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Sample records for matter theories volume

  1. Condensed Matter Theories: Volume 25

    NASA Astrophysics Data System (ADS)

    Ludeña, Eduardo V.; Bishop, Raymond F.; Iza, Peter

    2011-03-01

    pt. A. Fermi and Bose fluids, exotic systems. Reemergence of the collective mode in [symbol]He and electron layers / H. M. Bohm ... [et al.]. Dissecting and testing collective and topological scenarios for the quantum critical point / J. W. Clark, V. A. Khodel and M. V. Zverev. Helium on nanopatterned surfaces at finite temperature / E. S. Hernandez ... [et al.]. Towards DFT calculations of metal clusters in quantum fluid matrices / S. A. Chin ... [et al.]. Acoustic band gap formation in metamaterials / D. P. Elford ... [et al.]. Dissipative processes in low density strongly interacting 2D electron systems / D. Neilson. Dynamical spatially resolved response function of finite 1-D nano plasmas / T. Raitza, H. Reinholz and G. Ropke. Renormalized bosons and fermions / K. A. Gernoth and M. L. Ristig. Light clusters in nuclear matter / G. Ropke -- pt. B. Quantum magnets, quantum dynamics and phase transitions. Magnetic ordering of antiferromagnets on a spatially anisotropic triangular lattice / R. F. Bishop ... [et al.]. Thermodynamic detection of quantum phase transitions / M. K. G. Kruse ... [et al.]. The SU(2) semi quantum systems dynamics and thermodynamics / C. M. Sarris and A. N. Proto -- pt. C. Physics of nanosystems and nanotechnology. Quasi-one dimensional fluids that exhibit higher dimensional behavior / S. M. Gatica ... [et al.]. Spectral properties of molecular oligomers. A non-Markovian quantum state diffusion approach / J. Roden, W. T. Strunz and A. Eisfeld. Quantum properties in transport through nanoscopic rings: Charge-spin separation and interference effects / K. Hallberg, J. Rincon and S. Ramasesha. Cooperative localization-delocalization in the high T[symbol] cuprates / J. Ranninger. Thermodynamically stable vortex states in superconducting nanowires / W. M. Wu, M. B. Sobnack and F. V. Kusmartsev.pt. D. Quantum information. Quantum information in optical lattices / A. M. Guzman and M. A. Duenas E. -- pt. E. Theory and applications of molecular

  2. 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

  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. 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…

  5. 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. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  6. Theory of mind skills are related to gray matter volume in the ventromedial prefrontal cortex in schizophrenia

    PubMed Central

    Hooker, Christine I.; Bruce, Lori; Lincoln, Sarah Hope; Fisher, Melissa; Vinogradov, Sophia

    2011-01-01

    Background Among individuals with schizophrenia, deficits in theory of mind (ToM) skills predict poor social functioning. Therefore, identifying the neural basis of ToM may assist the development of treatments that improve social outcomes. Despite growing evidence that the ventromedial prefrontal cortex (VMPFC) facilitates ToM skills among healthy individuals, methodological challenges, such as the influence of general cognitive deficits, have made it difficult to identify the relationship between ToM processing and VMPFC function in schizophrenia. Methods We used voxel-based morphometry (VBM) and a multi-method behavioral assessment of ToM processing, including performance-based (Recognition of Faux Pas Test), self-report (Interpersonal Reactivity Index, Perspective-Taking), and interview-rated (Quality of Life Scale–Empathy score) ToM assessments, to investigate whether ToM skills were related to VMPFC gray matter volume (GMV). Standardized neuropsychological measures were used to assess global cognition. 21 schizophrenia and 17 healthy control subjects participated. Results Between-group behavioral analyses showed that, as compared to healthy participants, schizophrenia participants had worse ToM performance and lower self-reported ToM processing in daily life. The between-group analysis of GMV showed that schizophrenia participants had less VMPFC GMV than healthy participants. Moreover, among schizophrenia participants, all three measures of ToM processing were associated with VMPFC GMV, such that worse ToM skills were related to less VMPFC GMV. This association remained strong for self-reported and interview-rated ToM skills even when controlling for the influence of global cognition. Conclusions The findings suggest that among individuals with schizophrenia, reduced VMPFC GMV is specifically associated with deficits using ToM skills to enhance social relationships. PMID:21917239

  7. Theory of mind skills are related to gray matter volume in the ventromedial prefrontal cortex in schizophrenia.

    PubMed

    Hooker, Christine I; Bruce, Lori; Lincoln, Sarah Hope; Fisher, Melissa; Vinogradov, Sophia

    2011-12-15

    Among individuals with schizophrenia, deficits in theory of mind (ToM) skills predict poor social functioning. Therefore, identifying the neural basis of ToM may assist the development of treatments that improve social outcomes. Despite growing evidence that the ventromedial prefrontal cortex (VMPFC) facilitates ToM skills among healthy individuals, methodological challenges, such as the influence of general cognitive deficits, have made it difficult to identify the relationship between ToM processing and VMPFC function in schizophrenia. We used voxel-based morphometry and a multi-method behavioral assessment of ToM processing, including performance-based (Recognition of Faux Pas Test), self-report (Interpersonal Reactivity Index, Perspective-Taking), and interview-rated (Quality of Life Scale-Empathy score) ToM assessments, to investigate whether ToM skills were related to VMPFC gray matter volume (GMV). Standardized neuropsychological measures were used to assess global cognition. Twenty-one schizophrenia and 17 healthy control subjects participated. Between-group behavioral analyses showed that, as compared with healthy participants, schizophrenia participants had worse ToM performance and lower self-reported ToM processing in daily life. The between-group analysis of GMV showed that schizophrenia participants had less VMPFC GMV than healthy participants. Moreover, among schizophrenia participants, all three measures of ToM processing were associated with VMPFC GMV, such that worse ToM skills were related to less VMPFC GMV. This association remained strong for self-reported and interview-rated ToM skills, even when controlling for the influence of global cognition. The findings suggest that among individuals with schizophrenia, reduced VMPFC GMV is associated with deficits using ToM skills to enhance social relationships. 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  8. Why Matter Occupies so Large a Volume?

    NASA Astrophysics Data System (ADS)

    E. B., Manoukian

    2013-12-01

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

  9. 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)

  10. 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)

  11. 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.

  12. 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…

  13. 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…

  14. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. 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

  16. Variational theory of hot dense matter

    NASA Astrophysics Data System (ADS)

    Mukherjee, Abhishek

    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 correlation operators. The present approach uses microcanonical ensembles and the variational principle obeyed by the free energy. We show that the correlated states of the microcanonical ensemble at a given temperature T and density r can be orthonormalized preserving their diagonal matrix elements of the Hamiltonian. This allows for the minimization of the free energy without corrections from the nonorthogonality of the correlated basis states, similar to that of the ground state energy. Samples of the microcanonical ensemble can be used to study the response, and the neutrino luminosities and opacities of hot matter. We present methods to orthonormalize the correlated states that contribute to the response of hot matter. We apply this variational theory to symmetric nuclear matter and pure neutron matter. This extension generalizes to finite temperatures, the many body technique used in the construction of the zero temperature Akmal-Pandharipande-Ravenhall equation of state. We discuss how the formalism can be used for practical calculations of hot dense matter. Our calculations are a significant improvement over the previous calculation due to Friedman and Pandharipande. The Hamiltonian contains modern realistic two nucleon and three nucleon interactions along with relativistic boost corrections. Expectation values of various operators, including the Hamiltonian, are calculated using cluster expansion and chain summation techniques. The pair correlation operator is now calculated at every density and temperature. Neutral pion condensation along with the associated isovector spin longitudinal sum rule is analyzed. The equation

  17. Effective theory for electroweak doublet dark matter

    NASA Astrophysics Data System (ADS)

    Dedes, A.; Karamitros, D.; Spanos, V. C.

    2016-11-01

    We perform a detailed study of an effective field theory which includes the standard model particle content extended by a pair of Weyl fermionic SU(2) doublets with opposite hypercharges. A discrete symmetry guarantees that a linear combination of the doublet components is stable and can act as a candidate particle for dark matter. The dark sector fermions interact with the Higgs and gauge bosons through renormalizable d =4 operators, and nonrenormalizable d =5 operators that appear after integrating out extra degrees of freedom above the TeV scale. We study collider, cosmological and astrophysical probes for this effective theory of dark matter. We find that a weakly interacting dark matter particle with a mass nearby the electroweak scale, and thus observable at the LHC, is consistent with collider and astrophysical data only when fairly large magnetic dipole moment transition operators with the gauge bosons exist, together with moderate Yukawa interactions.

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

    NASA Astrophysics Data System (ADS)

    Ünsal, Mithat; Yaffe, Laurence G.

    2010-08-01

    Consequences of large N volume independence are examined in conformal and confining gauge theories. In the large N limit, gauge theories compactified on {mathbb{R}^{d - k}} × {left( {{S^1}} right)^k} are independent of the S 1 radii, provided the theory has unbroken center symmetry. In particular, this implies that a large N gauge theory which, on {mathbb{R}^d} , flowstoan IR fixed point, retains the infinite correlation length and other scale invariant properties of the decompactified theory even when compactified on {mathbb{R}^{d - k}} × {left( {{S^1}} right)^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 mathcal{N} = 4 supersymmetric Yang-Mills theory, the center symmetry realization is a matter of choice: the theory on {mathbb{R}^{4 - k}} × {left( {{S^1}} right)^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.

  19. 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.

  20. 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.

  1. Size matters: cerebral volume influences sex differences in neuroanatomy.

    PubMed

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

    2008-12-01

    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.

  2. 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

  3. 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…

  4. 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…

  5. Theory of coherent van der Waals matter.

    PubMed

    Kulić, Igor M; Kulić, Miodrag L

    2014-12-01

    We explain in depth the previously proposed theory of the coherent van der Waals (cvdW) interaction, the counterpart of van der Waals (vdW) force, emerging in spatially coherently fluctuating electromagnetic fields. We show that cvdW driven matter is dominated by many-body interactions, which are significantly stronger than those found in standard van der Waals (vdW) systems. Remarkably, the leading two- and three-body interactions are of the same order with respect to the distance (∝R(-6)), in contrast to the usually weak vdW three-body effects (∝R(-9)). From a microscopic theory we show that the anisotropic cvdW many-body interactions drive the formation of low-dimensional structures such as chains, membranes, and vesicles with very unusual, nonlocal properties. In particular, cvdW chains display a logarithmically growing stiffness with the chain length, while cvdW membranes have a bending modulus growing linearly with their size. We argue that the cvdW anisotropic many-body forces cause local cohesion but also a negative effective "surface tension." We conclude by deriving the equation of state for cvdW materials and propose experiments to test the theory, in particular the unusual three-body nature of cvdW.

  6. Theory of coherent van der Waals matter

    NASA Astrophysics Data System (ADS)

    Kulić, Igor M.; Kulić, Miodrag L.

    2014-12-01

    We explain in depth the previously proposed theory of the coherent van der Waals (cvdW) interaction, the counterpart of van der Waals (vdW) force, emerging in spatially coherently fluctuating electromagnetic fields. We show that cvdW driven matter is dominated by many-body interactions, which are significantly stronger than those found in standard van der Waals (vdW) systems. Remarkably, the leading two- and three-body interactions are of the same order with respect to the distance (∝R-6) , in contrast to the usually weak vdW three-body effects (∝R-9 ). From a microscopic theory we show that the anisotropic cvdW many-body interactions drive the formation of low-dimensional structures such as chains, membranes, and vesicles with very unusual, nonlocal properties. In particular, cvdW chains display a logarithmically growing stiffness with the chain length, while cvdW membranes have a bending modulus growing linearly with their size. We argue that the cvdW anisotropic many-body forces cause local cohesion but also a negative effective "surface tension." We conclude by deriving the equation of state for cvdW materials and propose experiments to test the theory, in particular the unusual three-body nature of cvdW.

  7. 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.

  8. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Regional White Matter Volumes Correlate with Delay Discounting

    PubMed Central

    Yu, Rongjun

    2012-01-01

    A preference for immediate gratification is a central feature in addictive processes. However, the neural structures underlying reward delay tolerance are still unclear. Healthy participants (n = 121) completed a delay discounting questionnaire assessing the extent to which they prefer smaller immediate rewards to larger delayed reward after undergoing magnetic resonance imaging (MRI) scanning. Whole brain voxel-based morphometric analysis shows that delay discounting severity was negatively correlated with right prefrontal subgyral white matter volume and positively correlated with white matter volume in parahippocampus/hippocampus, after whole brain correction. This study might better our understanding of the neural basis of impulsivity and addiction. PMID:22393420

  10. MR volume segmentation of gray matter and white matter using manual thresholding: Dependence on image brightness

    SciTech Connect

    Harris, G.J.; Barta, P.E.; Peng, L.W.; Lee, S.; Brettschneider, P.D.; Shah, A.; Henderer, J.D.; Schlaepfer, T.E.; Pearlson, G.D. Tufts Univ. School of Medicine, Boston, MA )

    1994-02-01

    To describe a quantitative MR imaging segmentation method for determination of the volume of cerebrospinal fluid, gray matter, and white matter in living human brain, and to determine the method's reliability. We developed a computer method that allows rapid, user-friendly determination of cerebrospinal fluid, gray matter, and white matter volumes in a reliable manner, both globally and regionally. This method was applied to a large control population (N = 57). Initially, image brightness had a strong correlation with the gray-white ratio (r = .78). Bright images tended to overestimate, dim images to underestimate gray matter volumes. This artifact was corrected for by offsetting each image to an approximately equal brightness. After brightness correction, gray-white ratio was correlated with age (r = -.35). The age-dependent gray-white ratio was similar to that for the same age range in a prior neuropathology report. Interrater reliability was high (.93 intraclass correlation coefficient). The method described here for gray matter, white matter, and cerebrospinal fluid volume calculation is reliable and valid. A correction method for an artifact related to image brightness was developed. 12 refs., 3 figs.

  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. Chronic Kidney Disease Is Associated With White Matter Hyperintensity Volume

    PubMed Central

    Khatri, Minesh; Wright, Clinton B.; Nickolas, Thomas L.; Yoshita, Mitsuhiro; Paik, Myunghee C.; Kranwinkel, Grace; Sacco, Ralph L.; DeCarli, Charles

    2010-01-01

    Background and Purpose White matter hyperintensities have been associated with increased risk of stroke, cognitive decline, and dementia. Chronic kidney disease is a risk factor for vascular disease and has been associated with inflammation and endothelial dysfunction, which have been implicated in the pathogenesis of white matter hyperintensities. Few studies have explored the relationship between chronic kidney disease and white matter hyperintensities. Methods The Northern Manhattan Study is a prospective, community-based cohort of which a subset of stroke-free participants underwent MRIs. MRIs were analyzed quantitatively for white matter hyperintensities volume, which was log-transformed to yield a normal distribution (log-white matter hyperintensity volume). Kidney function was modeled using serum creatinine, the Cockcroft-Gault formula for creatinine clearance, and the Modification of Diet in Renal Disease formula for estimated glomerular filtration rate. Creatinine clearance and estimated glomerular filtration rate were trichotomized to 15 to 60 mL/min, 60 to 90 mL/min, and >90 mL/min (reference). Linear regression was used to measure the association between kidney function and log-white matter hyperintensity volume adjusting for age, gender, race–ethnicity, education, cardiac disease, diabetes, homocysteine, and hypertension. Results Baseline data were available on 615 subjects (mean age 70 years, 60% women, 18% whites, 21% blacks, 62% Hispanics). In multivariate analysis, creatinine clearance 15 to 60 mL/min was associated with increased log-white matter hyperintensity volume (β 0.322; 95% CI, 0.095 to 0.550) as was estimated glomerular filtration rate 15 to 60 mL/min (β 0.322; 95% CI, 0.080 to 0.564). Serum creatinine, per 1-mg/dL increase, was also positively associated with log-white matter hyperintensity volume (β 1.479; 95% CI, 1.067 to 2.050). Conclusions The association between moderate–severe chronic kidney disease and white matter

  13. Coronary heart disease and cortical thickness, gray matter and white matter lesion volumes on MRI.

    PubMed

    Vuorinen, Miika; Damangir, Soheil; Niskanen, Eini; Miralbell, Julia; Rusanen, Minna; Spulber, Gabriela; Soininen, Hilkka; Kivipelto, Miia; Solomon, Alina

    2014-01-01

    Coronary heart disease (CHD) has been linked with cognitive decline and dementia in several studies. CHD is strongly associated with blood pressure, but it is not clear how blood pressure levels or changes in blood pressure over time affect the relation between CHD and dementia-related pathology. The aim of this study was to investigate relations between CHD and cortical thickness, gray matter volume and white matter lesion (WML) volume on MRI, considering CHD duration and blood pressure levels from midlife to three decades later. The study population included 69 elderly at risk of dementia who participated in the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study. CAIDE participants were examined in midlife, re-examined 21 years later, and then after additionally 7 years (in total up to 30 years follow-up). MRIs from the second re-examination were used to calculate cortical thickness, gray matter and WML volume. CHD diagnoses were obtained from the Finnish Hospital Discharge Register. Linear regression analyses were adjusted for age, sex, follow-up time and scanner type, and additionally total intracranial volume in GM volume analyses. Adding diabetes, cholesterol or smoking to the models did not influence the results. CHD was associated with lower thickness in multiple regions, and lower total gray matter volume, particularly in people with longer disease duration (>10 years). Associations between CHD, cortical thickness and gray matter volume were strongest in people with CHD and hypertension in midlife, and those with CHD and declining blood pressure after midlife. No association was found between CHD and WML volumes. Based on these results, long-term CHD seems to have detrimental effects on brain gray matter tissue, and these effects are influenced by blood pressure levels and their changes over time.

  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. SUPERSYMMETRIC INSTANTON CALCULUS: Gauge theories with matter

    NASA Astrophysics Data System (ADS)

    Novikov, V. A.; Shifman, M. A.; Vainshtein, A. I.; Zakharov, V. I.

    Within the framework of gauge SUSY theories we discuss correlation functions of the type (W2(x),S2(0)) where S is the chiral matter superfield (in the one-flavor model). SUSY implies that these correlation functions do not depend on coordinates and vanish identically in perturbation theory. We develop a technique for the systematic calculation of instanton effects. It is shown that even in the limit x → 0 the correlation functions at hand are not saturated by small-size instantons with radius ρ ˜ x; a contribution of the same order of magnitude comes from the instantons of characteristic size ρ ˜ l/v (v is the vacuum expectation value of the scalar field, and we concentrate on the models with v > Λ where Λ is the scale parameter fixing the running gauge coupling constant). If v > Λ both types of instantons can be consistently taken into account. The computational formalism proposed is explicitly supersymmetric and uses the language of instanton-associated superfields. We demonstrate, in particular, that one can proceed to a new variable, ρinv, which can be naturally considered as a supersymmetric generalization of the instanton radius. Unlike the ordinary radius ρ, this variable is invariant under the SUSY transformations. If one uses ρinv instead of ρ the expressions for the instanton contribution can be rewritten in the form saturated by the domain ρ2inv=0. The cluster decomposition as well as x-independence of the correlation functions considered turn out to be obvious in this formalism.

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

    PubMed

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

    2013-10-01

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

  17. Reduced Regional Grey Matter Volumes in Pediatric Obstructive Sleep Apnea

    PubMed Central

    Philby, Mona F.; Macey, Paul M.; Ma, Richard A.; Kumar, Rajesh; Gozal, David; Kheirandish-Gozal, Leila

    2017-01-01

    Pediatric OSA is associated with cognitive risk. Since adult OSA manifests MRI evidence of brain injury, and animal models lead to regional neuronal losses, pediatric OSA patients may also be affected. We assessed the presence of neuronal injury, measured as regional grey matter volume, in 16 OSA children (8 male, 8.1 ± 2.2 years, AHI:11.1 ± 5.9 events/hr), and 200 control subjects (84 male, 8.2 ± 2.0 years), 191 of whom were from the NIH-Pediatric MRI database. High resolution T1-weighted whole-brain images were assessed between groups with voxel-based morphometry, using ANCOVA (covariates, age and gender; family-wise error correction, P < 0.01). Significant grey matter volume reductions appeared in OSA throughout areas of the superior frontal and prefrontal, and superior and lateral parietal cortices. Other affected sites included the brainstem, ventral medial prefrontal cortex, and superior temporal lobe, mostly on the left side. Thus, pediatric OSA subjects show extensive regionally-demarcated grey matter volume reductions in areas that control cognition and mood functions, even if such losses are apparently independent of cognitive deficits. Since OSA disease duration in our subjects is unknown, these findings may result from either delayed neuronal development, neuronal damaging processes, or a combination thereof, and could either reflect neuronal atrophy or reductions in cellular volume (neurons and glia). PMID:28303917

  18. N=2 Chern-Simons-matter theories without vortices

    NASA Astrophysics Data System (ADS)

    Russo, Jorge G.; Schaposnik, Fidel A.

    2017-07-01

    We study N=2 Chern-Simons-matter theories with gauge group {U}_{k_1}(1)× {U}_{k2}(1) . We find that, when k 1 + k 2 = 0, the partition function computed by localization dramatically simplifies and collapses to a single term. We show that the same condition prevents the theory from having supersymmetric vortex configurations. The theories include mass-deformed ABJM theory with U(1) k × U -k (1) gauge group as a particular case. Similar features are shared by a class of CS-matter theories with gauge group {U_k}{_1}(1)× \\cdots × {U}_{k_N}(1).

  19. The NSF Condensed Matter and Materials Theory Program

    NASA Astrophysics Data System (ADS)

    Hess, Daryl

    The Condensed Matter and Materials Theory (CMMT) Program in the Division of Materials Research is the home of condensed matter theory at the National Science Foundation. CMMT awards reflect a vibrant community with expanding scientific horizons and opportunities. I will present an overview of the CMMT program. Opportunities for theory and computation to open new directions and stimulate emerging frontiers will be discussed. Engaging research across disciplinary boundaries maintains the vitality of the field, leads to an agile next generation of theoretical and computational condensed matter physicists, and advances understanding of the world on the scale of life.

  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. 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…

  2. Extensive Gray Matter Volume Reduction in Treatment-Resistant Schizophrenia

    PubMed Central

    Anderson, Valerie M; Goldstein, Meghan E; Kydd, Robert R.

    2015-01-01

    Background: Approximately one-third of people with schizophrenia are treatment-resistant and some do not achieve remission with clozapine, the gold-standard antipsychotic medication for treatment-resistant schizophrenia. This study compared global and regional brain volumes between treatment-respondent and treatment-resistant patients with schizophrenia, including a group of patients who were clozapine-resistant. Methods: T1-weighted brain MRIs were obtained on a 3T scanner in 20 controls and 52 people with schizophrenia who were selected based on their symptomatic responses to antipsychotic medication: 18 responded well to first-line atypical antipsychotics (FLR), 19 were treatment-resistant but responsive to clozapine monotherapy (TR), and 15 were ultra-treatment-resistant and did not respond to clozapine (UTR). Treatment groups were matched for disease duration and current psychopathology. SIENAX and FSL-VBM were used to investigate differences in the global brain, gray matter (GM), white matter, ventricular cerebrospinal fluid volumes, and regional GM volumes. Results: GM volume was significantly reduced in the TR and UTR groups compared with controls and the FLR group (p < 0.05). GM volume was significantly reduced in TR patients compared with FLRs in the superior, middle, and inferior temporal gyri, pre- and post-central gyri, middle and superior frontal gyri, right supramarginal gyrus, and right lateral occipital cortex. UTR patients showed reduced GM compared with FLRs in their right parietal operculum and left cerebellum. No significant volume differences were observed between TR and UTR groups. Conclusions: These differences are unlikely to be solely due to medication effects, and reduced GM volume in treatment-resistant schizophrenia may represent an accelerated disease course or a different underlying pathology. PMID:25716781

  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. Free Volume Theory of Hydrocarbon Mixture Transport in Nanoporous Materials.

    PubMed

    Obliger, Amaël; Pellenq, Roland; Ulm, Franz-Josef; Coasne, Benoit

    2016-10-06

    Despite recent focus on shale gas, hydrocarbon recovery from the ultraconfining and disordered porosity of organic matter in shales (kerogen) remains poorly understood. Key aspects such as the breakdown of hydrodynamics at the nanoscale and strong adsorption effects lead to unexplained non-Darcy behaviors. Here, molecular dynamics and statistical mechanics are used to elucidate hydrocarbon mixture transport through a realistic molecular model of kerogen [ Bousige, C.; et al. Nat. Mater. 2016 , 15 , 576 ]. Owing to strong adsorption effects, velocity cross-correlations between the mixture components and between molecules of the same species are shown to be negligible. This allows estimation of each component permeance from its self-diffusivity, which can be obtained from single-component data. These permeances are found to scale with the reciprocal of the alkane length and decrease with the number of adsorbed molecules following a simple free volume theory, therefore allowing mixture transport prediction as a function of the amount of trapped fluid.

  5. Serum vitamin D and hippocampal gray matter volume in schizophrenia.

    PubMed

    Shivakumar, Venkataram; Kalmady, Sunil V; Amaresha, Anekal C; Jose, Dania; Narayanaswamy, Janardhanan C; Agarwal, Sri Mahavir; Joseph, Boban; Venkatasubramanian, Ganesan; Ravi, Vasanthapuram; Keshavan, Matcheri S; Gangadhar, Bangalore N

    2015-08-30

    Disparate lines of evidence including epidemiological and case-control studies have increasingly implicated vitamin D in the pathogenesis of schizophrenia. Vitamin D deficiency can lead to dysfunction of the hippocampus--a brain region hypothesized to be critically involved in schizophrenia. In this study, we examined for potential association between serum vitamin D level and hippocampal gray matter volume in antipsychotic-naïve or antipsychotic-free schizophrenia patients (n = 35). Serum vitamin D level was estimated using 25-OH vitamin D immunoassay. Optimized voxel-based morphometry was used to analyze 3-Tesla magnetic resonance imaging (MRI) (1-mm slice thickness). Ninety-seven percent of the schizophrenia patients (n = 34) had sub-optimal levels of serum vitamin D (83%, deficiency; 14%, insufficiency). A significant positive correlation was seen between vitamin D and regional gray matter volume in the right hippocampus after controlling for age, years of education and total intracranial volume (Montreal Neurological Institute (MNI) coordinates: x = 35, y = -18, z = -8; t = 4.34 pFWE(Corrected) = 0.018). These observations support a potential role of vitamin D deficiency in mediating hippocampal volume deficits, possibly through neurotrophic, neuroimmunomodulatory and glutamatergic effects. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. 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

  7. Growth of the nonbaryonic dark matter theory

    NASA Astrophysics Data System (ADS)

    Peebles, P. J. E.

    2017-03-01

    The evidence that has accumulated since the 1930s is that the mass of the Universe is dominated by an exotic nonbaryonic form of matter largely draped around the galaxies. This dark matter approximates an initially low-pressure gas of particles that interact only with gravity, but we know little more than that. Searches for detection thus must follow many difficult paths to a great discovery: what the Universe is made of.

  8. Electroconvulsive therapy increases temporal gray matter volume and cortical thickness.

    PubMed

    Sartorius, Alexander; Demirakca, Traute; Böhringer, Andreas; Clemm von Hohenberg, Christian; Aksay, Suna Su; Bumb, Jan Malte; Kranaster, Laura; Ende, Gabriele

    2016-03-01

    Electroconvulsive therapy (ECT) is a treatment of choice for severe and therapy resistant forms of major depressive episodes (MDE). Temporal brain volume alterations in MDE have been described for more than two decades. In our prospective study we aimed to investigate individual pre-post ECT treatment whole brain gray matter (GM) volume changes (quantified with voxel-based morphometry) in a sample of 18 patients with MDE. In addition, we studied the effect of ECT on voxel-based cortical thickness in cortical brain regions. The most prominent longitudinal GM increases (significant at a whole brain corrected level) occurred in temporal lobe regions. Within specific region of interest analyses we detected highly significant increases of GM in the hippocampus and the amygdala and to a lesser extent in the habenula (left p=0.003, right p=0.032). A voxel based cortical thickness analysis revealed an increase in cortical temporal regions (basically temporal pole and insula) further corroborating our cortical voxel-based morphometry results. Neither GM decreases or white matter increases nor correlations of GM changes with basic psychopathological parameters were detected. We corroborate earlier findings of hippocampal and amygdala GM volume increase following an acute ECT series in patients with MDE. Temporal GM volume increase was significant on a whole brain level and further corroborated by a cortical thickness analysis. Our data widely exclude white matter loss as an indirect cause of GM growth. Our data add further evidence to the hypothesis that ECT enables plasticity falsifying older ideas of ECT induced "brain damaging".

  9. 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.

  10. 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

  11. Chiral effective theory of dark matter direct detection

    NASA Astrophysics Data System (ADS)

    Bishara, Fady; Brod, Joachim; Grinstein, Benjamin; Zupan, Jure

    2017-02-01

    We present the effective field theory for dark matter interactions with the visible sector that is valid at scales of Script O(1 GeV). Starting with an effective theory describing the interactions of fermionic and scalar dark matter with quarks, gluons and photons via higher dimension operators that would arise from dimension-five and dimension-six operators above electroweak scale, we perform a nonperturbative matching onto a heavy baryon chiral perturbation theory that describes dark matter interactions with light mesons and nucleons. This is then used to obtain the coefficients of the nuclear response functions using a chiral effective theory description of nuclear forces. Our results consistently keep the leading contributions in chiral counting for each of the initial Wilson coefficients.

  12. Bergson's "Matter and Memory" and modern selectionist theories of memory.

    PubMed

    McNamara, P

    1996-03-01

    Bergson's reflections (in Matter and Memory, 1896) on memory anticipated development of modern selectionist theories of memory. Selectionist models offer new and potentially useful approaches to a theory of remembering. On the model of natural selection, these selectionist theories require at least two processing components: a device which generates a range of memory representations and a selection process which preserves a subset of those representations. Bergson shows how the subjective experience of remembering might be understood within a selectionist framework.

  13. 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.

  14. 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.

  15. Volume Independence in Large Nc QCD-like Gauge Theories

    SciTech Connect

    Kovtun, Pavel; Unsal, Mithat; Yaffe, Laurence G.

    2007-02-06

    Volume independence in large N{sub c} gauge theories may be viewed as a generalized orbifold equivalence. The reduction to zero volume (or Eguchi-Kawai reduction) is a special case of this equivalence. So is temperature independence in confining phases. A natural generalization concerns volume independence in ''theory space'' of quiver gauge theories. In pure Yang-Mills theory, the failure of volume independence for sufficiently small volumes (at weak coupling) due to spontaneous breaking of center symmetry, together with its validity above a critical size, nicely illustrate the symmetry realization conditions which are both necessary and sufficient for large N{sub c} orbifold equivalence. The existence of a minimal size below which volume independence fails also applies to Yang-Mills theory with antisymmetric representation fermions [QCD(AS)]. However, in Yang-Mills theory with adjoint representation fermions [QCD(Adj)], endowed with periodic boundary conditions, volume independence remains valid down to arbitrarily small size. In sufficiently large volumes, QCD(Adj) and QCD(AS) have a large N{sub c} ''orientifold'' equivalence, provided charge conjugation symmetry is unbroken in the latter theory. Therefore, via a combined orbifold-orientifold mapping, a well-defined large N{sub c} equivalence exists between QCD(AS) in large, or infinite, volume and QCD(Adj) in arbitrarily small volume. Since asymptotically free gauge theories, such as QCD(Adj), are much easier to study (analytically or numerically) in small volume, this equivalence should allow greater understanding of large N{sub c} QCD in infinite volume.

  16. 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.

  17. Widespread reductions in gray matter volume in depression☆

    PubMed Central

    Grieve, Stuart M.; Korgaonkar, Mayuresh S.; Koslow, Stephen H.; Gordon, Evian; Williams, Leanne M.

    2013-01-01

    Abnormalities in functional limbic–anterior cingulate–prefrontal circuits associated with emotional reactivity, evaluation and regulation have been implicated in the pathophysiology of major depressive disorder (MDD). However, existing knowledge about structural alterations in depression is equivocal and based on cohorts of limited sample size. This study used voxel-based morphometry (VBM) and surface-based cortical thickness to investigate the structure of these circuits in a large and well-characterized patient cohort with MDD. Non-geriatric MDD outpatients (n = 102) and age- and gender-matched healthy control participants (n = 34) provided T1-weighted magnetic resonance imaging data during their baseline visit as part of the International Study to Predict Optimized Treatment for Depression. Whole-brain VBM volumetric and surface-based cortical thickness assessments were performed voxel-wise and compared (at p < 0.05 corrected for multiple comparisons) between the MDD and control groups. MDD participants had reduced gray matter volume in the anterior cingulate cortex, regions of the prefrontal circuits, including dorsolateral and dorsomedial prefrontal cortices, and lateral and medial orbitofrontal cortices, but not in limbic regions. Additional reductions were observed cortically in the posterior temporal and parieto-occipital cortices and, subcortically in the basal ganglia and cerebellum. Focal cortical thinning in the medial orbitofrontal cortex was also observed for the MDD group. These alterations in volume and cortical thickness were not associated with severity of depressive symptoms. The findings demonstrate that widespread gray matter structural abnormalities are present in a well-powered study of patients with depression. The patterns of gray matter loss correspond to the same brain functional network regions that were previously established to be abnormal in MDD, which may support an underlying structural abnormality for these circuits. PMID

  18. Teaching for Understanding: A Study of Students' Preinstruction Theories of Matter and a Comparison of the Effectiveness of Two Approaches to Teaching about Matter and Density.

    ERIC Educational Resources Information Center

    Smith, Carol; Maclin, Deborah; Grosslight, Lorraine; Davis, Helen

    1997-01-01

    Compared Introductory Physical Science (IPS) and Modified approaches to teaching physics concepts. Found that students' preinstruction ideas of matter and density were organized in commonsense theories that constrained understanding of density. Both curricula promoted quantitative understanding of mass, volume, and density, but the Modified…

  19. 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.

  20. 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.

  1. Correlations among Brain Gray Matter Volumes, Age, Gender, and Hemisphere in Healthy Individuals

    PubMed Central

    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. PMID:21818377

  2. 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.

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

    PubMed

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

    2010-10-19

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

  4. XX International Workshop on Condensed Matter Theories

    DTIC Science & Technology

    1998-01-01

    Density Matrix Theory J. W. Clark, M. L. Ristig, T. Lindenau and M. Serhan 7 Can BCS and BEC be Synthesized? V. C. Aguilera-Navarro, M. Casas, S...Louis, MO 63130 USA M. L. Ristig, T. Lindenau, and M. Serhan Institut für Theoretische Physik Universität zu Köln, D-50937 Köln, Germany 1...E. Campbell, and J. W. Clark, Ann. Phys. (N.Y.) 218, 116 (1992). [10] M. L. Ristig, G. Senger, M. Serhan , and J. W. Clark, Ann. Phys. (N.Y.) 243

  5. 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

  6. 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

  7. Increased cerebellar gray matter volume in head chefs

    PubMed Central

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

    2017-01-01

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

  8. Increased cerebellar gray matter volume in head chefs.

    PubMed

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

    2017-01-01

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

  9. Quantum Field Theory in Condensed Matter Physics

    NASA Astrophysics Data System (ADS)

    Tsvelik, Alexei M.

    2007-01-01

    Preface; Acknowledgements; Part I. Introduction to Methods: 1. QFT: language and goals; 2. Connection between quantum and classical: path integrals; 3. Definitions of correlation functions: Wick's theorem; 4. Free bosonic field in an external field; 5. Perturbation theory: Feynman diagrams; 6. Calculation methods for diagram series: divergences and their elimination; 7. Renormalization group procedures; 8. O(N)-symmetric vector model below the transition point; 9. Nonlinear sigma models in two dimensions: renormalization group and 1/N-expansion; 10. O(3) nonlinear sigma model in the strong coupling limit; Part II. Fermions: 11. Path integral and Wick's theorem for fermions; 12. Interaction electrons: the Fermi liquid; 13. Electrodynamics in metals; 14. Relativistic fermions: aspects of quantum electrodynamics; 15. Aharonov-Bohm effect and transmutation of statistics; Part III. Strongly Fluctuating Spin Systems: Introduction; 16. Schwinger-Wigner quantization procedure: nonlinear sigma models; 17. O(3) nonlinear sigma model in (2+1) dimensions: the phase diagram; 18. Order from disorder; 19. Jordan-Wigner transformations for spin S=1/2 models in D=1, 2, 3; 20. Majorana representation for spin S=1/2 magnets: relationship to Z2 lattice gauge theories; 21. Path integral representations for a doped antiferromagnet; Part IV. Physics in the World of One Spatial Dimension: Introduction; 22. Model of the free bosonic massless scalar field; 23. Relevant and irrelevant fields; 24. Kosterlitz-Thouless transition; 25. Conformal symmetry; 26. Virasoro algebra; 27. Differential equations for the correlation functions; 28. Ising model; 29. One-dimensional spinless fermions: Tomonaga-Luttinger liquid; 30. One-dimensional fermions with spin: spin-charge separation; 31. Kac-Moody algebras: Wess-Zumino-Novikov-Witten model; 32. Wess-Zumino-Novikov-Witten model in the Lagrangian form: non-Abelian bosonization; 33. Semiclassical approach to Wess-Zumino-Novikov-Witten models; 34

  10. Primordial black holes as dark matter in alternate gravity theories

    NASA Astrophysics Data System (ADS)

    Majumdar, A. S.

    We discuss the possibility of the survival of primordial black holes as dark matter candidates in various alternate gravity theories motivated from extra-dimensional scenarios. We show that in particular, braneworld black holes, as well as black holes in scalar-tensor models can survive up to late times by efficient accretion of radiation in the early universe.

  11. 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…

  12. 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.

  13. Empirical tests of a theory of language, mathematics, and matter.

    PubMed

    Abler, William L

    2008-01-01

    In an earlier paper (Abler, 2006), I proposed a theory of language, especially sentences, based on the symmetrical structure of the equation. Here, I use the structure of equations to deduce neural structures (e.g., mirror neurons or intra-cellular macromolecules, or crystals, or resonations) that might generate them. Ultimately, the properties described are a consequence of dimensional properties of matter

  14. 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.

  15. Fiber tracking of brain white matter based on graph theory.

    PubMed

    Lu, Meng

    2015-01-01

    Brain white matter tractography is reconstructed via diffusion-weighted magnetic resonance images. Due to the complex structure of brain white matter fiber bundles, fiber crossing and fiber branching are abundant in human brain. And regular methods with diffusion tensor imaging (DTI) can't accurately handle this problem. the biggest problems of the brain tractography. Therefore, this paper presented a novel brain white matter tractography method based on graph theory, so the fiber tracking between two voxels is transformed into locating the shortest path in a graph. Besides, the presented method uses Q-ball imaging (QBI) as the source data instead of DTI, because QBI can provide accurate information about multiple fiber crossing and branching in one voxel using orientation distribution function (ODF). Experiments showed that the presented method can accurately handle the problem of brain white matter fiber crossing and branching, and reconstruct brain tractograhpy both in phantom data and real brain data.

  16. The conformal manifold of Chern-Simons matter theories

    NASA Astrophysics Data System (ADS)

    Bianchi, Marco S.; Penati, Silvia

    2011-01-01

    We determine perturbatively the conformal manifold of mathcal{N} = 2 Chern-Simons matter theories with the aim of checking in the three dimensional case the general prescription based on global symmetry breaking, recently introduced in [1-3]. We discuss in details few remarkable cases like the mathcal{N} = 6 ABJM theory and its less supersymmetric generalizations with/without flavors. In all cases we find perfect agreement with the predictions of global symmetry breaking prescription. For unflavored theories the conformal manifold is a three dimensional compact surface. This feature is peculiar of three dimensions, as it has no direct analogue in four dimensional supersymmetric models.

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

    PubMed

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

    2014-06-13

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

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

    PubMed Central

    Varvaris, Mark; Vannorsdall, Tracy D.; Gordon, Barry; Harris, James C.; Jinnah, H.A.

    2015-01-01

    Objective: We sought to examine brain white matter abnormalities based on MRI in adults with Lesch-Nyhan disease (LND) or an attenuated variant (LNV) of this rare, X-linked neurodevelopmental disorder of purine metabolism. Methods: In this observational study, we compared 21 adults with LND, 17 with LNV, and 33 age-, sex-, and race-matched healthy controls using voxel-based morphometry and analysis of covariance to identify white matter volume abnormalities in both patient groups. Results: Patients with classic LND showed larger reductions of white (26%) than gray (17%) matter volume relative to healthy controls. Those with LNV showed comparable reductions of white (14%) and gray (15%) matter volume. Both patient groups demonstrated reduced volume in medial inferior white matter regions. Compared with LNV, the LND group showed larger reductions in inferior frontal white matter adjoining limbic and temporal regions and the motor cortex. These regions likely include such long association fibers as the superior longitudinal and uncinate fasciculi. Conclusions: Despite earlier reports that LND primarily involves the basal ganglia, this study reveals substantial white matter volume abnormalities. Moreover, white matter deficits are more severe than gray matter deficits in classic LND, and also characterize persons with LNV. The brain images acquired for these analyses cannot precisely localize white matter abnormalities or determine whether they involve changes in tract orientation or anisotropy. However, clusters of reduced white matter volume identified here affect regions that are consistent with the neurobehavioral phenotype. PMID:25503620

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

    PubMed

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

    2015-01-13

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

  20. 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.

  1. 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

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

    PubMed

    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.

  3. 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.

  4. Millicharged Dark Matter in Quantum Gravity and String Theory

    NASA Astrophysics Data System (ADS)

    Shiu, Gary; Soler, Pablo; Ye, Fang

    2013-06-01

    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.

  5. 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.

  6. 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.

  7. Seesaw theories at LHC and warm dark matter

    SciTech Connect

    Zhang, Yue

    2014-06-24

    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.

  8. Theory and Motivations of Dark Sector Dark Matter and Forces

    NASA Astrophysics Data System (ADS)

    Schuster, Philip

    2017-01-01

    We present the theory and motivations underlying ``dark'' or ``hidden'' sector dark matter and new force scenarios. Dark sector scenarios with sub-GeV mass scales have attracted particular attention in the past several years, motivated in part by findings from direct detection, satellite, and LHC experiments, as well as precision measurements. Moreover, these scenarios offer some of the simplest and least explored possibilities for dark matter. As such, sub-GeV dark sector scenarios have become the focus of a broad and growing international program of experiments.

  9. Higher Education: Handbook of Theory and Research, Volume XII.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    This volume contains nine papers on higher education theory and research. They include: (1) "Technology Transfer from Universities" (Irwin Feller); (2) "State Policy and Private Higher Education: Past, Present and Future" (William Zumeta); (3) "Appraising Tinto's Theory of College Student Departure" (John M. Braxton…

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

    PubMed

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

    2012-01-16

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

  11. 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

  12. 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.

  13. 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…

  14. 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.

  15. 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…

  16. Depressive Symptoms in Adolescents: Associations with White Matter Volume and Marijuana Use

    ERIC Educational Resources Information Center

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

    2007-01-01

    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…

  17. Drinking history associations with regional white matter volumes in alcoholic men and women.

    PubMed

    Ruiz, Susan Mosher; Oscar-Berman, Marlene; Sawyer, Kayle S; Valmas, Mary M; Urban, Trinity; Harris, Gordon J

    2013-01-01

    Alcoholism has been repeatedly associated with gray and white matter pathology. Although neuroimaging has shown alcoholism-related brain volume reductions and axonal compromise, the integrity of white matter volumes in chronic alcoholism has been challenging to measure on a regional level. We first examined the effects of alcoholism on cerebral white matter volumes by lobar and gyral subdivisions in 42 abstinent alcoholics and 42 control participants (split evenly by gender). We also examined cerebellar white matter and regions of the corpus callosum, as well as ventricular volumes. Next, relationships between white matter and ventricular volumes with measures of drinking patterns were assessed. Finally, an examination of early versus late abstinence was conducted. Within each examination, gender effects were explored. Differences in regional white matter volumes between alcoholics and controls were observed primarily in the corpus callosum, with a stronger group difference among men than women. Years of heavy drinking had a strong negative impact on frontal and temporal white matter among alcoholic women, and on the corpus callosum among alcoholic men. Quantity of alcohol consumption was associated with smaller corpus callosum and larger ventricular volumes among alcoholic women, whereas abstinence duration was associated with larger corpus callosum volume among alcoholic men. Preliminary data indicated that alcoholic women showed stronger positive associations between sobriety duration and white matter volume than men within the first year of abstinence, whereas men showed this association more so than women after 1 year of abstinence. Effects of drinking history on white matter and ventricular volumes vary by gender, with alcoholic women showing greatest sensitivity in frontal, temporal, ventricular, and corpus callosum regions, and alcoholic men showing effects mainly in the corpus callosum. Preliminary results indicate that recovery of white matter volume may

  18. Drinking History Associations with Regional White Matter Volumes in Alcoholic Men and Women

    PubMed Central

    Ruiz, Susan Mosher; Oscar-Berman, Marlene; Sawyer, Kayle S.; Valmas, Mary; Urban, Trinity; Harris, Gordon J.

    2012-01-01

    Background Alcoholism has been repeatedly associated with gray and white matter pathology. Although neuroimaging has shown alcoholism-related brain volume reductions and axonal compromise, the integrity of white matter volumes in chronic alcoholism has been challenging to measure on a regional level. Methods We first examined effects of alcoholism on cerebral white matter volumes by lobar and gyral subdivisions in 42 abstinent alcoholics and 42 control participants (split evenly by gender). We also examined cerebellar white matter and regions of the corpus callosum, as well as ventricular volumes. Next, relationships between white matter and ventricular volumes with measures of drinking patterns were assessed. Finally, an examination of early versus late abstinence was conducted. Within each examination, gender effects were explored. Results Differences in regional white matter volumes between alcoholics and controls were observed primarily in the corpus callosum, with a stronger group difference among men than among women. Years of heavy drinking had a strong negative impact on frontal and temporal white matter among alcoholic women, and on the corpus callosum among alcoholic men. Quantity of alcohol consumption was associated with smaller corpus callosum and larger ventricular volumes among alcoholic women, while abstinence duration was associated with larger corpus callosum volume among alcoholic men. Preliminary data indicated that alcoholic women showed stronger positive associations between sobriety duration and white matter volume than men within the first year of abstinence, while men showed this association more so than women after one year of abstinence. Conclusions Effects of drinking history on white matter and ventricular volumes vary by gender, with alcoholic women showing greatest sensitivity in frontal, temporal, ventricular, and corpus callosum regions, and alcoholic men showing effects mainly in the corpus callosum. Preliminary results indicate

  19. Advances in rheology. Volume 1: Theory

    SciTech Connect

    Mena, B.; Garcia-Rejon, A.; Rangel-Nafaile, C.

    1984-01-01

    This book contains over 50 papers. Some of the titles are: Non-Newtonian effects in porous media flow; Viscoelastic and thixotropic behavior of crude oil emulsions; Particle segregation in poiseuille flow: A continuum mixture theory; and Numerical simulation of the flow of an oldroyd fluid through a periodically constricted tube.

  20. 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.

  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. Gray matter volume changes following reading intervention in dyslexic children

    PubMed Central

    Krafnick, Anthony J.; Flowers, D. Lynn; Napoliello, Eileen M.; Eden, Guinevere F.

    2010-01-01

    Studies in children and adults with the reading disability developmental dyslexia have shown behavioral improvements after reading intervention. In another line of work, it has been shown that intensive training in a variety of cognitive and sensorimotor skills can result in changes in gray matter volume (GMV). This study examined changes in GMV following intensive reading intervention in children with dyslexia using voxel-based morphometry (VBM). Eleven dyslexic children underwent an eight week training focused on mental imagery, articulation and tracing of letters, groups of letters and words, which resulted in significant gains in reading skills. This was followed by an eight week null period (control) where no intervention was administered and no further significant gains in reading were observed. Structural scans were obtained before the intervention, after the intervention and after the null period. GMV increases between the first two time points were found in the left anterior fusiform gyrus/hippocampus, left precuneus, right hippocampus and right anterior cerebellum. However these areas did not change between time points two and three (control period), suggesting that the changes were specific to the intervention period. These results demonstrate for the first time that (1) training-induced changes in GMV can be observed in a pediatric sample and (2) reading improvements induced by intervention are accompanied by GMV changes. PMID:21029785

  4. Gray matter volumes and cognitive ability in the epileptogenic brain malformation of periventricular nodular heterotopia.

    PubMed

    Walker, Linsey M; Katzir, Tami; Liu, Tianming; Ly, Jenny; Corriveau, Kathleen; Barzillai, Mirit; Chu, Felicia; O'Connor, Margaret G; Hackney, David B; Chang, Bernard S

    2009-08-01

    Periventricular nodular heterotopia (PNH) is a brain malformation clinically characterized by the triad of epilepsy, normal intelligence, and dyslexia. We investigated the structure-function relationship between cerebral volumes and cognitive ability in this disorder by studying 12 subjects with PNH and 6 controls using volumetric analysis of high-resolution anatomical MRI and neuropsychological testing. Total cerebral volumes and specific brain compartment volumes (gray matter, white matter, and cerebrospinal fluid) in subjects with PNH were comparable to those in controls. There was a negative correlation between heterotopic gray matter volume and cortical gray matter volume. Cerebral and cortical volumes in PNH did not correlate with Full Scale IQ, unlike in normal individuals. Our findings support the idea that heterotopic nodules contain misplaced neurons that would normally have migrated to the cortex, and suggest that structural correlates of normal cognitive ability may be different in the setting of neuronal migration failure.

  5. A condensed matter field theory for quantum plasmonics

    NASA Astrophysics Data System (ADS)

    Ballout, Fouad; Hess, Ortwin

    In recent years plasmonics has advanced to ever decreasing length scales reaching dimensions comparable to the de broglie wavelength of an electron, which has a manifest influence on the plasmon dispersion relation. The associated phenomenology lies beyond the reach of the classical drude free electron theory or its nonlocal extension and adequate models are needed to address the quantum matter aspects of light-matter interaction that are responsible for plasmonicquantum size effects. We present on the basis of the jellium model a quantum field theory of surface-plasmon polaritons in which they emerge as extended objects as a result of an inhomogeneous condensation of bosons around a topological singularity describing the surface. The benefit of this approach lies in relating the electromagnetic fields belonging to such a macroscopic quantum state with the surface topology and nonlocal responsefunction (expressed in terms of the retarded photon self-energy) of the delimited electron gas sustaining that state.

  6. Nucleon propagation through nuclear matter in chiral effective field theory

    NASA Astrophysics Data System (ADS)

    Mallik, S.; Mishra, H.

    2007-05-01

    We treat the propagation of a nucleon in nuclear matter by evaluating the ensemble average of the two-point function of the nucleon currents in the framework of chiral effective field theory. We first derive the effective parameters of the nucleon to one loop. The resulting formula for the effective mass has been known since before and gives an absurd value at normal nuclear density. We then modify it following Weinberg’s method for the two-nucleon system in the effective theory. Our results for the effective mass and the width of the nucleon are compared with those in the literature.

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

    PubMed

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

    2014-04-01

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

  8. 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

  9. 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.

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

    PubMed

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

    2015-10-01

    Whether gray matter impairment occurs in neuromyelitis optica is a matter of ongoing debate, and the association of gray matter impairment with cognitive deficits remains largely unknown. The purpose of this study was to investigate gray matter volume reductions and their association with cognitive decline in patients with neuromyelitis optica. This study included 50 patients with neuromyelitis optica and 50 sex-, age-, handedness-, and education-matched healthy subjects who underwent high-resolution structural MR imaging examinations and a battery of cognitive assessments. Gray matter volume and cognitive differences were compared between the 2 groups. The correlations of the regional gray matter volume with cognitive scores and clinical variables were explored in the patients with neuromyelitis optica. Compared with healthy controls (635.9 ± 51.18 mL), patients with neuromyelitis optica (602.8 ± 51.03 mL) had a 5.21% decrease in the mean gray matter volume of the whole brain (P < .001). The significant gray matter volume reduction in neuromyelitis optica affected the frontal and temporal cortices and the right thalamus (false discovery rate correction, P < .05). The regional gray matter volumes in the frontal and temporal cortices were negatively correlated with disease severity in patients with neuromyelitis optica (Alphasim correction, P < .05). Patients with neuromyelitis optica had impairments in memory, information processing speed, and verbal fluency (P < .05), which were correlated with gray matter volume reductions in the medial prefrontal cortex and thalamus (Alphasim correction, P < .05). Gray matter volume reduction is present in patients with neuromyelitis optica and is associated with cognitive impairment and disease severity in this group. © 2015 by American Journal of Neuroradiology.

  11. Impact of gray matter reductions on theory of mind abilities in patients with schizophrenia.

    PubMed

    Koelkebeck, Katja; Hirao, Kazuyuki; Miyata, Jun; Kawada, Ryosaku; Saze, Teruyasu; Dannlowski, Udo; Ubukata, Shiho; Ohrmann, Patricia; Bauer, Jochen; Pedersen, Anya; Fukuyama, Hidenao; Sawamoto, Nobukatsu; Takahashi, Hidehiko; Murai, Toshiya

    2013-01-01

    To identify the brain regions involved in the interpretation of intentional movement by patients with schizophrenia, we investigated the association between cerebral gray matter (GM) volumes and performance on a theory of mind (ToM) task using voxel-based morphometry. Eighteen patients with schizophrenia and thirty healthy controls participated in the study. Participants were given a moving shapes task that employs the interpretation of intentional movement. Verbal descriptions were rated according to intentionality. ToM performance deficits in patients were found to be positively correlated with GM volume reductions in the superior temporal sulcus and medial prefrontal cortex. Our findings confirm that divergent brain regions contribute to mentalizing abilities and that GM volume reductions impact behavioral deficits in patients with schizophrenia.

  12. 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.

  13. Superconformal Chern-Simons-matter theories in N =4 superspace

    NASA Astrophysics Data System (ADS)

    Kuzenko, Sergei M.; Samsonov, Igor B.

    2015-11-01

    In three dimensions, every known N =4 supermultiplet has an off-shell completion. However, there is no off-shell N =4 formulation for the known extended superconformal Chern-Simons (CS) theories with eight and more supercharges. To achieve a better understanding of this issue, we provide N =4 superfield realizations for the equations of motion which correspond to various N =4 and N =6 superconformal CS theories, including the Gaiotto-Witten theory and the Aharony-Bergman-Jafferis-Maldacena (ABJM) theory. These superfield realizations demonstrate that the superconformal CS theories with N ≥4 (except for the Gaiotto-Witten theory) require a reducible long N =4 vector multiplet, from which the standard left and right N =4 vector multiplets are obtained by constraining the field strength to be either self-dual or antiself-dual. Such a long multiplet naturally originates upon reduction of any off-shell N >4 vector multiplet to N =4 superspace. For the long N =4 vector multiplet we develop a prepotential formulation. It makes use of two prepotentials being subject to the constraint which defines the so-called hybrid projective multiplets introduced in the framework of N =4 supergravity-matter systems in arXiv:1101.4013. We also couple N =4 superconformal CS theories to N =4 conformal supergravity.

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

    PubMed

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

    2013-12-01

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

  15. Age-related changes in prefrontal white matter volume across adolescence

    PubMed Central

    Nagel, Bonnie J.; Medina, Krista Lisdahl; Yoshii, June; Schweinsburg, Alecia D.; Moadab, Ida; Tapert, Susan F.

    2008-01-01

    Past research has suggested that white matter volume increases from childhood to adulthood; however, during adolescence, there is somewhat limited data to support this finding. In the present study, 65 typically developing adolescents underwent structural magnetic resonance imaging. Using magnetic resonance imaging, prefrontal white matter volumes were examined in relation to adolescent age and sex. Surprisingly, results suggested that prefrontal white matter volume decreased during late adolescence, particularly among the female sex. These findings are inconsistent with past research and suggest that perhaps some developmental processes in late adolescence are not yet fully explained. Possible methodological contributions and implications for the current findings are discussed PMID:16932152

  16. Toolbox for Abelian lattice gauge theories with synthetic matter

    NASA Astrophysics Data System (ADS)

    Dutta, Omjyoti; Tagliacozzo, Luca; Lewenstein, Maciej; Zakrzewski, Jakub

    2017-05-01

    Fundamental forces of nature are described by field theories, also known as gauge theories, based on a local gauge invariance. The simplest of them is quantum electrodynamics (QED), which is an example of an Abelian gauge theory. Such theories describe the dynamics of massless photons and their coupling to matter. However, in two spatial dimensions (2D), they are known to exhibit gapped phases at low temperature. In the realm of quantum spin systems, it remains a subject of considerable debate if their low-energy physics can be described by emergent gauge degrees of freedom. Here we present a class of simple two-dimensional models that admit a low-energy description in terms of an Abelian gauge theory. We find rich phase diagrams for these models comprising exotic deconfined phases and gapless phases—a rare example for 2D Abelian gauge theories. The counterintuitive presence of gapless phases in 2D results from the emergence of additional symmetry in the models. Moreover, we propose schemes to realize our model with current experiments using ultracold bosonic atoms in optical lattices.

  17. 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.

  18. 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

  19. 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.

  20. 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. 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

    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

  2. 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.

  3. Volume change theory for syringomyelia: A new perspective.

    PubMed

    Rai, Survendra Kumar Rajdeo; Rai, Pooja Survendra Kumar

    2015-01-01

    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. 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 methodology.

  4. 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

  5. The effective field theory of dark matter direct detection

    SciTech Connect

    Fitzpatrick, A. Liam; Haxton, Wick; Katz, Emanuel; Lubbers, Nicholas; Xu, Yiming

    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.

  6. 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…

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

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    This volume contains 10 papers on higher education theory and research. "Variation Among Academic Disciplines: Analytical Frameworks and Research" (John M. Braxton and Lowell L. Hargens) reviews work on disciplinary differences and proposed conceptual schemes for explaining these differences. "Public Policy and Public Trust: The Use…

  8. 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…

  9. Towards a quantitative kinetic theory of polar active matter

    NASA Astrophysics Data System (ADS)

    Ihle, T.

    2014-06-01

    A recent kinetic approach for Vicsek-like models of active particles is reviewed. The theory is based on an exact Chapman- Kolmogorov equation in phase space. It can handle discrete time dynamics and "exotic" multi-particle interactions. A nonlocal mean-field theory for the one-particle distribution function is obtained by assuming molecular chaos. The Boltzmann approach of Bertin, et al., Phys. Rev. E 74, 022101 (2006) and J. Phys. A 42, 445001 (2009), is critically assessed and compared to the current approach. In Boltzmann theory, a collision starts when two particles enter each others action spheres and is finished when their distance exceeds the interaction radius. The average duration of such a collision, τ0, is measured for the Vicsek model with continuous time-evolution. If the noise is chosen to be close to the flocking threshold, the average time between collisions is found to be roughly equal to τ0 at low densities. Thus, the continuous-time Vicsek-model near the flocking threshold cannot be accurately described by a Boltzmann equation, even at very small density because collisions take so long that typically other particles join in, rendering Boltzmann's binary collision assumption invalid. Hydrodynamic equations for the phase space approach are derived by means of a Chapman-Enskog expansion. The equations are compared to the Toner-Tu theory of polar active matter. New terms, absent in the Toner-Tu theory, are highlighted. Convergence problems of Chapman-Enskog and similar gradient expansions are discussed.

  10. Reduced caudate gray matter volume in women with major depressive disorder.

    PubMed

    Kim, M Justin; Hamilton, J Paul; Gotlib, Ian H

    2008-11-30

    Previous brain-imaging studies have reported that major depressive disorder (MDD) is characterized by decreased volumes of several cortical and subcortical structures, including the hippocampus, amygdala, anterior cingulate cortex, and caudate nucleus. The purpose of the present study was to identify structural volumetric differences between MDD and healthy participants using a method that allows a comparison of gray and white matter volume across the whole brain. In addition, we explored the relation between symptom severity and brain regions with decreased volumes in MDD participants. The study group comprised 22 women diagnosed with MDD and 25 healthy women with no history of major psychiatric disorders. Magnetic resonance brain images were analyzed using optimized voxel-based morphometry to examine group differences in regional gray and white matter volume. Compared with healthy controls, MDD participants were found to have decreased gray matter volume in the bilateral caudate nucleus and the thalamus. No group differences were found for white matter volume, nor were there significant correlations between gray matter volumes and symptom severity within the MDD group. The present results suggest that smaller volume of the caudate nucleus may be related to the pathophysiology of MDD and may account for abnormalities of the cortico-striatal-pallido-thalamic loop in MDD.

  11. Effects of cholinesterase inhibition on brain white matter volume in Alzheimer's disease.

    PubMed

    Venneri, Annalena; Lane, Roger

    2009-02-18

    Brain white matter volume changes were quantified by using voxel-based morphometry in 26 minimal-to-mild Alzheimer's disease patients receiving cholinesterase inhibitors over 20 weeks. Patients treated with rivastigmine, an inhibitor of acetylcholinesterase and butyrylcholinesterase, did not show those reductions in white matter volume that were observed in patients treated with acetylcholinesterase-selective agents, donepezil and galantamine. This is the first time that dual cholinesterase inhibition has been shown to influence white matter volume specifically. The findings are consistent with a thesis that dual cholinesterase inhibition may have neuroprotective potential. Attenuated loss of brain volumes and delayed/slower long-term clinical decline in patients treated with agents such as rivastigmine may be due to less extensive white matter damage and loss of corticosubcortical connectivity.

  12. The influence of age of lead exposure on adult gray matter volume.

    PubMed

    Brubaker, Christopher J; Dietrich, Kim N; Lanphear, Bruce P; Cecil, Kim M

    2010-06-01

    Childhood lead exposure is associated with decreased cognitive abilities and executive functioning localized within the prefrontal cortex. Several studies have observed stronger associations between blood lead measurements obtained later in life than earlier measures, but there are no imaging studies investigating the developmental trajectory of blood lead levels taken during childhood on adult gray matter volume. In this study, we recruited 157 adults (20.8+/-1.5 years of age) from the Cincinnati Lead Study to undergo high resolution volumetric magnetic resonance imaging. Adjusted voxel-wise regression analyses were performed for associations between adult gray matter volume loss and yearly mean blood lead levels from 1 to 6 years of age in the entire cohort and by sex. We observed significant inverse associations between gray matter volume loss and annual mean blood lead levels from 3 to 6 years of age. The extent of prefrontal gray matter associated with yearly mean blood lead levels increased with advancing age of the subjects. The inverse associations between gray matter volume loss and yearly mean blood lead measurements were more pronounced in the frontal lobes of men than women. Analysis of women yielded significantly weaker associations between yearly mean blood lead levels and gray matter volume at all ages than either men or the combined cohort of men and women together. These results suggest that blood lead concentrations obtained during later childhood demonstrate greater loss in gray matter volume than childhood mean or maximum values. The relationship between childhood blood lead levels and gray matter volume loss was predominantly observed in the frontal lobes of males. This study demonstrates that maximum blood lead levels do not fully account for gray matter changes associated with childhood lead exposure, particularly in the frontal lobes of young men.

  13. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Examining the effect of psychopathic traits on gray matter volume in a community substance abuse sample.

    PubMed

    Cope, Lora M; Shane, Matthew S; Segall, Judith M; Nyalakanti, Prashanth K; Stevens, Michael C; Pearlson, Godfrey D; Calhoun, Vince D; Kiehl, Kent A

    2012-11-30

    Psychopathy is believed to be associated with brain abnormalities in both paralimbic (i.e., orbitofrontal cortex, insula, temporal pole, parahippocampal gyrus, posterior cingulate) and limbic (i.e., amygdala, hippocampus, anterior cingulate) regions. Recent structural imaging studies in both community and prison samples are beginning to support this view. Sixty-six participants, recruited from community corrections centers, were administered the Hare psychopathy checklist-revised (PCL-R), and underwent magnetic resonance imaging (MRI). Voxel-based morphometry was used to test the hypothesis that psychopathic traits would be associated with gray matter reductions in limbic and paralimbic regions. Effects of lifetime drug and alcohol use on gray matter volume were covaried. Psychopathic traits were negatively associated with gray matter volumes in right insula and right hippocampus. Additionally, psychopathic traits were positively associated with gray matter volumes in bilateral orbital frontal cortex and right anterior cingulate. Exploratory regression analyses indicated that gray matter volumes within right hippocampus and left orbital frontal cortex combined to explain 21.8% of the variance in psychopathy scores. These results support the notion that psychopathic traits are associated with abnormal limbic and paralimbic gray matter volume. Furthermore, gray matter increases in areas shown to be functionally impaired suggest that the structure-function relationship may be more nuanced than previously thought.

  15. Examining the effect of psychopathic traits on gray matter volume in a community substance abuse sample

    PubMed Central

    Cope, Lora M.; Shane, Matthew S.; Segall, Judith M.; Nyalakanti, Prashanth K.; Stevens, Michael C.; Pearlson, Godfrey D.; Calhoun, Vince D.; Kiehl, Kent A.

    2012-01-01

    Psychopathy is believed to be associated with brain abnormalities in both paralimbic (i.e., orbitofrontal cortex, insula, temporal pole, parahippocampal gyrus, posterior cingulate) and limbic (i.e., amygdala, hippocampus, anterior cingulate) regions. Recent structural imaging studies in both community and prison samples are beginning to support this view. Sixty six participants, recruited from community corrections centers, were administered the Hare Psychopathy Checklist Revised (PCL R), and underwent magnetic resonance imaging (MRI). Voxel based morphometry was used to test the hypothesis that psychopathic traits would be associated with gray matter reductions in limbic and paralimbic regions. Effects of lifetime drug and alcohol use on gray matter volume were covaried. Psychopathic traits were negatively associated with gray matter volumes in right insula and right hippocampus. Additionally, psychopathic traits were positively associated with gray matter volumes in bilateral orbital frontal cortex and right anterior cingulate. Exploratory regression analyses indicated that gray matter volumes within right hippocampus and left orbital frontal cortex combined to explain 21.8% of the variance in psychopathy scores. These results support the notion that psychopathic traits are associated with abnormal limbic and paralimbic gray matter volume. Furthermore, gray matter increases in areas shown to be functionally impaired suggests that the structure function relationship may be more nuanced than previously thought. PMID:23217577

  16. Matter-enhanced transition probabilities in quantum field theory

    SciTech Connect

    Ishikawa, Kenzo Tobita, Yutaka

    2014-05-15

    The relativistic quantum field theory is the unique theory that combines the relativity and quantum theory and is invariant under the Poincaré transformation. The ground state, vacuum, is singlet and one particle states are transformed as elements of irreducible representation of the group. The covariant one particles are momentum eigenstates expressed by plane waves and extended in space. Although the S-matrix defined with initial and final states of these states hold the symmetries and are applied to isolated states, out-going states for the amplitude of the event that they are detected at a finite-time interval T in experiments are expressed by microscopic states that they interact with, and are surrounded by matters in detectors and are not plane waves. These matter-induced effects modify the probabilities observed in realistic situations. The transition amplitudes and probabilities of the events are studied with the S-matrix, S[T], that satisfies the boundary condition at T. Using S[T], the finite-size corrections of the form of 1/T are found. The corrections to Fermi’s golden rule become larger than the original values in some situations for light particles. They break Lorentz invariance even in high energy region of short de Broglie wave lengths. -- Highlights: •S-matrix S[T] for the finite-time interval in relativistic field theory. •S[T] satisfies the boundary condition and gives correction of 1/T . •The large corrections for light particles breaks Lorentz invariance. •The corrections have implications to neutrino experiments.

  17. 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

  18. EPA Science Matters Newsletter: Volume 3, Number 4

    EPA Pesticide Factsheets

    In this issue of EPA's Science Matters, learn more about how EPA researchers and their partners are working to protect children from environmental threats and promote environmental health wherever they live, learn, and play.

  19. EPA Science Matters Newsletter: Volume 3, Number 1

    EPA Pesticide Factsheets

    This issue of EPA's Science Matters highlights stories that exemplify some of the important impacts of EPA researchers and their partners working to provide the science and technology needed to protect human health and the environment.

  20. Astrophysics. Volume 2. Interstellar matter and galaxies. [Text book

    SciTech Connect

    Bowers, R.L.; Deeming, T.

    1984-01-01

    The astrophysics of interstellar matter, galaxies, and cosmology is presented in an intermediate-level college textbook. Chapters are devoted to interstellar matter, interstellar dust grains, gaseous nebulae, hydrodynamics, the virial theorem, star formation, supersonic flow and shock waves, diffuse supernova remnants, the expanding universe, galaxies, dynamics of stellar systems, axially symmetric galaxies, spiral structure, and galactic evolution. Diagrams, graphs, photographs, and problems are provided. 48 references.

  1. Brain grey matter volume alterations in late-life depression.

    PubMed

    Du, Mingying; Liu, Jia; Chen, Ziqi; Huang, Xiaoqi; Li, Jing; Kuang, Weihong; Yang, Yanchun; Zhang, Wei; Zhou, Dong; Bi, Feng; Kendrick, Keith M; Gong, Qiyong

    2014-11-01

    Voxel-based morphometry (VBM) studies have demonstrated that grey matter abnormalities are involved in the pathophysiology of late-life depression (LLD), but the findings are inconsistent and have not been quantitatively reviewed. The aim of the present study was to conduct a meta-analysis that integrated the reported VBM studies, to determine consistent grey matter alterations in individuals with LLD. A systematic search was conducted to identify VBM studies that compared patients with LLD and healthy controls. We performed a meta-analysis using the effect size signed differential mapping method to quantitatively estimate regional grey matter abnormalities in patients with LLD. We included 9 studies with 11 data sets comprising 292 patients with LLD and 278 healthy controls in our meta-analysis. The pooled and subgroup meta-analyses showed robust grey matter reductions in the right lentiform nucleus extending into the parahippocampus, the hippocampus and the amygdala, the bilateral medial frontal gyrus and the right subcallosal gyrus as well as a grey matter increase in the right lingual gyrus. Meta-regression analyses showed that mean age and the percentage of female patients with LLD were not significantly related to grey matter changes. The analysis techniques, patient characteristics and clinical variables of the studies included were heterogeneous, and most participants were medicated. The present meta-analysis is, to our knowledge, the first to overcome previous inconsistencies in the VBM studies of LLD and provide robust evidence for grey matter alterations within fronto-striatal-limbic networks, thereby implicating them in the pathophysiology of LLD. The mean age and the percentage of female patients with LLD did not appear to have a measurable impact on grey matter changes, although we cannot rule out the contributory effects of medication.

  2. The role of global and regional gray matter volume decrease in multiple sclerosis.

    PubMed

    Grothe, Matthias; Lotze, Martin; Langner, Sönke; Dressel, Alexander

    2016-06-01

    Disability in multiple sclerosis (MS) patients is associated with white matter (WM) and gray matter (GM) pathology, and both processes contribute differently over the disease course. Total and regional GM volume loss can be imaged via voxel-based morphometry (VBM). Here, we retrospectively analyzed a group of 213 MS patients [163 relapsing remitting (RR) and 50 secondary progressive (SP)] using semi-automated white matter (WM) lesion mapping and voxel-based morphometry (VBM). Our aim was to assess the association of increasing disability with decreasing total and regional GM volume. As expected, total GM volume and WM lesion load were associated with patients disability, measured with the Expanded Disability Status Scale (EDSS). The more impaired the patients, the greater the statistical association to the total GM volume. Regional volume loss in the cerebellar gray matter was associated with increasing EDSS and WM lesion volume. Furthermore, SPMS patients had significantly more gray matter volume loss in the cerebellum and the hippocampus compared to RRMS patients. Our results confirm histopathological studies emphasizing the important role of the cerebellum and the hippocampus in MS patients' disability.

  3. Cortical gray and white matter volume in unmedicated schizotypal and schizophrenia patients.

    PubMed

    Hazlett, Erin A; Buchsbaum, Monte S; Haznedar, M Mehmet; Newmark, Randall; Goldstein, Kim E; Zelmanova, Yuliya; Glanton, Cathryn F; Torosjan, Yuliya; New, Antonia S; Lo, Jennifer N; Mitropoulou, Vivian; Siever, Larry J

    2008-04-01

    Magnetic resonance imaging (MRI) studies have revealed fronto-temporal cortical gray matter volume reductions in schizophrenia. However, to date studies have not examined whether age- and sex-matched unmedicated schizotypal personality disorder (SPD) patients share some or all of the structural brain-imaging characteristics of schizophrenia patients. We examined cortical gray/white matter volumes in a large sample of unmedicated schizophrenia-spectrum patients (n=79 SPD, n=57 schizophrenia) and 148 healthy controls. MRI images were reoriented to standard position parallel to the anterior-posterior commissure line, segmented into gray and white matter tissue types, and assigned to Brodmann areas (BAs) using a postmortem-histological atlas. Group differences in regional volume of gray and white matter in the BAs were examined with MANOVA. Schizophrenia patients had significantly reduced gray matter volume widely across the cortex but more marked in frontal and temporal lobes. SPD patients had reductions in the same regions but only about half that observed in schizophrenia and sparing in key regions including BA10. In schizophrenia, greater fronto-temporal volume loss was associated with greater negative symptom severity and in SPD, greater interpersonal and cognitive impairment. Overall, our findings suggest that increased prefrontal volume in BA10 and sparing of volume loss in temporal cortex (BAs 22 and 20) may be a protective factor in SPD which reduces vulnerability to psychosis.

  4. Longitudinal assessment of subcortical gray matter volume, cortical thickness, and white matter integrity in HIV-positive patients.

    PubMed

    Corrêa, Diogo Goulart; Zimmermann, Nicolle; Tukamoto, Gustavo; Doring, Thomas; Ventura, Nina; Leite, Sarah C B; Cabral, Rafael Ferracini; Fonseca, Rochele Paz; Bahia, Paulo R V; Gasparetto, Emerson Leandro

    2016-11-01

    To longitudinally evaluate the cortical thickness and deep gray matter structures volume, measured from T1 three-dimensional (3D) Gradient echo-weighted imaging, and white matter integrity, assessed from diffusion tensor imaging (DTI) of HIV-positive patients. Twenty-one HIV-positive patients on stable highly active antiretroviral therapy (HAART) with CD4+ T lymphocytes count >200 cells/mL and viral load <50 copies/mL underwent two magnetic resonance imaging (MRI) scans with a median interval of 26.6 months. None of the patients had HIV-related dementia. T1 3D magnetization prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5 Tesla MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis, a white matter skeleton was created, and a permutation-based inference with 5000 permutations, with a threshold of P < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The median, radial, and axial diffusivities were also projected onto the mean FA skeleton. There were no significant differences in cortical thickness, deep gray matter structures volumes or diffusivity parameters between scans at the two time points (considering P < 0.05). No longitudinal differences in cortical thickness, deep gray matter volumes, or white matter integrity were observed in an HIV-positive population on stable HAART, with undetectable viral load and high CD4+ T lymphocytes count. J. Magn. Reson. Imaging 2016;44:1262-1269. © 2016 International Society for Magnetic Resonance in Medicine.

  5. 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.

  6. Prefrontal gray matter volume mediates genetic risks for obesity.

    PubMed

    Opel, N; Redlich, R; Kaehler, C; Grotegerd, D; Dohm, K; Heindel, W; Kugel, H; Thalamuthu, A; Koutsouleris, N; Arolt, V; Teuber, A; Wersching, H; Baune, B T; Berger, K; Dannlowski, U

    2017-05-01

    Genetic and neuroimaging research has identified neurobiological correlates of obesity. However, evidence for an integrated model of genetic risk and brain structural alterations in the pathophysiology of obesity is still absent. Here we investigated the relationship between polygenic risk for obesity, gray matter structure and body mass index (BMI) by the use of univariate and multivariate analyses in two large, independent cohorts (n=330 and n=347). Higher BMI and higher polygenic risk for obesity were significantly associated with medial prefrontal gray matter decrease, and prefrontal gray matter was further shown to significantly mediate the effect of polygenic risk for obesity on BMI in both samples. Building on this, the successful individualized prediction of BMI by means of multivariate pattern classification algorithms trained on whole-brain imaging data and external validations in the second cohort points to potential clinical applications of this imaging trait marker.

  7. Diametrical relationship between gray and white matter volumes in autism spectrum disorder and schizophrenia.

    PubMed

    Mitelman, Serge A; Bralet, Marie-Cecile; Haznedar, M Mehmet; Hollander, Eric; Shihabuddin, Lina; Hazlett, Erin A; Buchsbaum, Monte S

    2016-11-23

    Autism spectrum disorders and schizophrenia have been variously characterized as separate nosological entities with overlapping deficits in social cognition or diametrical extremes of a phenotypic continuum. This study aimed to determine how these models apply to comparative morphometric data. MRI scans of the brain were obtained in 49 subjects with schizophrenia, 20 subjects with autism and 39 healthy controls. Images were parcellated into 40 Brodmann areas and entered into repeated-measures ANOVA for between-group comparison of global and localized gray and white matter volumes. A pattern of lower gray mater volumes and greater white matter volumes was found in subjects with schizophrenia in comparison to subjects with autism. For both gray and white matter, this pattern was most pronounced in regions associated with motor-premotor and anterior frontal cortex, anterior cingulate, fusiform, superior and middle temporal gyri. Patient groups tended to diverge from healthy controls in opposite directions, with greater-than-normal gray matter volumes and lower-than-normal white matter volumes in subjects with autism and reversed patterns in subjects with schizophrenia. White matter reductions in subjects with autism were seen in posterior frontal lobe and along the cingulate arch. Normal hemispheric asymmetry in the temporal lobe was effaced in subjects with autism and schizophrenia, especially in the latter. Nearly identical distribution of changes and diametrically divergent volumetry suggest that autism and schizophrenia may occupy opposite extremes of the same cognitive continuum.

  8. REDUCED THALAMIC VOLUME IN PRETERM INFANTS IS ASSOCIATED WITH ABNORMAL WHITE MATTER METABOLISM INDEPENDENT OF INJURY

    PubMed Central

    Wisnowski, Jessica L.; Ceschin, Rafael C.; Choi, So Young; Schmithorst, Vincent J.; Painter, Michael J.; Nelson, Marvin D.; Blüml, Stefan; Panigrahy, Ashok

    2015-01-01

    Introduction Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Methods Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23–36 weeks) who underwent MR examinations under clinical indications were included in this study. Results Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and amongst the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. Conclusion These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. PMID:25666231

  9. Global Symmetries, Volume Independence, and Continuity in Quantum Field Theories.

    PubMed

    Sulejmanpasic, Tin

    2017-01-06

    We discuss quantum field theories with global SU(N) and O(N) symmetries for which temporal direction is compactified on a circle of size L with periodicity of fields up to a global symmetry transformation, i.e., twisted boundary conditions. Such boundary conditions correspond to an insertion of the global symmetry operator in the partition function. We argue in general and prove in particular for CP(N-1) and O(N) nonlinear sigma models that large-N volume independence holds. Further we show that the CP(N-1) theory is free from the Affleck phase transition confirming the Ünsal-Dunne continuity conjecture.

  10. 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

  11. [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.

  12. 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.

  13. 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.

  14. 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

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

    PubMed

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

    2015-01-01

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

  16. Gray-matter volume in methamphetamine dependence: cigarette smoking and changes with abstinence from methamphetamine.

    PubMed

    Morales, Angelica M; Lee, Buyean; Hellemann, Gerhard; O'Neill, Joseph; London, Edythe D

    2012-10-01

    Group differences in brain structure between methamphetamine-dependent and healthy research participants have been reported, but findings in the literature present discrepancies. Although most methamphetamine-abusing individuals also smoke cigarettes, the effects of smoking on brain structure have not been distinguished from those of methamphetamine. Changes with abstinence from methamphetamine have also been relatively unexplored. This study, therefore, attempted to account for effects of smoking and brief abstinence from methamphetamine on gray-matter measures in methamphetamine-dependent research participants. Gray matter was measured using voxel-based morphometry in three groups: 18 control nonsmokers, 25 control smokers, and 39 methamphetamine-dependent smokers (methamphetamine-abstinent 4-7 days). Subgroups of methamphetamine-dependent and control participants (n=12/group) were scanned twice to determine change in gray matter over the first month of methamphetamine abstinence. Compared with Control Nonsmokers, Control Smokers and Methamphetamine-dependent Smokers had smaller gray-matter volume in the orbitofrontal cortex and caudate nucleus. Methamphetamine-dependent Smokers also had smaller gray-matter volumes in frontal, parietal and temporal cortices than Control Nonsmokers or Smokers, and smaller gray-matter volume in insula than control nonsmokers. Longitudinal assessment revealed gray matter increases in cortical regions (inferior frontal, angular, and superior temporal gyri, precuneus, insula, occipital pole) in methamphetamine-dependent but not control participants; the cerebellum showed a decrease. Gray-matter volume deficits in the orbitofrontal cortex and caudate of methamphetamine-dependent individuals may be in part attributable to cigarette smoking or pre-morbid conditions. Increase in gray matter with methamphetamine abstinence suggests that some gray-matter deficits are partially attributable to methamphetamine abuse. Copyright © 2012

  17. Gray-Matter Volume in Methamphetamine Dependence: Cigarette Smoking and Changes with Abstinence from Methamphetamine*

    PubMed Central

    Morales, Angelica; Lee, Buyean; Hellemann, Gerhard; O’Neill, Joseph; London, Edythe D.

    2012-01-01

    Background Group differences in brain structure between methamphetamine-dependent and healthy research participants have been reported, but findings in the literature present discrepancies. Although most methamphetamine-abusing individuals also smoke cigarettes, the effects of smoking on brain structure have not been distinguished from those of methamphetamine. Changes with abstinence from methamphetamine have also been relatively unexplored. This study, therefore, attempted to account for effects of smoking and brief abstinence from methamphetamine on gray-matter measures in methamphetamine-dependent research participants. Methods Gray matter was measured using voxel-based morphometry in three groups: 18 Control Nonsmokers, 25 Control Smokers, and 39 Methamphetamine-dependent Smokers (methamphetamine-abstinent 4–7 days). Subgroups of methamphetamine-dependent and control participants (n = 12/group) were scanned twice to determine change in gray matter over the first month of methamphetamine abstinence. Results Compared with Control Nonsmokers, Control Smokers and Methamphetamine-dependent Smokers had smaller gray-matter volume in the orbitofrontal cortex and caudate nucleus. Methamphetamine-dependent smokers also had smaller gray-matter volumes in frontal, parietal and temporal cortices than Control Nonsmokers or Smokers, and smaller gray-matter volume in insula than Control Nonsmokers. Longitudinal assessment revealed gray matter increases in cortical regions (inferior frontal, angular, and superior temporal gyri, precuneus, insula, occipital pole) in methamphetamine-dependent but not control participants; the cerebellum showed a decrease. Conclusions Gray-matter volume deficits in the orbitofronal cortex and caudate of methamphetamine-dependent individuals may be in part attributable to cigarette smoking or pre-morbid conditions. Increase in gray matter with methamphetamine abstinence suggests that some gray-matter deficits are partially attributable to

  18. 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

    2015-04-02

    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. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  19. The pitfalls of inguinal herniorrhaphy: Surgeon volume matters.

    PubMed

    Aquina, Christopher T; Probst, Christian P; Kelly, Kristin N; Iannuzzi, James C; Noyes, Katia; Fleming, Fergal J; Monson, John R T

    2015-09-01

    There is currently little information regarding the impact of procedure volume on outcomes after open inguinal hernia repair in the United States. Our hypothesis was that increasing procedure volume is associated with lesser rates of reoperation and resource use. The database of the Statewide Planning and Research Cooperative System was queried for elective open initial inguinal hernia repairs performed in New York State from 2001 to 2008 via the use of International Classification of Diseases, 9th Revision and Current Procedural Terminology codes. Surgeon and hospital procedure volumes were grouped into tertiles based on the number of open inguinal hernia repairs performed per year. Bivariate, hierarchical mixed effects Cox proportional-hazards, and negative binomial regression analyses were performed assessing for factors associated with reoperation for recurrence, procedure time, and downstream total charges. Among 151,322 patients who underwent open inguinal hernia repair, the overall rate of reoperation for recurrence within 5 years was 1.7% with a median time to reoperation of 1.9 years. An inverse relationship was seen between surgeon volume and reoperation rate, procedure time, and health care costs (P < .001). After we controlled for surgeon, facility, operative and patient characteristics, low-volume surgeons (<25 repairs/year) had greater rates of reoperation (hazard ratio 1.23,95% confidence interval [95% CI] 1.11-1.36), longer procedure times (incidence rate ratio 1.22, 95% CI 1.21-1.24), and greater downstream costs (incidence rate ratio 1.13,95% CI 1.10-1.17) than high-volume surgeons (≥25 repairs/year). Surgeon volume <25 cases per year for open inguinal hernia repair was independently associated with greater rates of reoperation for recurrence, worse operative efficiency, and greater health care costs. Referral to surgeons who perform ≥25 inguinal hernia repairs per year should be considered to decrease reoperation rates and resource use

  20. 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

  1. The last gasp of dark matter effective theory

    NASA Astrophysics Data System (ADS)

    Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo

    2016-11-01

    We discuss an interesting class of models, based on strongly coupled Dark Matter (DM), where sizable effects can be expected in LHC missing energy (MET) searches, compatibly with a large separation of scales. In this case, an effective field theory (EFT) is appropriate (and sometimes necessary) to describe the most relevant interactions at the LHC. The selection rules implied by the structure of the new strong dynamics shape the EFT in an unusual way, revealing the importance of higher-derivative interactions previously ignored. We compare indications from relic density and direct detection experiments with consistent LHC constraints, and asses the relative importance of the latter. Our analysis provides an interesting and well-motivated scenario to model MET at the LHC in terms of a handful of parameters.

  2. Random Matrix Theory of Rigidity in Soft Matter

    NASA Astrophysics Data System (ADS)

    Yamanaka, Masanori

    2015-06-01

    We study the rigidity or softness of soft matter using the characteristic scale of coupling formation developed in random matrix theory. The eigensystems of the timescale-dependent cross-correlation matrix, which are obtained from the time series data of the atomic coordinates of a protein produced by the all-atom molecular dynamics of the solvent, are analyzed. As an example, we present a result for a protein lysozyme, PDBID:1AKI. We find that there are at least three different time scales involved in the coupling formation of correlated sectors of atoms and at least two different time scales for the size of the correlated sectors. These five time scales coexist simultaneously. We compare the results with those of the normal mode analysis and find a crossover of the distribution of the dominant vibrational components.

  3. Extensive deep gray matter volume reductions in children and adolescents with fetal alcohol spectrum disorders.

    PubMed

    Nardelli, Alexa; Lebel, Catherine; Rasmussen, Carmen; Andrew, Gail; Beaulieu, Christian

    2011-08-01

    The link between the numerous cognitive, motor, and behavioral difficulties of individuals with fetal alcohol spectrum disorders (FASD) and underlying specific structural brain injuries can be investigated using high-resolution imaging. Differential sensitivity of the brain's "relay" stations, namely the deep gray matter structures, may play a key factor given their multifaceted role in brain function. The purpose of our study was to analyze differences in deep gray matter volumes of children and adolescents with FASD relative to age/sex-matched controls and to examine whether any volume differences were consistent across the age range of neurodevelopment. Children and adolescents (N = 28, 6 to 17 years) diagnosed with FASD and 56 age- and sex-matched healthy controls (i.e., 2 matched controls per FASD subject) underwent 3-dimensional T1-weighted MRI scans that were used for the automated volume measurement (FreeSurfer) of the intracranial space, total white matter, cortical gray matter, and 6 deep gray matter structures, namely the hippocampus, amygdala, thalamus, caudate, putamen, and globus pallidus, with left and right measured separately. Volumes were compared between FASD and controls, as well as changes with age. Significant reductions of volume in FASD were observed for the intracranial vault (7.6%), total white matter (8.6%), total cortical gray matter (7.8%), and total deep gray matter (13.1%). All 6 deep gray matter structures showed significant volume reductions bilaterally with the caudate (approximately 16%) and globus pallidus (approximately 18%) being most affected. The hippocampus, thalamus, and globus pallidus showed reductions in all 3 age subgroups (6 to 9, 10 to 13, and 14 to 17 years) but the caudate and putamen had smaller volumes for FASD only within the 2 youngest subgroups; the amygdala was only smaller for FASD in the 2 oldest subgroups. Significant, but variable, volume reductions throughout the deep gray matter are observed over a wide

  4. Grey matter volume in adolescents with anorexia nervosa and associated eating disorder symptoms.

    PubMed

    Martin Monzon, Beatriz; Henderson, Luke A; Madden, Sloane; Macefield, Vaughan G; Touyz, Stephen; Kohn, Michael R; Clarke, Simon; Foroughi, Nasim; Hay, Phillipa

    2017-10-01

    Anorexia nervosa (AN) is a mental health disorder of complex aetiology. Previous neuroimaging studies have found consistent global reductions in global grey matter volume of underweight girls with AN; however, differences in regional grey matter volumes are less consistent. The aims of this study were to investigate grey matter regional volumes of adolescent girls with AN before and after weight recovery and the relationship of any changes with clinical characteristics. We collected high-resolution T1-weighted images from 26 underweight girls with AN before weight gain and 20 healthy control volunteers. Clinical features were assessed using the Eating Disorder Examination Questionnaire. AN subjects displayed reduced grey matter volumes in the insula, amygdala, prefrontal, hippocampal and cingulate cortices and the precuneus, relative to healthy controls. In a subset of 10 AN subjects who were followed after weight recovery, grey matter volumes increased to near-control levels in the orbito- and medial prefrontal, insular, left hippocampal and mid- and posterior cingulate cortices and precuneus. The recovery of the right anterior thalamus and the left orbitofrontal cortex was correlated with improvements in eating concerns and shape concerns, respectively. However, large parts of the anterior cingulate cortex, caudate nuclei and right hippocampus did not display any grey matter recovery following a short-term of treatment. These results show that in adolescents with AN, some brain regions display marked recovery in grey matter volume following weight recovery, whereas others do not, considering grey mater recovery possibly linked to symptom improvement. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  5. Hemoglobin and mean platelet volume predicts diffuse T1-MRI white matter volume decrease in sickle cell disease patients.

    PubMed

    Choi, Soyoung; Bush, Adam M; Borzage, Matthew T; Joshi, Anand A; Mack, William J; Coates, Thomas D; Leahy, Richard M; Wood, John C

    2017-01-01

    Sickle cell disease (SCD) is a life-threatening genetic condition. Patients suffer from chronic systemic and cerebral vascular disease that leads to early and cumulative neurological damage. Few studies have quantified the effects of this disease on brain morphometry and even fewer efforts have been devoted to older patients despite the progressive nature of the disease. This study quantifies global and regional brain volumes in adolescent and young adult patients with SCD and racially matched controls with the aim of distinguishing between age related changes associated with normal brain maturation and damage from sickle cell disease. T1 weighted images were acquired on 33 clinically asymptomatic SCD patients (age = 21.3 ± 7.8; F = 18, M = 15) and 32 racially matched control subjects (age = 24.4 ± 7.5; F = 22, M = 10). Exclusion criteria included pregnancy, previous overt stroke, acute chest, or pain crisis hospitalization within one month. All brain volume comparisons were corrected for age and sex. Globally, grey matter volume was not different but white matter volume was 8.1% lower (p = 0.0056) in the right hemisphere and 6.8% (p = 0.0068) in the left hemisphere in SCD patients compared with controls. Multivariate analysis retained hemoglobin (β = 0.33; p = 0.0036), sex (β = 0.35; p = 0.0017) and mean platelet volume (β = 0.27; p = 0.016) as significant factors in the final prediction model for white matter volume for a combined r(2) of 0.37 (p < 0.0001). Lower white matter volume was confined to phylogenetically younger brain regions in the anterior and middle cerebral artery distributions. Our findings suggest that there are diffuse white matter abnormalities in SCD patients, especially in the frontal, parietal and temporal lobes, that are associated with low hemoglobin levels and mean platelet volume. The pattern of brain loss suggests chronic microvascular insufficiency and tissue hypoxia as the causal mechanism

  6. 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.

  7. Cerebellar gray matter volume correlates with duration of cocaine use in cocaine-dependent subjects.

    PubMed

    Sim, Minyoung E; Lyoo, In Kyoon; Streeter, Chris C; Covell, Julie; Sarid-Segal, Ofra; Ciraulo, Domenic A; Kim, Minue J; Kaufman, Marc J; Yurgelun-Todd, Deborah A; Renshaw, Perry F

    2007-10-01

    This study was conducted to explore differences in gray and white matter volume between cocaine-dependent and healthy comparison subjects using optimized voxel-based morphometry (VBM). Brain magnetic resonance imaging (MRI) and neuropsychological function tests were performed for 40 cocaine-dependent subjects (41.4+/-6.9 years, 27 men) and 41 healthy age- and sex-matched comparison subjects (38.7+/-8.8 years, 26 men). Optimally normalized whole brain MR images were segmented, modulated, smoothed, and compared between groups with statistical parametric mapping. The cocaine-dependent group had lower gray matter volumes in bilateral premotor cortex (Brodmann area (BA) 6, 8; 16.6%), right orbitofrontal cortex (BA 10, 15.1%), bilateral temporal cortex (BA 20, 38; 15.9%), left thalamus (12.6%), and bilateral cerebellum (13.4%) as well as lower right cerebellar white matter volume (10.0%) relative to the comparison group at a corrected p<0.05 for multiple comparisons. Duration of cocaine use negatively correlated with right and left cerebellar gray matter volumes (r=-0.37, r=-0.39, respectively). In cocaine-dependent subjects, lower cerebellar hemispheric gray and white matter volumes were correlated with deficits in executive function and decreased motor performance. This study reports that cocaine-dependent subjects have lower gray matter volumes in cerebellar hemispheres as well as in frontal, temporal cortex, and thalamus. These findings are the first to suggest that the cerebellum may be vulnerable to cocaine-associated brain volume changes, and that cerebellar deficits may contribute to neuropsychological deficits and motor dysfunction frequently observed in cocaine-dependent subjects.

  8. 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

    2010-12-08

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

  9. Quantum cosmology with matter in scalar-tensor theory

    NASA Astrophysics Data System (ADS)

    Lee, S.; Lim, H.

    2016-11-01

    The cosmological application of the low energy effective action of string theory with perfect fluid type matter (satisfying p=γ ρ ) is reconsidered. First, its isotropic and anisotropic spacetime cosmological solutions are obtained for general γ . The scale factor duality is applied and checked for our model as well as in the presence of γ of which possible extension to nonvanishing γ is pioneered before. The asymptotic behavior of the solutions is investigated because of the complexity of the solutions. Second, as a quantization, we apply the canonical quantization and the corresponding Wheeler-De Witt equation is constructed for this scalar-tensor theory. By solving the Wheeler-De Witt equation the wave function is found for general value of γ . On the basis of its wave function, the tunneling rate turns out to be just the ratio of norms of the wave function for pre- and post-big-bang phases. This result shows that the rate grows as γ gets value close to a specific value. This resolves the undetermined value for the behavior of the scale factors.

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

    PubMed

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

    2016-12-13

    Cortical grey matter volume deficits and neuro-inflammation exist in patients with schizophrenia, although it is not clear whether elevated cytokines contribute to the cortical volume reduction. We quantified cortical and regional brain volumes in fixed postmortem brains from people with schizophrenia and matched controls using stereology. Interleukin (IL)-6, IL-1β, IL-8 and SERPINA3 messenger RNAs (mRNAs) were quantified in the contralateral fresh frozen orbitofrontal cortex. We found a small, but significant reduction in cortical grey matter (1.3%; F(1,85)=4.478, P=0.037) and superior frontal gyrus (6.5%; F(1,80)=5.700, P=0.019) volumes in individuals with schizophrenia compared with controls. Significantly reduced cortical grey matter (9.2%; F(1,24)=8.272, P=0.008) and superior frontal gyrus (13.9%; F(1,20)=5.374, P=0.031) volumes were found in cases with schizophrenia and 'high inflammation' status relative to schizophrenia cases with 'low inflammation' status in the prefrontal cortex. The expression of inflammatory mRNAs in the orbitofrontal cortex was significantly correlated with those in dorsolateral prefrontal cortex (all r>0.417, all P<0.022), except for IL-8. Moreover, average daily and lifetime antipsychotic intake negatively correlated with cortical grey matter and superior frontal gyrus volumes (all r<-0.362, all P<0.05). The results suggest that the reduction in cortical grey matter volume in people with schizophrenia is exaggerated in those who have high expression of inflammatory cytokines. Further, antipsychotic medication intake does not appear to ameliorate the reduction in brain volume.

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

    PubMed Central

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

    2016-01-01

    Cortical grey matter volume deficits and neuro-inflammation exist in patients with schizophrenia, although it is not clear whether elevated cytokines contribute to the cortical volume reduction. We quantified cortical and regional brain volumes in fixed postmortem brains from people with schizophrenia and matched controls using stereology. Interleukin (IL)-6, IL-1β, IL-8 and SERPINA3 messenger RNAs (mRNAs) were quantified in the contralateral fresh frozen orbitofrontal cortex. We found a small, but significant reduction in cortical grey matter (1.3% F(1,85)=4.478, P=0.037) and superior frontal gyrus (6.5% F(1,80)=5.700, P=0.019) volumes in individuals with schizophrenia compared with controls. Significantly reduced cortical grey matter (9.2% F(1,24)=8.272, P=0.008) and superior frontal gyrus (13.9% F(1,20)=5.374, P=0.031) volumes were found in cases with schizophrenia and ‘high inflammation' status relative to schizophrenia cases with ‘low inflammation' status in the prefrontal cortex. The expression of inflammatory mRNAs in the orbitofrontal cortex was significantly correlated with those in dorsolateral prefrontal cortex (all r>0.417, all P<0.022), except for IL-8. Moreover, average daily and lifetime antipsychotic intake negatively correlated with cortical grey matter and superior frontal gyrus volumes (all r<−0.362, all P<0.05). The results suggest that the reduction in cortical grey matter volume in people with schizophrenia is exaggerated in those who have high expression of inflammatory cytokines. Further, antipsychotic medication intake does not appear to ameliorate the reduction in brain volume. PMID:27959331

  12. 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

  13. 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.

  14. 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.

  15. Gray matter volume and white matter lesions in chronic kidney disease: exploring the association with depressive symptoms.

    PubMed

    Meurs, Maaike; Roest, Annelieke M; Groenewold, Nynke A; Franssen, Casper F M; Westerhuis, Ralf; Kloppenburg, Wybe Douwe; Doornbos, Bennard; Beukema, Lindy; Lindmäe, Hanna; de Groot, Jan Cees; van Tol, Marie-José; de Jonge, Peter

    2016-01-01

    Chronic kidney disease (CKD) is associated with structural brain damage and with a high prevalence of depression. We therefore investigated structural brain alterations in both gray and white matter in CKD patients, focusing on depression-related (frontal-subcortical) regions. This cross-sectional MRI study in 24 CKD patients and 24 age- and sex-matched controls first tested whether CKD was associated with regionally lower gray matter (GM) volumes and more severe white matter lesions (WMLs). In exploratory subanalyses, we examined whether differences were more pronounced in CKD patients with depressive symptoms. CKD patients showed lower global GM volume (P=.04) and more severe WMLs (P=.04) compared to controls. In addition, we found substantial clusters of lower GM in the bilateral orbitofrontal-cortex for CKD patients, which were however nonsignificant after proper multiple-comparison correction. In exploratory analyses for depressed CKD patients, reduced GM clusters were mainly detected within the frontal lobe. WML severity was unrelated to depression. CKD was characterized by differences in brain structure. Although subthreshold, lower GM volumes were observed in depression-related brain areas and were more pronounced for depressed patients. There is a need for replication in larger and longitudinal studies to investigate whether WMLs and regional GM reductions may render CKD patients more susceptible for depression. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    PubMed

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

    2015-06-04

    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. 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. 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. 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. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  17. A note on Kahler potential of charged matter in F-theory

    NASA Astrophysics Data System (ADS)

    Kawano, Teruhiko; Tsuchiya, Yoichi; Watari, Taizan

    2012-03-01

    We study the Kahler potential of charged matter fields, whose profiles have a peak on their matter curve - on an "intersection" of 7-branes, in an F-theory compactification. It is shown that the Kahler potential is exactly given by the integral over the matter curve, but not by the integral over the whole GUT surface of 7-branes.

  18. Sex dimorphism in gray/white matter volume and diffusion tensor during normal aging.

    PubMed

    Abe, Osamu; Yamasue, Hidenori; Yamada, Haruyasu; Masutani, Yoshitaka; Kabasawa, Hiroyuki; Sasaki, Hiroki; Takei, Kunio; Suga, Motomu; Kasai, Kiyoto; Aoki, Shigeki; Ohtomo, Kuni

    2010-06-01

    The purpose of this study is to elucidate sex differences in global and regional gray/white matter volume, mean diffusivity (MD), and fractional anisotropy (FA) during normal aging using voxel-based analysis. We studied 245 healthy right-handed subjects with a wide range of ages (115 women, 22-70 years; 130 men, 21-71 years). Regarding global effects, inclusion of a quadratic age term improved the fit to data for white matter fraction and MD, but not for global gray matter volume/fraction or FA. Regarding regional effects, we found anterior-dominant volume loss, FA decrease predominantly in the anterior white matter, and MD increase predominantly in perisylvian regions and periventricular white matter against age for both sexes. Compared with women, we found a steeper FA decline for men in the right inferior fronto-temporal areas, extending to the anterior cingulate cortex, and an accelerated MD increase for men in the bilateral frontal, temporal, and parietal areas. There was no area in which interaction of sex with age was significant for regional volume, or in which a steeper FA decline or accelerated MD increase for women was significant. Our results provide strong evidence of sex dimorphism in global and focal diffusion characteristics during normal aging.

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

    PubMed Central

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

    2016-01-01

    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

  20. 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.

  1. Dark matter in ghost-free bigravity theory: From a galaxy scale to the universe

    NASA Astrophysics Data System (ADS)

    Aoki, Katsuki; Maeda, Kei-ichi

    2014-12-01

    We study the origin of dark matter based on the ghost-free bigravity theory with twin matter fluids. The present cosmic acceleration can be explained by the existence of graviton mass, while dark matter is required in several cosmological situations (the galactic missing mass, the cosmic structure formation and the cosmic microwave background observation). Assuming that the Compton wavelength of the massive graviton is shorter than a galactic scale, we show the bigravity theory can explain dark matter by twin matter fluid as well as the cosmic acceleration by tuning appropriate coupling constants.

  2. 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.

  3. 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.

  4. Sleep duration during weekdays affects hippocampal gray matter volume in healthy children.

    PubMed

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

    2012-03-01

    Sleep is essential for living beings, and sleep loss has been shown to affect hippocampal structure and function in rats by inhibiting cell proliferation and neurogenesis in this region of the brain. We aimed to analyze the correlation between sleep duration and the hippocampal volume using brain magnetic resonance images of 290 healthy children aged 5-18 years. We examined the volume of gray matter, white matter, and the cerebrospinal fluid (CSF) space in the brain using a fully automated and established neuroimaging technique, voxel-based morphometry, which enabled global analysis of brain structure without bias towards any specific brain region while permitting the identification of potential differences or abnormalities in brain structures. We found that the regional gray matter volume of the bilateral hippocampal body was significantly positively correlated with sleep duration during weekdays after adjusting for age, sex, and intracranial volume. Our results indicated that sleep duration affects the hippocampal regional gray matter volume of healthy children. These findings advance our understanding of the importance of sleep habits in the daily lives of healthy children. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Age-related effects in the neocortical organization of chimpanzees: gray and white matter volume, cortical thickness, and gyrification.

    PubMed

    Autrey, Michelle M; Reamer, Lisa A; Mareno, Mary Catherine; Sherwood, Chet C; Herndon, James G; Preuss, Todd; Schapiro, Steve J; Hopkins, William D

    2014-11-01

    Among primates, humans exhibit the most profound degree of age-related brain volumetric decline in particular regions, such as the hippocampus and the frontal lobe. Recent studies have shown that our closest living relatives, the chimpanzees, experience little to no volumetric decline in gray and white matter over the adult lifespan. However, these previous studies were limited with a small sample of chimpanzees of the most advanced ages. In the present study, we sought to further test for potential age-related decline in cortical organization in chimpanzees by expanding the sample size of aged chimpanzees. We used the BrainVisa software to measure total brain volume, gray and white matter volumes, gray matter thickness, and gyrification index in a cross-sectional sample of 219 captive chimpanzees (8-53 years old), with 38 subjects being 40 or more years of age. Mean depth and cortical fold opening of 11 major sulci of the chimpanzee brains were also measured. We found that chimpanzees showed increased gyrification with age and a cubic relationship between age and white matter volume. For the association between age and sulcus depth and width, the results were mostly non-significant with the exception of one negative correlation between age and the fronto-orbital sulcus. In short, results showed that chimpanzees exhibit few age-related changes in global cortical organization, sulcus folding and sulcus width. These findings support previous studies and the theory that the age-related changes in the human brain is due to an extended lifespan. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Global and local development of gray and white matter volume in normal children and adolescents.

    PubMed

    Wilke, Marko; Krägeloh-Mann, Ingeborg; Holland, Scott K

    2007-04-01

    Over the last decade, non-invasive, high-resolution magnetic resonance imaging has allowed investigating normal brain development. However, much is still not known in this context, especially with regard to regional differences in brain morphology between genders. We conducted a large-scale study utilizing fully automated analysis-approaches, using high-resolution MR-imaging data from 200 normal children and aimed at providing reference data for future neuroimaging studies. Global and local aspects of normal development of gray and white matter volume were investigated as a function of age and gender while covarying for known nuisance variables. Global developmental patterns were apparent in both gray and white matter, with gray matter decreasing and white matter increasing significantly with age. Gray matter loss was most pronounced in the parietal lobes and least in the cingulate and in posterior temporal regions. White matter volume gains with age were almost uniform, with an accentuation of the pyramidal tract. Gender influences were detectable for both gray and white matter. Voxel-based analyses confirmed significant differences in brain morphology between genders, like a larger amygdala in boys or a larger caudate in girls. We could demonstrate profound influences of both age and gender on normal brain morphology, confirming and extending earlier studies. The knowledge of such influence allows for the consideration of age- and gender-effects in future pediatric neuroimaging studies and advances our understanding of normal and abnormal brain development.

  7. Association of SOD2, a mitochondrial antioxidant enzyme, with gray matter volume shrinkage in alcoholics.

    PubMed

    Srivastava, Vibhuti; Buzas, Beata; Momenan, Reza; Oroszi, Gabor; Pulay, Attila J; Enoch, Mary-Anne; Hommer, Daniel W; Goldman, David

    2010-04-01

    Chronic alcoholism leads to gray matter shrinkage and induces the formation of superoxide anions (O(2)(-)) that can cause neuronal cell death. The mitochondrial superoxide dismutase 2 (SOD2) enzyme is critical in the metabolism of superoxide. An Ala16Val polymorphism putatively affects SOD2 enzyme activity in vivo. Brain volumes of 76 treatment-seeking alcohol-dependent individuals were measured with a 1.5T MRI. Intracranial tissue margins were manually outlined on coronal sections. Gray matter, white matter, sulcal, and ventricular CSF volumes were estimated using intensity-based K-means clustering. Ala16Val (rs4880) and a second haplotype tagging SNP, rs10370, were genotyped. The q-value package was used to correct for multiple comparisons. In the alcoholics, cerebrospinal fluid and intra-cranial volumes showed significant differences across the six diplotype categories. The homozygous Ala16-containing diplotype rs10370TT-rs4880GG was associated with lowest gray matter ratio (greater shrinkage; p=0.005). Presence of one or two copies of the low activity Ala16 allele was a risk factor for lower gray matter volume in alcoholics below the median alcohol consumption (p=0.03) but not in alcoholics above this level. White matter ratio was associated with sex (p=0.002) and lifetime total alcohol consumption (p=0.01) but not with diplotypes. In this exploratory analysis, a putative functional missense variant of SOD2 appears to influence gray matter loss in alcoholics. This may be due to impaired clearance of reactive oxygen species formed as a result of alcohol exposure. The risk/protective effect was observed in alcoholics with lower levels of lifetime alcohol consumption. Highest levels of exposure may overwhelm the protective action of the SOD2 enzyme.

  8. Association of SOD2, a Mitochondrial Antioxidant Enzyme, with Gray Matter Volume Shrinkage in Alcoholics

    PubMed Central

    Srivastava, Vibhuti; Buzas, Beata; Momenan, Reza; Oroszi, Gabor; Pulay, Attila J; Enoch, Mary-Anne; Hommer, Daniel W; Goldman, David

    2010-01-01

    Chronic alcoholism leads to gray matter shrinkage and induces the formation of superoxide anions (O2−) that can cause neuronal cell death. The mitochondrial superoxide dismutase 2 (SOD2) enzyme is critical in the metabolism of superoxide. An Ala16Val polymorphism putatively affects SOD2 enzyme activity in vivo. Brain volumes of 76 treatment-seeking alcohol-dependent individuals were measured with a 1.5T MRI. Intracranial tissue margins were manually outlined on coronal sections. Gray matter, white matter, sulcal, and ventricular CSF volumes were estimated using intensity-based K-means clustering. Ala16Val (rs4880) and a second haplotype tagging SNP, rs10370, were genotyped. The q-value package was used to correct for multiple comparisons. In the alcoholics, cerebrospinal fluid and intra-cranial volumes showed significant differences across the six diplotype categories. The homozygous Ala16-containing diplotype rs10370TT-rs4880GG was associated with lowest gray matter ratio (greater shrinkage; p=0.005). Presence of one or two copies of the low activity Ala16 allele was a risk factor for lower gray matter volume in alcoholics below the median alcohol consumption (p=0.03) but not in alcoholics above this level. White matter ratio was associated with sex (p=0.002) and lifetime total alcohol consumption (p=0.01) but not with diplotypes. In this exploratory analysis, a putative functional missense variant of SOD2 appears to influence gray matter loss in alcoholics. This may be due to impaired clearance of reactive oxygen species formed as a result of alcohol exposure. The risk/protective effect was observed in alcoholics with lower levels of lifetime alcohol consumption. Highest levels of exposure may overwhelm the protective action of the SOD2 enzyme. PMID:20043000

  9. Hypothalamic tumors impact gray and white matter volumes in fronto-limbic brain areas.

    PubMed

    Özyurt, Jale; Müller, Hermann L; Warmuth-Metz, Monika; Thiel, Christiane M

    2017-04-01

    Patients with hypothalamic involvement of a sellar/parasellar tumor often suffer from cognitive and social-emotional deficits that a lesion in the hypothalamus cannot fully explain. It is conceivable that these deficits are partly due to distal changes in hypothalamic networks, evolving secondary to a focal lesion. Focusing on childhood-onset craniopharyngioma patients, we aimed at investigating the impact of hypothalamic lesions on gray and white matter areas densely connected to the hypothalamus, and to relate structural changes to neuropsychological deficits frequently observed in patients. We performed a voxel-based morphometric analysis based on data of 11 childhood-onset craniopharyngioma patients with hypothalamic tumor involvement, and 18 healthy controls (median age: 17.2 and 17.4 yrs.). Whole-brain analyses were used to test for volumetric differences between the groups (T-tests) and subsequent regression analyses were used to correlate neuropsychological performance with gray and white matter volumes within the patient group. Patients compared to controls had significantly reduced gray matter volumes in areas of the anterior and posterior limbic subsystems which are densely connected with the hypothalamus. In addition, a reduction in white matter volumes was observed in tracts connecting the hypothalamus to other limbic areas. Worse long-term memory retrieval was correlated with smaller gray matter volumes in the posterior cingulate cortex. Our data provide the first evidence that hypothalamic tumor involvement impacts gray and white matter volumes in limbic areas, outside the area of tumor growth. Notably, the functional range of the two limbic subsystems affected, strikingly parallels the two major domains of psychological complaints in patients i.e., deficits in episodic memory and in socio-emotional functioning. We suggest that focal hypothalamic lesions may trigger distal changes in connected brain areas, which then contribute to the impairments in

  10. Cortical Thickness or Grey Matter Volume? The Importance of Selecting the Phenotype for Imaging Genetics Studies

    PubMed Central

    Kochunov, Peter; Blangero, John; Almasy, Laura; Zilles, Karl; Fox, Peter T.; Duggirala, Ravindranath; Glahn, David C.

    2010-01-01

    Choosing the appropriate neuroimaging phenotype is critical to successfully identify genes that influence brain structure or function. While neuroimaging methods provide numerous potential phenotypes, their role for imaging genetics studies are unclear. Here we examine the relationship between brain volume, grey matter volume, cortical thickness and surface area, from a genetic standpoint. Four hundred and eighty-six individuals from randomly ascertained extended pedigrees with high-quality T1-weighted neuroanatomic MRI images participated in the study. Surface-based and voxel-based representations of brain structure were derived, using automated methods, and these measurements were analysed using a variance-components method to identify the heritability of these traits and their genetic correlations. All neuroanatomic traits were significantly influenced by genetic factors. Cortical thickness and surface area measurements were found to be genetically and phenotypically independent. While both thickness and area influenced volume measurements of cortical grey matter, volume was more closely related to surface area than cortical thickness. This trend was observed for both the volume-based and surface-based techniques. The results suggest that surface area and cortical thickness measurements should be considered separately and preferred over gray matter volumes for imaging genetic studies. PMID:20006715

  11. Quantum corrections to the generalized Proca theory via a matter field

    NASA Astrophysics Data System (ADS)

    Amado, André; Haghani, Zahra; Mohammadi, Azadeh; Shahidi, Shahab

    2017-09-01

    We study the quantum corrections to the generalized Proca theory via matter loops. We consider two types of interactions, linear and nonlinear in the vector field. Calculating the one-loop correction to the vector field propagator, three- and four-point functions, we show that the non-linear interactions are harmless, although they renormalize the theory. The linear matter-vector field interactions introduce ghost degrees of freedom to the generalized Proca theory. Treating the theory as an effective theory, we calculate the energy scale up to which the theory remains healthy.

  12. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2013-05-01

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

  14. Antidepressant exposure may protect against decrement in frontal gray matter volumes in geriatric depression.

    PubMed

    Lavretsky, Helen; Roybal, Donna J; Ballmaier, Martina; Toga, Arthur W; Kumar, Anand

    2005-08-01

    Depressed elderly patients with and without antidepressant exposure were compared to normal controls to examine the effects of prior antidepressant exposure on regional brain gray matter volumes using magnetic resonance imaging (MRI). The study was conducted from October 1999 to January 2003. Patients and controls were closely matched by age and education. They underwent comprehensive neuropsychiatric and physical examinations. Measures of the total frontal lobe and the frontal gray and white matter volumes corrected by the intracranial volume were obtained using MRI, together with clinical measures of medical burden. Historical information about prior exposure to antidepressant drugs was collected using multiple information sources. The groups were compared using multivariate analyses of covariance, controlling for age, sex, and medical burden. The study sample comprised 41 patients who met the DSM-IV criteria for major depressive disorder (32 women; 11 antidepressant exposure and 30 drug-naive; mean age 70.5 years) and 41 controls (20 women; mean age 72.2 years). In the multivariate analysis, the depressed group had smaller corrected orbitofrontal cortex (OFC) total and gray matter volumes compared to the controls (p < .01). However, depressed patients with prior antidepressant exposure had larger OFC gray matter volumes compared to drug-naive depressed patients, but smaller than those in normal controls (p = .005). This effect was not explained by the group differences in sex ratio, age at onset of depression, or the number or duration of depressive episodes. We observed larger OFC regional volumes in depressed patients exposed to antidepressants compared to the drug-naive depressed subjects, but smaller than those in age-matched controls. Antidepressant exposure may protect against gray matter loss in geriatric depression.

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

    PubMed

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

    2012-04-07

    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.

  16. Partial volume correction and image segmentation for accurate measurement of standardized uptake value of grey matter in the brain.

    PubMed

    Bural, Gonca; Torigian, Drew; Basu, Sandip; Houseni, Mohamed; Zhuge, Ying; Rubello, Domenico; Udupa, Jayaram; Alavi, Abass

    2015-12-01

    Our aim was to explore a novel quantitative method [based upon an MRI-based image segmentation that allows actual calculation of grey matter, white matter and cerebrospinal fluid (CSF) volumes] for overcoming the difficulties associated with conventional techniques for measuring actual metabolic activity of the grey matter. We included four patients with normal brain MRI and fluorine-18 fluorodeoxyglucose (F-FDG)-PET scans (two women and two men; mean age 46±14 years) in this analysis. The time interval between the two scans was 0-180 days. We calculated the volumes of grey matter, white matter and CSF by using a novel segmentation technique applied to the MRI images. We measured the mean standardized uptake value (SUV) representing the whole metabolic activity of the brain from the F-FDG-PET images. We also calculated the white matter SUV from the upper transaxial slices (centrum semiovale) of the F-FDG-PET images. The whole brain volume was calculated by summing up the volumes of the white matter, grey matter and CSF. The global cerebral metabolic activity was calculated by multiplying the mean SUV with total brain volume. The whole brain white matter metabolic activity was calculated by multiplying the mean SUV for the white matter by the white matter volume. The global cerebral metabolic activity only reflects those of the grey matter and the white matter, whereas that of the CSF is zero. We subtracted the global white matter metabolic activity from that of the whole brain, resulting in the global grey matter metabolism alone. We then divided the grey matter global metabolic activity by grey matter volume to accurately calculate the SUV for the grey matter alone. The brain volumes ranged between 1546 and 1924 ml. The mean SUV for total brain was 4.8-7. Total metabolic burden of the brain ranged from 5565 to 9617. The mean SUV for white matter was 2.8-4.1. On the basis of these measurements we generated the grey matter SUV, which ranged from 8.1 to 11.3. The

  17. 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

  18. Gray Matter Volume Deficits are Associated with Motor and Attentional Impairments in Adolescents with Schizophrenia

    PubMed Central

    Kumra, Sanjiv; Ashtari, Manzar; Wu, Jinghui; Hongwanishkul, Donaya; White, Tonya; Cervellione, Kelly; Cottone, John; Szeszko, Philip R.

    2012-01-01

    Cognitive deficits have been well described in adolescents with schizophrenia, but little is known about the neuroanatomical basis of these abnormalities. The authors examined whether neuropsychological deficits observed in adolescents with schizophrenia were associated with cortical gray matter volume deficits. Volumes of the superior frontal gyrus, anterior cingulate gyrus and orbital frontal lobe were outlined manually from contiguous MR images and automatically segmented into gray and white matter in 52 patients and 48 healthy volunteers. Subjects received a comprehensive neuropsychological test battery, assessing five different functional domains: executive, attention, verbal memory, motor and sensory motor. Children and adolescents with schizophrenia were found to have lower total cortical and lower superior frontal gyrus gray matter volumes and lower test scores across all functional domains compared to healthy volunteers. Among patients, lower total cortical gray matter volume was associated with worse functioning on the attention and motor domains. Our findings point to widespread, perhaps multifocal, pathology as contributing to cognitive dysfunction in adolescents with schizophrenia. PMID:21216271

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

    EPA Science Inventory

    There is no abstract available for these documents.

    If further information is requested, please refer to the bibliographic citation and contact the Technical Information Staff at the number listed above.

    • Air Quality Criteria for Particulate Matter, Volume I, Extern...

    • 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…

  1. 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…

  2. Deaf Children's Judgments on Conservation Problems of Liquid, Matter, Weight and Volume: A Pilot Study.

    ERIC Educational Resources Information Center

    Rittenhouse, Robert K.

    Twenty-four profoundly deaf children (7 to 13 years old) from a residential school were presented with conservation problems of liquid, matter, weight, and volume. Analyses of variance showed that age was significant beyond the .01 level and type of task (conservation) at the .25 level. No significant sex effect was found. Differences among means…

  3. Normal volumes and microstructural integrity of deep gray matter structures in AQP4+ NMOSD

    PubMed Central

    Heine, Josephine; Pache, Florence; Lacheta, Anna; Borisow, Nadja; Kuchling, Joseph; Bellmann-Strobl, Judith; Ruprecht, Klemens; Brandt, Alexander U.; Paul, Friedemann

    2016-01-01

    Objective: To assess volumes and microstructural integrity of deep gray matter structures in a homogeneous cohort of patients with neuromyelitis optica spectrum disorder (NMOSD). Methods: This was a cross-sectional study including 36 aquaporin-4 antibody-positive (AQP4 Ab-positive) Caucasian patients with NMOSD and healthy controls matched for age, sex, and education. Volumetry of deep gray matter structures (DGM; thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, nucleus accumbens) was performed using 2 independent automated methods. Microstructural integrity was assessed based on diffusion tensor imaging. Results: Both volumetric analysis methods consistently revealed similar volumes of DGM structures in patients and controls without significant group differences. Moreover, no differences in DGM microstructural integrity were observed between groups. Conclusions: Deep gray matter structures are not affected in AQP4 Ab-positive Caucasian patients with NMOSD. NMOSD imaging studies should be interpreted with respect to Ab status, educational background, and ethnicity of included patients. PMID:27144219

  4. Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

    NASA Astrophysics Data System (ADS)

    Hirano, Shin'ichi; Nishi, Sakine; Kobayashi, Tsutomu

    2017-07-01

    We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F(Script R) theory is plagued with the Ostrogradsky instability.

  5. Localized Brain Volume and White Matter Integrity Alterations in Adolescent Anorexia Nervosa

    PubMed Central

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

    2014-01-01

    Objective The neurobiological underpinnings of anorexia nervosa (AN) are poorly understood. In this study we tested whether brain gray matter (GM) and white matter (WM) in adolescents with AN would show alterations comparable to adults. Method We used magnetic resonance imaging to study GM and WM volume, and diffusion tensor imaging to assess fractional anisotropy for WM integrity in 19 adolescents with AN and 22 controls. Results Individuals with AN showed greater left orbitofrontal, right insular, and bilateral temporal cortex GM, as well as temporal lobe WM volumes compared to controls. WM integrity in adolescents with AN was lower (lower fractional anisotropy) in fornix, posterior frontal, and parietal areas, but higher in anterior frontal, orbitofrontal, and temporal lobes. In individuals with AN, orbitofrontal GM volume correlated negatively with sweet taste pleasantness. An additional comparison of this study cohort with adult individuals with AN and healthy controls supported greater orbitofrontal cortex and insula volumes in AN across age groups. Conclusions This study indicates larger orbitofrontal and insular GM volumes, as well as lower fornix WM integrity in adolescents with AN, similar to adults. The pattern of larger anteroventral GM and WM volume as well as WM integrity, but lower WM integrity in posterior frontal and parietal regions may indicate that developmental factors such as GM pruning and WM growth could contribute to brain alterations in AN. The negative correlation between taste pleasantness and orbitofrontal cortex volume in individuals with AN could contribute to food avoidance in this disorder. PMID:24074473

  6. Serotonin transporter gene methylation is associated with hippocampal gray matter volume.

    PubMed

    Dannlowski, Udo; Kugel, Harald; Redlich, Ronny; Halik, Adriane; Schneider, Ilona; Opel, Nils; Grotegerd, Dominik; Schwarte, Kathrin; Schettler, Christiane; Ambrée, Oliver; Rust, Stephan; Domschke, Katharina; Arolt, Volker; Heindel, Walter; Baune, Bernhard T; Suslow, Thomas; Zhang, Weiqi; Hohoff, Christa

    2014-11-01

    The serotonin transporter (5-HTT) and the 5-HTTLPR/rs25531 polymorphisms in its gene (SLC6A4) have been associated with depression, increased stress-response, and brain structural alterations such as reduced hippocampal volumes. Recently, epigenetic processes including SLC6A4 promoter methylation were shown to be affected by stress, trauma, or maltreatment and are regarded to be involved in the etiology of affective disorders. However, neurobiological correlates of SLC6A4 promoter methylation have never been studied or compared to genotype effects by means of human neuroimaging hitherto Healthy subjects were recruited in two independent samples (N = 94, N = 95) to obtain structural gray matter images processed by voxel-based morphometry (VBM8), focusing on hippocampal, amygdala, and anterior cingulate gyrus gray matter structure. SLC6A4 promoter methylation within an AluJb element and 5-HTTLPR/rs25531 genotypes were analyzed in view of a possible impact on local gray matter volume Strong associations of AluJb methylation and hippocampal gray matter volumes emerged within each sample separately, which in the combined sample withstood most conservative alpha-corrections for the entire brain. The amygdala, insula, and caudate nucleus showed similar associations. The 5-HTTLPR/rs25531 showed no main effect on gray matter, and the effect of methylation rates on hippocampal structure was comparable among the genotype groups Methylation within the AluJb appears to have strong effects on hippocampal gray matter volumes, indicating that epigenetic processes can alter brain structures crucially involved in stress-related disorders. Different ways of regulating SLC6A4 expression might involve exonization or transcription factor binding as potentially underlying mechanisms, which, however, is speculative and warrants further investigation. Copyright © 2014 Wiley Periodicals, Inc.

  7. 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

  8. Are Anesthesia and Surgery during Infancy Associated with Decreased White Matter Integrity and Volume During Childhood?

    PubMed

    Block, Robert I; Magnotta, Vincent A; Bayman, Emine O; Choi, James Y; Thomas, Joss J; Kimble, Karolie K

    2017-08-24

    Anesthetics have neurotoxic effects in neonatal animals. Relevant human evidence is limited. We sought such evidence in a structural neuroimaging study. Two groups of children underwent structural magnetic resonance imaging: patients who, during infancy, had one of four operations commonly performed in otherwise healthy children and comparable, nonexposed control subjects. Total and regional brain tissue composition and volume, as well as regional indicators of white matter integrity (fractional anisotropy and mean diffusivity), were analyzed. Analyses included 17 patients, without potential confounding central nervous system problems or risk factors, who had general anesthesia and surgery during infancy and 17 control subjects (age ranges, 12.3 to 15.2 yr and 12.6 to 15.1 yr, respectively). Whole brain white matter volume, as a percentage of total intracranial volume, was lower for the exposed than the nonexposed group, 37.3 ± 0.4% and 38.9 ± 0.4% (least squares mean ± SE), respectively, a difference of 1.5 percentage points (95% CI, 0.3 to 2.8; P = 0.016). Corresponding decreases were statistically significant for parietal and occipital lobes, infratentorium, and brainstem separately. White matter integrity was lower for the exposed than the nonexposed group in superior cerebellar peduncle, cerebral peduncle, external capsule, cingulum (cingulate gyrus), and fornix (cres) and/or stria terminalis. The groups did not differ in total intracranial, gray matter, and cerebrospinal fluid volumes. Children who had anesthesia and surgery during infancy showed broadly distributed, decreased white matter integrity and volume. Although the findings may be related to anesthesia and surgery during infancy, other explanations are possible.

  9. 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

  10. 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.

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

    PubMed

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

    2013-12-12

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

  12. 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

  13. 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.

  14. Schizophrenia risk variants modulate white matter volume across the psychosis spectrum: Evidence from two independent cohorts

    PubMed Central

    Oertel-Knöchel, Viola; Lancaster, Thomas M.; Knöchel, Christian; Stäblein, Michael; Storchak, Helena; Reinke, Britta; Jurcoane, Alina; Kniep, Jonathan; Prvulovic, David; Mantripragada, Kiran; Tansey, Katherine E.; O’Donovan, Michael C.; Owen, Michael J.; Linden, David E.J.

    2015-01-01

    Polygenic risk scores, based on risk variants identified in genome-wide-association-studies (GWAS), explain a considerable portion of the heritability for schizophrenia (SZ) and bipolar disorder (BD). However, little is known about the combined effects of these variants, although polygenic neuroimaging has developed into a powerful tool of translational neuroscience. In this study, we used genome wide significant SZ risk variants to test the predictive capacity of the polygenic model and explored potential associations with white matter volume, a key candidate in imaging phenotype for psychotic disorders. By calculating the combined additive schizophrenia risk of seven SNPs (significant hits from a recent schizophrenia GWAS study), we show that increased additive genetic risk for SZ was associated with reduced white matter volume in a group of participants (n = 94) consisting of healthy individuals, SZ first-degree relatives, SZ patients and BD patients. This effect was also seen in a second independent sample of healthy individuals (n = 89). We suggest that a moderate portion of variance (~4%) of white matter volume can be explained by the seven hits from the recent schizophrenia GWAS. These results provide evidence for associations between cumulative genetic risk for schizophrenia and intermediate neuroimaging phenotypes in models of psychosis. Our work contributes to a growing body of literature suggesting that polygenic risk may help to explain white matter alterations associated with familial risk for psychosis. PMID:25844328

  15. Polygenic determinants of white matter volume derived from GWAS lack reproducibility in a replicate sample

    PubMed Central

    Papiol, S; Mitjans, M; Assogna, F; Piras, F; Hammer, C; Caltagirone, C; Arias, B; Ehrenreich, H; Spalletta, G

    2014-01-01

    A recent publication reported an exciting polygenic effect of schizophrenia (SCZ) risk variants, identified by a large genome-wide association study (GWAS), on total brain and white matter volumes in schizophrenic patients and, even more prominently, in healthy subjects. The aim of the present work was to replicate and then potentially extend these findings. According to the original publication, polygenic risk scores—using single nucleotide polymorphism (SNP) information of SCZ GWAS—(polygenic SCZ risk scores; PSS) were calculated in 122 healthy subjects, enrolled in a structural magnetic resonance imaging (MRI) study. These scores were computed based on P-values and odds ratios available through the Psychiatric GWAS Consortium. In addition, polygenic white matter scores (PWM) were calculated, using the respective SNP subset in the original publication. None of the polygenic scores, either PSS or PWM, were found to be associated with total brain, white matter or gray matter volume in our replicate sample. Minor differences between the original and the present study that might have contributed to lack of reproducibility (but unlikely explain it fully), are number of subjects, ethnicity, age distribution, array technology, SNP imputation quality and MRI scanner type. In contrast to the original publication, our results do not reveal the slightest signal of association of the described sets of GWAS-identified SCZ risk variants with brain volumes in adults. Caution is indicated in interpreting studies building on polygenic risk scores without replication sample. PMID:24548877

  16. The Edges Of Dark Matter Halos: Theory And Observations

    NASA Astrophysics Data System (ADS)

    More, Surhud

    2017-06-01

    I discuss recent theoretical advances which have led us to suggest a physical definition for the boundary of dark matter halos. We propose using the "splashback radius" which corresponds to the apocenter of recently infalling material as a physical boundary for dark matter halos. We also present how the splashback radius can be detected in observations.

  17. 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'…

  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. Regional white matter volume differences in nondemented aging and Alzheimer's disease.

    PubMed

    Salat, David H; Greve, Douglas N; Pacheco, Jennifer L; Quinn, Brian T; Helmer, Karl G; Buckner, Randy L; Fischl, Bruce

    2009-02-15

    Accumulating evidence suggests that altered cerebral white matter (WM) influences normal aging, and further that WM degeneration may modulate the clinical expression of Alzheimer's disease (AD). Here we conducted a study of differences in WM volume across the adult age span and in AD employing a newly developed, automated method for regional parcellation of the subcortical WM that uses curvature landmarks and gray matter (GM)/WM surface boundary information. This procedure measures the volume of gyral WM, utilizing a distance constraint to limit the measurements from extending into the centrum semiovale. Regional estimates were first established to be reliable across two scan sessions in 20 young healthy individuals. Next, the method was applied to a large clinically-characterized sample of 299 individuals including 73 normal older adults and 91 age-matched participants with very mild to mild AD. The majority of measured regions showed a decline in volume with increasing age, with strong effects found in bilateral fusiform, lateral orbitofrontal, superior frontal, medial orbital frontal, inferior temporal, and middle temporal WM. The association between WM volume and age was quadratic in many regions suggesting that WM volume loss accelerates in advanced aging. A number of WM regions were further reduced in AD with parahippocampal, entorhinal, inferior parietal and rostral middle frontal WM showing the strongest AD-associated reductions. There were minimal sex effects after correction for intracranial volume, and there were associations between ventricular volume and regional WM volumes in the older adults and AD that were not apparent in the younger adults. Certain results, such as the loss of WM in the fusiform region with aging, were unexpected and provide novel insight into patterns of age associated neural and cognitive decline. Overall, these results demonstrate the utility of automated regional WM measures in revealing the distinct patterns of age and AD

  20. Genetic schizophrenia risk variants jointly modulate total brain and white matter volume

    PubMed Central

    Terwisscha van Scheltinga, AF; Bakker, Steven C.; van Haren, Neeltje E.M.; Derks, Eske M.; Buizer-Voskamp, Jacobine E.; Boos, Heleen B.M.; Cahn, Wiepke; Hulshoff Pol, HE; Ripke, Stephan; Ophoff, Roel A.; Kahn, RS

    2012-01-01

    Background Thousands of common single nucleotide polymorphisms (SNPs) are weakly associated with schizophrenia. It is likely that subsets of disease-associated SNPs are associated with distinct heritable disease-associated phenotypes. Therefore, we examined the shared genetic susceptibility modulating schizophrenia and brain volume. Methods Odds ratios for genome-wide SNP data were calculated in the sample collected by the Psychiatric GWAS Consortium (8,690 schizophrenia patients and 11,831 controls, excluding subjects from the present study). These were used to calculate individual polygenic schizophrenia (“risk”) scores (PSSs) in an independent sample of 152 schizophrenia patients and 142 healthy controls with available structural MRI scans. Results In the entire group, the PSS was significantly associated with total brain volume (R2=0.048, p=1.6×10−4) and white matter volume (R2=0.051, p=8.6×10−5) equally in patients and controls. The number of (independent) SNPs that substantially influenced both disease risk and white matter (n=2,020) was much smaller than the entire set of SNPs that modulated disease status (n=14,751). From the set of 2,020 SNPs, a group of 186 SNPs showed most evidence for association with white matter volume and an explorative functional analysis showed that these SNPs were located in genes with neuronal functions. Conclusions These results indicate that a relatively small subset of schizophrenia genetic risk variants is related to the (normal) development of white matter. This in turn suggests that disruptions in white matter growth increase the susceptibility to develop schizophrenia. PMID:23039932

  1. Breastfeeding and Childhood IQ: The Mediating Role of Gray Matter Volume.

    PubMed

    Luby, Joan L; Belden, Andy C; Whalen, Diana; Harms, Michael P; Barch, Deanna M

    2016-05-01

    A substantial body of literature has established the positive effect of breastfeeding on child developmental outcomes. There is increasing consensus that breastfed children have higher IQs after accounting for key variables, including maternal education, IQ, and socioeconomic status. Cross-sectional investigations of the effects of breastfeeding on structural brain development suggest that breastfed infants have larger whole brain, cortical, and white matter volumes. To date, few studies have related these measures of brain structure to IQ in breastfed versus nonbreastfed children in a longitudinal sample. Data were derived from the Preschool Depression Study (PDS), a prospective longitudinal study in which children and caregivers were assessed annually for 8 waves over 11 years. A subset completed neuroimaging between the ages of 9.5 and 14.11 years. A total of 148 individuals had breastfeeding data at baseline and complete data on all variables of interest, including IQ and structural neuroimaging. General linear models and process mediation models were used. Breastfed children had significantly higher IQ scores and larger whole brain, total gray matter, total cortical gray matter, and subcortical gray matter volumes compared with the nonbreastfed group in models that covaried for key variables. Subcortical gray matter volume significantly mediated the association between breastfeeding and children's IQ scores. The study findings suggest that the effects of breastfeeding on child IQ are mediated through subcortical gray volume. This effect and putative mechanism is of public health significance and further supports the importance of breastfeeding in mental health promotion. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  2. Relationship between Prefrontal Grey Matter Volumes and Working Memory Performance in Schizophrenia: A Family Study

    PubMed Central

    Goghari, Vina M; MacDonald, Angus W; Sponheim, Scott R

    2014-01-01

    Diffuse structural abnormalities in the prefrontal cortex have been reported in both schizophrenia patients and their nonpsychotic biological relatives. Additionally, working memory difficulties have long been documented in schizophrenia patients and have been associated with the genetic liability for the disorder. The present analysis investigated the relationship between prefrontal regional grey matter volumes and two facets of working memory in schizophrenia using a family study. Structural neuroimaging scans provided measurements of rostral middle, superior, and inferior prefrontal cortical grey matter volumes. Participants also completed a spatial working memory task that measured both short-term maintenance and manipulation of material in memory. Both schizophrenia patients and relatives had reduced superior and inferior frontal grey matter volumes. Schizophrenia patients demonstrated a spatial working memory deficit compared to both controls and relatives, with no greater impairment when required to manipulate material. Smaller prefrontal volumes in schizophrenia patients were associated with worse working memory performance. These relationships were absent in the nonpsychotic relatives and controls. Despite normative behavioural performance, nonpsychotic relatives demonstrated abnormalities in brain structure similar to those found in schizophrenia patients. Manipulation abilities were not more impaired than maintenance in schizophrenia patients. Consistent with other neuroimaging research, our results suggest that direct measures of the underlying biology may be more sensitive to the effects of the genetic liability for schizophrenia than behavioural measures. PMID:24529364

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

    PubMed

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

    2017-01-01

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

  4. Relationship between prefrontal gray matter volumes and working memory performance in schizophrenia: a family study.

    PubMed

    Goghari, Vina M; Macdonald, Angus W; Sponheim, Scott R

    2014-03-01

    Diffuse structural abnormalities in the prefrontal cortex have been reported in both schizophrenia patients and their nonpsychotic biological relatives. Additionally, working memory difficulties have long been documented in schizophrenia patients and have been associated with the genetic liability for the disorder. The present analysis investigated the relationship between prefrontal regional gray matter volumes and two facets of working memory in schizophrenia using a family study. Structural neuroimaging scans provided measurements of rostral middle, superior, and inferior prefrontal cortical gray matter volumes. Participants also completed a spatial working memory task that measured both short-term maintenance and manipulation of material in memory. Both schizophrenia patients and relatives had reduced superior and inferior frontal gray matter volumes. Schizophrenia patients demonstrated a spatial working memory deficit compared to both controls and relatives, with no greater impairment when required to manipulate material. Smaller prefrontal volumes in schizophrenia patients were associated with worse working memory performance. These relationships were absent in the nonpsychotic relatives and controls. Despite normative behavioral performance, nonpsychotic relatives demonstrated abnormalities in brain structure similar to those found in schizophrenia patients. Manipulation abilities were not more impaired than maintenance in schizophrenia patients. Consistent with other neuroimaging research, our results suggest that direct measures of the underlying biology may be more sensitive to the effects of the genetic liability for schizophrenia than behavioral measures. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Global and Regional Associations of Smaller Cerebral Gray and White Matter Volumes with Gait in Older People

    PubMed Central

    Phan, Thanh G.; Chen, Jian; Srikanth, Velandai K.

    2014-01-01

    Background Gait impairments increase with advancing age and can lead to falls and loss of independence. Brain atrophy also occurs in older age and may contribute to gait decline. We aimed to investigate global and regional relationships of cerebral gray and white matter volumes with gait speed, and its determinants step length and cadence, in older people. Methods In a population-based study, participants aged >60 years without Parkinson's disease or brain infarcts underwent magnetic resonance imaging and gait measurements using a computerized walkway. Linear regression was used to study associations of total gray and white matter volumes with gait, adjusting for each other, age, sex, height and white matter hyperintensity volume. Other covariates considered in analyses included weight and vascular disease history. Voxel-based morphometry was used to study regional relationships of gray and white matter with gait. Results There were 305 participants, mean age 71.4 (6.9) years, 54% male, mean gait speed 1.16 (0.22) m/s. Smaller total gray matter volume was independently associated with poorer gait speed (p = 0.001) and step length (p<0.001), but not cadence. Smaller volumes of cortical and subcortical gray matter in bilateral regions important for motor control, vision, perception and memory were independently associated with slower gait speed and shorter steps. No global or regional associations were observed between white matter volume and gait independent of gray matter volume, white matter hyperintensity volume and other covariates. Conclusion Smaller gray matter volume in bilaterally distributed brain networks serving motor control was associated with slower gait speed and step length, but not cadence. PMID:24416309

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

    PubMed

    Callisaya, Michele L; Beare, Richard; Phan, Thanh G; Chen, Jian; Srikanth, Velandai K

    2014-01-01

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

  7. Increased gray matter volume in the right angular and posterior parahippocampal gyri in loving-kindness meditators.

    PubMed

    Leung, Mei-Kei; Chan, Chetwyn C H; Yin, Jing; Lee, Chack-Fan; So, Kwok-Fai; Lee, Tatia M C

    2013-01-01

    Previous voxel-based morphometry (VBM) studies have revealed that meditation is associated with structural brain changes in regions underlying cognitive processes that are required for attention or mindfulness during meditation. This VBM study examined brain changes related to the practice of an emotion-oriented meditation: loving-kindness meditation (LKM). A 3 T magnetic resonance imaging (MRI) scanner captured images of the brain structures of 25 men, 10 of whom had practiced LKM in the Theravada tradition for at least 5 years. Compared with novices, more gray matter volume was detected in the right angular and posterior parahippocampal gyri in LKM experts. The right angular gyrus has not been previously reported to have structural differences associated with meditation, and its specific role in mind and cognitive empathy theory suggests the uniqueness of this finding for LKM practice. These regions are important for affective regulation associated with empathic response, anxiety and mood. At the same time, gray matter volume in the left temporal lobe in the LKM experts appeared to be greater, an observation that has also been reported in previous MRI meditation studies on meditation styles other than LKM. Overall, the findings of our study suggest that experience in LKM may influence brain structures associated with affective regulation.

  8. 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.

  9. DARK MATTER HALO PROFILES OF MASSIVE CLUSTERS: THEORY VERSUS OBSERVATIONS

    SciTech Connect

    Bhattacharya, Suman; Habib, Salman; Heitmann, Katrin; Vikhlinin, Alexey

    2013-03-20

    Dark-matter-dominated cluster-scale halos act as an important cosmological probe and provide a key testing ground for structure formation theory. Focusing on their mass profiles, we have carried out (gravity-only) simulations of the concordance {Lambda}CDM cosmology, covering a mass range of 2 Multiplication-Sign 10{sup 12} to 2 Multiplication-Sign 10{sup 15} h {sup -1} M{sub Sun} and a redshift range of z = 0-2, while satisfying the associated requirements of resolution and statistical control. When fitting to the Navarro-Frenk-White profile, our concentration-mass (c-M) relation differs in normalization and shape in comparison to previous studies that have limited statistics in the upper end of the mass range. We show that the flattening of the c-M relation with redshift is naturally expressed if c is viewed as a function of the peak height parameter, {nu}. Unlike the c-M relation, the slope of the c-{nu} relation is effectively constant over the redshift range z = 0-2, while the amplitude varies by {approx}30% for massive clusters. This relation is, however, not universal: using a simulation suite covering the allowed wCDM parameter space, we show that the c-{nu} relation varies by about {+-}20% as cosmological parameters are varied. At fixed mass, the c(M) distribution is well fit by a Gaussian with {sigma}{sub c}/(c) {approx_equal} 1/3, independent of the radius at which the concentration is defined, the halo dynamical state, and the underlying cosmology. We compare the {Lambda}CDM predictions with observations of halo concentrations from strong lensing, weak lensing, galaxy kinematics, and X-ray data, finding good agreement for massive clusters (M{sub vir} > 4 Multiplication-Sign 10{sup 14} h {sup -1} M{sub Sun }), but with some disagreements at lower masses. Because of uncertainty in observational systematics and modeling of baryonic physics, the significance of these discrepancies remains unclear.

  10. Opposite effects of suicidality and lithium on gray matter volumes in bipolar depression.

    PubMed

    Benedetti, Francesco; Radaelli, Daniele; Poletti, Sara; Locatelli, Clara; Falini, Andrea; Colombo, Cristina; Smeraldi, Enrico

    2011-12-01

    Mood disorders are associated with the highest increase of attempted and completed suicide. Suicidality in major depressive disorder and in schizophrenia has been associated with reduced gray matter volumes in orbitofrontal cortex. Lithium reduces the suicide risk of patients with bipolar disorder (BD) to the same levels of the general population, and can increase GM volumes. We studied the effect of a positive history of attempted suicide and ongoing lithium treatment on regional GM volumes of patients affected by bipolar depression. With a correlational design, we studied 57 currently depressed inpatients with bipolar disorder: 19 with and 38 without a positive history of suicide attempts, 39 unmedicated and 18 with ongoing lithium treatment. Total and regional gray matter volumes were assessed using voxel-based morphometry. Total GM volume is inversely correlated with depression severity. A positive history of suicide attempts was associated with higher stress in early life. Suicide attempters showed reduced GM volumes in several brain areas including dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate, superior temporal cortex, parieto-occipital cortex, and basal ganglia. Long term lithium treatment was associated with increased GM volumes in the same areas where suicide was associated with decreased GM. Reduced GM volumes in critical cortical areas of suicidal patients could be a biological correlate of an impaired ability to associate choices and outcomes and to plan goal-directed behaviors based on a lifetime historical perspective, which, coupled with mood-congruent depressive cognitive distortions, could lead to more hopelessness and suicide. Lithium could exert its specific therapeutic effect on suicide by acting in the same areas. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Reduced gray matter volume and increased white matter fractional anisotropy in women with hypoactive sexual desire disorder.

    PubMed

    Bloemers, Jos; Scholte, H Steven; van Rooij, Kim; Goldstein, Irwin; Gerritsen, Jeroen; Olivier, Berend; Tuiten, Adriaan

    2014-03-01

    Models of hypoactive sexual desire disorder (HSDD) imply altered central processing of sexual stimuli. Imaging studies have identified areas which show altered processing as compared with controls, but to date, structural neuroanatomical differences have not been described. The aim of this study is to investigate differences in brain structure between women with HSDD and women with no history of sexual dysfunction, and to determine sexual behavioral correlates of identified structural deviations. Sexual functioning and gray matter (GM) and white matter (WM) were assessed in 29 women with HSDD and 16 healthy control subjects of comparable age and socioeconomic status with no history of sexual dysfunction. WM properties were measured using diffusion-weighted imaging and analyzed using fractional anisotropy (FA). GM volume was measured using three-dimensional T1-weighted recordings and analyzed using voxel-based morphometry. Sexual functioning was measured using the Sexual Function Questionnaire. Women with HSDD, as compared with controls, had reduced GM volume in the right insula, bilateral anterior temporal cortices, left occipitotemporal cortex, anterior cingulate gyrus, and right dorsolateral prefrontal cortex. Also, increased WM FA was observed within, amongst others, the bilateral amygdalae. Sexual interest and arousal correlated mostly with GM volume in these regions, whereas orgasm function correlated mostly with WM FA. HSDD coincides with anatomical differences in the central nervous system, in both GM and WM. The findings suggest that decreased salience attribution to sexual stimuli, decreased perception of bodily responses and sexual emotional stimulus perception, and concomitant altered attentional mechanisms associated with sexual response induction. © 2013 International Society for Sexual Medicine.

  12. Matter-parity as a residual gauge symmetry: Probing a theory of cosmological dark matter

    NASA Astrophysics Data System (ADS)

    Alves, Alexandre; Arcadi, Giorgio; Dong, P. V.; Duarte, Laura; Queiroz, Farinaldo S.; Valle, José W. F.

    2017-09-01

    We discuss a non-supersymmetric scenario which addresses the origin of the matter-parity symmetry, PM =(- 1) 3 (B - L) + 2 s, leading to a viable Dirac fermion dark matter candidate. Implications to electroweak precision, muon anomalous magnetic moment, flavor changing interactions, lepton flavor violation, dark matter and collider physics are discussed in detail. We show that this non-supersymmetric model is capable of generating the matter-parity symmetry in agreement with existing data with gripping implications to particle physics and cosmology.

  13. 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.

  14. 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

  15. Ordinary matter in non-linear affine gauge theories of gravitation

    NASA Astrophysics Data System (ADS)

    López-Pinto, A.; Tiemblo, A.; Tresguerres, R.

    1995-06-01

    We present a general framework to include ordinary fermionic matter in the metric--affine gauge theories of gravity. It is based on a nonlinear gauge realization of the affine group, with the Lorentz group as the classification subgroup of the matter and gravitational fields.

  16. Grey matter volume alterations in CADASIL: a voxel-based morphometry study.

    PubMed

    Rossi Espagnet, Maria Camilla; Romano, Andrea; Carducci, Filippo; Calabria, Luigi Fausto; Fiorillo, Martina; Orzi, Francesco; Bozzao, Alessandro

    2012-04-01

    CADASIL is a hereditary disease characterized by cerebral subcortical microangiopathy leading to early onset cerebral strokes and progressive severe cognitive impairment. Until now, only few studies have investigated the extent and localization of grey matter (GM) involvement. The purpose of our study was to evaluate GM volume alterations in CADASIL patients compared to healthy subjects. We also looked for correlations between global and regional white matter (WM) lesion load and GM volume alterations. 14 genetically proved CADASIL patients and 12 healthy subjects were enrolled in our study. Brain MRI (1.5 T) was acquired in all subjects. Optimized-voxel based morphometry method was applied for the comparison of brain volumes between CADASIL patients and controls. Global and lobar WM lesion loads were calculated for each patient and used as covariate-of-interest for regression analyses with SPM-8. Compared to controls, patients showed GM volume reductions in bilateral temporal lobes (p < 0.05; FDR-corrected). Regression analysis in the patient group revealed a correlation between total WM lesion load and temporal GM atrophy (p < 0.05; uncorrected), not between temporal lesion load and GM atrophy. Temporal GM volume reduction was demonstrated in CADASIL patients compared to controls; it was related to WM lesion load involving the whole brain but not to lobar and, specifically, temporal WM lesion load. Complex interactions between sub-cortical and cortical damage should be hypothesized.

  17. 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. Copyright 2009 Elsevier Inc. All rights reserved.

  18. Theories of gravitation with nonminimal coupling of matter and the gravitational field

    SciTech Connect

    Goenner, H.F.M.

    1984-09-01

    The foundations of a theory of nonminimal coupling of matter and the gravitational field in the framework of Riemannian (or Riemann-Cartan) geometry are presented. In the absence of matter, the Einstein vacuum field equations hold. In order to allow for a Newtonian limit, the theory contains a new parameter l/sub 0/ of dimension length. For systems with finite total mass, l/sub 0/ is set equal to the Schwarzschild radius.

  19. Strongly Interacting Matter in Magnetic Fields: A Guide to This Volume

    NASA Astrophysics Data System (ADS)

    Kharzeev, Dmitri E.; Landsteiner, Karl; Schmitt, Andreas; Yee, Ho-Ung

    This is an introduction to the volume of Lecture Notes in Physics on "Strongly interacting matter in magnetic fields". The volume combines contributions written by a number of experts on different aspects of the problem. The response of QCD matter to intense magnetic fields has attracted a lot of interest recently. On the theoretical side, this interest stems from the possibility to explore the plethora of novel phenomena arising from the interplay of magnetic field with QCD dynamics. On the experimental side, the interest is motivated by the recent results on the behavior of quark-gluon plasma in a strong magnetic field created in relativistic heavy ion collisions at RHIC and LHC. The purpose of this introduction is to provide a brief overview and a guide to the individual contributions where these topics are covered in detail.

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

    PubMed

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

    2013-12-01

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

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

    PubMed

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

    2017-06-30

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

  2. 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. © 2016 Wiley Periodicals, Inc.

  3. Multiple White Matter Volume Reductions in Patients with Panic Disorder: Relationships between Orbitofrontal Gyrus Volume and Symptom Severity and Social Dysfunction

    PubMed Central

    Konishi, Jun; Asami, Takeshi; Hayano, Fumi; Yoshimi, Asuka; Hayasaka, Shunsuke; Fukushima, Hiroshi; Whitford, Thomas J.; Inoue, Tomio; Hirayasu, Yoshio

    2014-01-01

    Numerous brain regions are believed to be involved in the neuropathology of panic disorder (PD) including fronto-limbic regions, thalamus, brain stem, and cerebellum. However, while several previous studies have demonstrated volumetric gray matter reductions in these brain regions, there have been no studies evaluating volumetric white matter changes in the fiber bundles connecting these regions. In addition, although patients with PD typically exhibit social, interpersonal and occupational dysfunction, the neuropathologies underlying these dysfunctions remain unclear. A voxel-based morphometry study was conducted to evaluate differences in regional white matter volume between 40 patients with PD and 40 healthy control subjects (HC). Correlation analyses were performed between the regional white matter volumes and patients' scores on the Panic Disorder Severity Scale (PDSS) and the Global Assessment of Functioning (GAF). Patients with PD demonstrated significant volumetric reductions in widespread white matter regions including fronto-limbic, thalamo-cortical and cerebellar pathways (p<0.05, FDR corrected). Furthermore, there was a significant negative relationship between right orbitofrontal gyrus (OFG) white matter volume and the severity of patients' clinical symptoms, as assessed with the PDSS. A significant positive relationship was also observed between patients' right OFG volumes and their scores on the GAF. Our results suggest that volumetric reductions in widespread white matter regions may play an important role in the pathology of PD. In particular, our results suggest that structural white matter abnormalities in the right OFG may contribute to the social, personal and occupational dysfunction typically experienced by patients with PD. PMID:24663245

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

    PubMed

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

    2016-01-01

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

  5. 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.

  6. Evaluation of Regional White Matter Volume Reduction after Diffuse Axonal Injury using Voxel-based Morphometry.

    PubMed

    Uruma, Go; Hashimoto, Keiji; Abo, Masahiro

    2015-01-01

    We developed a new and convenient method that employs voxel-based morphometry (VBM) to evaluate regional reduction in the volume of white matter after diffuse axonal injury (DAI). We studied 29 patients with moderate cognitive disability after DAI. Each subject underwent 3-dimensional volumetric magnetic resonance (MR) imaging. Images were preprocessed automatically using stand-alone software running on a Windows PC for VBM of volumetric MR imaging utilizing a statistical parametric mapping (SPM) version 8 software engine and an algorithm for diffeomorphic anatomic registration through exponentiated lie algebra (DARTEL). We then computed a Z-score for all coordinates on the white matter, which represented the relative reduction in white matter volume. Finally, we used voxel-based stereotactic extraction estimation (vbSEE) to compute the extent of regional reduction in the volume of white matter (rWMVR) for each region of interest (ROI), defined as the rate of coordinates with Z-scores exceeding 2.0 in the ROI. For each ROI, we used Pearson's correlation analysis to examine the correlation between the extent of regional volume reduction and patient scores on the Wechsler Adult Intelligence Scale III (WAIS-III). We detected marked rWMVR in several ROIs, including the corpus callosum, and rWMVR correlated significantly with performance IQ and processing speed index in the splenium of the corpus callosum. The results indicate the utility of our applications for the daily clinical evaluation of DAI. That they can be used on a PC and allow acquisition of volumetric data from standard MR images are their advantages.

  7. Alcohol consumption during adolescence is associated with reduced grey matter volumes.

    PubMed

    Heikkinen, Noora; Niskanen, Eini; Könönen, Mervi; Tolmunen, Tommi; Kekkonen, Virve; Kivimäki, Petri; Tanila, Heikki; Laukkanen, Eila; Vanninen, Ritva

    2017-04-01

    Cognitive impairment has been associated with excessive alcohol use, but its neural basis is poorly understood. Chronic excessive alcohol use in adolescence may lead to neuronal loss and volumetric changes in the brain. Our objective was to compare the grey matter volumes of heavy- and light-drinking adolescents. This was a longitudinal study: heavy-drinking adolescents without an alcohol use disorder and their light-drinking controls were followed-up for 10 years using questionnaires at three time-points. Magnetic resonance imaging was conducted at the last time-point. The area near Kuopio University Hospital, Finland. The 62 participants were aged 22-28 years and included 35 alcohol users and 27 controls who had been followed-up for approximately 10 years. Alcohol use was measured by the Alcohol Use Disorders Identification Test (AUDIT)-C at three time-points during 10 years. Participants were selected based on their AUDIT-C score. Magnetic resonance imaging was conducted at the last time-point. Grey matter volume was determined and compared between heavy- and light-drinking groups using voxel-based morphometry on three-dimensional T1-weighted magnetic resonance images using predefined regions of interest and a threshold of P < 0.05, with small volume correction applied on cluster level. Grey matter volumes were significantly smaller among heavy-drinking participants in the bilateral anterior cingulate cortex, right orbitofrontal and frontopolar cortex, right superior temporal gyrus and right insular cortex compared to the control group (P < 0.05, family-wise error-corrected cluster level). Excessive alcohol use during adolescence appears to be associated with an abnormal development of the brain grey matter. Moreover, the structural changes detected in the insula of alcohol users may reflect a reduced sensitivity to alcohol's negative subjective effects. © 2016 Society for the Study of Addiction.

  8. Magnetic resonance morphometry of the loss of gray matter volume in Parkinson's disease patients

    PubMed Central

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

    2013-01-01

    Voxel-based morphometry can be used to quantitatively compare structural differences and func-tional changes of gray matter in subjects. In the present study, we compared gray matter images of 32 patients with Parkinson's disease and 25 healthy controls using voxel-based morphometry based on 3.0 T high-field magnetic resonance T1-weighted imaging and clinical neurological scale scores. Results showed that the scores in Mini-Mental State Examination and Montreal Cognitive Assessment were lower in patients compared with controls. In particular, the scores of visuospa-tial/executive function items in Montreal Cognitive Assessment were significantly reduced, but mean scores of non-motor symptoms significantly increased, in patients with Parkinson's disease. In dition, gray matter volume was significantly diminished in Parkinson's disease patients compared with normal controls, including bilateral temporal lobe, bilateral occipital lobe, bilateral parietal lobe, bilateral frontal lobe, bilateral insular lobe, bilateral parahippocampal gyrus, bilateral amygdale, right uncus, and right posterior lobe of the cerebellum. These findings indicate that voxel-based phometry can accurately and quantitatively assess the loss of gray matter volume in patients with Parkinson' disease, and provide essential neuroimaging evidence for multisystem pathological mechanisms involved in Parkinson's disease. PMID:25206566

  9. Baseline gray- and white-matter volume predict successful weight loss in the elderly.

    PubMed

    Mokhtari, Fatemeh; Paolini, Brielle M; Burdette, Jonathan H; Marsh, Anthony P; Rejeski, W Jack; Laurienti, Paul J

    2016-12-01

    The purpose of this study was to investigate whether structural brain phenotypes could be used to predict weight loss success following behavioral interventions in older adults with overweight or obesity and cardiometabolic dysfunction. A support vector machine with a repeated random subsampling validation approach was used to classify participants into the upper and lower halves of the weight loss distribution following 18 months of a weight loss intervention. Predictions were based on baseline brain gray matter and white matter volume from 52 individuals who completed the intervention and a magnetic resonance imaging session. The support vector machine resulted in an average classification accuracy of 72.62% based on gray matter and white matter volume. A receiver operating characteristic analysis indicated that classification performance was robust based on an area under the curve of 0.82. Findings suggest that baseline brain structure was able to predict weight loss success following 18 months of treatment. The identification of brain structure as a predictor of successful weight loss was an innovative approach to identifying phenotypes for responsiveness to intensive lifestyle interventions. This phenotype could prove useful in future research focusing on the tailoring of treatment for weight loss. © 2016 The Obesity Society.

  10. Insular and hippocampal gray matter volume reductions in patients with major depressive disorder.

    PubMed

    Stratmann, Mirjam; Konrad, Carsten; Kugel, Harald; Krug, Axel; Schöning, Sonja; Ohrmann, Patricia; Uhlmann, Christina; Postert, Christian; Suslow, Thomas; Heindel, Walter; Arolt, Volker; Kircher, Tilo; Dannlowski, Udo

    2014-01-01

    Major depressive disorder is a serious psychiatric illness with a highly variable and heterogeneous clinical course. Due to the lack of consistent data from previous studies, the study of morphometric changes in major depressive disorder is still a major point of research requiring additional studies. The aim of the study presented here was to characterize and quantify regional gray matter abnormalities in a large sample of clinically well-characterized patients with major depressive disorder. For this study one-hundred thirty two patients with major depressive disorder and 132 age- and gender-matched healthy control participants were included, 35 with their first episode and 97 with recurrent depression. To analyse gray matter abnormalities, voxel-based morphometry (VBM8) was employed on T1 weighted MRI data. We performed whole-brain analyses as well as a region-of-interest approach on the hippocampal formation, anterior cingulate cortex and amygdala, correlating the number of depressive episodes. Compared to healthy control persons, patients showed a strong gray-matter reduction in the right anterior insula. In addition, region-of-interest analyses revealed significant gray-matter reductions in the hippocampal formation. The observed alterations were more severe in patients with recurrent depressive episodes than in patients with a first episode. The number of depressive episodes was negatively correlated with gray-matter volume in the right hippocampus and right amygdala. The anterior insula gray matter structure appears to be strongly affected in major depressive disorder and might play an important role in the neurobiology of depression. The hippocampal and amygdala volume loss cumulating with the number of episodes might be explained either by repeated neurotoxic stress or alternatively by higher relapse rates in patients showing hippocampal atrophy.

  11. Insular and Hippocampal Gray Matter Volume Reductions in Patients with Major Depressive Disorder

    PubMed Central

    Kugel, Harald; Krug, Axel; Schöning, Sonja; Ohrmann, Patricia; Uhlmann, Christina; Postert, Christian; Suslow, Thomas; Heindel, Walter; Arolt, Volker; Kircher, Tilo; Dannlowski, Udo

    2014-01-01

    Background Major depressive disorder is a serious psychiatric illness with a highly variable and heterogeneous clinical course. Due to the lack of consistent data from previous studies, the study of morphometric changes in major depressive disorder is still a major point of research requiring additional studies. The aim of the study presented here was to characterize and quantify regional gray matter abnormalities in a large sample of clinically well-characterized patients with major depressive disorder. Methods For this study one-hundred thirty two patients with major depressive disorder and 132 age- and gender-matched healthy control participants were included, 35 with their first episode and 97 with recurrent depression. To analyse gray matter abnormalities, voxel-based morphometry (VBM8) was employed on T1 weighted MRI data. We performed whole-brain analyses as well as a region-of-interest approach on the hippocampal formation, anterior cingulate cortex and amygdala, correlating the number of depressive episodes. Results Compared to healthy control persons, patients showed a strong gray-matter reduction in the right anterior insula. In addition, region-of-interest analyses revealed significant gray-matter reductions in the hippocampal formation. The observed alterations were more severe in patients with recurrent depressive episodes than in patients with a first episode. The number of depressive episodes was negatively correlated with gray-matter volume in the right hippocampus and right amygdala. Conclusions The anterior insula gray matter structure appears to be strongly affected in major depressive disorder and might play an important role in the neurobiology of depression. The hippocampal and amygdala volume loss cumulating with the number of episodes might be explained either by repeated neurotoxic stress or alternatively by higher relapse rates in patients showing hippocampal atrophy. PMID:25051163

  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.

  13. 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.

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

    PubMed

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

    2013-10-01

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

  15. Cumulative Adversity and Smaller Gray Matter Volume in Medial Prefrontal, Anterior Cingulate, and Insula Regions

    PubMed Central

    Ansell, Emily B.; Rando, Kenneth; Tuit, Keri; Guarnaccia, Joseph; Sinha, Rajita

    2012-01-01

    Background Cumulative adversity and stress are associated with risk of psychiatric disorders. While basic science studies show repeated and chronic stress effects on prefrontal and limbic neurons, human studies examining cumulative stress and effects on brain morphology are rare. Thus, we assessed whether cumulative adversity is associated with differences in gray matter volume, particularly in regions regulating emotion, self-control, and top-down processing in a community sample. Methods One hundred three healthy community participants, aged 18 to 48 and 68% male, completed interview assessment of cumulative adversity and a structural magnetic resonance imaging protocol. Whole-brain voxel-based-morphometry analysis was performed adjusting for age, gender, and total intracranial volume. Results Cumulative adversity was associated with smaller volume in medial prefrontal cortex (PFC), insular cortex, and subgenual anterior cingulate regions (familywise error corrected, p <.001). Recent stressful life events were associated with smaller volume in two clusters: the medial PFC and the right insula. Life trauma was associated with smaller volume in the medial PFC, anterior cingulate, and subgenual regions. The interaction of greater subjective chronic stress and greater cumulative life events was associated with smaller volume in the orbitofrontal cortex, insula, and anterior and subgenual cingulate regions. Conclusions Current results demonstrate that increasing cumulative exposure to adverse life events is associated with smaller gray matter volume in key prefrontal and limbic regions involved in stress, emotion and reward regulation, and impulse control. These differences found in community participants may serve to mediate vulnerability to depression, addiction, and other stress-related psychopathology. PMID:22218286

  16. The family theory-practice gap: a matter of clarity?

    PubMed

    Segaric, Cheryl A; Hall, Wendy A

    2005-09-01

    Despite recognition of the importance of family in health-care and progress in family theory development, there has been limited transfer of family theory to acute care nursing practice. We argue that this family theory-practice gap results from a persistent lack of conceptual clarity in family nursing and other barriers. Lack of conceptual clarity takes the form of conceptual overlap and semantic inconsistency, as well as the complexity of language found in the family nursing literature. Barriers include practice contexts, relational problems, and knowledge types. Our exploration begins with a brief discussion of the intimate link between nursing theory and practice followed by an overview of some issues associated with the family nursing theory-practice gap. Based on a synthesis of family nursing literature, problems associated with conceptual clarity in family nursing theory are explored. We conclude with recommendations for family nursing research to develop concepts grounded in nursing practice.

  17. 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.

  18. Dark matter from dark energy in q-theory

    NASA Astrophysics Data System (ADS)

    Klinkhamer, F. R.; Volovik, G. E.

    2017-01-01

    A constant (spacetime-independent) q-field may play a crucial role for the cancellation of Planck-scale contributions to the gravitating vacuum energy density. We now show that a small spacetime-dependent perturbation of the equilibrium q-field behaves gravitationally as a pressureless perfect fluid. This makes the fluctuating part of the q-field a candidate for the inferred dark-matter component of the present universe. For a Planck-scale oscillation frequency of the q-field perturbation, the implication would be that direct searches for dark-matter particles would remain unsuccessful in the foreseeable future.

  19. Irradiance Inversion Theory to Retrieve Volume Scattering Function of Seawater

    NASA Astrophysics Data System (ADS)

    Hirata, Takafumi

    2003-03-01

    An attempt to retrieve the volume scattering function (VSF) of source-free and no-inelastic-scattering ocean water is made from the upwelling irradiance Eu and downwelling irradiance Ed . It will be shown, from the radiative transfer equation, that the VSF of seawater can be calculated by the planar irradiances when the scattering phase function of the suspended particles in the backward direction and the molecular VSF are known. On the derivation of the hydrosol VSF, several optical properties such as the absorption coefficient a ; the scattering coefficients of hydrosol, b , bf , bb and those of the suspended particles, bp , bfp , bbp ; the beam attenuation coefficient c ; the average cosines μ, μd , and μu ; and the backscattering shape factor for the downwelling light stream, rdu , will also be obtained. On the derivation of those optical parameters, classical knowledge related to interrelationships between inherent optical properties and apparent optical properties and obtained with Monte Carlo numerical simulations is analytically verified. The present theory can be applied to surface waters and any wavelengths, except for waters and wavelengths with an extremely low bb/a ratio.

  20. 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.

  1. Association of Ideomotor Apraxia With Frontal Gray Matter Volume Loss in Corticobasal Syndrome

    PubMed Central

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

    2010-01-01

    Objective To determine the brain areas associated with specific components of ideomotor apraxia (IMA) in corticobasal syndrome (CBS). Design Case-control and cross-sectional study. Participants Forty-eight patients with CBS and 14 control subjects. Intervention Administration of the Test of Oral and Limb Apraxia. Main Outcome Measures Differences between patients with CBS and healthy controls and associations between areas of gray matter volume and IMA determined by voxel-based morphometry in patients with CBS. Results Overall, IMA was associated with decreased gray matter volume in the left supplemental motor area, pre-motor cortex, and caudate nucleus of patients with CBS. The overall degree of apraxia was independent of the side of motor impairment. Praxis to imitation (vs command) was particularly impaired in the patients with CBS. Patients demonstrated equal impairment in transitive and intransitive praxis. Conclusions In patients with CBS, IMA is associated with left posterior frontal cortical and subcortical volume loss. Despite showing left frontal volume loss associated with IMA, patients with CBS have particularly impaired imitation of gestures. These findings suggest either that the IMA of CBS affects a route of praxis that bypasses motor engrams or that motor engrams are affected but that they exist in areas other than the inferior parietal cortex. PMID:19822784

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

    PubMed

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

    2009-10-01

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

  3. Relationships between years of education and gray matter volume, metabolism and functional connectivity in healthy elders.

    PubMed

    Arenaza-Urquijo, Eider M; Landeau, Brigitte; La Joie, Renaud; Mevel, Katell; Mézenge, Florence; Perrotin, Audrey; Desgranges, Béatrice; Bartrés-Faz, David; Eustache, Francis; Chételat, Gaël

    2013-12-01

    More educated elders are less susceptible to age-related or pathological cognitive changes. We aimed at providing a comprehensive contribution to the neural mechanism underlying this effect thanks to a multimodal approach. Thirty-six healthy elders were selected based on neuropsychological assessments and cerebral amyloid imaging, i.e. as presenting normal cognition and a negative florbetapir-PET scan. All subjects underwent structural MRI, FDG-PET and resting-state functional MRI scans. We assessed the relationships between years of education and i) gray matter volume, ii) gray matter metabolism and iii) functional connectivity in the brain areas showing associations with both volume and metabolism. Higher years of education were related to greater volume in the superior temporal gyrus, insula and anterior cingulate cortex and to greater metabolism in the anterior cingulate cortex. The latter thus showed both volume and metabolism increases with education. Seed connectivity analyses based on this region showed that education was positively related to the functional connectivity between the anterior cingulate cortex and the hippocampus as well as the inferior frontal lobe, posterior cingulate cortex and angular gyrus. Increased connectivity was in turn related with improved cognitive performances. Reinforcement of the connectivity of the anterior cingulate cortex with distant cortical areas of the frontal, temporal and parietal lobes appears as one of the mechanisms underlying education-related reserve in healthy elders.

  4. Dark matter relics and the expansion rate in scalar-tensor theories

    NASA Astrophysics Data System (ADS)

    Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne

    2017-06-01

    We study the impact of a modified expansion rate on the dark matter relic abundance in a class of scalar-tensor theories. The scalar-tensor theories we consider are motivated from string theory constructions, which have conformal as well as disformally coupled matter to the scalar. We investigate the effects of such a conformal coupling to the dark matter relic abundance for a wide range of initial conditions, masses and cross-sections. We find that exploiting all possible initial conditions, the annihilation cross-section required to satisfy the dark matter content can differ from the thermal average cross-section in the standard case. We also study the expansion rate in the disformal case and find that physically relevant solutions require a nontrivial relation between the conformal and disformal functions. We study the effects of the disformal coupling in an explicit example where the disformal function is quadratic.

  5. 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.

  6. Indirect association of DAT1 genotype with executive function through white matter volume in orbitofrontal cortex

    PubMed Central

    Chung, Tammy; Ferrell, Robert; Clark, Duncan B.

    2015-01-01

    The dopamine transporter (DAT1) gene has been associated with impulsivity and executive functioning. Further, DAT1 has been associated with brain structural characteristics and resting state connectivity. This study tested an indirect effect model in which DAT1 genotype (9-repeat carriers vs. 10-repeat homozygotes) is linked to phenotypes representing impulsivity and executive function (planning behavior) through effects on white matter (WM) volumes in prefrontal cortex (PFC), particularly orbitofrontal cortex (OFC). Adolescents (ages 14–18, n=38), were recruited from substance use treatment (n=22) and the community (n=16) to increase phenotype variation. Results indicated that DAT1 10/10 genotype was associated with lower WM volume in the PFC, specifically the left OFC. Further, lower WM volume in the left OFC predicted more difficulties in self-reported planning behavior, but not impulsivity. Indirect effect analysis indicated that lower WM volume in the left OFC mediated the association between DAT1 10/10 genotype and difficulties in planning behavior. Results suggest a brain structural mechanism, involving lower WM volume in the left OFC, as a link in the association between DAT1 genotype and a specific aspect of executive function. Genetic effects on regional WM volume that are linked to behavioral outcomes could ultimately inform the development of tailored interventions that address an individual’s unique risk factors. PMID:25704259

  7. 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.

  8. Why Knowledge Matters: Rescuing Our Children from Failed Educational Theories

    ERIC Educational Resources Information Center

    Hirsch, E. D., Jr.

    2016-01-01

    In "Why Knowledge Matters," influential scholar E. D. Hirsch, Jr., addresses critical issues in contemporary education reform and shows how cherished truisms about education and child development have led to unintended and negative consequences. Hirsch, author of "The Knowledge Deficit," draws on recent findings in neuroscience…

  9. Why Knowledge Matters: Rescuing Our Children from Failed Educational Theories

    ERIC Educational Resources Information Center

    Hirsch, E. D., Jr.

    2016-01-01

    In "Why Knowledge Matters," influential scholar E. D. Hirsch, Jr., addresses critical issues in contemporary education reform and shows how cherished truisms about education and child development have led to unintended and negative consequences. Hirsch, author of "The Knowledge Deficit," draws on recent findings in neuroscience…

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

    PubMed

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

    2017-01-01

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

  11. Consistency relations for spinning matter in gravitational theories

    NASA Technical Reports Server (NTRS)

    Ray, John R.; Smalley, Larry L.

    1986-01-01

    The consistency equations for a charged spinning fluid in the Einstein-Cartan theory are examined. The hydrodynamic laws associated with the theory of Ray and Smalley (1982, 1983) and the electromagnetic extension of Amorim (1984, 1985) are studied. The derivation of the consistency equation from the Euler equations for an improved perfect-fluid energy-momentum tensor is described.

  12. Strategy and Intervention versus Nonintervention: A Matter of Theory?

    ERIC Educational Resources Information Center

    Goolishian, Harold A.; Anderson, Harlene

    1992-01-01

    Considers whether or not intervention and strategy are necessary components of competent therapy. Sees passive listening and expert interpretations as consequences of psychodynamic theory; active manipulation of social structure and strategic intervention into feedback as consequences of mechanical assumptions of structural and cybernetic theory;…

  13. 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.

  14. A New Approach for Deep Gray Matter Analysis Using Partial-Volume Estimation.

    PubMed

    Bonnier, Guillaume; Kober, Tobias; Schluep, Myriam; Du Pasquier, Renaud; Krueger, Gunnar; Meuli, Reto; Granziera, Cristina; Roche, Alexis

    2016-01-01

    The existence of partial volume effects in brain MR images makes it challenging to understand physio-pathological alterations underlying signal changes due to pathology across groups of healthy subjects and patients. In this study, we implement a new approach to disentangle gray and white matter alterations in the thalamus and the basal ganglia. The proposed method was applied to a cohort of early multiple sclerosis (MS) patients and healthy subjects to evaluate tissue-specific alterations related to diffuse inflammatory or neurodegenerative processes. Forty-three relapsing-remitting MS patients and nineteen healthy controls underwent 3T MRI including: (i) fluid-attenuated inversion recovery, double inversion recovery, magnetization-prepared gradient echo for lesion count, and (ii) T1 relaxometry. We applied a partial volume estimation algorithm to T1 relaxometry maps to gray and white matter local concentrations as well as T1 values characteristic of gray and white matter in the thalamus and the basal ganglia. Statistical tests were performed to compare groups in terms of both global T1 values, tissue characteristic T1 values, and tissue concentrations. Significant increases in global T1 values were observed in the thalamus (p = 0.038) and the putamen (p = 0.026) in RRMS patients compared to HC. In the Thalamus, the T1 increase was associated with a significant increase in gray matter characteristic T1 (p = 0.0016) with no significant effect in white matter. The presented methodology provides additional information to standard MR signal averaging approaches that holds promise to identify the presence and nature of diffuse pathology in neuro-inflammatory and neurodegenerative diseases.

  15. 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.

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

    PubMed

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

    2015-04-01

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

  17. Reduced Cortical Gray Matter Volume In Male Adolescents With Substance And Conduct Problems

    PubMed Central

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

    2011-01-01

    Boys with serious conduct and substance problems (“Antisocial Substance Dependence” (ASD)) repeatedly make impulsive and risky decisions in spite of possible negative consequences. Because prefrontal cortex (PFC) is involved in planning behavior in accord with prior rewards and punishments, structural abnormalities in PFC could contribute to a person's propensity to make risky decisions. Methods We acquired high-resolution structural images of 25 male ASD patients (ages 14–18 years) and 19 controls of similar ages using a 3T MR system. We conducted whole-brain voxel-based morphometric analysis (p<0.05, corrected for multiple comparisons at whole-brain cluster-level) using Statistical Parametric Mapping version-5 and tested group differences in regional gray matter (GM) volume with analyses of covariance, adjusting for total GM volume, age, and IQ; we further adjusted between-group analyses for ADHD and depression. As secondary analyses, we tested for negative associations between GM volume and impulsivity within groups and separately, GM volume and symptom severity within patients using whole-brain regression analyses. Results ASD boys had significantly lower GM volume than controls in left dorsolateral PFC (DLPFC), right lingual gyrus and bilateral cerebellum, and significantly higher GM volume in right precuneus. Left DLPFC GM volume showed negative association with impulsivity within controls and negative association with substance dependence severity within patients. Conclusions ASD boys show reduced GM volumes in several regions including DLPFC, a region highly relevant to impulsivity, disinhibition, and decision-making, and cerebellum, a region important for behavioral regulation, while they showed increased GM in precuneus, a region associated with self-referential and self-centered thinking. PMID:21592680

  18. 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

  19. Exact results for Wilson loops in superconformal Chern-Simons theories with matter

    NASA Astrophysics Data System (ADS)

    Kapustin, Anton; Willett, Brian; Yaakov, Itamar

    2010-03-01

    We use localization techniques to compute the expectation values of supersymmetric Wilson loops in Chern-Simons theories with matter. We find the path-integral reduces to a non-Gaussian matrix model. The Wilson loops we consider preserve a single complex supersymmetry, and exist in any mathcal{N}= 2 theory, though the localization requires superconformal symmetry. We present explicit results for the cases of pure Chern-Simons theory with gauge group U(N), showing agreement with the known results, and ABJM, showing agreement with perturbative calculations. Our method applies to other theories, such as Gaiotto-Witten theories, BLG, and their variants.

  20. Z boson mediated dark matter beyond the effective theory

    NASA Astrophysics Data System (ADS)

    Kearney, John; Orlofsky, Nicholas; Pierce, Aaron

    2017-02-01

    Direct detection bounds are beginning to constrain a very simple model of weakly interacting dark matter—a Majorana fermion with a coupling to the Z boson. In a particularly straightforward gauge-invariant realization, this coupling is introduced via a higher-dimensional operator. While attractive in its simplicity, this model generically induces a large ρ parameter. An ultraviolet completion that avoids an overly large contribution to ρ is the singlet-doublet model. We revisit this model, focusing on the Higgs blind spot region of parameter space where spin-independent interactions are absent. This model successfully reproduces dark matter with direct detection mediated by the Z boson but whose cosmology may depend on additional couplings and states. Future direct detection experiments should effectively probe a significant portion of this parameter space, aside from a small coannihilating region. As such, Z -mediated thermal dark matter as realized in the singlet-doublet model represents an interesting target for future searches.

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

    PubMed Central

    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

  2. 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.

  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. 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.

  5. 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''.

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

    PubMed

    Michalska, Kalina J; Decety, Jean; Zeffiro, Thomas A; Lahey, Benjamin B

    2015-01-01

    Because the disruptive behavior disorders are highly impairing conditions, it is important to determine if structural variations in brain are associated early in life with these problems among children. Structural MRI data were acquired from 111 9-11 year olds (58 girls and 53 boys), 43 who met diagnostic criteria for oppositional defiant disorder and/or conduct disorder and 68 healthy controls. Voxel-based morphometry was used to examine associations of behavioral measures with gray matter volumes in whole-brain analyses. Unlike previous studies, variation in gray matter volume was not found to be associated with a disruptive behavior disorder diagnosis in any brain region at p < .05 with FWE correction. Nonetheless, an inverse nonlinear association of the number of conduct disorder (CD) symptoms with gray matter volume along the left superior temporal sulcus was significant in the full sample (p < .05 with FWE correction), with a trend in the right hemisphere (p < 0.001 uncorrected). There also was a trend toward a stronger association of the number of CD symptoms with gray matter volume along the left superior temporal sulcus in girls than boys. The present findings did not replicate previous findings of reduced gray matter volumes in the anterior insula, amygdala, and frontal cortex in youth with CD, but are consistent with previous findings of reduced gray matter volumes in temporal regions, particularly in girls.

  7. A Mediterranean-Style Diet and White Matter Hyperintensity Volume: the Northern Manhattan Study

    PubMed Central

    Gardener, Hannah; Scarmeas, Nikolaos; Gu, Yian; Boden-Albala, Bernadette; Elkind, Mitchell S.V.; Sacco, Ralph L.; DeCarli, Charles; Wright, Clinton B.

    2011-01-01

    Objective To examine the association between a Mediterranean-style diet (MeDi) and brain MRI white matter hyperintensities (WMH). The MeDi has previously been associated with a reduced risk of cardiovascular morbidity, possibly including stroke. A greater understanding of modifiable risk factors for small vessel damage may facilitate the prevention of stroke and cognitive decline. Design A cross-sectional analysis within a longitudinal population-based cohort study. A semi-quantitative food frequency questionnaire was administered and a score (range 0-9) was calculated to reflect increasing similarity to the MeDi pattern. Setting The Northern Manhattan Study. Participants 1,091 participants, of which 966 had dietary information (mean age 72, 59% women, 65% Hispanic, 16% White, 17% Black). Main outcome measures WMH volume was measured by quantitative brain MRI. Linear regression models were constructed to examine the relation between the MeDi score and the log-transformed WMH volume as a proportion of total cranial volume, controlling for sociodemographic and vascular risk factors. Results On the MeDi scale, 12% scored 0-2, 16 scored 3, 23% scored 4, 23% scored 5, 26% scored 6-9. Each 1-point increase in MeDi score was associated with a lower log WMH volume (β=-0.04, p=0.02). The only MeDi score component that was an independent predictor of WMH volume was the ratio of monounsaturated to saturated fat (β=-0.20, p=0.001). Conclusions A Mediterranean-style diet was associated with a lower WMH burden, a marker of small vessel damage in the brain. However, white matter hyperintensities are etiologically heterogenous and can include neurodegeneration. Replication by other population-based studies is needed. PMID:22332193

  8. Center-stabilized Yang-Mills Theory:Confinement and Large N Volume Independence

    SciTech Connect

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

    2008-03-21

    We examine a double trace deformation of SU(N) Yang-Mills theory which, for large N and large volume, is equivalent to unmodified Yang-Mills theory up to O(1/N{sup 2}) corrections. In contrast to the unmodified theory, large N volume independence is valid in the deformed theory down to arbitrarily small volumes. The double trace deformation prevents the spontaneous breaking of center symmetry which would otherwise disrupt large N volume independence in small volumes. For small values of N, if the theory is formulated on R{sup 3} x S{sup 1} with a sufficiently small compactification size L, then an analytic treatment of the non-perturbative dynamics of the deformed theory is possible. In this regime, we show that the deformed Yang-Mills theory has a mass gap and exhibits linear confinement. Increasing the circumference L or number of colors N decreases the separation of scales on which the analytic treatment relies. However, there are no order parameters which distinguish the small and large radius regimes. Consequently, for small N the deformed theory provides a novel example of a locally four-dimensional pure gauge theory in which one has analytic control over confinement, while for large N it provides a simple fully reduced model for Yang-Mills theory. The construction is easily generalized to QCD and other QCD-like theories.

  9. A structural model of age, grey matter volumes, education, and personality traits.

    PubMed

    Kitamura, Soichiro; Yasuno, Fumihiko; Yamamoto, Akihide; Kazui, Hiroaki; Kudo, Takashi; Matsuoka, Kiwamu; Kiuchi, Kuniaki; Kosaka, Jun; Nagatsuka, Kazuyuki; Iida, Hidehiro; Kishimoto, Toshifumi

    2016-01-01

    When the relationship between ageing and changes in personality traits is considered, it is important to know how they are influenced by biological and environmental factors. The present study examined the relationships between various factors associated with the effect of ageing on personality traits, including structural changes of the brain and environmental factors such as education. We recruited 41 healthy subjects. We administered the NEO Five-Factor Inventory to assess personality factors. Magnetic resonance imaging was performed, and regional grey matter (GM) volumes were obtained. We identified associations in the correlation analysis of age, cerebral GM volume, years of education, and the personality trait of openness. Path analysis was used to estimate the relationships among these factors. The path analysis model of age, GM volume, years of education, and the personality trait of openness revealed that age has an indirect negative association with openness through GM volume and years of education. Ageing was related to a decrease in GM volume, which was in turn related to a decrease in the openness score. Older subjects generally had fewer years of education, which was related to a lower openness score. Maintaining openness against the effects of ageing is desirable, and our results imply that interventions against age-related cerebral atrophy and the promotion of opportunities for higher education may contribute to the development and stability of a healthy personality during the adult life course. © 2015 The Authors. Psychogeriatrics © 2015 Japanese Psychogeriatric Society.

  10. Light clusters in nuclear matter: Excluded volume versus quantum many-body approaches

    NASA Astrophysics Data System (ADS)

    Hempel, Matthias; Schaffner-Bielich, Jürgen; Typel, Stefan; Röpke, Gerd

    2011-11-01

    The formation of clusters in nuclear matter is investigated, which occurs, e.g., in low-energy heavy-ion collisions or core-collapse supernovae. In astrophysical applications, the excluded volume concept is commonly used for the description of light clusters. Here we compare a phenomenological excluded volume approach to two quantum many-body models, the quantum statistical model and the generalized relativistic mean-field model. All three models contain bound states of nuclei with mass number A≤4. It is explored to which extent the complex medium effects can be mimicked by the simpler excluded volume model, regarding the chemical composition and thermodynamic variables. Furthermore, the role of heavy nuclei and excited states is investigated by use of the excluded volume model. At temperatures of a few MeV the excluded volume model gives a poor description of the medium effects on the light clusters, but there the composition is actually dominated by heavy nuclei. At larger temperatures there is a rather good agreement, whereas some smaller differences and model dependencies remain.

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2017-03-27

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

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

    PubMed

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

    2014-04-01

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

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

    SciTech Connect

    Catena, Riccardo; Ibarra, Alejandro; Wild, Sebastian

    2016-05-17

    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.

  15. 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.

  16. Covariantly constant curvature tensors and D=3, N=4, 5, 8 Chern-Simons matter theories

    NASA Astrophysics Data System (ADS)

    Chen, Fa-Min

    2012-03-01

    We construct some examples of D=3, N=4 GW theory and N=5 superconformal Chern-Simons matter theory by using the covariantly constant curvature of a quaternionic-Kahler manifold to construct the symplectic 3-algebra in the theories. Comparing with the previous theories, the N=4, 5 theories constructed in this way possess a local Sp(2n) symmetry and a diffeomorphism symmetry associated with the quaternionic-Kahler manifold. We also construct a generalized N=8 BLG theory by utilizing the dual curvature operator of a maximally symmetric space of dimension 4 to construct the Nambu 3-algebra. Comparing with the previous N=8 BLG theory, the theory has a diffeomorphism invariance and a local SO(4) invariance associated with the symmetric space.

  17. 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

  18. Voxel Level Survival Analysis of Grey Matter Volume and Incident Mild Cognitive Impairment or Alzheimer's Disease.

    PubMed

    Zeifman, Lubov E; Eddy, William F; Lopez, Oscar L; Kuller, Lewis H; Raji, Cyrus; Thompson, Paul M; Becker, James T

    2015-01-01

    The purpose of this study was to identify, at the voxel level, brain regions associated with the time to develop mild cognitive impairment (MCI) or Alzheimer's disease (AD) from normal cognition. We analyzed incident MCI (n = 58) or AD (n = 151) in 292 cognitively normal participants in the Cardiovascular Health Study-Cognition Study (mean age = 79.2 ± 3.6 years). We used segmented, modulated grey matter maps from 3D (spoiled gradient echo) MRI scans obtained in 1998/99 (with clinical follow-up through 2012) that were smoothed with a 3-D 4 mm Gaussian filter. We fit approximately 1.92 million voxel-level Cox proportional hazard models to examine the grey matter volume effect on time to event, adjusting for age, sex, and diabetes. We used the significance threshold of p <  0.005 with contiguity threshold of at least 68 voxels (false detection probability <2.5×10 -8). Areas within the mesial temporal lobe (MTL), anterior temporal lobe, hippocampus, and posterior cingulate gyrus were associated with time to MCI or AD. The presence of white matter lesions (a marker of small vessel disease in the brain) was associated with the volumes of the MTL and precuneus; MRI-identified infarcts also predicted MTL volume. These findings are important because we identified critical brain regions that predict a person's increased likelihood of developing MCI or AD over a decade prior to the onset of clinical symptoms; these critical brain regions were themselves affected by the presence of vascular disease.

  19. Reduced Gray Matter Volume in the Social Brain Network in Adults with Autism Spectrum Disorder

    PubMed Central

    Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Yoshimura, Sayaka; Kubota, Yasutaka; Sawada, Reiko; Sakihama, Morimitsu; Toichi, Motomi

    2017-01-01

    Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by behavioral impairment in social interactions. Although theoretical and empirical evidence suggests that impairment in the social brain network could be the neural underpinnings of ASD, previous structural magnetic resonance imaging (MRI) studies in adults with ASD have not provided clear support for this, possibly due to confounding factors, such as language impairments. To further explore this issue, we acquired structural MRI data and analyzed gray matter volume in adults with ASD (n = 36) who had no language impairments (diagnosed with Asperger’s disorder or pervasive developmental disorder not otherwise specified, with symptoms milder than those of Asperger’s disorder), had no comorbidity, and were not taking medications, and in age- and sex-matched typically developing (TD) controls (n = 36). Univariate voxel-based morphometry analyses revealed that regional gray matter volume was lower in the ASD than in the control group in several brain regions, including the right inferior occipital gyrus, left fusiform gyrus, right middle temporal gyrus, bilateral amygdala, right inferior frontal gyrus, right orbitofrontal cortex, and left dorsomedial prefrontal cortex. A multivariate approach using a partial least squares (PLS) method showed that these regions constituted a network that could be used to discriminate between the ASD and TD groups. A PLS discriminant analysis using information from these regions showed high accuracy, sensitivity, specificity, and precision (>80%) in discriminating between the groups. These results suggest that reduced gray matter volume in the social brain network represents the neural underpinnings of behavioral social malfunctioning in adults with ASD. PMID:28824399

  20. Reduced Gray Matter Volume in the Social Brain Network in Adults with Autism Spectrum Disorder.

    PubMed

    Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Yoshimura, Sayaka; Kubota, Yasutaka; Sawada, Reiko; Sakihama, Morimitsu; Toichi, Motomi

    2017-01-01

    Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by behavioral impairment in social interactions. Although theoretical and empirical evidence suggests that impairment in the social brain network could be the neural underpinnings of ASD, previous structural magnetic resonance imaging (MRI) studies in adults with ASD have not provided clear support for this, possibly due to confounding factors, such as language impairments. To further explore this issue, we acquired structural MRI data and analyzed gray matter volume in adults with ASD (n = 36) who had no language impairments (diagnosed with Asperger's disorder or pervasive developmental disorder not otherwise specified, with symptoms milder than those of Asperger's disorder), had no comorbidity, and were not taking medications, and in age- and sex-matched typically developing (TD) controls (n = 36). Univariate voxel-based morphometry analyses revealed that regional gray matter volume was lower in the ASD than in the control group in several brain regions, including the right inferior occipital gyrus, left fusiform gyrus, right middle temporal gyrus, bilateral amygdala, right inferior frontal gyrus, right orbitofrontal cortex, and left dorsomedial prefrontal cortex. A multivariate approach using a partial least squares (PLS) method showed that these regions constituted a network that could be used to discriminate between the ASD and TD groups. A PLS discriminant analysis using information from these regions showed high accuracy, sensitivity, specificity, and precision (>80%) in discriminating between the groups. These results suggest that reduced gray matter volume in the social brain network represents the neural underpinnings of behavioral social malfunctioning in adults with ASD.

  1. 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.

  2. Testing two alternative theories to dark matter with the Milky Way dynamics

    NASA Astrophysics Data System (ADS)

    de Oliveira, P. L. C.; de Freitas Pacheco, J. A.; Reinisch, G.

    2015-02-01

    Two alternative theories to dark matter are investigated by testing their ability to describe consistently the dynamics of the Milky Way. The first one refers to a modified gravity theory having a running gravitational constant and the second assumes that dark matter halos are constituted by a Bose-Einstein condensation (BEC). The parameters of each model as well as those characterizing the stellar subsystems of the Galaxy were estimated by fitting the rotation curve of the Milky Way. Then, using these parameters, the vertical acceleration profile at the solar position was computed and compared with observations. The modified gravity theory overestimates the vertical acceleration derived from stellar kinematics while predictions of the BEC halo model are barely consistent with observations. However, a dark matter halo based on a collisionless fluid satisfies our consistency test, being the best model able to describe equally well the rotation curve and the vertical acceleration of the Galaxy.

  3. Z boson mediated dark matter beyond the effective theory

    DOE PAGES

    Kearney, John; Orlofsky, Nicholas; Pierce, Aaron

    2017-02-17

    Here, direct detection bounds are beginning to constrain a very simple model of weakly interacting dark matter—a Majorana fermion with a coupling to the Z boson. In a particularly straightforward gauge-invariant realization, this coupling is introduced via a higher-dimensional operator. While attractive in its simplicity, this model generically induces a large ρ parameter. An ultraviolet completion that avoids an overly large contribution to ρ is the singlet-doublet model. We revisit this model, focusing on the Higgs blind spot region of parameter space where spin-independent interactions are absent. This model successfully reproduces dark matter with direct detection mediated by the Zmore » boson but whose cosmology may depend on additional couplings and states. Future direct detection experiments should effectively probe a significant portion of this parameter space, aside from a small coannihilating region. As such, Z-mediated thermal dark matter as realized in the singlet-doublet model represents an interesting target for future searches.« less

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

    PubMed Central

    Valverde, Sergi; Oliver, Arnau; Lladó, Xavier

    2014-01-01

    Multiple sclerosis white matter (WM) lesions can affect brain tissue volume measurements of voxel-wise segmentation methods if these lesions are included in the segmentation process. Several authors have presented different techniques to improve brain tissue volume estimations by filling WM lesions before segmentation with intensities similar to those of WM. Here, we propose a new method to refill WM lesions, where contrary to similar approaches, lesion voxel intensities are replaced by random values of a normal distribution generated from the mean WM signal intensity of each two-dimensional slice. We test the performance of our method by estimating the deviation in tissue volume between a set of 30 T1-w 1.5 T and 30 T1-w 3 T images of healthy subjects and the same images where: WM lesions have been previously registered and afterwards replaced their voxel intensities to those between gray matter (GM) and WM tissue. Tissue volume is computed independently using FAST and SPM8. When compared with the state-of-the-art methods, on 1.5 T data our method yields the lowest deviation in WM between original and filled images, independently of the segmentation method used. It also performs the lowest differences in GM when FAST is used and equals to the best method when SPM8 is employed. On 3 T data, our method also outperforms the state-of-the-art methods when FAST is used while performs similar to the best method when SPM8 is used. The proposed technique is currently available to researchers as a stand-alone program and as an SPM extension. PMID:25379419

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

    PubMed

    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

    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. 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. 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. 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.

  6. 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

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

    PubMed Central

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

    2016-01-01

    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

  8. 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.

  9. 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. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Altered gray matter volume and school age anxiety in children born late preterm.

    PubMed

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

    2014-11-01

    To determine if late preterm (LP) children differ from full term (FT) children in volumes of the cortex, hippocampus, corpus callosum, or amygdala and whether these differences are associated with anxiety symptoms at school-age. LP children born between 34 and 36 weeks gestation and FT children born between 39 and 41 weeks gestation from a larger longitudinal cohort had magnetic resonance imaging scans at school-age. Brain volumes, cortical surface area, and thickness measures were obtained. Anxiety symptoms were assessed using a structured diagnostic interview annually beginning at preschool-age and following the magnetic resonance imaging. LP children (n = 21) had a smaller percentage of total, right parietal, and right temporal lobe gray matter volume than FT children (n = 87). There were no differences in hippocampal, callosal, or amygdala volumes or cortical thickness. LP children also had a relative decrease in right parietal lobe cortical surface area. LP children had greater anxiety symptoms over all assessments. The relationship between late prematurity and school-age anxiety symptoms was mediated by the relative decrease in right temporal lobe volume. LP children, comprising 70% of preterm children, are also at increased risk for altered brain development particularly in the right temporal and parietal cortices. Alterations in the right temporal lobe cortical volume may underlie the increased rate of anxiety symptoms among these LP children. These findings suggest that LP delivery may disrupt temporal and parietal cortical development that persists until school-age with the right temporal lobe conferring risk for elevated anxiety symptoms. Copyright © 2014 Elsevier Inc. All rights reserved.

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

    PubMed Central

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

    2014-01-01

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

  12. Gray matter volume correlates of global positive alcohol expectancy in non-dependent adult drinkers

    PubMed Central

    Ide, Jaime S.; Zhang, Sheng; Hu, Sien; Matuskey, David; Bednarski, Sarah R.; Erdman, Emily; Farr, Olivia M.; Li, Chiang-shan R.

    2013-01-01

    Alcohol use and misuse is known to involve structural brain changes. Numerous imaging studies have examined changes in gray matter (GM) volumes in dependent drinkers, but there is little information on whether non-dependent drinking is associated with structural changes and whether these changes are related to psychological factors – such as alcohol expectancy – that influence drinking behavior. We used voxel based morphometry (VBM) to examine whether the global positive scale of alcohol expectancy, as measured by the Alcohol Expectancy Questionnaire AEQ-3, is associated with specific structural markers and whether such markers are associated with drinking behavior in 113 adult non-dependent drinkers (66 women). Alcohol expectancy is positively correlated with GM volume of left precentrral gyrus (PCG) in men and women combined and bilateral superior frontal gyri (SFG) in women, and negatively correlated with GM volume of the right ventral putamen in men. Furthermore, mediation analyses showed that the GM volume of PCG mediate the correlation of alcohol expectancy and the average number of drinks consumed per occasion and monthly total number of drinks in the past year. When recent drinking was directly accounted for in multiple regressions, GM volume of bilateral dorsolateral prefrontal cortices (DLPFC) correlated positively with alcohol expectancy in the combined sample. To our knowledge, these results are the first to identify the structural brain correlates of alcohol expectancy and its mediation of drinking behaviors. These findings suggest that more studies are needed to investigate increased GM volume in the frontal cortices as a neural correlate of alcohol expectancy. PMID:23461484

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

    SciTech Connect

    Hernandez, Daniel

    2016-06-21

    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){sub ν} is required if light fermionic new states are to exist. Anomaly cancellations mandate the existence of several new fields with nontrivial U(1){sub 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.

  14. 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.

  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. 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…

  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. Supersize my brain: A cross-sectional voxel-based morphometry study on the association between self-reported dietary restraint and regional grey matter volumes.

    PubMed

    van der Laan, Laura N; Charbonnier, Lisette; Griffioen-Roose, Sanne; Kroese, Floor M; van Rijn, Inge; Smeets, Paul A M

    2016-05-01

    Restrained eaters do not eat less than their unrestrained counterparts. Proposed underlying mechanisms are that restrained eaters are more reward sensitive and that they have worse inhibitory control. Although fMRI studies assessed these mechanisms, it is unknown how brain anatomy relates to dietary restraint. Voxel-based morphometry was performed on anatomical scans from 155 normal-weight females to investigate how regional grey matter volume correlates with restraint. A positive correlation was found in several areas, including the parahippocampal gyrus, hippocampus, striatum and the amygdala (bilaterally, p<0.05, corrected). A negative correlation was found in several areas, including the inferior frontal gyrus, superior frontal gyrus, supplementary motor area, middle cingulate cortex and precentral gyrus (p<0.05, corrected). That higher restraint relates to higher grey matter volume in reward-related areas and lower grey matter volume in regions involved in inhibition, provides a neuroanatomical underpinning of theories relating restraint to increased reward sensitivity and reduced inhibitory capacity.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. NRSN1 associated grey matter volume of the visual word form area reveals dyslexia before school.

    PubMed

    Skeide, Michael A; Kraft, Indra; Müller, Bent; Schaadt, Gesa; Neef, Nicole E; Brauer, Jens; Wilcke, Arndt; Kirsten, Holger; Boltze, Johannes; Friederici, Angela D

    2016-10-01

    Literacy learning depends on the flexibility of the human brain to reconfigure itself in response to environmental influences. At the same time, literacy and disorders of literacy acquisition are heritable and thus to some degree genetically predetermined. Here we used a multivariate non-parametric genetic model to relate literacy-associated genetic variants to grey and white matter volumes derived by voxel-based morphometry in a cohort of 141 children. Subsequently, a sample of 34 children attending grades 4 to 8, and another sample of 20 children, longitudinally followed from kindergarten to first grade, were classified as dyslexics and controls using linear binary support vector machines. The NRSN1-associated grey matter volume of the 'visual word form area' achieved a classification accuracy of ~ 73% in literacy-experienced students and distinguished between later dyslexic individuals and controls with an accuracy of 75% at kindergarten age. These findings suggest that the cortical plasticity of a region vital for literacy might be genetically modulated, thereby potentially preconstraining literacy outcome. Accordingly, these results could pave the way for identifying and treating the most common learning disorder before it manifests itself in school.

  4. Thalamic and Cerebellar Gray Matter Volume Reduction in Synthetic Cannabinoids Users.

    PubMed

    Nurmedov, Serdar; Metin, Baris; Ekmen, Sehadet; Noyan, Onur; Yilmaz, Onat; Darcin, Asli; Dilbaz, Nesrin

    2015-01-01

    Synthetic cannabinoids are compounds that bind cannabinoid receptors with a high potency and have been used widely in Europe by young people. However, little is known about the pharmacology and morphological effects of this group of substances in the brain. This study is aimed at investigating the morphological differences among synthetic cannabinoids users and healthy controls. Voxel-based morphometry was used to investigate the differences in brain tissue composition in 20 patients with synthetic cannabinoids use and 20 healthy controls. All participants were male. Compared to healthy controls, voxel of interest analyses showed that regional grey matter volume in both left and right thalamus and left cerebellum was significantly reduced in synthetic cannabinoids users (p < 0.05). No correlation has been found between the age of first cannabis use, duration of use, frequency of use and grey matter volume. These preliminary results suggest an evidence of some structural differences in the brain of synthetic cannabinoids users, and point the need for further investigation of morphological effects of synthetic cannabinoids in the brain. © 2015 S. Karger AG, Basel.

  5. Perturbation theory approach for the power spectrum: from dark matter in real space to massive haloes in redshift space

    SciTech Connect

    Gil-Marín, Héctor; Wagner, Christian; Verde, Licia; Jimenez, Raul; Porciani, Cristiano E-mail: cwagner@icc.ub.edu E-mail: porciani@astro.uni-bonn.de

    2012-11-01

    We investigate the accuracy of Eulerian perturbation theory for describing the matter and galaxy power spectra in real and redshift space in light of future observational probes for precision cosmology. Comparing the analytical results with a large suite of N-body simulations (160 independent boxes of 13.8 (Gpc/h){sup 3} volume each, which are publicly available), we find that re-summing terms in the standard perturbative approach predicts the real-space matter power spectrum with an accuracy of ∼<2% for k ≤ 0.20 h/Mpc at redshifts z∼<1.5. This is obtained following the widespread technique of writing the resummed propagator in terms of 1-loop contributions. We show that the accuracy of this scheme increases by considering higher-order terms in the resummed propagator. By combining resummed perturbation theories with several models for the mappings from real to redshift space discussed in the literature, the multipoles of the dark-matter power spectrum can be described with sub-percent deviations from N-body results for k ≤ 0.15 h/Mpc at z∼<1. As a consequence, the logarithmic growth rate, f, can be recovered with sub-percent accuracy on these scales. Extending the models to massive dark-matter haloes in redshift space, our results describe the monopole term from N-body data within 2% accuracy for scales k ≤ 0.15 h/Mpc at z∼<0.5; here f can be recovered within < 5% when the halo bias is known. We conclude that these techniques are suitable to extract cosmological information from future galaxy surveys.

  6. On the Theory of Fragmentation Process with Initial Particle Volume

    NASA Astrophysics Data System (ADS)

    Alexandrov, D. V.

    2017-08-01

    The problem of fragmentation (disintegration) process is theoretically studied with allowance for the initial particle volume. An exact analytical solution of integro-differential model governing the fragmentation phenomenon is obtained. The key role of a finite initial volume of particles leading to substantial changes of the particle-size distribution function is demonstrated. Supported by the Russian Science Foundation under Grant No. 16-11-10095

  7. Theory of sediment volumes of compressible, particulate structures

    SciTech Connect

    Tiller, F.M.; Khatib, Z.

    1984-07-01

    Specific sediment volume or its reciprocal, average volume fraction of solids, plays a significant role in determining the state of particle aggregation in a suspension. It is determined by the properties of the rising sediment (or cake) in a batch setting tube. A close relations exists between the sediment volume and sedimentation characteristics involved in design of thickeners and clarifiers. Qualitatively, the average porosity of a particulate bed is shown to be principally a function of particle size, shape, and state of aggregation. Slurry concentration, mechanical agitation, and vibration also affects the state of the sediment. Assuming that porosity is a function of the buoyed weight of solids (effective pressure) and the initial porosity of unstressed sediment, formulas are developed which give the average specific sediment volume as a function of height and bed compressibility. For highly compressible materials, the value of the specific sediment volume changes rapidly with height. The limiting value of the specific sediment volume for a cake with differential thickness or the value of the volume fraction of solids epsilon/sub s0/ for an unstressed bed is probably the best assessing the state of aggregation of a suspension. Two experimental methods are presented for its determination. In the first method, the volume of particulates is plotted as a function of thickness; and the limiting slope for a cake of zero thickness is obtained. In the second method, the initial rates of fall and rise, respectively, of the upper particle-supernatant boundary and the sediment are experimentally measured; and epsilon/sub s0/ is obtained through a material balance. 31 references, 12 figures, 3 tables.

  8. Descendants constructed from matter field in Landau-Ginzburg theories coupled to topological gravity

    NASA Astrophysics Data System (ADS)

    Losev, A.

    1993-05-01

    It is argued that gravitational descendants in the theory of topological gravity coupled to topological Landau-Ginzburg theory (not necessarily conformal) can be constructed from matter fields alone (without metric fields and ghosts). In this sense topological gravity is “induced.” We discuss the mechanism of this effect (that turns out to be connected with K. Saito's higher residue pairing: Ki(σi(Φ1),Φ2)=K0(Φ1,Φ2)), and demonstrate how it works in a simplest nontrivial example: correlator on a sphere with four marked points. We also discuss some results on k-point correlators on a sphere. From the idea of “induced” topological gravity it follows that the theory of “pure” topological gravity (without topological matter) is equivalent to the “trivial” Landau-Ginzburg theory (with quadratic superpotential).

  9. Detecting boosted dark matter from the Sun with large volume neutrino detectors

    SciTech Connect

    Berger, Joshua; Cui, Yanou; Zhao, Yue E-mail: ycui@perimeterinstitute.ca

    2015-02-01

    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.

  10. 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.

  11. Detecting boosted dark matter from the Sun with large volume neutrino detectors

    NASA Astrophysics Data System (ADS)

    Berger, Joshua; Cui, Yanou; Zhao, Yue

    2015-02-01

    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.

  12. Theory of the equation of state of hot dense matter

    SciTech Connect

    Barbee, T W; Surh, M; Yang, L H

    1999-07-23

    Ab initio molecular dynamics calculations are adapted to treat dense plasmas for temperatures exceeding the electronic Fermi temperature. Extended electronic states are obtained in a plane wave basis by using pseudopotentials for the ion cores in the local density approximation to density functional theory. The method reduces to conventional first principles molecular dynamics at low temperatures with the expected high level of accuracy. The occurrence of thermally excited ion cores at high temperatures is treated by means of final state pseudopotentials. The method is applied to the shock compression Hugoniot equation of state for aluminum. Good agreement with experiment is found for temperatures ranging from zero through 105K.

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. Cultural evolutionary theory: How culture evolves and why it matters

    PubMed Central

    Creanza, Nicole; Kolodny, Oren; Feldman, Marcus W.

    2017-01-01

    Human cultural traits—behaviors, ideas, and technologies that can be learned from other individuals—can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics because cultural evolution has many parallels with, as well as clear differences from, genetic evolution. Furthermore, cultural and genetic evolution can interact with one another and influence both transmission and selection. This interaction requires theoretical treatments of gene–culture coevolution and dual inheritance, in addition to purely cultural evolution. In addition, cultural evolutionary theory is a natural component of studies in demography, human ecology, and many other disciplines. Here, we review the core concepts in cultural evolutionary theory as they pertain to the extension of biology through culture, focusing on cultural evolutionary applications in population genetics, ecology, and demography. For each of these disciplines, we review the theoretical literature and highlight relevant empirical studies. We also discuss the societal implications of the study of cultural evolution and of the interactions of humans with one another and with their environment. PMID:28739941

  18. Cultural evolutionary theory: How culture evolves and why it matters.

    PubMed

    Creanza, Nicole; Kolodny, Oren; Feldman, Marcus W

    2017-07-24

    Human cultural traits-behaviors, ideas, and technologies that can be learned from other individuals-can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics because cultural evolution has many parallels with, as well as clear differences from, genetic evolution. Furthermore, cultural and genetic evolution can interact with one another and influence both transmission and selection. This interaction requires theoretical treatments of gene-culture coevolution and dual inheritance, in addition to purely cultural evolution. In addition, cultural evolutionary theory is a natural component of studies in demography, human ecology, and many other disciplines. Here, we review the core concepts in cultural evolutionary theory as they pertain to the extension of biology through culture, focusing on cultural evolutionary applications in population genetics, ecology, and demography. For each of these disciplines, we review the theoretical literature and highlight relevant empirical studies. We also discuss the societal implications of the study of cultural evolution and of the interactions of humans with one another and with their environment.

  19. Retain or repel? Droplet volume does matter when measuring leaf wetness traits.

    PubMed

    Matos, Ilaíne S; Rosado, Bruno H P

    2016-05-01

    Leaf wetness is an important characteristic linked to a plant's strategies for water acquisition, use and redistribution. A trade-off between leaf water retention (LWR) and hydrophobicity (LWH) may be expected, since a higher LWH/lower LWR may enhance photosynthesis, while the opposite combination may increase the leaf water uptake (LWU). However, the validation of the ecological meaning of both traits and the influence of droplet volume when measuring them have been largely neglected. To address these questions, LWR and LWH of 14 species were measured using droplets of between 5 and 50 μL. Furthermore, the ability of those species to perform LWU was evaluated through leaf submergence in water. The droplet-volume effect on absolute values and on species ranking for LWR and LWH was tested, as well as the influence of water droplet volume on the relationship between leaf wetness traits and LWU. Variations in droplet volume significantly affected the absolute values and the species ranking for both LWR and LWH. The expected negative correlation between leaf wetness traits was not observed, and they were not validated as a proxy for LWU. The water droplet volume does matter when measuring leaf wetness traits. Therefore, it is necessary to standardize the methodological approach used to measure them. The use of a standard 5 μL droplet for LWH and a 50 μL droplet for LWR is proposed. It is cautioned that the validation of both traits is also needed before using them as proxies to describe responses and effects in functional approaches. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Grey Matter Volumes in Children with Conduct Problems and Varying Levels of Callous-Unemotional Traits.

    PubMed

    Sebastian, Catherine L; De Brito, Stéphane A; McCrory, Eamon J; Hyde, Zoe H; Lockwood, Patricia L; Cecil, Charlotte A M; Viding, Essi

    2016-05-01

    Genetic, behavioural and functional neuroimaging studies have revealed that different vulnerabilities characterise children with conduct problems and high levels of callous-unemotional traits (CP/HCU) compared with children with conduct problems and low callous-unemotional traits (CP/LCU). We used voxel-based morphometry to study grey matter volume (GMV) in 89 male participants (aged 10-16), 60 of whom exhibited CP. The CP group was subdivided into CP/HCU (n = 29) and CP/LCU (n = 31). Whole-brain and regional GMV were compared across groups (CP vs. typically developing (TD) controls (n = 29); and CP/HCU vs. CP/LCU vs. TD). Whole-brain analyses showed reduced GMV in left middle frontal gyrus in the CP/HCU group compared with TD controls. Region-of-interest analyses showed reduced volume in bilateral orbitofrontal cortex (OFC) in the CP group as a whole compared with TD controls. Reduced volume in left OFC was found to be driven by the CP/HCU group only, with significant reductions relative to both TD controls and the CP/LCU group, and no difference between these latter two groups. Within the CP group left OFC volume was significantly predicted by CU traits, but not conduct disorder symptoms. Reduced right anterior cingulate cortex volume was also found in CP/HCU compared with TD controls. Our results support previous findings indicating that GMV differences in brain regions central to decision-making and empathy are implicated in CP. However, they extend these data to suggest that some of these differences might specifically characterise the subgroup with CP/HCU, with GMV reduction in left OFC differentiating children with CP/HCU from those with CP/LCU.

  1. 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.

  2. 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.

  3. Childhood Maltreatment Is Associated with Larger Left Thalamic Gray Matter Volume in Adolescents with Generalized Anxiety Disorder

    PubMed Central

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

    2013-01-01

    Background Generalized anxiety disorder (GAD) is a common anxiety disorder that usually begins in adolescence. Childhood maltreatment is highly prevalent and increases the possibility for developing a variety of mental disorders including anxiety disorders. An earlier age at onset of GAD is significantly related to maltreatment in childhood. Exploring the underpinnings of the relationship between childhood maltreatment and adolescent onset GAD would be helpful in identifying the potential risk markers of this condition. Methods Twenty-six adolescents with GAD and 25 healthy controls participated in this study. A childhood trauma questionnaire (CTQ) was introduced to assess childhood maltreatment. All subjects underwent high-resolution structural magnetic resonance scans. Voxel-based morphometry (VBM) was used to investigate gray matter alterations. Results Significantly larger gray matter volumes of the right putamen were observed in GAD patients compared to healthy controls. In addition, a significant diagnosis-by-maltreatment interaction effect for the left thalamic gray matter volume was revealed, as shown by larger volumes of the left thalamic gray matter in GAD patients with childhood maltreatment compared with GAD patients without childhood maltreatment as well as with healthy controls with/without childhood maltreatment. A significant positive association between childhood maltreatment and left thalamic gray matter volume was only seen in GAD patients. Conclusions These findings revealed an increased volume in the subcortical regions in adolescent GAD, and the alterations in the left thalamus might be involved in the association between childhood maltreatment and the occurrence of GAD. PMID:23951265

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

    PubMed

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

    2013-01-01

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

  5. 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. © 2014 European Sleep Research Society.

  6. Gray matter volume abnormalities in depressive patients with and without anxiety disorders.

    PubMed

    Qi, Haochen; Ning, Yuping; Li, Jie; Guo, Shengwen; Chi, Minyue; Gao, Minjian; Guo, Yangbo; Yang, Yuling; Peng, Hongjun; Wu, Kai

    2014-12-01

    Comorbidity with anxiety disorder is a relatively common occurrence in major depressive disorder. However, the unique and shared neuroanatomical characteristics of depression and anxiety disorders have not been fully identified. The aim of this study was to identify gray matter abnormalities and their clinical correlates in depressive patients with and without anxiety disorders. We applied voxel-based morphometry and region-of-interest analyses of gray matter volume (GMV) in normal controls (NC group, n = 28), depressive patients without anxiety disorder (DP group, n = 18), and depressive patients with anxiety disorder (DPA group, n = 20). The correlations between regional GMV and clinical data were analyzed. The DP group showed decreased GMV in the left insula (INS) and left triangular part of the inferior frontal gyrus when compared to the NC group. The DPA group showed greater GMV in the midbrain, medial prefrontal cortex, and primary motor/somatosensory cortex when compared to the NC group. Moreover, the DPA group showed greater GMV than the DP group in the frontal, INS, and temporal lobes. Most gray matter anomalies were significantly correlated with depression severity or anxiety symptoms. These correlations were categorized into 4 trend models, of which 3 trend models (ie, Models I, II, and IV) revealed the direction of the correlation between regional GMV and depression severity to be the opposite of that between regional GMV and anxiety symptoms. Importantly, the left INS showed a trend Model I, which might be critically important for distinguishing depressive patients with and without anxiety disorder. Our findings of gray matter abnormalities, their correlations with clinical data, and the trend models showing opposite direction may reflect disorder-specific symptom characteristics and help explain the neurobiological differences between depression and anxiety disorder.

  7. Gray Matter Volume Abnormalities in Depressive Patients With and Without Anxiety Disorders

    PubMed Central

    Qi, Haochen; Ning, Yuping; Li, Jie; Guo, Shengwen; Chi, Minyue; Gao, Minjian; Guo, Yangbo; Yang, Yuling; Peng, Hongjun; Wu, Kai

    2014-01-01

    Abstract Comorbidity with anxiety disorder is a relatively common occurrence in major depressive disorder. However, the unique and shared neuroanatomical characteristics of depression and anxiety disorders have not been fully identified. The aim of this study was to identify gray matter abnormalities and their clinical correlates in depressive patients with and without anxiety disorders. We applied voxel-based morphometry and region-of-interest analyses of gray matter volume (GMV) in normal controls (NC group, n = 28), depressive patients without anxiety disorder (DP group, n = 18), and depressive patients with anxiety disorder (DPA group, n = 20). The correlations between regional GMV and clinical data were analyzed. The DP group showed decreased GMV in the left insula (INS) and left triangular part of the inferior frontal gyrus when compared to the NC group. The DPA group showed greater GMV in the midbrain, medial prefrontal cortex, and primary motor/somatosensory cortex when compared to the NC group. Moreover, the DPA group showed greater GMV than the DP group in the frontal, INS, and temporal lobes. Most gray matter anomalies were significantly correlated with depression severity or anxiety symptoms. These correlations were categorized into 4 trend models, of which 3 trend models (ie, Models I, II, and IV) revealed the direction of the correlation between regional GMV and depression severity to be the opposite of that between regional GMV and anxiety symptoms. Importantly, the left INS showed a trend Model I, which might be critically important for distinguishing depressive patients with and without anxiety disorder. Our findings of gray matter abnormalities, their correlations with clinical data, and the trend models showing opposite direction may reflect disorder-specific symptom characteristics and help explain the neurobiological differences between depression and anxiety disorder. PMID:25546687

  8. Sleep Duration is Associated with White Matter Hyperintensity Volume in Older Adults: The Northern Manhattan Study

    PubMed Central

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

    2014-01-01

    Summary 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 MRI in the Northern Manhattan Study. We used multivariable linear regression models to assess associations between both short (< 6 hours) and long (≥ 9 hours) sleep durations and log-transformed WMHV, adjusting for demographic, behavioral and vascular risk factors. A total of 1244 participants, mean age 70 ± 9 years, 61% women and 68% Hispanics were analyzed 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 non-diabetics (β = 0.022; p = 0.2), whereas short sleep was not associated with white matter hyperintensities in those with diabetes or non-diabetics. In conclusion, long sleep duration was associated with a greater burden of white matter lesions in this stroke-free urban sample. The association was mainly seen among those with diabetes mellitus. PMID:25040435

  9. Effects of early nutrition and growth on brain volumes, white matter microstructure and neurodevelopmental outcome in preterm newborns.

    PubMed

    Coviello, Caterina; Keunen, Kristin; Kersbergen, Karina J; Groenendaal, Floris; Leemans, Alexander; Peels, Barbara; Isgum, Ivana; Viergever, Max A; de Vries, Linda S; Buonocore, Giuseppe; Carnielli, Virgilio P; Benders, Manon J N L

    2017-09-15

    This study aimed to investigate the effect of nutrition and growth during the first 4 weeks after birth on cerebral volumes and white matter maturation at term equivalent age(TEA) and on neurodevelopmental outcome at 2 years corrected age(CA), in preterm infants. 131 infants born at a gestational age(GA)<31weeks with MRI at TEA were studied. Cortical gray matter volumes(CGM), basal ganglia and thalami(BGT) volumes, cerebellar volumes and total brain volume(TBV) were computed. Fractional anisotropy(FA) in the posterior limb of internal capsule(PLIC) was obtained. Cognitive and motor scores were assessed at 2 years CA. Cumulative fat and enteral intakes were positively related to larger cerebellar and BGT volumes. Weight gain was associated with larger cerebellar, BGT and CGM volume. Cumulative fat and caloric intake, and enteral intakes were positively associated with FA in the PLIC. Cumulative protein intake was positively associated with higher cognitive and motor scores(all P<0.05). Our study demonstrated a positive association between nutrition, weight gain and brain volumes. Moreover we found a positive relationship between nutrition, white matter maturation at TEA and neurodevelopment in infancy. These findings emphasize the importance of growth and nutrition with a balanced protein, fat and caloric content for brain development.Pediatric Research accepted article preview online, 15 September 2017. doi:10.1038/pr.2017.227.

  10. When matching matters: Loop effects in Higgs effective theory

    NASA Astrophysics Data System (ADS)

    Freitas, Ayres; López-Val, David; Plehn, Tilman

    2016-11-01

    Effective Lagrangians are a useful tool for a data-driven approach to physics beyond the Standard Model at the LHC. However, for the new physics scales accessible at the LHC, the effective operator expansion is only relatively slowly converging at best. For tree-level processes, it has been found that the agreement between the effective Lagrangian and a range of UV-complete models depends sensitively on the appropriate definition of the matching. We extend this analysis to the one-loop level, which is relevant for electroweak precision data and Higgs decay to photons. We show that near the scale of electroweak symmetry breaking the validity of the effective theory description can be systematically improved through an appropriate matching procedure. In particular, we find a significant increase in accuracy when including suitable terms suppressed by the Higgs vacuum expectation value in the matching.

  11. Grey matter volume increase following electroconvulsive therapy in patients with late life depression: a longitudinal MRI study.

    PubMed

    Bouckaert, Filip; De Winter, François-Laurent; Emsell, Louise; Dols, Annemieke; Rhebergen, Didi; Wampers, Martien; Sunaert, Stefan; Stek, Max; Sienaert, Pascal; Vandenbulcke, Mathieu

    2016-03-01

    The evidence on the mechanisms of action of electroconvulsive therapy (ECT) has grown over the past decades. Recent studies show an ECT-related increase in hippocampal, amygdala and subgenual cortex volume. We examined grey matter volume changes following ECT using voxel-based morphometry (VBM) whole brain analysis in patients with severe late life depression (LLD). Elderly patients with unipolar depression were treated twice weekly with right unilateral ECT until remission on the Montgomery-Åsberg Depression Rating Scale (MADRS) was achieved. Cognition (Mini Mental State Examination) and psychomotor changes (CORE Assessment) were monitored at baseline and 1 week after the last session of ECT. We performed 3 T structural MRI at both time points. We used the VBM8 toolbox in SPM8 to study grey matter volume changes. Paired t tests were used to compare pre- and post-ECT grey matter volume (voxel-level family-wise error threshold p < 0.05) and to assess clinical response. Twenty-eight patients (mean age 71.9 ± 7.8 yr, 8 men) participated in our study. Patients received a mean of 11.2 ± 4 sessions of ECT. The remission rate was 78.6%. Cognition, psychomotor agitation and psychomotor retardation improved significantly (p < 0.001). Right-hemispheric grey matter volume was increased in the caudate nucleus, medial temporal lobe (including hippocampus and amygdala), insula and posterior superior temporal regions but did not correlate with MADRS score. Grey matter volume increase in the caudate nucleus region correlated significantly with total CORE Assessment score (r = 0.63; p < 0.001). Not all participants were medication-free. Electroconvulsive therapy in patients with LLD is associated with significant grey matter volume increase, which is most pronounced ipsilateral to the stimulation side.

  12. Grey matter volume increase following electroconvulsive therapy in patients with late life depression: a longitudinal MRI study

    PubMed Central

    Bouckaert, Filip; De Winter, François-Laurent; Emsell, Louise; Dols, Annemieke; Rhebergen, Didi; Wampers, Martien; Sunaert, Stefan; Stek, Max; Sienaert, Pascal; Vandenbulcke, Mathieu

    2016-01-01

    Background The evidence on the mechanisms of action of electroconvulsive therapy (ECT) has grown over the past decades. Recent studies show an ECT-related increase in hippocampal, amygdala and subgenual cortex volume. We examined grey matter volume changes following ECT using voxel-based morphometry (VBM) whole brain analysis in patients with severe late life depression (LLD). Methods Elderly patients with unipolar depression were treated twice weekly with right unilateral ECT until remission on the Montgomery–Åsberg Depression Rating Scale (MADRS) was achieved. Cognition (Mini Mental State Examination) and psychomotor changes (CORE Assessment) were monitored at baseline and 1 week after the last session of ECT. We performed 3 T structural MRI at both time points. We used the VBM8 toolbox in SPM8 to study grey matter volume changes. Paired t tests were used to compare pre- and post-ECT grey matter volume (voxel-level family-wise error threshold p < 0.05) and to assess clinical response. Results Twenty-eight patients (mean age 71.9 ± 7.8 yr, 8 men) participated in our study. Patients received a mean of 11.2 ± 4 sessions of ECT. The remission rate was 78.6%. Cognition, psychomotor agitation and psychomotor retardation improved significantly (p < 0.001). Right- hemispheric grey matter volume was increased in the caudate nucleus, medial temporal lobe (including hippocampus and amygdala), insula and posterior superior temporal regions but did not correlate with MADRS score. Grey matter volume increase in the caudate nucleus region correlated significantly with total CORE Assessment score (r = 0.63; p < 0.001). Limitations Not all participants were medication-free. Conclusion Electroconvulsive therapy in patients with LLD is associated with significant grey matter volume increase, which is most pronounced ipsilateral to the stimulation side. PMID:26395813

  13. 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.

    2015-01-01

    We test a particular theory of dark matter, in which dark matter axions form ring 'caustics' in the plane of the Milky Way. According to this theory, cold collisionless dark matter particles with angular momentum flow in and out of the Milky Way as it forms. These flows form caustic rings (at the positions of the rings, the density of the flow is 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 known Galaxy rotation curve. We explore the effects of the caustic rings on dwarf galaxy tidal disruption using N-body simulations. Simulations of the Sagittarius dwarf galaxy in a caustic halo potential match observations as far as 90 kpc from the Galactic center. The source code for calculating the caustic halo acceleration has been made publicly available in the NEMO Stellar Dynamics Toolbox and the Milkyway@home client repository. This research was funded by NSF grant AST 10-09670, the NASA-NY Space Grant, and the American Fellowship from AAUW.

  14. 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.

  15. Elevated Gray Matter Volume of the Emotional Cerebellum in Women with Premenstrual Dysphoric Disorder Disorder

    PubMed Central

    Berman, Steven M.; London, Edythe D.; Morgan, Melinda; Rapkin, Andrea J.

    2012-01-01

    OBJECTIVE Premenstrual dysphoric disorder (PMDD) is characterized by severe, negative mood symptoms during the luteal phase of each menstrual cycle. We recently reported that women with PMDD show a greater increase in relative glucose metabolism in the posterior cerebellum from the follicular to the luteal phase, as compared with healthy women, and that the phase-related increase is proportional to PMDD symptom severity. We extended this work with a study of brain structure in PMDD. METHODS High-resolution magnetic resonance imaging (MRI) scans were obtained from 12 women with PMDD and 13 healthy control subjects (whole-brain volume-corrected p<.05). Voxel-based morphometry was used to assess group differences in cerebral grey-matter volume (GMV), using a statistical criterion of p<.05, correcting for multiple comparisons in the whole-brain volume. RESULTS PMDD subjects had greater GMV than controls in the posterior cerebellum but not in any other brain area. Age was negatively correlated with GMV within this region in healthy women, but not in women with PMDD. The group difference in GMV was significant for women over age 30 (p=.0002) but not younger participants (p>.1). CONCLUSIONS PMDD appears to be associated with reduced age-related loss in posterior cerebellar GMV. Although the mechanism underlying this finding is unclear, cumulative effects of symptom-related cerebellar activity may be involved. PMID:22868063

  16. Correlations between ventricular enlargement and gray and white matter volumes of cortex, thalamus, striatum, and internal capsule in schizophrenia.

    PubMed

    Horga, Guillermo; Bernacer, Javier; Dusi, Nicola; Entis, Jonathan; Chu, Kingwai; Hazlett, Erin A; Haznedar, M Mehmet; Kemether, Eileen; Byne, William; Buchsbaum, Monte S

    2011-10-01

    Ventricular enlargement is one of the most consistent abnormal structural brain findings in schizophrenia and has been used to infer brain shrinkage. However, whether ventricular enlargement is related to local overlying cortex and/or adjacent subcortical structures or whether it is related to brain volume change globally has not been assessed. We systematically assessed interrelations of ventricular volumes with gray and white matter volumes of 40 Brodmann areas (BAs), the thalamus and its medial dorsal nucleus and pulvinar, the internal capsule, caudate and putamen. We acquired structural MRI ( patients with schizophrenia (n = 64) and healthy controls (n = 56)) and diffusion tensor fractional anisotropy (FA) (untreated schizophrenia n = 19, controls n = 32). Volumes were assessed by manual tracing of central structures and a semi-automated parcellation of BAs. Patients with schizophrenia had increased ventricular size associated with decreased cortical gray matter volumes widely across the brain; a similar but less pronounced pattern was seen in normal controls; local correlations (e.g. temporal horn with temporal lobe volume) were not appreciably higher than non-local correlations (e.g. temporal horn with prefrontal volume). White matter regions adjacent to the ventricles similarly did not reveal strong regional relationships. FA and center of mass of the anterior limb of the internal capsule also appeared differentially influenced by ventricular volume but findings were similarly not regional. Taken together, these findings indicate that ventricular enlargement is globally interrelated with gray matter volume diminution but not directly correlated with volume loss in the immediately adjacent caudate, putamen, or internal capsule.

  17. 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.

  18. 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

  19. Rocket Radiation Handbook. Volume I. Rocket Radiation Phenomenology and Theory

    DTIC Science & Technology

    1974-06-01

    transmission data become available using tunable laser spectrometry, it should be possible to replace Eqs. (H. 14) through (H.26) with much more...exactly according to calculation. Another interesting example is the laser . Although the basic theory that could have predicted the principle of the... laser existed in 1930, unfamil- iarity of applied scientists and engineers with this theory, delayed the discovery-of the laser until 1960. The current

  20. 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…

  1. 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…

  2. 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…

  3. Higher Serum 25-Hydroxyvitamin D and Lower Plasma Glucose Are Associated with Larger Gray Matter Volume but Not with White Matter or Total Brain Volume in Dutch Community-Dwelling Older Adults.

    PubMed

    Brouwer-Brolsma, Elske M; van der Zwaluw, Nikita L; van Wijngaarden, Janneke P; Dhonukshe-Rutten, Rosalie A; in 't Veld, Paulette H; Feskens, Edith J; Smeets, Paul A; Kessels, Roy P; van de Rest, Ondine; de Groot, Lisette C

    2015-08-01

    Previous studies have shown beneficial associations between 25-hydroxyvitamin D [25(OH)D] status and cognitive performance, but results are inconclusive. Studies on 25(OH)D status and brain volumetric measures may provide more insight in the potential role of vitamin D in cognitive performance. The aims of this study were to cross-sectionally investigate the association between vitamin D status and brain tissue volumes in 217 Dutch community-dwelling older adults aged ≥65 y and to examine whether surrogate markers of glucose homeostasis act as modifiers in these associations. Serum 25(OH)D, plasma glucose, and plasma insulin were analyzed, serving as exposure measures. Estimates of total brain volume, gray matter volume, and white matter volume were obtained using MRI, serving as outcome measures. Associations of serum 25(OH)D, plasma glucose, and plasma insulin concentrations with brain tissue volumes were evaluated using multiple linear regression analyses. Potential effect modification by glucose homeostasis in the association between 25(OH)D and brain volumetric measures was examined by stratification and testing for interaction. After full adjustment, higher serum 25(OH)D concentrations and lower plasma glucose concentrations were associated with larger gray matter volume, [β ± SE: 0.20 ± 0.08 mL (P = 0.02) and -3.26 ± 1.59 mL (P = 0.04), respectively]. There were no associations between serum 25(OH)D and plasma insulin concentrations with total brain volume and white matter volume. Furthermore, there was no evidence for a mediation or modification effect of plasma glucose on the associations between serum 25(OH)D and brain tissue volumes. Higher serum 25(OH)D and lower plasma glucose are associated with larger gray matter volume, but not white matter or total brain volume, in a population of Dutch adults aged ≥65 y. This trial was registered at clinicaltrials.gov as NCT00696514. © 2015 American Society for Nutrition.

  4. 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.

  5. 'O' blood type is associated with larger grey-matter volumes in the cerebellum.

    PubMed

    De Marco, Matteo; Venneri, Annalena

    2015-07-01

    Recent evidence indicated higher incidence of cognitive deficits in ABO blood-type system 'AB' individuals. Since this statistical difference might originate from the lack of protective effects exerted by 'O' alleles on the brain via vascular or non-vascular routes, this study investigated volumetric differences in grey matter between 'O' and non-'O' adults to explore the possibility of a structural endophenotype visible in 'O' adults without cognitive impairment or neurodegeneration. A large sample of cognitively healthy adults who had previously undergone structural MRI for research purposes were contacted telephonically and enquired about their ABO blood type. Out of the 189 individuals who were able to retrieve and communicate this information, 'O' (n=76) and 'A' adults (n=65) were included in Model 1. In Model 2, all non-'O' (n=113) were instead collapsed in a single group. Voxel-Based Morphometry analyses were carried out on three-dimensional T1-weighted scans, and between-sample t tests were run to compare the maps of grey-matter volumes of the subgroups of interest, controlling for major nuisance variables. In Model 1, 'O' adults had larger grey-matter volumes in two symmetrical clusters within the posterior ventral portion of the cerebellum. This was confirmed in Model 2. Additionally, non-'O' adults showed lower volume values in temporal and limbic regions, including the left hippocampus. The cerebellar clusters were located in regions previously found to be part of a network responsible for sensorimotor integration. It is speculated that the structural reductions seen in non-'O' adults might result in a susceptibility to down-regulation of this network. This occurrence is likely to intensify along the ageing process and may contribute to foster cognitive decline. Although Model 2 seems to suggest that having a 'O' blood type might play a role in protection against those conditions in which temporal and mediotemporal volumetric loss is observed (Alzheimer

  6. Methods of Quantum Field Theory in Condensed Matter Physics ---New Perspectives, Extensions and Applications---

    NASA Astrophysics Data System (ADS)

    Umezawa, H.

    Throughout the course of its development in the past four decades quantum field theory has gradually acquired a very rich structure (much richer in fact than it was originally intended) and now provides us with an effective method in the analysis of many diverse areas of physics; condensed matter physics, high energy particle physics general relativity and cosmology are among the more notable examples. Since condensed matter physics deals with those phenomena in which a system of quanta exist together with a variety of macroscopic objects at finite temperature, it may be said to manifest the fundamental properties of quantum field theory in its widest sense. Thus condensed matter physics has served as a powerful motivating force throughout the growth and development of quantum field theory. This process was indeed initiated by the celebrated Matsubara formalism of finite temperature Green's function method. This process is by no means complete since recent developments in many areas of physics demand a more sophisticated understanding with regard to the fundamental nature of quantum field theory. A brief description of this maturing process of quantum field theory in the past, present and prospects for the future will be the main content of this article.

  7. Evaluating the effects of white matter multiple sclerosis lesions on the volume estimation of 6 brain tissue segmentation methods.

    PubMed

    Valverde, S; Oliver, A; Díez, Y; Cabezas, M; Vilanova, J C; Ramió-Torrentà, L; Rovira, À; Lladó, X

    2015-06-01

    The accuracy of automatic tissue segmentation methods can be affected by the presence of hypointense white matter lesions during the tissue segmentation process. Our aim was to evaluate the impact of MS white matter lesions on the brain tissue measurements of 6 well-known segmentation techniques. These include straightforward techniques such as Artificial Neural Network and fuzzy C-means as well as more advanced techniques such as the Fuzzy And Noise Tolerant Adaptive Segmentation Method, fMRI of the Brain Automated Segmentation Tool, SPM5, and SPM8. Thirty T1-weighted images from patients with MS from 3 different scanners were segmented twice, first including white matter lesions and then masking the lesions before segmentation and relabeling as WM afterward. The differences in total tissue volume and tissue volume outside the lesion regions were computed between the images by using the 2 methodologies. Total gray matter volume was overestimated by all methods when lesion volume increased. The tissue volume outside the lesion regions was also affected by white matter lesions with differences up to 20 cm(3) on images with a high lesion load (≈50 cm(3)). SPM8 and Fuzzy And Noise Tolerant Adaptive Segmentation Method were the methods less influenced by white matter lesions, whereas the effect of white matter lesions was more prominent on fuzzy C-means and the fMRI of the Brain Automated Segmentation Tool. Although lesions were removed after segmentation to avoid their impact on tissue segmentation, the methods still overestimated GM tissue in most cases. This finding is especially relevant because on images with high lesion load, this bias will most likely distort actual tissue atrophy measurements. © 2015 by American Journal of Neuroradiology.

  8. Cortical Thickness and Subcortical Gray Matter Volume in Pediatric Anxiety Disorders.

    PubMed

    Gold, Andrea L; Steuber, Elizabeth R; White, Lauren K; Pacheco, Jennifer; Sachs, Jessica F; Pagliaccio, David; Berman, Erin; Leibenluft, Ellen; Pine, Daniel S

    2017-04-24

    Perturbations in the prefrontal cortex (PFC), hippocampus, and amygdala are implicated in the development of anxiety disorders. However, most structural neuroimaging studies of patients with anxiety disorders utilize adult samples, and the few studies in youths examine small samples, primarily with volume-based measures. This study tested the hypothesis that cortical thickness of PFC regions and gray matter volume of the hippocampus and amygdala differ between pediatric anxiety disorder patients and healthy volunteers (HVs). High-resolution 3-Tesla T1-weighted MRI scans were acquired in 151 youths (75 anxious, 76 HV; ages 8-18). Analyses tested associations of brain structure with anxiety diagnosis and severity across both groups, as well as response to cognitive-behavioral therapy in a subset of 53 patients. Cortical thickness was evaluated both within an a priori PFC mask (small-volume corrected) and using an exploratory whole-brain-corrected (p<0.05) approach. Anxious relative to healthy youths exhibited thicker cortex in the left ventromedial PFC (vmPFC) and left precentral gyrus. Both anxiety diagnosis and symptom severity were associated with smaller right hippocampal volume. In patients, thinner cortex in parietal and occipital cortical regions was associated with worse treatment response. Pediatric anxiety was associated with structural differences in vmPFC and hippocampus, regions implicated in emotional processing and in developmental models of anxiety pathophysiology. Parietal and occipital cortical thickness were related to anxiety treatment response but not baseline anxiety.Neuropsychopharmacology advance online publication, 31 May 2017; doi:10.1038/npp.2017.83.

  9. Toward Practical Theory: A State of Practice Assessment of Reading Comprehension Instruction. Final Report. Volume II.

    ERIC Educational Resources Information Center

    Harste, Jerome C., Ed.; Stephens, Diane, Ed.

    Written for language educators, this volume about reading and research suggests that the theory-practice and research-teaching gaps are dysfunctional and calls for a collaborative pedagogy between colleges and schools to develop a practical theory of reading instruction. In the opening article, Jerome Harste discusses issues that emerged from…

  10. Global grey matter volume in adult bipolar patients with and without lithium treatment: A meta-analysis.

    PubMed

    Sun, Yue Ran; Herrmann, Nathan; Scott, Christopher J M; Black, Sandra E; Khan, Maisha M; Lanctôt, Krista L

    2018-01-01

    The goal of this meta-analysis was to quantitatively summarize the evidence available on the differences in grey matter volume between lithium-treated and lithium-free bipolar patients. A systematic search was conducted in Cochrane Central, Embase, MEDLINE, and PsycINFO databases for original peer-reviewed journal articles that reported on global grey matter volume in lithium-medicated and lithium-free bipolar patients. Standard mean difference and Hedges' g were used to calculate effect size in a random-effects model. Risk of publication bias was assessed using Egger's test and quality of evidence was assessed using standard criteria. There were 15 studies with a total of 854 patients (368 lithium-medicated, 486 lithium-free) included in the meta-analysis. Global grey matter volume was significantly larger in lithium-treated bipolar patients compared to lithium-free patients (SMD: 0.17, 95% CI: 0.01-0.33; z = 2.11, p = 0.035). Additionally, there was a difference in global grey matter volume between groups in studies that employed semi-automated segmentation methods (SMD: 0.66, 95% CI: 0.01-1.31; z = 1.99, p = 0.047), but no significant difference in studies that used fully-automated segmentation. No publication bias was detected (bias coefficient = - 0.65, p = 0.46). Variability in imaging methods and lack of high-quality evidence limits the interpretation of the findings. Results suggest that lithium-treated patients have a greater global grey matter volume than those who were lithium-free. Further study of the relationship between lithium and grey matter volume may elucidate the therapeutic potential of lithium in conditions characterized by abnormal changes in brain structure. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  11. 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

  12. Spinor matter fields in SL(2,C) gauge theories of gravity: Lagrangian and Hamiltonian approaches

    NASA Astrophysics Data System (ADS)

    Antonowicz, Marek; Szczyrba, Wiktor

    1985-06-01

    We consider the SL(2,C)-covariant Lagrangian formulation of gravitational theories with the presence of spinor matter fields. The invariance properties of such theories give rise to the conservation laws (the contracted Bianchi identities) having in the presence of matter fields a more complicated form than those known in the literature previously. A general SL(2,C) gauge theory of gravity is cast into an SL(2,C)-covariant Hamiltonian formulation. Breaking the SL(2,C) symmetry of the system to the SU(2) symmetry, by introducing a spacelike slicing of spacetime, we get an SU(2)-covariant Hamiltonian picture. The qualitative analysis of SL(2,C) gauge theories of gravity in the SU(2)-covariant formulation enables us to define the dynamical symplectic variables and the gauge variables of the theory under consideration as well as to divide the set of field equations into the dynamical equations and the constraints. In the SU(2)-covariant Hamiltonian formulation the primary constraints, which are generic for first-order matter Lagrangians (Dirac, Weyl, Fierz-Pauli), can be reduced. The effective matter symplectic variables are given by SU(2)-spinor-valued half-forms on three-dimensional slices of spacetime. The coupled Einstein-Cartan-Dirac (Weyl, Fierz-Pauli) system is analyzed from the (3+1) point of view. This analysis is complete; the field equations of the Einstein-Cartan-Dirac theory split into 18 gravitational dynamical equations, 8 dynamical Dirac equations, and 7 first-class constraints. The system has 4+8=12 independent degrees of freedom in the phase space.

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

    PubMed

    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.

  14. 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

  15. APOE ɛ2 is associated with white matter hyperintensity volume in CADASIL.

    PubMed

    Gesierich, Benno; Opherk, Christian; Rosand, Jonathan; Gonik, Mariya; Malik, Rainer; Jouvent, Eric; Hervé, Dominique; Adib-Samii, Poneh; Bevan, Steve; Pianese, Luigi; Silvestri, Serena; Dotti, Maria T; De Stefano, Nicola; van der Grond, Jeroen; Boon, Elles M J; Pescini, Francesca; Rost, Natalia; Pantoni, Leonardo; Oberstein, Saskia A Lesnik; Federico, Antonio; Ragno, Michele; Markus, Hugh S; Tournier-Lasserve, Elisabeth; Chabriat, Hugues; Dichgans, Martin; Duering, Marco; Ewers, Michael

    2016-01-01

    Apolipoprotein E (APOE) increases the risk for Alzheimer’s disease (ɛ4 allele) and cerebral amyloid angiopathy (ɛ2 and ɛ4), but its role in small vessel disease (SVD) is debated. Here we studied the effects of APOE on white matter hyperintensity volume (WMHV) in CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), a nonamyloidogenic angiopathy and inherited early-onset form of pure SVD. Four hundred and eighty-eight subjects were recruited through a multicenter consortium. Compared with APOE ɛ3/ɛ3, WMHV was increased in APOE ɛ2 (P = 0.02) but not APOE ɛ4. The results remained significant when controlled for genome-wide genetic background variation. Our findings suggest a modifying influence of APOE ɛ2 on WMHV caused by pure SVD.

  16. Finite volume effects and N-body matter correlations in a CDM simulation

    NASA Astrophysics Data System (ADS)

    Colombi, S.; Bouchet, F. R.

    1992-12-01

    We study, using count probabilities measurements, the consequences of finite sample effects on N-body (2 <= N <= 5) averaged matter correlation functions barξ_N inside cubic volumes for a CDM universe (Efstathiou et al. 1988) with approx 3 10^5 particles generated with a PM code. We try to assess the importance of this effect by applying some correction to the data. The results show that finite effects should be important on N-body correlation functions for N >= 3, and not negligible even on the two-point correlation function. Moreover, once corrected, the statistical properties of this CDM universe appear compatible with the scaling relation (Groth & Peebles 1977; Davis & Peebles 1983; Fry & Peebles 1978; Sharp, Bonometto & Lucchin 1984) barξ_N/barξ_2^{N-1}= constant with respect to scale, over all scales investigated, which was not the case with direct uncorrected measurements.

  17. Enhanced functional connectivity and increased gray matter volume of insula related to action video game playing

    PubMed Central

    Gong, Diankun; He, Hui; Liu, Dongbo; Ma, Weiyi; Dong, Li; Luo, Cheng; Yao, Dezhong

    2015-01-01

    Research has shown that distinct insular subregions are associated with particular neural networks (e.g., attentional and sensorimotor networks). Based on the evidence that playing action video games (AVGs) facilitates attentional and sensorimotor functions, this study examined the relation between AVG experience and the plasticity of insular subregions and the functional networks therein that are related to attentional and sensorimotor functions. By comparing AVG experts and amateurs, we found that AVG experts had enhanced functional connectivity and grey matter volume in insular subregions. Furthermore, AVG experts exhibited increased functional connectivity between the attentional and sensorimotor networks, and the experience-related enhancement was predominantly evident in the left insula, an understudied brain area. Thus, AVG playing may enhance functional integration of insular subregions and the pertinent networks therein. PMID:25880157

  18. Enhanced functional connectivity and increased gray matter volume of insula related to action video game playing.

    PubMed

    Gong, Diankun; He, Hui; Liu, Dongbo; Ma, Weiyi; Dong, Li; Luo, Cheng; Yao, Dezhong

    2015-04-16

    Research has shown that distinct insular subregions are associated with particular neural networks (e.g., attentional and sensorimotor networks). Based on the evidence that playing action video games (AVGs) facilitates attentional and sensorimotor functions, this study examined the relation between AVG experience and the plasticity of insular subregions and the functional networks therein that are related to attentional and sensorimotor functions. By comparing AVG experts and amateurs, we found that AVG experts had enhanced functional connectivity and grey matter volume in insular subregions. Furthermore, AVG experts exhibited increased functional connectivity between the attentional and sensorimotor networks, and the experience-related enhancement was predominantly evident in the left insula, an understudied brain area. Thus, AVG playing may enhance functional integration of insular subregions and the pertinent networks therein.

  19. Gray matter volumes of early sensory regions are associated with individual differences in sensory processing.

    PubMed

    Yoshimura, Sayaka; Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Sawada, Reiko; Kubota, Yasutaka; Toichi, Motomi

    2017-09-20

    Sensory processing (i.e., the manner in which the nervous system receives, modulates, integrates, and organizes sensory stimuli) is critical when humans are deciding how to react to environmental demands. Although behavioral studies have shown that there are stable individual differences in sensory processing, the neural substrates that implement such differences remain unknown. To investigate this issue, structural magnetic resonance imaging scans were acquired from 51 healthy adults and individual differences in sensory processing were assessed using the Sensory Profile questionnaire (Brown et al.: Am J Occup Ther 55 (2001) 75-82). There were positive relationships between the Sensory Profile modality-specific subscales and gray matter volumes in the primary or secondary sensory areas for the visual, auditory, touch, and taste/smell modalities. Thus, the present results suggest that individual differences in sensory processing are implemented by the early sensory regions. Hum Brain Mapp, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. APOE ɛ2 is associated with white matter hyperintensity volume in CADASIL

    PubMed Central

    Gesierich, Benno; Opherk, Christian; Rosand, Jonathan; Gonik, Mariya; Malik, Rainer; Jouvent, Eric; Hervé, Dominique; Adib-Samii, Poneh; Bevan, Steve; Pianese, Luigi; Silvestri, Serena; Dotti, Maria T; De Stefano, Nicola; van der Grond, Jeroen; Boon, Elles M J; Pescini, Francesca; Rost, Natalia; Pantoni, Leonardo; Lesnik Oberstein, Saskia A; Federico, Antonio; Ragno, Michele; Markus, Hugh S; Tournier-Lasserve, Elisabeth; Chabriat, Hugues; Dichgans, Martin; Duering, Marco

    2016-01-01

    Apolipoprotein E (APOE) increases the risk for Alzheimer’s disease (ɛ4 allele) and cerebral amyloid angiopathy (ɛ2 and ɛ4), but its role in small vessel disease (SVD) is debated. Here we studied the effects of APOE on white matter hyperintensity volume (WMHV) in CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), a nonamyloidogenic angiopathy and inherited early-onset form of pure SVD. Four hundred and eighty-eight subjects were recruited through a multicenter consortium. Compared with APOE ɛ3/ɛ3, WMHV was increased in APOE ɛ2 (P = 0.02) but not APOE ɛ4. The results remained significant when controlled for genome-wide genetic background variation. Our findings suggest a modifying influence of APOE ɛ2 on WMHV caused by pure SVD. PMID:25920955

  1. 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.

  2. 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.

  3. ETHOS—an effective theory of structure formation: From dark particle physics to the matter distribution of the Universe

    NASA Astrophysics Data System (ADS)

    Cyr-Racine, Francis-Yan; Sigurdson, Kris; Zavala, Jesús; Bringmann, Torsten; Vogelsberger, Mark; Pfrommer, Christoph

    2016-06-01

    We formulate an effective theory of structure formation (ETHOS) that enables cosmological structure formation to be computed in almost any microphysical model of dark matter physics. This framework maps the detailed microphysical theories of particle dark matter interactions into the physical effective parameters that shape the linear matter power spectrum and the self-interaction transfer cross section of nonrelativistic dark matter. These are the input to structure formation simulations, which follow the evolution of the cosmological and galactic dark matter distributions. Models with similar effective parameters in ETHOS but with different dark particle physics would nevertheless result in similar dark matter distributions. We present a general method to map an ultraviolet complete or effective field theory of low-energy dark matter physics into parameters that affect the linear matter power spectrum and carry out this mapping for several representative particle models. We further propose a simple but useful choice for characterizing the dark matter self-interaction transfer cross section that parametrizes self-scattering in structure formation simulations. Taken together, these effective parameters in ETHOS allow the classification of dark matter theories according to their structure formation properties rather than their intrinsic particle properties, paving the way for future simulations to span the space of viable dark matter physics relevant for structure formation.

  4. Sex-related difference in human white matter volumes studied: Inspection of the corpus callosum and other white matter by VBM

    NASA Astrophysics Data System (ADS)

    Shiino, Akihiko; Chen, Yen-Wei; Tanigaki, Kenji; Yamada, Atsushi; Vigers, Piers; Watanabe, Toshiyuki; Tooyama, Ikuo; Akiguchi, Ichiro

    2017-01-01

    It has been contended that any observed difference of the corpus callosum (CC) size between men and women is not sex-related but brain-size-related. A recent report, however, showed that the midsagittal CC area was significantly larger in women in 37 brain-size-matched pairs of normal young adults. Since this constituted strong evidence of sexual dimorphism and was obtained from publicly available data in OASIS, we examined volume differences within the CC and in other white matter using voxel-based morphometry (VBM). We created a three-dimensional region of interest of the CC and measured its volume. The VBM statistics were analyzed by permutation test and threshold-free cluster enhancement (TFCE) with the significance levels at FWER < 0.05. The CC volume was significantly larger in women in the same 37 brain-size-matched pairs. We found that the CC genu was the subregion showing the most significant sex-related difference. We also found that white matter in the bilateral anterior frontal regions and the left lateral white matter near to Broca’s area were larger in women, whereas there were no significant larger regions in men. Since we used brain-size-matched subjects, our results gave strong volumetric evidence of localized sexual dimorphism of white matter.

  5. Sex-related difference in human white matter volumes studied: Inspection of the corpus callosum and other white matter by VBM

    PubMed Central

    Shiino, Akihiko; Chen, Yen-wei; Tanigaki, Kenji; Yamada, Atsushi; Vigers, Piers; Watanabe, Toshiyuki; Tooyama, Ikuo; Akiguchi, Ichiro

    2017-01-01

    It has been contended that any observed difference of the corpus callosum (CC) size between men and women is not sex-related but brain-size-related. A recent report, however, showed that the midsagittal CC area was significantly larger in women in 37 brain-size-matched pairs of normal young adults. Since this constituted strong evidence of sexual dimorphism and was obtained from publicly available data in OASIS, we examined volume differences within the CC and in other white matter using voxel-based morphometry (VBM). We created a three-dimensional region of interest of the CC and measured its volume. The VBM statistics were analyzed by permutation test and threshold-free cluster enhancement (TFCE) with the significance levels at FWER < 0.05. The CC volume was significantly larger in women in the same 37 brain-size-matched pairs. We found that the CC genu was the subregion showing the most significant sex-related difference. We also found that white matter in the bilateral anterior frontal regions and the left lateral white matter near to Broca’s area were larger in women, whereas there were no significant larger regions in men. Since we used brain-size-matched subjects, our results gave strong volumetric evidence of localized sexual dimorphism of white matter. PMID:28045130

  6. 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.

  7. Cortical thickness, cortical and subcortical volume, and white matter integrity in patients with their first episode of major depression.

    PubMed

    Han, Kyu-Man; Choi, Sunyoung; Jung, Jeyoung; Na, Kyoung-Sae; Yoon, Ho-Kyoung; Lee, Min-Soo; Ham, Byung-Joo

    2014-02-01

    The uncertainty over the true morphological changes in brains with major depressive disorder (MDD) underlines the necessity of comprehensive studies with multimodal structural brain imaging analyses. This study aimed to evaluate the differences in cortical thickness, cortical and subcortical volume, and white matter integrity between first episode, medication-naïve MDD patients and healthy controls. Subjects with their first episode of MDD whose illness duration had not exceeded 6 months (n=20) were enrolled in this study and were compared to age-, sex-, and education level-matched healthy controls (n=22). All participants were subjected to T1-weighted structural magnetic resonance imaging (MRI). We used an automated procedure of FreeSurfer and Tract-based spatial statistics (TBSS) to analyze differences in cortical thickness, cortical and subcortical volume, and white matter integrity between two groups. The patients with first episode MDD exhibited significantly reduced cortical volume in the caudal anterior cingulate gyrus (P<0.0015) compared to healthy controls. We also observed altered white matter integrity in the body of the corpus callosum (P<0.01), reduced cortical volume of the caudal middle frontal gyrus and medial orbitofrontal gyrus, and enlarged hippocampal volume in the first episode MDD patients. We relied on a relatively small sample size and cortical volume reduction in several brain regions was not replicated in the analysis of cortical thickness. Using multimodal imaging analyses on medication-naïve first episode MDD patients, we demonstrated fundamental structural alteration of brain gray and white matter, such as reduced cortical volume of the caudal ACC and white matter integrity in the body of the corpus callosum. © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Reduced gray matter volume in normal adults with a maternal family history of Alzheimer disease.

    PubMed

    Honea, R A; Swerdlow, R H; Vidoni, E D; Goodwin, J; Burns, J M

    2010-01-12

    A consistently identified risk factor for Alzheimer disease (AD) is family history of dementia, with maternal transmission significantly more frequent than paternal transmission. A history of maternal AD may be related to AD-like glucose consumption in cognitively healthy subjects. In this cross-sectional study, we tested whether cognitively healthy people with a family history of AD have less gray matter volume (GMV), an endophenotype for late-onset AD, than individuals with no family history, and whether decreases in GMV are different in subjects with a maternal family history. As part of the Kansas University Brain Aging Project, 67 cognitively intact individuals with a maternal history of late-onset AD (FHm, n = 16), a paternal history of AD (FHp, n = 8), or no parental history of AD (FH-, n = 43), similar in age, gender, education, and Mini-Mental State Examination score, were scanned at 3 T. We used voxel-based morphometry to examine GMV differences between groups, controlling for age, gender, and apoE4. Cognitively healthy individuals with a family history of late-onset AD had significantly decreased GMV in the precuneus, middle frontal, inferior frontal, and superior frontal gyri compared with FH- individuals. FHm subjects had significantly smaller inferior frontal, middle frontal, precuneus, and lingual gyri compared with FH- and FHp subjects. Overall, maternal family history of Alzheimer disease (AD) in cognitively normal individuals is associated with lower gray matter volume in AD-vulnerable brain regions. These data complement and extend reports of cerebral metabolic differences in subjects with a maternal family history.

  9. 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.

  10. 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.

  11. 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…

  12. 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…

  13. 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…

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

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Ten papers on theory and research in higher education have the following titles and authors: "An Analysis of the Paradigmatic Evolution of U.S. Higher Education and Implications for the Year 2000" (Hasan Simsek and Richard B. Heydinger); "A Motivational Analysis of Academic Life in College" (Martin V. Covington); "The…

  15. 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);…

  16. 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…

  17. 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…

  18. Higher Education: Handbook of Theory and Research. Volume IX.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    Ten papers on theory and research in higher education have the following titles and authors: "An Analysis of the Paradigmatic Evolution of U.S. Higher Education and Implications for the Year 2000" (Hasan Simsek and Richard B. Heydinger); "A Motivational Analysis of Academic Life in College" (Martin V. Covington); "The…

  19. 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…

  20. 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…

  1. 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.…

  2. MAOA rs1137070 and heroin addiction interactively alter gray matter volume of the salience network

    PubMed Central

    Sun, Yan; Liu, Linwen; Feng, Jiajia; Yue, Weihua; Lu, Lin; Fan, Yong; Shi, Jie

    2017-01-01

    The rs1137070 polymorphism of monoamine oxidase A (MAOA) is associated with alcoholism and smoking behavior. However, the association between rs1137070 and heroin addiction remains unclear. In this study, we examined the allelic distribution of rs1137070 in 1,035 heroin abusers and 2,553 healthy controls and investigated the interactive effects of rs1137070 and heroin addiction on gray matter volume (GMV) based on 78 heroin abusers and 79 healthy controls. The C allele frequency of rs1137070 was significantly higher in heroin abusers. Heroin addiction and the rs1137070 variant interactively altered measures of GMV in the anterior cingulate cortex, orbital frontal cortex, temporal pole, and insula, which were correlated with cognitive function. Heroin abusers with the C allele had lower measures of GMV in these regions than the healthy controls with the same allele, whereas those with the T allele displayed a different trend. The altered brain regions were connected with white matter tracts, yielding a structural network that partially overlapped with the salience network. These findings suggest that the low activity-related C allele of MAOA rs1137070 is associated with an increase in the sensitivity to heroin addiction and the damaging effects of heroin abuse on cognition and the salience network. PMID:28345608

  3. Reduced frontal white matter volume in children with early onset of adrenarche.

    PubMed

    Klauser, Paul; Whittle, Sarah; Simmons, Julian G; Byrne, Michelle L; Mundy, Lisa K; Patton, George C; Fornito, Alex; Allen, Nicholas B

    2015-02-01

    While there is growing evidence that puberty affects brain development, very little is known about the structural brain changes associated with dehydroepiandrosterone (DHEA), an adrenal hormone that exhibits dramatic increases during adrenarche, the earliest phase of puberty. Moreover, no research has investigated whether relatively early exposure to DHEA (i.e., early adrenarche) during this period is associated with differences in brain structure. We ran a whole-brain voxel-based morphometry analysis on T1-weighted magnetic resonance imaging brain scans to compare gray (GMV) and white matter volumes (WMV) between children experiencing relatively early (n=41) vs. relatively late (n=44) adrenarche. We also investigated the correlations between GMV or WMV and DHEA levels, and finally, tested for sex differences in group and correlation analyses. We observed reduced frontal WMV in a cluster located on the left corona radiata in children experiencing earlier adrenarche. In addition, WMV in this area was negatively correlated with DHEA levels. We did not observe any effect of gender in both the group and the correlation analyses. Early onset of adrenarche (as defined by relatively early exposure to DHEA) may be associated with differences in the development of frontal white matter tracts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. 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.

  5. Volume reduction of cesium contaminated soil by magnetic separation - Pretreatment of organic matters -

    NASA Astrophysics Data System (ADS)

    Horie, Hiroki; Yukumatsu, Kazuki; Mishima, Fumihito; Akiyama, Yoko; Nishijima, Shigehiro; Sekiyama, Tomio; Mitsui, Seiichiro; Kato, Mitsugu

    2017-07-01

    By the accident of Fukushima Daiichi Nuclear Power Plant, a large amount of soil was contaminated by radioactive cesium. We developed a new volume reduction method of contaminated soil combining classification and magnetic separation. In magnetic separation, 2:1 type clay minerals, which adsorb cesium strongly and show paramagnetism, are removed from soil suspension of silt and clay, and then the contaminated soil can be separated into two groups that is high and low dose soil. However, there is an issue that the clay aggregates induced by organic matters prevent 2:1 type clay minerals from selective separation magnetically. The purpose of this study is to disperse aggregates by means of the alkaline K2CO3 solution treatment for selective separation of 2:1 type clay minerals. Firstly, particle size distribution was measured and the dispersion by K2CO3 treatment was investigated. Moreover, the radioactivity of passed soils after magnetic separation was measured to investigate the effect of dispersion treatment before magnetic separation. The result showed the possibility of more selective separation for 2:1 type clay minerals by treatment of organic matters.

  6. Brain grey matter volume alterations associated with antidepressant response in major depressive disorder.

    PubMed

    Liu, Jia; Xu, Xin; Luo, Qiang; Luo, Ya; Chen, Ying; Lui, Su; Wu, Min; Zhu, Hongyan; Kemp, Graham J; Gong, Qiyong

    2017-09-05

    Not all patients with major depressive disorder respond to adequate pharmacological therapy. Psychoradiological studies have reported that antidepressant responders and nonresponders show different alterations in brain grey matter, but the findings are inconsistent. The present study reports a meta-analysis of voxel-based morphometric studies of patients with major depressive disorder, both antidepressant responders and nonresponders, using the anisotropic effect size version of Seed-based D Mapping to identify brain regions correlated to clinical response. A systematic search was conducted up to June 2016 to identify studies focussing on antidepressant response. In responders across 9 datasets grey matter volume (GMV) was significantly higher in the left inferior frontal gyrus and insula, while GMV was significantly lower in the bilateral anterior cingulate cortex (ACC) and the right superior frontal gyrus (SFG). In nonresponders across 5 datasets GMV was significantly lower in the bilateral ACC, median cingulate cortex (MCC) and right SFG. Conjunction analysis confirmed significant differences in the bilateral ACC and right SFG, where GMV was significantly lower in nonresponders but higher in responders. The current study adds to psychoradiology, an evolving subspecialty of radiology mainly for psychiatry and clinical psychology.

  7. Independent and interactive effects of blood pressure and cardiac function on brain volume and white matter hyperintensities in heart failure.

    PubMed

    Alosco, Michael L; Brickman, Adam M; Spitznagel, Mary Beth; Griffith, Erica Y; Narkhede, Atul; Raz, Naftali; Cohen, Ronald; Sweet, Lawrence H; Hughes, Joel; Rosneck, Jim; Gunstad, John

    2013-01-01

    Reduced systemic perfusion and comorbid medical conditions are key contributors to adverse brain changes in heart failure (HF). Hypertension, the most common co-occurring condition in HF, accelerates brain atrophy in aging populations. However, the independent and interactive effects of blood pressure and systemic perfusion on brain structure in HF have yet to be investigated. Forty-eight older adults with HF underwent impedance cardiography to assess current systolic blood pressure status and cardiac index to quantify systemic perfusion. All participants underwent brain magnetic resonance imaging to quantify total brain, total and subcortical gray matter volume, and white matter hyperintensities (WMH) volume. Regression analyses adjusting for medical and demographic factors showed decreased cardiac index was associated with smaller subcortical gray matter volume (P < .01), and higher systolic blood pressure predicted reduced total gray matter volume (P = .03). The combination of higher blood pressure and lower cardiac index exacerbated WMH (P = .048). Higher blood pressure and systemic hypoperfusion are associated with smaller brain volume, and these factors interact to exacerbate WMH in HF. Prospective studies are needed to clarify the effects of blood pressure on the brain in HF, including the role of long-term blood pressure fluctuations. Copyright © 2013 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  8. Independent and Interactive Effects of Blood Pressure and Cardiac Function on Brain Volume and White Matter Hyperintensities in Heart Failure

    PubMed Central

    Alosco, Michael L.; Brickman, Adam M.; Spitznagel, Mary Beth; Griffith, Erica Y.; Narkhede, Atul; Raz, Naftali; Cohen, Ronald; Sweet, Lawrence H.; Hughes, Joel; Rosneck, Jim; Gunstad, John

    2013-01-01

    Background Reduced systemic perfusion and comorbid medical conditions are key contributors to adverse brain changes in heart failure (HF). Hypertension, the most common co-occurring condition in HF, accelerates brain atrophy in aging populations. However, the independent and interactive effects of blood pressure and systemic perfusion on brain structure in HF have yet to be investigated. Methods Forty-eight older adults with HF underwent impedance cardiography to assess current systolic blood pressure status, and cardiac index to quantify systemic perfusion. All participants underwent brain magnetic resonance imaging to quantify total brain, total and subcortical gray matter volume, and white matter hyperintensities (WMH) volume. Results Regression analyses adjusting for medical and demographic factors showed decreased cardiac index was associated with smaller subcortical gray matter volume (p < .01) and higher systolic blood pressure predicted reduced total gray matter volume (p = .03). The combination of higher blood pressure and lower cardiac index exacerbated WMH (p = .048). Conclusions Higher blood pressure and systemic hypoperfusion are associated with smaller brain volume and these factors interact to exacerbate WMH in HF. Prospective studies are needed to clarify the effects of blood pressure on the brain in HF, including the role of long-term blood pressure fluctuations. PMID:23735419

  9. Regional Gray Matter Volumes as Related to Psychomotor Slowing in Adults with Type 1 Diabetes.

    PubMed

    Nunley, Karen A; Ryan, Christopher M; Aizenstein, Howard J; Jennings, J Richard; MacCloud, Rebecca L; Orchard, Trevor J; Rosano, Caterina

    2017-06-01

    Psychomotor slowing is a common cognitive complication in type 1 diabetes (T1D), but its neuroanatomical correlates and risk factors are unclear. In nondiabetic adults, smaller gray matter volume (GMV) and presence of white matter hyperintensities are associated with psychomotor slowing. We hypothesize that smaller GMV in prefronto-parietal regions explains T1D-related psychomotor slowing. We also inspect the contribution of microvascular disease and hyperglycemia. GMV, white matter hyperintensities (WMH), and glucose levels were measured concurrently with a test of psychomotor speed (Digit Symbol Substitution Test [DSST]) in 95 adults with childhood-onset T1D (mean age/duration = 49/41 years) and 135 similarly aged non-T1D adults. Linear regression models tested associations between DSST and regional GMV, controlling for T1D, sex, and education; a bootstrapping method tested whether regional GMV explained between-group differences in DSST. For the T1D cohort, voxel-based and a priori regions-of-interest methods further tested associations between GMV and DSST, adjusting for WMH, hyperglycemia, and age. Bilateral putamen, but no other regions examined, significantly attenuated DSST differences between the cohorts (bootstrapped unstandardized indirect effects: -3.49, -3.26; 95% confidence interval = -5.49 to -1.80, -5.29 to -1.44, left and right putamen, respectively). Among T1D, DSST was positively associated with GMV of bilateral putamen and left thalamus. Neither WMH, hyperglycemia, age, nor other factors substantially modified these relationships. For middle-aged adults with T1D and cerebral microvascular disease, GMV of basal ganglia may play a critical role in regulating psychomotor speed, as measured via DSST. Studies to quantify the impact of basal ganglia atrophy concurrent with WMH progression on psychomotor slowing are warranted.

  10. 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.

  11. The D-D-bar mesons matter in Walecka's mean field theory

    SciTech Connect

    Farias Freire, M. L. de; Rodrigues da Silva, R.

    2010-11-12

    We study the D-D-bar mesons matter in the framework of {sigma} and {omega} meson exchange model using Walecka's mean field theory. We choose the equal number of D and anti-D meson then we get <{omega}{sup 0}> = 0 and the <{sigma}> field exhibits a critical temperature around 1.2 GeV. We investigate effective mass and pressure. We conclude that this matter is a gas and these results are not favorable for the existence of D-D-bar bound state.

  12. On the stability conditions for theories of modified gravity in the presence of matter fields

    NASA Astrophysics Data System (ADS)

    De Felice, Antonio; Frusciante, Noemi; Papadomanolakis, Georgios

    2017-03-01

    We present a thorough stability analysis of modified gravity theories in the presence of matter fields. We use the Effective Field Theory framework for Dark Energy and Modified Gravity to retain a general approach for the gravity sector and a Sorkin-Schutz action for the matter one. Then, we work out the proper viability conditions to guarantee in the scalar sector the absence of ghosts, gradient and tachyonic instabilities. The absence of ghosts can be achieved by demanding a positive kinetic matrix, while the lack of a gradient instability is ensured by imposing a positive speed of propagation for all the scalar modes. In case of tachyonic instability, the mass eigenvalues have been studied and we work out the appropriate expressions. For the latter, an instability occurs only when the negative mass eigenvalue is much larger, in absolute value, than the Hubble parameter. We discuss the results for the minimally coupled quintessence model showing for a particular set of parameters two typical behaviours which in turn lead to a stable and an unstable configuration. Moreover, we find that the speeds of propagation of the scalar modes strongly depend on matter densities, for the beyond Horndeski theories. Our findings can be directly employed when testing modified gravity theories as they allow to identify the correct viability space.

  13. 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

  14. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Anorexia Nervosa during Adolescence Is Associated with Decreased Gray Matter Volume in the Inferior Frontal Gyrus

    PubMed Central

    Mabe, Hiroyo; Yamada, Eiji; Masuda, Masato; Tomoda, Akemi

    2015-01-01

    Anorexia nervosa (AN) is an eating disorder characterized by the relentless pursuit to lose weight, mostly through self-starvation, and a distorted body image. AN tends to begin during adolescence among women. However, the underlying neural mechanisms related to AN remain unclear. Using voxel-based morphometry based on magnetic resonance imaging scans, we investigated whether the presence of AN was associated with discernible changes in brain morphology. Participants were 20 un-medicated, right-handed patients with early-onset AN and 14 healthy control subjects. Group differences in gray matter volume (GMV) were assessed using high-resolution, T1-weighted, volumetric magnetic resonance imaging datasets (3T Trio scanner; Siemens AG) and analyzed after controlling for age and total GMV, which was decreased in the bilateral inferior frontal gyrus (IFG) (left IFG: FWE corrected, p < 0.05; right IFG: uncorrected, p < 0.05) of patients with AN. The GMV in the bilateral IFG correlated significantly with current age (left IFG: r = -.481, p < .05; right IFG: r = -.601, p < .01) and was limited to the AN group. We speculate that decreased IFG volume might lead to deficits in executive functioning or inhibitory control within neural reward systems. Precocious or unbalanced neurological trimming within this particular region might be an important factor for the pathogenesis of AN onset. PMID:26067825

  16. Anorexia Nervosa during Adolescence Is Associated with Decreased Gray Matter Volume in the Inferior Frontal Gyrus.

    PubMed

    Fujisawa, Takashi X; Yatsuga, Chiho; Mabe, Hiroyo; Yamada, Eiji; Masuda, Masato; Tomoda, Akemi

    2015-01-01

    Anorexia nervosa (AN) is an eating disorder characterized by the relentless pursuit to lose weight, mostly through self-starvation, and a distorted body image. AN tends to begin during adolescence among women. However, the underlying neural mechanisms related to AN remain unclear. Using voxel-based morphometry based on magnetic resonance imaging scans, we investigated whether the presence of AN was associated with discernible changes in brain morphology. Participants were 20 un-medicated, right-handed patients with early-onset AN and 14 healthy control subjects. Group differences in gray matter volume (GMV) were assessed using high-resolution, T1-weighted, volumetric magnetic resonance imaging datasets (3T Trio scanner; Siemens AG) and analyzed after controlling for age and total GMV, which was decreased in the bilateral inferior frontal gyrus (IFG) (left IFG: FWE corrected, p < 0.05; right IFG: uncorrected, p < 0.05) of patients with AN. The GMV in the bilateral IFG correlated significantly with current age (left IFG: r = -.481, p < .05; right IFG: r = -.601, p < .01) and was limited to the AN group. We speculate that decreased IFG volume might lead to deficits in executive functioning or inhibitory control within neural reward systems. Precocious or unbalanced neurological trimming within this particular region might be an important factor for the pathogenesis of AN onset.

  17. 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.

  18. Relationships between years of education, regional grey matter volumes, and working memory-related brain activity in healthy older adults.

    PubMed

    Boller, Benjamin; Mellah, Samira; Ducharme-Laliberté, Gabriel; Belleville, Sylvie

    2017-04-01

    The aim of this study was to examine the relationships between educational attainment, regional grey matter volume, and functional working memory-related brain activation in older adults. The final sample included 32 healthy older adults with 8 to 22 years of education. Structural magnetic resonance imaging (MRI) was used to measure regional volume and functional MRI was used to measure activation associated with performing an n-back task. A positive correlation was found between years of education and cortical grey matter volume in the right medial and middle frontal gyri, in the middle and posterior cingulate gyri, and in the right inferior parietal lobule. The education by age interaction was significant for cortical grey matter volume in the left middle frontal gyrus and in the right medial cingulate gyrus. In this region, the volume loss related to age was larger in the low than high-education group. The education by age interaction was also significant for task-related activity in the left superior, middle and medial frontal gyri due to the fact that activation increased with age in those with higher education. No correlation was found between regions that are structurally related with education and those that are functionally related with education and age. The data suggest a protective effect of education on cortical volume. Furthermore, the brain regions involved in the working memory network are getting more activated with age in those with higher educational attainment.

  19. Gray matter blood flow and volume are reduced in association with white matter hyperintensity lesion burden: a cross-sectional MRI study.

    PubMed

    Crane, David E; Black, Sandra E; Ganda, Anoop; Mikulis, David J; Nestor, Sean M; Donahue, Manus J; MacIntosh, Bradley J

    2015-01-01

    Cerebral White Matter Hyperintensities (WMH) are associated with vascular risk factors and age-related cognitive decline. WMH have primarily been associated with global white matter and gray matter (GM) changes and less is known about regional effects in GM. The purpose of this study was to test for an association between WMH and two GM imaging measures: cerebral blood flow (CBF) and voxel-based morphometry (VBM). Twenty-six elderly adults with mild to severe WMH participated in this cross-sectional 3 Tesla magnetic resonance imaging (MRI) study. MRI measures of GM CBF and VBM were derived from arterial spin labeling (ASL) and T1-weighted images, respectively. Fluid-attenuated inversion recovery (FLAIR) images were used to quantify the WMH lesion burden (mL). GM CBF and VBM data were used as dependent variables. WMH lesion burden, age and sex were used in a regression model. Visual rating of WMH with the Fazekas method was used to compare the WMH lesion volume regression approach. WMH volume was normally distributed for this group (mean volume of 22.7 mL, range: 2.2-70.6 mL). CBF analysis revealed negative associations between WMH volume and CBF in the left anterior putamen, subcallosal, accumbens, anterior caudate, orbital frontal, anterior insula, and frontal pole (corrected p < 0.05). VBM analysis revealed negative associations between WMH and GM volume in lingual gyrus, intracalcarine, and bilateral hippocampus (corrected p < 0.05). The visual rating scale corroborated the regression findings (corrected p < 0.05). WMH lesion volume was associated with intra-group GM CBF and structural differences in this cohort of WMH adults with mild to severe lesion burden.

  20. 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. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Distinct effects of late adulthood cognitive and physical activities on gray matter volume.

    PubMed

    Arenaza-Urquijo, Eider M; de Flores, Robin; Gonneaud, Julie; Wirth, Miranka; Ourry, Valentin; Callewaert, William; Landeau, Brigitte; Egret, Stéphanie; Mézenge, Florence; Desgranges, Béatrice; Chételat, Gaël

    2017-04-01

    Engagement in cognitive activity (CA) and physical activity (PA) during the lifespan may counteract brain atrophy later in life. Here, we investigated engagement in CA and PA during late adulthood in association with gray matter volume (GM) in normal older adults, with special focus on the hippocampus. Forty-five cognitively normal older individuals (mean age: 72) underwent T1-weighted MRI and self-reported CA and PA assessment. Whole brain voxel-wise multiple regression models were carried out to assess the relationships between CA, PA and GM volume adjusted by age and sex. Further adjustment for years of education and risk factors were performed. Voxel-wise analyses were projected on 3D hippocampal surface views. Cognitive activity and PA demonstrated independent regional associations with GM after adjustment for confounders. Cognitive activity was related to greater GM in extended brain areas including frontal, temporal and parietal cortices, while PA was associated with increased GM in the prefrontal, insular and motor cortices. Regression maps projected on the hippocampal surface showed a common association of PA and CA within the anterior part of the hippocampus, although the effect of CA was more subtle and also extended to the posterior part. Engagement in PA and CA in late adulthood were independently related to regional GM volume, notably in aging and AD vulnerable areas. These results support the idea that both PA and CA- based interventions may be suitable to promote brain health in late adulthood. The potential synergistic effects of PA and CA need to be addressed in future studies including larger samples.

  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. Gray-Matter Volume, Midbrain Dopamine D2/D3 Receptors and Drug Craving in Methamphetamine Users

    PubMed Central

    Morales, Angelica A.; Kohno, Milky; Robertson, Chelsea L.; Dean, Andy C.; Mandelkern, Mark A.; London, Edythe D.

    2015-01-01

    Dysfunction of the mesocorticolimbic system plays 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 [18F]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. PMID:25896164

  4. 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.

  5. Modified free volume theory of self-diffusion and molecular theory of shear viscosity of liquid carbon dioxide.

    PubMed

    Nasrabad, Afshin Eskandari; Laghaei, Rozita; Eu, Byung Chan

    2005-04-28

    In previous work on the density fluctuation theory of transport coefficients of liquids, it was necessary to use empirical self-diffusion coefficients to calculate the transport coefficients (e.g., shear viscosity of carbon dioxide). In this work, the necessity of empirical input of the self-diffusion coefficients in the calculation of shear viscosity is removed, and the theory is thus made a self-contained molecular theory of transport coefficients of liquids, albeit it contains an empirical parameter in the subcritical regime. The required self-diffusion coefficients of liquid carbon dioxide are calculated by using the modified free volume theory for which the generic van der Waals equation of state and Monte Carlo simulations are combined to accurately compute the mean free volume by means of statistical mechanics. They have been computed as a function of density along four different isotherms and isobars. A Lennard-Jones site-site interaction potential was used to model the molecular carbon dioxide interaction. The density and temperature dependence of the theoretical self-diffusion coefficients are shown to be in excellent agreement with experimental data when the minimum critical free volume is identified with the molecular volume. The self-diffusion coefficients thus computed are then used to compute the density and temperature dependence of the shear viscosity of liquid carbon dioxide by employing the density fluctuation theory formula for shear viscosity as reported in an earlier paper (J. Chem. Phys. 2000, 112, 7118). The theoretical shear viscosity is shown to be robust and yields excellent density and temperature dependence for carbon dioxide. The pair correlation function appearing in the theory has been computed by Monte Carlo simulations.

  6. Cosmology in bimetric theory with an effective composite coupling to matter

    SciTech Connect

    Gümrükçüoğlu, A. Emir; Heisenberg, Lavinia; Mukohyama, Shinji; Tanahashi, Norihiro E-mail: laviniah@kth.se E-mail: N.Tanahashi@damtp.cam.ac.uk

    2015-04-01

    We study the cosmology of bimetric theory with a composite matter coupling. We find two possible branches of background evolution. We investigate the question of stability of cosmological perturbations. For the tensor and vector perturbations, we derive conditions on the absence of ghost and gradient instabilities. For the scalar modes, we obtain conditions for avoiding ghost degrees. In the first branch, we find that one of the scalar modes becomes a ghost at the late stages of the evolution. Conversely, this problem can be avoided in the second branch. However, we also find that the constraint for the second branch prevents the doubly coupled matter fields from being the standard ingredients of cosmology. We thus conclude that a realistic and stable cosmological model requires additional minimally coupled matter fields.

  7. 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.

  8. Unified theory to describe and engineer conservation laws in light-matter interactions

    NASA Astrophysics Data System (ADS)

    Fernandez-Corbaton, Ivan; Rockstuhl, Carsten

    2017-05-01

    The effects of the electromagnetic field on material systems are governed by joint light-matter conservation laws. An increasing number of these balance equations are currently being considered both theoretically and with an eye to their practical applicability. We present a unified theory to treat conservation laws in light-matter interactions. It can be used to describe and engineer the transfer of any measurable property from the electromagnetic field to any object. The theory allows one to explicitly characterize and separately compute the transfer due to asymmetry of the object and the transfer due to field absorption by the object. It also allows one to compute the upper bound of the transfer rate of any given property to any given object, together with the corresponding most efficient illumination which achieves the bound. Due to its algebraic nature, the approach is inherently suited for computer implementation.

  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.

  10. Superalgebra realization of the 3-algebras in N=6, 8 Chern-Simons-matter theories

    NASA Astrophysics Data System (ADS)

    Chen, Fa-Min

    2012-01-01

    We use superalgebras to realize the 3-algebras used to construct N=6, 8 Chern-Simons-matter (CSM) theories. We demonstrate that the superalgebra realization of the 3-algebras provides a unified framework for classifying the gauge groups of the Nge 5 theories based on 3-algebras. Using this realization, we rederive the ordinary Lie algebra construction of the general N=6 CSM theory from its 3-algebra counterpart and reproduce all known examples as well. In particular, we explicitly construct the Nambu 3-bracket in terms of a double graded commutator of PSU(2|2). The N=8 theory of Bagger, Lambert and Gustavsson (BLG) with SO(4) gauge group is constructed by using several different ways. A quantization scheme for the 3-brackets is proposed by promoting the double graded commutators as quantum mechanical double graded commutators.

  11. 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

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

    NASA Astrophysics Data System (ADS)

    Hu, Jinniu; Toki, Hiroshi; Shen, Hong

    2016-10-01

    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.

  13. 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

  14. 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.

  15. Lectures on localization and matrix models in supersymmetric Chern-Simons-matter theories

    NASA Astrophysics Data System (ADS)

    Mariño, Marcos

    2011-11-01

    In these lectures, I give a pedagogical presentation of some of the recent progress in supersymmetric Chern-Simons-matter theories, coming from the use of localization and matrix model techniques. The goal is to provide a simple derivation of the exact interpolating function for the free energy of ABJM theory on the three-sphere, which implies in particular the N3/2 behavior at strong coupling. I explain in detail part of the background needed to understand this derivation, like holographic renormalization, localization of path integrals and large N techniques in matrix models.

  16. Novel BPS Wilson loops in three-dimensional quiver Chern-Simons-matter theories

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    We show that generic three-dimensional N = 2 quiver super Chern-Simons-matter theories admit Bogomol'nyi-Prasad-Sommerfield (BPS) Drukker-Trancanelli (DT) type Wilson loops. We investigate both Wilson loops along timelike infinite straight lines in Minkowski spacetime and circular Wilson loops in Euclidean space. In Aharnoy-Bergman-Jafferis-Maldacena theory, we find that generic BPS DT type Wilson loops preserve the same number of supersymmetries as Gaiotto-Yin type Wilson loops. There are several free parameters for generic BPS DT type Wilson loops in the construction, and supersymmetry enhancement for Wilson loops happens for special values of the parameters.

  17. Dissolved deconfinement: Phase structure of large N gauge theories with fundamental matter

    SciTech Connect

    Basu, Pallab; Mukherjee, Anindya

    2008-08-15

    A class of large N U(N) gauge theories on a compact manifold S{sup 3}xR (with possible inclusion of adjoint matter) is known to show first-order deconfinement transition at the deconfinement temperature. This includes the familiar example of pure YM theory and N=4 Supersymmetric Yang-Mills theory. Here we study the effect of introduction of N{sub f} fundamental matter fields in the phase diagram of the above mentioned gauge theories at small coupling and in the limit of large N and finite N{sub f}/N. We find some interesting features like the termination of the line of first-order deconfinement phase transition at a critical point as the ratio N{sub f}/N is increased and absence of deconfinement transition thereafter (there is only a smooth crossover). This result may have some implication for QCD, which unlike a pure gauge theory does not show a first-order deconfinement transition and only displays a smooth crossover at the transition temperature.

  18. 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.

  19. Spectral equation-of-state theory for dense, partially ionized matter

    NASA Astrophysics Data System (ADS)

    Ritchie, Burke

    2005-07-01

    The Schrödinger equation is solved in time and space to implement a finite-temperature equation-of-state theory for dense, partially ionized matter. The time-dependent calculation generates a spectrum of quantum states. Eigenfunctions are calculated from a knowledge of the spectrum and used to calculate the electronic pressure and energy. Results are given for Be and LiD and compared with results from the INFERNO model [D. A. Liberman, Phys. Rev. B 20, 4981 (1979)].

  20. Evaluation of deep gray matter volume, cortical thickness and white matter integrity in patients with typical absence epilepsy: a study using voxelwise-based techniques.

    PubMed

    Corrêa, D G; Ventura, N; Zimmermann, N; Doring, T M; Tukamoto, G; Leme, J; Pereira, M; D'Andrea, I; Rêgo, C; Alves-Leon, S V; Gasparetto, E L

    2017-03-01

    The objective of this study was to evaluate the cortical thickness and the volume of deep gray matter structures, measured from 3D T1-weighted gradient echo imaging, and white matter integrity, by diffusion tensor imaging (DTI) in patients with typical absence epilepsy (AE). Patients (n = 19) with typical childhood AE and juvenile AE, currently taking antiepileptic medication, were compared with control subjects (n = 19), matched for gender and age. 3D T1 magnetization-prepared rapid gradient echo-weighted imaging and DTI along 30 noncolinear directions were performed using a 1.5-T MR scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of deep gray matter structures. For tract-based spatial statistics analysis of DTI, a white matter skeleton was created, along with a permutation-based inference with 5000 permutations. A threshold of p < 0.05 was used to identify abnormalities in fractional anisotropy (FA). The mean, radial, and axial diffusivities were also projected onto the mean FA skeleton. Patients with AE presented decreased FA and increased mean diffusivity and radial diffusivity values in the genu and the body of the corpus callosum and right anterior corona radiata, as well as decreased axial diffusivity in the left posterior thalamic radiation, inferior cerebellar peduncle, right cerebral peduncle, and right corticospinal tract. However, there were no significant differences in cortical thickness or deep gray matter structure volumes between patients with AE and controls. Abnormalities found in white matter integrity may help to better understand the pathophysiology of AE and optimize diagnosis and treatment strategies.

  1. Nilpotent Symmetries for Matter Fields in Non-Abelian Gauge Theory:

    NASA Astrophysics Data System (ADS)

    Malik, R. P.

    In the framework of superfield approach to Becchi-Rouet-Stora-Tyutin (BRST) formalism, the derivation of the BRST and anti-BRST nilpotent symmetry transformations for the matter fields, present in any arbitrary interacting gauge theory, has been a long-standing problem. In our present investigation, the local, covariant, continuous and off-shell nilpotent (anti-)BRST symmetry transformations for the Dirac fields (ψ ,bar ψ ) are derived in the framework of the augmented superfield formulation where the four (3 + 1)-dimensional (4D) interacting non-Abelian gauge theory is considered on the six (4 + 2)-dimensional supermanifold parametrized by the four even space-time coordinates xμ and a couple of odd elements (θ and bar θ ) of the Grassmann algebra. The requirement of the invariance of the matter (super)currents and the horizontality condition on the (super)manifolds leads to the derivation of the nilpotent symmetries for the matter fields as well as the gauge and the (anti)ghost fields of the theory in the general scheme of augmented superfield formalism.

  2. 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.

  3. Source-based morphometry of gray matter volume in patients with schizophrenia who have persistent auditory verbal hallucinations.

    PubMed

    Kubera, Katharina M; Sambataro, Fabio; Vasic, Nenad; Wolf, Nadine D; Frasch, Karel; Hirjak, Dusan; Thomann, Philipp A; Wolf, R Christian

    2014-04-03

    Abnormal structure of frontal and temporal brain regions has been suggested to occur in patients with schizophrenia who have frequent auditory verbal hallucinations (AVH). However, it is unknown whether this is specific to this patient subgroup. This study tested the hypothesis that frontotemporal gray matter volume changes would characterize patients with persistent AVH (pAVH) in contrast to healthy controls and patients without AVH. Using structural magnetic resonance imaging at 3T, we studied 20 patients with schizophrenia and 14 matched healthy controls. Ten patients were classified as having chronic and treatment resistant AVH, whereas the remaining 10 patients either never had AVH in the past or were in full remission with regard to AVH (nAVH). Using a multivariate statistical technique for structural data, i.e. "source-based morphometry" (SBM), we investigated naturally grouping patterns of gray matter volume variation among individuals, the magnitude of their expression between-groups and the relationship between gray matter volume and AVH-specific measures. SBM identified a reduction of medial and inferior frontal, insular and bilateral temporal gray matter volume between pAVH and nAVH. This pattern did not differ between nAVH patients and controls and was associated with "physical" AVH characteristics (such as symptom duration, location, frequency and intensity) in the pAVH patient group. These results suggest that a pattern of lower gray matter volume in medial frontal, insular and bilateral temporal cortical regions differentiates between patients with persistent AVH and non-hallucinating patients. Moreover, the data support a specific role of this neural pattern in AVH symptom expression.

  4. Progressive Decrease of Left Heschl Gyrus and Planum Temporale Gray Matter Volume in First-Episode Schizophrenia

    PubMed Central

    Kasai, Kiyoto; Shenton, Martha E.; Salisbury, Dean F.; Hirayasu, Yoshio; Onitsuka, Toshiaki; Spencer, Magdalena H.; Yurgelun-Todd, Deborah A.; Kikinis, Ron; Jolesz, Ferenc A.; McCarley, Robert W.

    2010-01-01

    Background The Heschl gyrus and planum temporale have crucial roles in auditory perception and language processing. Our previous investigation using magnetic resonance imaging (MRI) indicated smaller gray matter volumes bilaterally in the Heschl gyrus and in left planum temporale in patients with first-episode schizophrenia but not in patients with first-episode affective psychosis. We sought to determine whether there are progressive decreases in anatomically defined MRI gray matter volumes of the Heschl gyrus and planum temporale in patients with first-episode schizophrenia and also in patients with first-episode affective psychosis. Methods At a private psychiatric hospital, we conducted a prospective high spatial resolution MRI study that included initial scans of 28 patients at their first hospitalization (13 with schizophrenia and 15 with affective psychosis, 13 of whom had a manic psychosis) and 22 healthy control subjects. Follow-up scans occurred, on average, 1.5 years after the initial scan. Results Patients with first-episode schizophrenia showed significant decreases in gray matter volume over time in the left Heschl gyrus (6.9%) and left planum temporale (7.2%) compared with patients with first-episode affective psychosis or control subjects. Conclusions These findings demonstrate a left-biased progressive volume reduction in the Heschl gyrus and planum temporale gray matter in patients with first-episode schizophrenia in contrast to patients with first-episode affective psychosis and control subjects. Schizophrenia but not affective psychosis seems to be characterized by a postonset progression of neocortical gray matter volume loss in the left superior temporal gyrus and thus may not be developmentally fixed. PMID:12912760

  5. 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.

  6. Influence of personality on the relationship between gray matter volume and neuropsychiatric symptoms in multiple sclerosis.

    PubMed

    Benedict, Ralph H B; Schwartz, Carolyn E; Duberstein, Paul; Healy, Brian; Hoogs, Marietta; Bergsland, Niels; Dwyer, Michael G; Weinstock-Guttman, Bianca; Zivadinov, Robert

    2013-04-01

    Research has revealed an association between personality traits and health outcomes, and in multiple sclerosis (MS), there are preliminary data showing a correlation between personality traits and brain volume. We examined the general hypothesis that personality influences the relationship between gray matter volume (GMV) and cognitive/neuropsychiatric MS features. Participants were 98 patients with MS who underwent magnetic resonance imaging and were tested with the Symbol Digit Modalities Test and the Neuropsychiatric Inventory, the latter providing measures of depression and euphoria that can be characteristic of MS, that is, cheerful indifference and disinhibition. Personality traits were assessed with the NEO Five Factor Inventory. We examined the correlation between personality traits and both GMV and symptoms, and then modeled mediation and moderation influences on the relationships between GMV and cognitive/neuropsychiatric features. Linear regression modeling revealed that GMV (r = 0.54, p < .001) and NEO Five Factor Inventory low conscientiousness (r = 0.36, p = .001) were associated with cognitive function, but no mediator or moderator effects were observed. However, conscientiousness mediated the relationship between GMV and symptoms of euphoria (p = .002). The moderator analysis revealed a significant influence of high neuroticism on the GMV-euphoria relationship (p = .029). Low conscientiousness and high neuroticism are associated with neuropsychiatric complications in MS, and each influences the relationship between GMV and euphoria. The findings suggest that patients with low conscientiousness are at higher risk for MS-associated cognitive dysfunction and neuropsychiatric symptoms, a conclusion that has implications for the emerging role of personality in clinical neuroscience.

  7. Association of frontal gray matter volume and cerebral perfusion in heroin addiction: a multimodal neuroimaging study.

    PubMed

    Denier, Niklaus; Schmidt, André; Gerber, Hana; Schmid, Otto; Riecher-Rössler, Anita; Wiesbeck, Gerhard A; Huber, Christian G; Lang, Undine E; Radue, Ernst-Wilhelm; Walter, Marc; Borgwardt, Stefan

    2013-01-01

    Structure and function are closely related in the healthy human brain. In patients with chronic heroin exposure, brain imaging studies have identified long-lasting changes in gray matter (GM) volume. More recently, we showed that acute application of heroin in dependent patients results in hypoperfusion of fronto-temporal areas compared with the placebo condition. However, the relationship between structural and cerebral blood flow (CBF) changes in heroin addiction has not yet been investigated. Moreover, it is not known whether there is any interaction between the chronic structural changes and the short and long-term effects on perfusion caused by heroin. Using a double-blind, within-subject design, heroin or placebo (saline) was administered to 14 heroin-dependent patients from a stable heroin-assisted treatment program, in order to observe acute short-term effects. Arterial spin labeling (ASL) was used to calculate perfusion quantification maps in both treatment conditions, while Voxel-Based Morphometry (VBM) was conducted to calculate regional GM density. VBM and ASL data were used to calculate homologous correlation fields by Biological Parametric Mapping (BPM) and a whole-brain Pearson r correlation. We correlated each perfusion condition (heroin and placebo) separately with a VBM sample that was identical for the two treatment conditions. It was assumed that heroin-associated perfusion is manifested in short-term effects, while placebo-associated perfusion is more related to long-term effects. In order to restrict our analyses to fronto-temporal regions, we used an explicit mask for our analyses. Correlation analyses revealed a significant positive correlation in frontal areas between GM and both perfusion conditions (heroin and placebo). Heroin-associated perfusion was also negatively correlated with GM in the inferior temporal gyrus on both hemispheres. These findings indicate that, in heroin-dependent patients, low GM volume is positively associated with

  8. 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

  9. 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.

  10. Incorporation of excluded-volume correlations into Poisson-Boltzmann theory.

    PubMed

    Antypov, Dmytro; Barbosa, Marcia C; Holm, Christian

    2005-06-01

    We investigate the effect of excluded-volume interactions on the electrolyte distribution around a charged macroion. First, we introduce a criterion for determining when hard-core effects should be taken into account beyond standard mean-field Poisson-Boltzmann (PB) theory. Next, we demonstrate that several commonly proposed local-density-functional approaches for excluded-volume interactions cannot be used for this purpose. Instead, we employ a nonlocal excess free energy by using a simple constant-weight approach. We compare the ion distribution and osmotic pressure predicted by this theory with Monte Carlo simulations. They agree very well for weakly developed correlations and give the correct layering effect for stronger ones. In all investigated cases our simple weighted-density theory yields more realistic results than the standard PB approach, whereas all local density theories do not improve on the PB density profiles, but on the contrary, deviate even more from the simulation results.

  11. 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.

  12. 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.

  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. 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

  15. Altered Gray Matter Volume, Cerebral Blood Flow and Functional Connectivity in Chronic Stroke Patients.

    PubMed

    Miao, Peifang; Wang, Caihong; Li, Peng; Wei, Sen; Deng, Chunshan; Zheng, Dandan; Cheng, Jingliang

    2017-09-14

    It is entangled connections and intensive functional interactions between cortex and subcortical structures that enable our brain to perform delicate movement, and poses plasticity to recover from stroke. However, it is still unclear how cortical structures and functions change in well-recovered patients from subcortical infarctions in motor pathway. In order to reveal neuroplasticity underlying well-recovered stroke patients, both structural (gray matter volume, GMV) and functional reorganizations (cerebral blood flow, CBF and resting-state functional connectivity, rsFC) were investigated by using multi-modal MRI. Our results showed that well-recovered stroke patients exhibited significantly increased GMV in contralesional supplementary motor area (SMA), increased CBFs in contralesional superior frontal gyrus (SFG) and supramarginal gyrus (SMG) irrespective of GMV correction. Furthermore, our results showed increased rsFC between contralesional middle temporal gyrus (MTG) and SMG. Negative correlations between CBF increases and behavior test scores were also observed, suggesting neural mechanism underlying clinical improvement. Our results suggested that neuroplasticity after chronic stroke showed in both structural and functional levels, and correlation between CBF change and clinical test suggested possible biomarker for stroke recovery. Copyright © 2017. Published by Elsevier B.V.

  16. Tai Chi Chuan and Baduanjin Increase Grey Matter Volume in Older Adults: A Brain Imaging Study.

    PubMed

    Tao, Jing; Liu, Jiao; Liu, Weilin; Huang, Jia; Xue, Xiehua; Chen, Xiangli; Wu, Jinsong; Zheng, Guohua; Chen, Bai; Li, Ming; Sun, Sharon; Jorgenson, Kristen; Lang, Courtney; Hu, Kun; Chen, Shanjia; Chen, Lidian; Kong, Jian

    2017-01-01

    The aim of this study is to investigate and compare how 12-weeks of Tai Chi Chuan and Baduanjin exercise can modulate brain structure and memory function in older adults. Magnetic resonance imaging and memory function measurements (Wechsler Memory Scale-Chinese revised, WMS-CR) were applied at both the beginning and end of the study. Results showed that both Tai Chi Chuan and Baduanjin could significantly increase grey matter volume (GMV) in the insula, medial temporal lobe, and putamen after 12-weeks of exercise. No significant differences were observed in GMV between the Tai Chi Chuan and Baduanjin groups. We also found that compared to healthy controls, Tai Chi Chuan and Baduanjin significantly improved visual reproduction subscores on the WMS-CR. Baduanjin also improved mental control, recognition, touch, and comprehension memory subscores of the WMS-CR compared to the control group. Memory quotient and visual reproduction subscores were both associated with GMV increases in the putamen and hippocampus. Our results demonstrate the potential of Tai Chi Chuan and Baduanjin exercise for the prevention of memory deficits in older adults.

  17. Grey matter volume correlates with virtual water maze task performance in boys with androgen excess

    PubMed Central

    Mueller, Sven C.; Merke, Deborah P.; Leschek, Ellen W.; Fromm, Stephen; Grillon, Christian; Cornwell, Brian R.; VanRyzin, Carol; Ernst, Monique

    2011-01-01

    Major questions remain about the specific role of testosterone in human spatial navigation. We tested 10 boys (mean age 11.65 years) with an extremely rare disorder of androgen excess (Familial Male Precocious Puberty, FMPP) and 40 healthy boys (mean age 12.81 years) on a virtual version of the Morris Water Maze task. In addition, anatomical magnetic resonance images were collected for all patients and a subsample of the controls (n=21) after task completion. Behaviourally, no significant differences were found between both groups. However, in the MRI analyses, grey matter volume (GMV) was correlated with performance using voxel-based morphometry (VBM). Group differences in correlations of performance with GMV were apparent in medial regions of the prefrontal cortex as well as the middle occipital gyrus and the cuneus. By comparison, similar correlations for both groups were found in the inferior parietal lobule. These data provide novel insight into the relation between testosterone and brain development and suggest that morphological differences in a spatial navigation network covary with performance in spatial ability. PMID:21964472

  18. 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

  19. Structural Brain Anomalies and Chronic Pain: A Quantitative Meta-Analysis of Gray Matter Volume

    PubMed Central

    Smallwood, Rachel F.; Laird, Angela R.; Ramage, Amy E.; Parkinson, Amy L.; Lewis, Jeffrey; Clauw, Daniel J.; Williams, David A.; Schmidt-Wilcke, Tobias; Farrell, Michael J.; Eickhoff, Simon B.; Robin, Donald A.

    2016-01-01

    The diversity of chronic pain syndromes and the methods employed to study them make integrating experimental findings challenging. This study performed coordinate-based meta-analyses using voxel-based morphometry imaging results to examine gray matter volume (GMV) differences between chronic pain patients and healthy controls. There were 12 clusters where GMV was decreased in patients compared with controls, including many regions thought to be part of the “pain matrix” of regions involved in pain perception, but also including many other regions that are not commonly regarded as pain-processing areas. The right hippocampus and parahippocampal gyrus were the only regions noted to have increased GMV in patients. Functional characterizations were implemented using the BrainMap database to determine which behavioral domains were significantly represented in these regions. The most common behavioral domains associated with these regions were cognitive, affective, and perceptual domains. Because many of these regions are not classically connected with pain and because there was such significance in functionality outside of perception, it is proposed that many of these regions are related to the constellation of comorbidities of chronic pain, such as fatigue and cognitive and emotional impairments. Further research into the mechanisms of GMV changes could provide a perspective on these findings. Perspective Quantitative meta-analyses revealed structural differences between brains of individuals with chronic pain and healthy controls. These differences may be related to comorbidities of chronic pain. PMID:23685185

  20. Structural brain anomalies and chronic pain: a quantitative meta-analysis of gray matter volume.

    PubMed

    Smallwood, Rachel F; Laird, Angela R; Ramage, Amy E; Parkinson, Amy L; Lewis, Jeffrey; Clauw, Daniel J; Williams, David A; Schmidt-Wilcke, Tobias; Farrell, Michael J; Eickhoff, Simon B; Robin, Donald A

    2013-07-01

    The diversity of chronic pain syndromes and the methods employed to study them make integrating experimental findings challenging. This study performed coordinate-based meta-analyses using voxel-based morphometry imaging results to examine gray matter volume (GMV) differences between chronic pain patients and healthy controls. There were 12 clusters where GMV was decreased in patients compared with controls, including many regions thought to be part of the "pain matrix" of regions involved in pain perception, but also including many other regions that are not commonly regarded as pain-processing areas. The right hippocampus and parahippocampal gyrus were the only regions noted to have increased GMV in patients. Functional characterizations were implemented using the BrainMap database to determine which behavioral domains were significantly represented in these regions. The most common behavioral domains associated with these regions were cognitive, affective, and perceptual domains. Because many of these regions are not classically connected with pain and because there was such significance in functionality outside of perception, it is proposed that many of these regions are related to the constellation of comorbidities of chronic pain, such as fatigue and cognitive and emotional impairments. Further research into the mechanisms of GMV changes could provide a perspective on these findings. Quantitative meta-analyses revealed structural differences between brains of individuals with chronic pain and healthy controls. These differences may be related to comorbidities of chronic pain. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  1. 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

  2. A supermatrix model for mathcal{N} = 6 super Chern-Simons-matter theory

    NASA Astrophysics Data System (ADS)

    Drukker, Nadav; Trancanelli, Diego

    2010-02-01

    We construct the Wilson loop operator of mathcal{N} = 6 super Chern-Simons-matter which is invariant under half of the supercharges of the theory and is dual to the simplest macroscopic open string in AdS 4 ×ℂℙ3. The Wilson loop couples, in addition to the gauge and scalar fields of the theory, also to the fermions in the bi-fundamental representation of the U( N) × U( M) gauge group. These ingredients are naturally combined into a superconnection whose holonomy gives the Wilson loop, which can be defined for any representation of the supergroup U( N| M). Explicit expressions for loops supported along an infinite straight line and along a circle are presented. Using the localization calculation of Kapustin et al. we show that the circular loop is computed by a supermatrix model and discuss the connection to pure Chern-Simons theory with supergroup U( N| M).

  3. 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.

  4. Many-particle theory of nuclear system with application to neutron-star matter and other systems

    NASA Technical Reports Server (NTRS)

    Yang, C. H.

    1978-01-01

    General problems in nuclear-many-body theory were considered. Superfluid states of neutron star matter and other strongly interacting many-fermion systems were analyzed by using the soft-core potential of Reid. The pion condensation in neutron star matter was also treated.

  5. Relationship between white matter volume and cognitive performance during adolescence: effects of age, sex and risk for drug use.

    PubMed

    Silveri, Marisa M; Tzilos, Golfo K; Yu