinear evolution of the matter power spectrum in modified theories of gravity

    SciTech Connect

    Koyama, Kazuya; Taruya, Atsushi; Hiramatsu, Takashi

    2009-06-15

    We present a formalism to calculate the nonlinear matter power spectrum in modified gravity models that explain the late-time acceleration of the Universe without dark energy. Any successful modified gravity models should contain a mechanism to recover general relativity (GR) on small scales in order to avoid the stringent constrains on deviations from GR at solar system scales. Based on our formalism, the quasi-nonlinear power spectrum in the Dvali-Gabadadze-Porratti braneworld models and f(R) gravity models are derived by taking into account the mechanism to recover GR properly. We also extrapolate our predictions to fully nonlinear scales using the parametrized post-Friedmann framework. In the Dvali-Gabadadze-Porratti and f(R) gravity models, the predicted nonlinear power spectrum is shown to reproduce N-body results. We find that the mechanism to recover GR suppresses the difference between the modified gravity models and dark energy models with the same expansion history, but the difference remains large at the weakly nonlinear regime in these models. Our formalism is applicable to a wide variety of modified gravity models and it is ready to use once consistent models for modified gravity are developed.

  1. Multi-instanton calculus in N=2 supersymmetric gauge theory. II. Coupling to matter

    NASA Astrophysics Data System (ADS)

    Dorey, Nicholas; Khoze, Valentin V.; Mattis, Michael P.

    1996-12-01

    We further discuss the N=2 superinstantons in SU(2) gauge theory, obtained from the general self-dual solutions of topological charge n constructed by Atiyah, Drinfeld, Hitchin, and Manin (ADHM). We realize the N=2 supersymmetry algebra as actions on the superinstanton moduli. This allows us to recast in concise superfield notation our previously obtained expression for the exact classical interaction between n ADHM superinstantons mediated by the adjoint Higgs bosons, and, moreover, to incorporate NF flavors of hypermultiplets. We perform explicit one- and two-instanton checks of the Seiberg-Witten prepotentials for all NF and arbitrary hypermultiplet masses. Our results for the low-energy couplings are all in precise agreement with the predictions of Seiberg and Witten except for NF=4, where we find a finite renormalization of the coupling which is absent in the proposed solution.

  2. Does habituation matter? Emotional processing theory and exposure therapy for acrophobia.

    PubMed

    Baker, Aaron; Mystkowski, Jayson; Culver, Najwa; Yi, Rena; Mortazavi, Arezou; Craske, Michelle G

    2010-11-01

    Clinically, there is wide subscription to emotional processing theory (EPT; Foa & Kozak, 1986) as a model of therapeutic effectiveness of exposure therapy: EPT purports that exposure is maximal when (1) fear is activated (IFA), (2) fear subsides within sessions (WSH), and (3) fear subsides between sessions (BSH). This study examined these assumptions, using in vivo exposure therapy for 44 students scoring high on acrophobia measures. Results indicated that no EPT variables were consistently predictive of treatment outcome. No support was found for IFA or WSH; measures of BSH were predictive of short-term change, but these effects were attenuated at follow-up. Furthermore, EPT variables were not predictive of each other as previously hypothesized, indicating the variables are not functionally related.

  3. STICAP: A linear circuit analysis program with stiff systems capability. Volume 1: Theory manual. [network analysis

    NASA Technical Reports Server (NTRS)

    Cooke, C. H.

    1975-01-01

    STICAP (Stiff Circuit Analysis Program) is a FORTRAN 4 computer program written for the CDC-6400-6600 computer series and SCOPE 3.0 operating system. It provides the circuit analyst a tool for automatically computing the transient responses and frequency responses of large linear time invariant networks, both stiff and nonstiff (algorithms and numerical integration techniques are described). The circuit description and user's program input language is engineer-oriented, making simple the task of using the program. Engineering theories underlying STICAP are examined. A user's manual is included which explains user interaction with the program and gives results of typical circuit design applications. Also, the program structure from a systems programmer's viewpoint is depicted and flow charts and other software documentation are given.

  4. SCDAP/RELAP5/MOD 3.1 code manual: Interface theory. Volume 1

    SciTech Connect

    Coryell, E.W.; Allison, C.M.; Berna, G.A.

    1995-06-01

    The SCDAP/RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during a severe accident. The code models the coupled behavior of the reactor coolant system, core, fission product released during a severe accident transient as well as large and small break loss of coolant accidents, operational transients such as anticipated transient without SCRAM, loss of off-site power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits as much of a particular system to be modeled as necessary. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater conditioning systems. This volume describes the organization and manner of the interface between severe accident models which are resident in the SCDAP portion of the code and hydrodynamic models which are resident in the RELAP5 portion of the code. A description of the organization and structure of SCDAP/RELAP5 is presented. Additional information is provided regarding the manner in which models in one portion of the code impact other parts of the code, and models which are dependent on and derive information from other subcodes.

  5. SCDAP/RELAP5/MOD 3.1 code manual: Damage progression model theory. Volume 2

    SciTech Connect

    Davis, K.L.; Allison, C.M.; Berna, G.A.

    1995-06-01

    The SCDAP/RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during a severe accident. The code models the coupled behavior of the reactor coolant system, the core, fission products released during a severe accident transient as well as large and small break loss of coolant accidents, operational transients such as anticipated transient without SCRAM, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits as much of a particular system to be modeled as necessary. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater conditioning systems. This volume contains detailed descriptions of the severe accident models and correlations. It provides the user with the underlying assumptions and simplifications used to generate and implement the basic equations into the code, so an intelligent assessment of the applicability and accuracy of the resulting calculation can be made.

  6. Tap density equations of granular powders based on the rate process theory and the free volume concept.

    PubMed

    Hao, Tian

    2015-02-28

    The tap density of a granular powder is often linked to the flowability via the Carr index that measures how tight a powder can be packed, under an assumption that more easily packed powders usually flow poorly. Understanding how particles are packed is important for revealing why a powder flows better than others. There are two types of empirical equations that were proposed to fit the experimental data of packing fractions vs. numbers of taps in the literature: the inverse logarithmic and the stretched exponential. Using the rate process theory and the free volume concept under the assumption that particles will obey similar thermodynamic laws during the tapping process if the "granular temperature" is defined in a different way, we obtain the tap density equations, and they are reducible to the two empirical equations currently widely used in literature. Our equations could potentially fit experimental data better with an additional adjustable parameter. The tapping amplitude and frequency, the weight of the granular materials, and the environmental temperature are grouped into this parameter that weighs the pace of the packing process. The current results, in conjunction with our previous findings, may imply that both "dry" (granular) and "wet" (colloidal and polymeric) particle systems are governed by the same physical mechanisms in term of the role of the free volume and how particles behave (a rate controlled process).

  7. Tap density equations of granular powders based on the rate process theory and the free volume concept.

    PubMed

    Hao, Tian

    2015-02-28

    The tap density of a granular powder is often linked to the flowability via the Carr index that measures how tight a powder can be packed, under an assumption that more easily packed powders usually flow poorly. Understanding how particles are packed is important for revealing why a powder flows better than others. There are two types of empirical equations that were proposed to fit the experimental data of packing fractions vs. numbers of taps in the literature: the inverse logarithmic and the stretched exponential. Using the rate process theory and the free volume concept under the assumption that particles will obey similar thermodynamic laws during the tapping process if the "granular temperature" is defined in a different way, we obtain the tap density equations, and they are reducible to the two empirical equations currently widely used in literature. Our equations could potentially fit experimental data better with an additional adjustable parameter. The tapping amplitude and frequency, the weight of the granular materials, and the environmental temperature are grouped into this parameter that weighs the pace of the packing process. The current results, in conjunction with our previous findings, may imply that both "dry" (granular) and "wet" (colloidal and polymeric) particle systems are governed by the same physical mechanisms in term of the role of the free volume and how particles behave (a rate controlled process). PMID:25589375

  8. Impact of the volume change on the ageing effects in Cu-Al-Ni martensite: experiment and theory.

    PubMed

    Kosogor, Anna; Xue, Dezhen; Zhou, Yumei; Ding, Xiangdong; Otsuka, Kazuhiro; L'vov, Victor A; Sun, Jun; Ren, Xiaobing

    2013-08-21

    The time evolution of the physical properties of martensite during martensite ageing is traditionally explained by the symmetry-conforming short-range order (SC-SRO) principle, which requires the spatial configuration of crystal defects to follow the symmetry change of the host lattice. In the present study, we show that the volume change of the host lattice also contributes to the ageing effects in Cu-Al-Ni shape memory alloy besides the symmetry change. To substantiate this statement the gradual increase of the storage modulus with time at constant temperature was measured by dynamic mechanical analysis (DMA) and the experimental results were quantitatively described in the framework of the symmetry-conforming Landau theory of martensitic transformations in a crystal with defects. The comparison of experimental and theoretical results confirmed that the time dependence of the storage modulus is caused by two different physical mechanisms. Evaluations showing that the first mechanism is driven by the spontaneous symmetry change and the second mechanism is caused by the volume change after the martensitic transformation was carried out.

  9. Becoming a Teacher: Using Narrative as Reflective Practice. A Cross-Disciplinary Approach. Counterpoints: Studies in the Postmodern Theory of Education. Volume 411

    ERIC Educational Resources Information Center

    Blake, Robert W., Jr., Ed.; Blake, Brett Elizabeth, Ed.

    2012-01-01

    "Becoming a Teacher" revisits the concept of Teacher Lore (Schubert and Ayers, 1992), by providing a cross-disciplinary approach linking elements of narrative theory to all aspects of pre- and in-service teaching. In essence, it embraces the notion that what teachers say matters. The rationale behind this text is the idea that narrative can not…

  10. Effect of Alzheimer's Disease Risk Variant rs3824968 at SORL1 on Regional Gray Matter Volume and Age-Related Interaction in Adult Lifespan

    PubMed Central

    Huang, Chu-Chung; Liu, Mu-En; Kao, Hung-Wen; Chou, Kun-Hsien; Yang, Albert C.; Wang, Ying-Hsiu; Chen, Tong-Ru; Tsai, Shih-Jen; Lin, Ching-Po

    2016-01-01

    Sortilin receptor 1 (SORL1) is involved in cellular trafficking of amyloid precursor protein and plays an essential role in amyloid-beta peptide generation in Alzheimer disease (AD). The major A allele in a SORL1 single nucleotide polymorphism (SNP), rs3824968, is associated with an increased AD risk. However, the role of SORL1 rs3824968 in the normal ageing process has rarely been examined in relation to brain structural morphology. This study investigated the association between SORL1 rs3824968 and grey matter (GM) volume in a nondemented Chinese population of 318 adults within a wide age range (21–92 years). Through voxel-based morphometry, we found that participants carrying SORL1 allele A exhibited significantly smaller GM volumes in the right posterior cingulate, left middle occipital, medial frontal, and superior temporal gyri. Considerable interaction between age and SORL1 suggested a detrimental and accelerated ageing effect of allele A on putamen. These findings provide evidence that SORL1 rs3824968 modulates regional GM volume and is associated with brain trajectory during the adult lifespan. PMID:26996954

  11. Does Accuracy Matter? the Role of Approximations in Geophysical Inverse Theory

    NASA Astrophysics Data System (ADS)

    Valentine, A. P.; Trampert, J.

    2014-12-01

    In recent years, the computational techniques and resources available to geophysicists have advanced enormously: for many geophysical problems, physically-complete simulations are now feasible. Nevertheless, the computational costs remain daunting, encouraging the development of various hybrid inversion schemes that combine fully-accurate modelling techniques with those based upon various approximations. These are argued to give more accurate results than those based solely on approximate techniques, but at much lower cost than would be required if full simulations were conducted throughout.While these arguments are superficially attractive, we do not believe that they have yet been fully justified within the framework of inverse theory. It is therefore important to investigate how modelling approximations propagate into the solutions to inverse problems. Understanding this will enable us to develop algorithms that optimally balance accuracy with efficiency, and will aid the interpretation of models produced by hybrid techniques.We present results from mathematical and experimental analysis of geophysical inverse problems, focussing particularly on the framework of the least squares algorithm. We suggest that the efficacy of hybrid approaches depends significantly upon the particular approximations used, and on the character of their manifestation in the data. The interaction between approximations and regularisation is also important for both convergence and accuracy.

  12. Density-functional-theory calculations of matter in strong magnetic fields. I. Atoms and molecules

    NASA Astrophysics Data System (ADS)

    Medin, Zach; Lai, Dong

    2006-12-01

    We present calculations of the electronic structure of various atoms and molecules in strong magnetic fields ranging from B=1012Gto2×1015G , appropriate for radio pulsars and magnetars. For these field strengths, the magnetic forces on the electrons dominate over the Coulomb forces, and to a good approximation the electrons are confined to the ground Landau level. Our calculations are based on the density functional theory, and use a local magnetic exchange-correlation function which is tested to be reliable in the strong field regime. Numerical results of the ground-state energies are given for HN (up to N=10 ), HeN (up to N=8 ), CN (up to N=5 ), and FeN (up to N=3 ), as well as for various ionized atoms. Fitting formulae for the B dependence of the energies are also given. In general, as N increases, the binding energy per atom in a molecule, ∣EN∣/N , increases and approaches a constant value. For all the field strengths considered in this paper, hydrogen, helium, and carbon molecules are found to be bound relative to individual atoms (although for B less than a few ×1012G , carbon molecules are very weakly bound relative to individual atoms). Iron molecules are not bound at B≲1013G , but become energetically more favorable than individual atoms at larger field strengths.

  13. Convergent evidence of the contribution of TP53 genetic variation (Pro72Arg) to metabolic activity and white matter volume in the frontal lobe in schizophrenia patients.

    PubMed

    Molina, Vicente; Papiol, Sergi; Sanz, Javier; Rosa, Araceli; Arias, Bárbara; Fatjó-Vilas, Mar; Calama, Julia; Hernández, Ana I; Bécker, Joemir; Fañanás, Lourdes

    2011-05-01

    Abnormalities in white matter (WM) volumes and integrity in schizophrenia, together with post-mortem studies showing reduced expression of oligodendrocyte/myelination genes and apoptotic processes taking place in oligodendrocytes, suggest the interest of major regulators of apoptosis as candidate genes for some features related to myelin integrity in schizophrenia. Protein p53, encoded by TP53 gene, has a central role in the control of apoptosis and is involved in oligodendrocyte development. TP53 gene polymorphisms may account for variability in WM features, metabolic activity and biochemical markers of neuronal integrity and membrane turnover. Pro72Arg and Ins16bp polymorphisms at TP53 gene were analyzed in 20 DSM-IV schizophrenia patients. T1/T2-weighted sequences of these patients were acquired using a 1.5T Philips Gyroscan system. Scans were transformed into Talairach space and segmented into gray matter (GM), WM and cerebrospinal fluid (CSF) using Statistical Parametric Mapping under a ROI approach. Likewise dorsolateral prefrontal cortex (DLPFC) metabolic activity was measured using a procedure based on MRI/PET image fusion. In 13 of these patients proton magnetic resonance spectroscopy was used to examine N-acetylaspartate (NAA), creatine (Cr) and choline (Cho) levels in dorsolateral-medial prefrontal cortex (DLMPFC). MRI data were adjusted for age and brain volume using regression parameters from a healthy control group (n=45). Patients Pro/Arg heterozygous (Pro72Arg polymorphism) showed a generalized deficit in whole-brain WM that was especially prominent in frontal lobe and a lower metabolic activity in the DLPFC as compared to Pro/Pro homozygous. Pro/Arg subjects also showed decreased NAA/Cho and increased Cho/Cr ratios in right DLMPFC. TP53 genetic variability influences WM volumes in frontal lobes and it seems to modulate the metabolic activity in this region. Our results suggest that TP53 might influence aspects of myelin and white matter integrity

  14. A pilot study of gray matter volume changes associated with paroxetine treatment and response in social anxiety disorder.

    PubMed

    Talati, Ardesheer; Pantazatos, Spiro P; Hirsch, Joy; Schneier, Franklin

    2015-03-30

    Social anxiety disorder (SAD) has received relatively little attention in neurobiological studies. We sought to identify neuro-anatomical changes associated with successful treatment for the disorder. Fourteen patients (31 years; 57% female) with DSM-IV generalized SAD were imaged before and after 8-weeks of paroxetine treatment on a 1.5 T GE Signa MRI scanner. Symptoms were assessed by a clinician using the Liebowitz Social Anxiety Scale (LSAS). Longitudinal changes in voxel based morphometry (VBM) were determined using the VBM8 Toolbox for SPM8. Symptom severity decreased by 46% following treatment (p<0.001). At week 8, significant gray matter reductions were detected in bilateral caudate and putamen, and right thalamus, and increases in the cerebellum. Gray matter decreases in left thalamus were correlated with clinical response. This is the first study to our knowledge to identify treatment related correlates of symptom improvement for SAD. Replication in larger samples with control groups is needed to confirm these findings, as well as to test their specificity and temporal stability.

  15. Coupled 2-dimensional cascade theory for noise and unsteady aerodynamics of blade row interaction in turbofans. Volume 1: Theory development and parametric studies

    NASA Technical Reports Server (NTRS)

    Hanson, Donald B.

    1994-01-01

    Typical analytical models for interaction between rotor and stator in a turbofan analyze the effect of wakes from the rotor impinging on the stator, producing unsteady loading, and thereby generating noise. Reflection/transmission characteristics of the rotor are sometimes added in a separate calculation. In those models, there is a one-to-one relationship between wake harmonics and noise harmonics; that is, the BPF (blade passing frequency) wake harmonic causes only the BPF noise harmonic, etc. This report presents a more complete model in which flow tangency boundary conditions are satisfied on two cascades in relative motion for several harmonics simultaneously. By an extension of S.N. Smith's code for two dimensional flat plate cascades, the noise generation/frequency scattering/blade row reflection problem is solved in a single matrix inversion. It is found that the BPF harmonic excitation of the stator scatters considerable energy in the higher BPF harmonics due to relative motion between the blade rows. Furthermore, when swirl between the rotor and stator is modeled, a 'mode trapping' effect occurs which explains observations on fans operating at rotational speeds below BFP cuton: the BPF mode amplifies between blade rows by multiple reflections but cannot escape to the inlet and exit ducts. However, energy scattered into higher harmonics does propagate and dominates the spectrum at two and three times BPF. This report presents the complete derivation of the theory, comparison with a previous (more limited) coupled rotor/stator interaction theory due to Kaji and Okazaki, exploration of the mode trapping phenomenon, and parametric studies showing the effects of vane/blade ratio and rotor/stator interaction. For generality, the analysis applies to stages where the rotor is either upstream or downstream of the stator and to counter rotation stages. The theory has been coded in a FORTRAN program called CUP2D, documented in Volume 2 of this report. It is

  16. General U(1)×U(1) F-theory compactifications and beyond: geometry of unHiggsings and novel matter structure

    NASA Astrophysics Data System (ADS)

    Cvetič, Mirjam; Klevers, Denis; Piragua, Hernan; Taylor, Washington

    2015-11-01

    We construct the general form of an F-theory compactification with two U(1) factors based on a general elliptically fibered Calabi-Yau manifold with Mordell-Weil group of rank two. This construction produces broad classes of models with diverse matter spectra, including many that are not realized in earlier F-theory constructions with U(1)×U(1) gauge symmetry. Generic U(1)×U(1) models can be related to a Higgsed non-Abelian model with gauge group SU(2)×SU(2)×SU(3), SU(2)3×SU(3), or a subgroup thereof. The nonlocal horizontal divisors of the Mordell-Weil group are replaced with local vertical divisors associated with the Cartan generators of non-Abelian gauge groups from Kodaira singularities. We give a global resolution of codimension two singularities of the Abelian model; we identify the full anomaly free matter content, and match it to the unHiggsed non-Abelian model. The non-Abelian Weierstrass model exhibits a new algebraic description of the singularities in the fibration that results in the first explicit construction of matter in the symmetric representation of SU(3). This matter is realized on double point singularities of the discriminant locus. The construction suggests a generalization to U(1) k factors with k > 2, which can be studied by Higgsing theories with larger non-Abelian gauge groups.

  17. A voxel-based morphometry (VBM) analysis of regional grey and white matter volume abnormalities within the speech production network of children who stutter.

    PubMed

    Beal, Deryk S; Gracco, Vincent L; Brettschneider, Jane; Kroll, Robert M; De Nil, Luc F

    2013-09-01

    It is well documented that neuroanatomical differences exist between adults who stutter and their fluently speaking peers. Specifically, adults who stutter have been found to have more grey matter volume (GMV) in speech relevant regions including inferior frontal gyrus, insula and superior temporal gyrus (Beal et al., 2007; Song et al., 2007). Despite stuttering having its onset in childhood only one study has investigated the neuroanatomical differences between children who do and do not stutter. Chang et al. (2008) reported children who stutter had less GMV in the bilateral inferior frontal gyri and middle temporal gyrus relative to fluently speaking children. Thus it appears that children who stutter present with unique neuroanatomical abnormalities as compared to those of adults who stutter. In order to better understand the neuroanatomical correlates of stuttering earlier in its development, near the time of onset, we used voxel-based morphometry to examine volumetric differences between 11 children who stutter and 11 fluent children. Children who stutter had less GMV in the bilateral inferior frontal gyri and left putamen but more GMV in right Rolandic operculum and superior temporal gyrus relative to fluent children. Children who stutter also had less white matter volume bilaterally in the forceps minor of the