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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. 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.

  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. 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)

  6. 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.

  7. 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…

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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…

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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…

  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. 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.

  5. 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

  6. 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".

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. Dark Matter Reality Check: Chandra Casts Cloud On Alternative Theory

    NASA Astrophysics Data System (ADS)

    2002-10-01

    New evidence from NASA's Chandra X-ray Observatory challenges an alternative theory of gravity that eliminates the need for dark matter. The observation also narrows the field for competing forms of dark matter, the elusive material thought to be the dominant form of matter in the universe. An observation of the galaxy NGC 720 shows it is enveloped in a slightly flattened, or ellipsoidal cloud of hot gas that has an orientation different from that of the optical image of the galaxy. The flattening is too large to be explained by theories in which stars and gas are assumed to contain most of the mass in the galaxy. "The shape and orientation of the hot gas cloud require it to be confined by an egg-shaped dark matter halo," said David Buote of the University of California, Irvine, and lead author of a report on this research in the 2002 September 20 issue of The Astrophysical Journal. "This means that dark matter is not just an illusion due to a shortcoming of the standard theory of gravity - it is real." According to the generally accepted standard theory of gravity, the hot X-ray cloud would need an additional source of gravity - a halo of dark matter - to keep the hot gas from expanding away. The mass of dark matter required would be about five to ten times the mass of the stars in the galaxy. If the dark matter tracked the optical light from the stars in the galaxy, the hot X-ray cloud would be more round than it is. The flattened shape of the hot gas cloud requires a flattened dark matter halo. An alternative theory of gravity called MOND, for Modified Newtonian Dynamics, was proposed in 1983 by Mordecai Milgrom of the Weizmann Institute in Israel, and has remained viable over the years. MOND does away with the need for dark matter by modifying the theory where the acceleration produced by gravity is very small, such as the outskirts of galaxies. However, MOND cannot explain the Chandra observation of NGC 720. This is apparently the first dynamical evidence that

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. XX International Workshop on Condensed Matter Theories

    DTIC Science & Technology

    1998-01-01

    Rojo5, M.A. Solis6 and A.A. Valladares4 1 Institute de Fisica Teorica -UNESP, 01405 Säo Paulo, BRAZIL and Departamento de Fisica, Universidade...an elegant functional integral approach which in lowest-order gives a Ginzburg- Landau theory. Following Ref. [30] a generalized coherence length (or...representing Landau damping due to the wave particle interactions [16]. For a nonequilibrium plasma with a two peaked distribution function f0(u) (e.g

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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…

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Seesaw theories at LHC and warm dark matter

    NASA Astrophysics Data System (ADS)

    Zhang, Yue

    2014-06-01

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

  14. 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.

  15. 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

  16. 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…

  17. 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.

  18. 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…

  19. 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…

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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…

  1. 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…

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  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. 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.

  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. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

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

    SciTech Connect

    Catena, Riccardo

    2015-07-01

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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Identifying the theory of dark matter with direct detection

    SciTech Connect

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

  10. Identifying the theory of dark matter with direct detection

    SciTech Connect

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

    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.

  11. 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.

  12. 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

  13. Thermophysical Properties of Matter - The TPRC Data Series. Volume 9. Thermal Radiative Properties - Coatings

    DTIC Science & Technology

    1972-01-01

    34Validity of the Drude Theory for Silver, Gold, and Aluminum in the Infrared," from Optical Properties and Electronic Structure of Metals and Alloys (F...Comprehensive Compilation of Data by the Thermophysical Properties Research Center (TPRC), Purdue University Y. 8. Touloukian , Series Editor C. Y. Ho, Series...Volume 6. Specific Heat-Nonmetallic Liquids and Gases Volume 7. Thermal Radiative Properties -Metallic Elements and Alloys Volume 8. Thermal Radiative

  14. 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.

  15. 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

  16. 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…

  17. 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...

    • 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

    • 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

    • 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

  1. 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.

  2. 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.

  3. 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

  4. 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'…

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

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

    PubMed

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

    2016-08-01

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

  20. 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

  1. 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.

  2. 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.

  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. 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.

  5. 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…

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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''.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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…

  14. 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

  15. 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

  16. 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.

  17. 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.

  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. 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).

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

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

    PubMed

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

    2011-10-30

    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 × 10(6) 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.

  12. 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

  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. The Proof of the ``Vortex Theory of Matter''

    NASA Astrophysics Data System (ADS)

    Gridnev, Konstantin; Moon, Russell; Vasiliev, Victor

    2009-10-01

    According to the Vortex Theory, protons and electrons are three-dimensional holes connected by fourth-dimensional vortices. It was further theorized that when photons are absorbed then readmitted by atoms, the photon is absorbed into the proton, moves through the fourth-dimensional vortex, then reemerges back into three-dimensional space through the electron^2. To prove this hypothesis, an experiment was conducted using a hollow aluminum sphere containing a powerful permanent magnet suspended directly above a zinc plate. Ultraviolet light was then shined upon the zinc. The zinc emits electrons via the photoelectric effect that are attracted to the surface of the aluminum sphere. The sphere was removed from above the zinc plate and repositioned above a sensitive infrared digital camera in another room. The ball and camera were placed within a darkened box inside a Faraday cage. Light was shined upon the zinc plate and the picture taken by the camera was observed. When the light was turned on above the zinc plate in one room, the camera recorded increased light coming from the surface of the sphere within the other room; when the light was turned off, the intensity of the infrared light coming from the surface of the sphere was suddenly diminished. Five other tests were then performed to eliminate other possible explanations such as quantum-entangled electrons.

  16. The Proof of the ``Vortex Theory of Matter''

    NASA Astrophysics Data System (ADS)

    Moon, Russell

    2009-11-01

    According to the Vortex Theory, protons and electrons are three-dimensional holes connected by fourth-dimensional vortices. It was further theorized that when photons are absorbed then readmitted by atoms, the photon is absorbed into the proton, moves through the fourth-dimensional vortex, then reemerges back into three-dimensional space through the electron. To prove this hypothesis, an experiment was conducted using a hollow aluminum sphere containing a powerful permanent magnet suspended directly above a zinc plate. Ultraviolet light was then shined upon the zinc. The zinc emits electrons via the photoelectric effect that are attracted to the surface of the aluminum sphere. The sphere was removed from above the zinc plate and repositioned above a sensitive infrared digital camera in another room. The ball and camera were placed within a darkened box inside a Faraday cage. Light was shined upon the zinc plate and the picture taken by the camera was observed. When the light was turned on above the zinc plate in one room, the camera recorded increased light coming from the surface of the sphere within the other room; when the light was turned off, the intensity of the infrared light coming from the surface of the sphere was suddenly diminished. Five other tests were then performed to eliminate other possible explanations such as quantum-entangled electrons.

  17. The Proof of the ``Vortex Theory of Matter''

    NASA Astrophysics Data System (ADS)

    Gridnev, Konstantin; Moon, Russell; Vasiliev, Victor

    2009-11-01

    According to the Vortex Theory, protons and electrons are three-dimensional holes connected by fourth-dimensional vortices. It was further theorized that when photons are absorbed then readmitted by atoms, the photon is absorbed into the proton, moves through the fourth-dimensional vortex, then reemerges back into three-dimensional space through the electron^2. To prove this hypothesis, an experiment was conducted using a hollow aluminum sphere containing a powerful permanent magnet suspended directly above a zinc plate. Ultraviolet light was then shined upon the zinc. The zinc emits electrons via the photoelectric effect that are attracted to the surface of the aluminum sphere. The sphere was removed from above the zinc plate and repositioned above a sensitive infrared digital camera in another room. The ball and camera were placed within a darkened box inside a Faraday cage. Light was shined upon the zinc plate and the picture taken by the camera was observed. When the light was turned on above the zinc plate in one room, the camera recorded increased light coming from the surface of the sphere within the other room; when the light was turned off, the intensity of the infrared light coming from the surface of the sphere was suddenly diminished. Five other tests were then performed to eliminate other possible explanations such as quantum-entangled electrons.

  18. The Proof of the ``Vortex Theory of Matter''

    NASA Astrophysics Data System (ADS)

    Moon, Russell; Gridnev, Konstantin; Vasiliev, Victor

    2010-02-01

    According to the Vortex Theory, protons and electrons are three-dimensional holes connected by fourth-dimensional vortices. It was further theorized that when photons are absorbed then readmitted by atoms, the photon is absorbed into the proton, moves through the fourth-dimensional vortex, then reemerges back into three-dimensional space through the electron. To prove this hypothesis, an experiment was conducted using a hollow aluminum sphere containing a powerful permanent magnet suspended directly above a zinc plate. Ultraviolet light was then shined upon the zinc. The zinc emits electrons via the photoelectric effect that are attracted to the surface of the aluminum sphere. The sphere was removed from above the zinc plate and repositioned above a sensitive infrared digital camera in another room. The ball and camera were placed within a darkened box inside a Faraday cage. Light was shined upon the zinc plate and the picture taken by the camera was observed. When the light was turned on above the zinc plate in one room, the camera recorded increased light coming from the surface of the sphere within the other room; when the light was turned off, the intensity of the infrared light coming from the surface of the sphere was suddenly diminished. Five other tests were then performed to eliminate other possible explanations such as quantum-entangled electrons. )

  19. 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.

  20. '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

  1. 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.

  2. 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…

  3. 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…

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

    PubMed

    Kannemann, Felix O; Becke, Axel D

    2012-01-21

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

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

    PubMed

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

    2015-10-01

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

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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…

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

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

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

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

  9. 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.…

  10. 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…

  11. 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…

  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. 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…

  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. Fermion frontiers in vector lattice gauge theories: Proceedings. Volume 8

    SciTech Connect

    1998-11-01

    The inclusion of fermions into simulations of lattice gauge theories is very difficult both theoretically and numerically. With the presence of Teraflops-scale computers for lattice gauge theory, the authors wanted a forum to discuss new approaches to lattice fermions. The workshop concentrated on approaches which are ripe for study on such large machines. Although lattice chiral fermions are vitally important to understand, there is not technique at hand which is viable on these Teraflops-scale machines for real-world problems. The discussion was therefore focused on recent developments and future prospects for QCD-like theories. For the well-known fermion formulations, the Aoki phase in Wilson fermions, novelties of U{sub A}(1) symmetry and the {eta}{prime} for staggered fermions and new approaches for simulating the determinant for Wilson fermions were discussed. The newer domain-wall fermion formulation was reviewed, with numerical results given by many speakers. The fermion proposal of Friedberg, Lee and Pang was introduced. They also were able to compare and contrast the dependence of QCD and QCD-like SUSY theories on the number of quark flavors. These proceedings consist of several transparencies and a summary page from each speaker. This should serve to outline the major points made in each talk.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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)].

  8. 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.

  9. 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.

  10. A Test of MOND theory and the model of dark matter

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Zhao, W.; Han, J. L.

    2003-11-01

    The predictions of the modified gravitational model MOND and the model of dark matter for the earth's gravitational system are examined. We focus on the commonly used MOND models. For the simplest of these models, we present a general expression for the gravitational potential in the case of spherical symmetry, and calculate the predicted angular velocity of a satellite moving in the field. It is found that the angular velocity is different in the different MOND models, that the differences between the predictions of these models and the Newtonian theory are very small, but that the difference in the simplest case (n=1) is larger. In the case of the moon, actual measurements with exiting techniques can be possibly made for this difference in angular velocity. We have also estimated the influence on the angular velocity of the moon due to the model of dark matter. and found it to be far smaller than the effect of the MOND theory. Therefore, the measurement of this difference in angular velocity may provide a criterion for discriminating the MOND theory and the model of dark matter.

  11. 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.

  12. 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.

  13. 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.

  14. 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

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

    PubMed Central

    Shimada, Koji; Takiguchi, Shinichiro; Mizushima, Sakae; Fujisawa, Takashi X.; Saito, Daisuke N.; Kosaka, Hirotaka; Okazawa, Hidehiko; Tomoda, Akemi

    2015-01-01

    Child maltreatment increases the risk for psychiatric disorders throughout childhood and into adulthood. One negative outcome of child maltreatment can be a disorder of emotional functioning, reactive attachment disorder (RAD), where the child displays wary, watchful, and emotionally withdrawn behaviours. Despite its clinical importance, little is known about the potential neurobiological consequences of RAD. The aim of this study was to elucidate whether RAD was associated with alterations in grey matter volume (GMV). High-resolution magnetic resonance imaging datasets were obtained for children and adolescents with RAD (n = 21; mean age = 12.76 years) and typically developing (TD) control subjects (n = 22; mean age = 12.95 years). Using a whole-brain voxel-based morphometry approach, structural images were analysed controlling for age, gender, full scale intelligence quotient, and total brain volume. The GMV was significantly reduced by 20.6% in the left primary visual cortex (Brodmann area 17) of the RAD group compared to the TD group (p = .038, family-wise error-corrected cluster level). This GMV reduction was related to an internalising problem measure of the Strength and Difficulties Questionnaire. The visual cortex has been viewed as part of the neurocircuit regulating the stress response to emotional visual images. Combined with previous studies of adults with childhood maltreatment, early adverse experience (e.g. sensory deprivation) may affect the development of the primary visual system, reflecting in the size of the visual cortex in children and adolescents with RAD. These visual cortex GMV abnormalities may also be associated with the visual emotion regulation impairments of RAD, leading to an increased risk for later psychopathology. PMID:26288752

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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

  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. 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.

  4. 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.

  5. 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.

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

    SciTech Connect

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

    1997-02-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    SciTech Connect

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

    1998-12-31

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

  10. Intercultural Communication Theory: Current Perspectives. International and Intercultural Communication Annual, Volume VII.

    ERIC Educational Resources Information Center

    Gudykunst, William B., Ed.

    The seventh in a series dealing with intercultural communication, this volume is organized around the theme of theorizing in intercultural communication. Papers in the introductory section of the book discuss theory building, cultural assumptions of East and West, and an overview of theorizing in intercultural communication. The second section…

  11. Thermophysical Properties of Matter - The TPRC Data Series. Volume 8. Thermal Radiative Properties - Nonmetallic Solids

    DTIC Science & Technology

    1972-01-01

    Touloukian , Series Editor C. Y. Ho, Series Teohnloal Editor Volume 1. Thermal Conductivity-Metallic Elements and Alloys Volume 2. Thermal...Elements and Alloys Volume 8. Thermal Radiative Properties -Nonmetallic Solids Volume 9. Thermal Radiative Properties -Coatings Volume 10. Thermal...Thermophysicul Properties Reseanh Literulure Retriexul (JutJe. 3 Vols.. Plenum Press. 1967. 116. Touloukian . Y. S. and DeWitt. D. P.. Thermal

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

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

    SciTech Connect

    Chernov, S. V.

    2015-06-15

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

  14. A short guide to topological terms in the effective theories of condensed matter

    NASA Astrophysics Data System (ADS)

    Tanaka, Akihiro; Takayoshi, Shintaro

    2015-02-01

    This article is meant as a gentle introduction to the topological terms that often play a decisive role in effective theories describing topological quantum effects in condensed matter systems. We first take up several prominent examples, mainly from the area of quantum magnetism and superfluids/superconductors. We then briefly discuss how these ideas are now finding incarnations in the studies of symmetry-protected topological phases, which are in a sense a generalization of the concept of topological insulators to a wider range of materials, including magnets and cold atoms.

  15. A short guide to topological terms in the effective theories of condensed matter

    PubMed Central

    Tanaka, Akihiro; Takayoshi, Shintaro

    2015-01-01

    This article is meant as a gentle introduction to the topological terms that often play a decisive role in effective theories describing topological quantum effects in condensed matter systems. We first take up several prominent examples, mainly from the area of quantum magnetism and superfluids/superconductors. We then briefly discuss how these ideas are now finding incarnations in the studies of symmetry-protected topological phases, which are in a sense a generalization of the concept of topological insulators to a wider range of materials, including magnets and cold atoms. PMID:27877742

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

    SciTech Connect

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

    2014-07-04

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

  17. Altered Regional Gray Matter Volume in Obese Men: A Structural MRI Study

    PubMed Central

    Zhang, Bin; Tian, Xiao; Tian, Derun; Wang, Jinhong; Wang, Qiming; Yu, Chunshui; Li, Chunbo; Wang, Jijun

    2017-01-01

    Obesity is associated with a number of health problems, especial insulin resistance and Type 2 diabetes. Our previous study showed that obese males had decreased neural activity in the orbital frontal cortex (OFC) and increased activity in the left putamen (Zhang et al., 2015b), which could indicate altered eating behaviors in obesity related to a hyper-functioning striatum and hypo-functioning inhibitory control. Accordingly, our goal of the current study was to determine whether there are alterations in the brain structures within these two neural systems in obese individuals. Twenty obese men (age: 20–28 years) and 20 age-matched lean male subjects were involved in the current study. Plasma glucose and insulin were tested during hunger state, and homeostasis model assessment of insulin resistance (HOMA-IR) was based on the blood samples. In the study, we used structural MRI and a voxel-based morphometry (VBM) method to investigate regional structures in obese subjects and find out whether there are correlations between the insulin and the brain structures. We found that obese men only showed a significantly increased gray matter volume (GMV) in the left putamen and that the GMV of the left putamen was positively correlated with body mass index, plasma insulin and HOMA-IR. The putamen is a core region participating in insulin signal regulation, and our results showed an abnormal GMV of the putamen is a core alternation in aberrant insulin. Furthermore, the GMV of the OFC was negatively correlated with hunger rating, despite there being no significant difference between the two groups in the OFC. In conclusion, the altered structure and function of the putamen could play important roles in obesity and aberrant insulin. PMID:28197123

  18. Conscientiousness is Negatively Associated with Grey Matter Volume in Young APOE ɛ4-Carriers.

    PubMed

    Kunz, Lukas; Reuter, Martin; Axmacher, Nikolai; Montag, Christian

    2017-01-01

    The etiology of late onset Alzheimer's disease (LOAD) depends on multiple factors, among which the APOE ɛ4 allele is the most adverse genetic determinant and conscientiousness represents an influential personality trait. A potential association of both factors with brain structure in young adulthood may constitute a constellation that sets the course toward or against the subtle disease progression of LOAD that starts decades before clinical manifestation. Hence, in the present study, we examined the modulating effects of APOE ɛ4 on the relation between personality dimensions, including conscientiousness, and total grey matter volume (GMV) in young healthy adults using an a priori genotyping design. 105 participants completed an inventory assessing the Five Factor Model of Personality (NEO-FFI) and a structural MRI scan. Total GMV was estimated using both Freesurfer as well as VBM8. Across all participants, total GMV was positively associated with extraversion and negatively related to age. In APOE ɛ4-carriers- but not in APOE ɛ4-non-carriers- conscientiousness was negatively associated with total GMV. In line with the hypothesis of antagonistic pleiotropy of the APOE ɛ4 allele, this result suggests that young APOE ɛ4-carriers with increased total GMV may particularly benefit from cognitive advantages and thus have a lower need to engage in conscientious behavior. In this subset of young APOE ɛ4-carriers, the reduction in conscientiousness could then bring along adverse health behavior in the long run, potentiating the risk for LOAD. Hence, young APOE ɛ4-carriers with increased total GMV may be at a particularly high risk for LOAD.

  19. Reproducibility of hormone-driven regional grey matter volume changes in women using SPM8 and SPM12.

    PubMed

    De Bondt, Timo; Pullens, Pim; Van Hecke, Wim; Jacquemyn, Yves; Parizel, Paul M

    2016-12-01

    Aim of this work was to evaluate the reproducibility of hormone driven regional grey matter volume differences in women, and their correlations with premenstrual symptoms, as determined by voxel-based morphometry (VBM). After data quality control, a total of 138 T1-weighted MR images were included in this longitudinal study, and were analyzed as three different subgroups. Women with a natural menstrual cycle were scanned at three time-points: follicular, ovulatory and luteal phase. Two groups of women, using androgenic and anti-androgenic hormonal contraceptives, respectively, were scanned twice: during the pill-free week and during pill intake. Additionally, subjects were asked to complete a "daily rating of severity of problems" questionnaire, to quantify premenstrual symptoms. All data were analyzed using SPM8 and SPM12 with identical parameter settings. In the natural menstrual cycle group, the regional grey matter volume of the insula is larger at ovulation, as compared to the luteal phase. Premenstrual symptoms correlate differently with regional grey matter volumes between women with a natural cycle and hormonal contraceptive users. Changes in hormonal environment can to various extents affect VBM findings in women. We suggest that researchers take these confounding factors into account while applying this technique, to avoid heterogeneity in data acquisition and to safeguard the sensitivity of findings. Additionally, we suggest validating the consistency of results using more than one software package.

  20. Abnormalities in gray and white matter volumes associated with explicit memory dysfunction in patients with generalized anxiety disorder.

    PubMed

    Moon, Chung-Man; Jeong, Gwang-Woo

    2017-03-01

    Background The neuroanatomical abnormalities associated with behavioral dysfunction on explicit memory in patients generalized anxiety disorder (GAD) have not yet been clearly identified. Purpose To investigate the regional gray matter (GM) and white matter (WM) volume alterations over the whole brain in patients with GAD, as well as the correlation between the brain structural abnormality and explicit memory dysfunction. Material and Methods Twenty patients with GAD and 20 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted magnetic resonance imaging (MRI). The participants performed the explicit memory tasks with the neutral and anxiety-inducing words. Results Patients with GAD showed significantly reduced GM volumes in the midbrain (MB), thalamus, hippocampus (Hip), insula, and superior temporal gyrus (STG); and reduced WM volumes in the MB, anterior limb of the internal capsule (ALIC), dorsolateral prefrontal cortex (DLPFC), and precentral gyrus (PrG). It is important to note that the GM volume of the Hip and the WM volume of the DLPFC were positively correlated with the recognition accuracy (%) in the explicit memory tasks with neutral and anxiety-inducing words, respectively. On the other hand, the WM volume of the PrG was negatively correlated with the reaction time in the same memory tasks. Conclusion This study demonstrated the regional volume changes on whole-brain GM and WM and the correlation between the brain structural alteration and explicit memory dysfunction in GAD patients. These findings would be helpful to understand the association between the brain structure abnormality and the functional deficit in the explicit memory in GAD.

  1. Whole-brain gray matter volume abnormalities in patients with generalized anxiety disorder: voxel-based morphometry.

    PubMed

    Moon, Chung-Man; Kim, Gwang-Won; Jeong, Gwang-Woo

    2014-02-12

    Patients with generalized anxiety disorder (GAD) experience psychological distress because of excessive and uncontrollable anxiety in everyday life. Only a few morphological studies have so far focused on specific brain regions of interest as well as the gray matter volume changes in GAD patients. This study evaluated gray matter volume alterations in whole-brain areas between GAD patients and healthy controls, and sex differences between the specific brain areas with significant volume changes in GAD patients using voxel-based morphometry. Twenty-two patients with GAD (13 men and nine women), who were diagnosed using the DSM-IV-TR, and 22 age-matched healthy controls (13 men and nine women) participated in this study. The high-resolution MRI data were processed using voxel-based morphometry analysis on the basis of diffeomorphic anatomical registration through an exponentiated Lie algebra algorithm in Statistical Parametric Mapping 8. There was no significant difference in the total intracranial volume between GAD patients and controls, but a significant difference was observed between sexes (P<0.05). Patients with GAD showed significant volume reductions in the hippocampus, midbrain, thalamus, insula, and superior temporal gyrus compared with the controls. As for the sex comparison, female patients showed a significant increase in the volume of the dorsolateral prefrontal cortex relative to male patients. Also, the volume of the dorsolateral prefrontal cortex in female patients was correlated positively with the Hamilton Anxiety Rating Scale score (γ=0.68, P=0.04). The specific morphological variations in patient with GAD will be helpful to understand the neural mechanism associated with a symptom of GAD. Furthermore, the findings would be valuable for the diagnostic accuracy of GAD using morphometric MRI analysis.

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  3. Quantification of γ-aminobutyric acid (GABA) in (1) H MRS volumes composed heterogeneously of grey and white matter.

    PubMed

    Mikkelsen, Mark; Singh, Krish D; Brealy, Jennifer A; Linden, David E J; Evans, C John

    2016-11-01

    The quantification of γ-aminobutyric acid (GABA) concentration using localised MRS suffers from partial volume effects related to differences in the intrinsic concentration of GABA in grey (GM) and white (WM) matter. These differences can be represented as a ratio between intrinsic GABA in GM and WM: rM . Individual differences in GM tissue volume can therefore potentially drive apparent concentration differences. Here, a quantification method that corrects for these effects is formulated and empirically validated. Quantification using tissue water as an internal concentration reference has been described previously. Partial volume effects attributed to rM can be accounted for by incorporating into this established method an additional multiplicative correction factor based on measured or literature values of rM weighted by the proportion of GM and WM within tissue-segmented MRS volumes. Simulations were performed to test the sensitivity of this correction using different assumptions of rM taken from previous studies. The tissue correction method was then validated by applying it to an independent dataset of in vivo GABA measurements using an empirically measured value of rM . It was shown that incorrect assumptions of rM can lead to overcorrection and inflation of GABA concentration measurements quantified in volumes composed predominantly of WM. For the independent dataset, GABA concentration was linearly related to GM tissue volume when only the water signal was corrected for partial volume effects. Performing a full correction that additionally accounts for partial volume effects ascribed to rM successfully removed this dependence. With an appropriate assumption of the ratio of intrinsic GABA concentration in GM and WM, GABA measurements can be corrected for partial volume effects, potentially leading to a reduction in between-participant variance, increased power in statistical tests and better discriminability of true effects.

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

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

    PubMed

    Kim, Gwang-Won; Jeong, Gwang-Woo

    2015-12-16

    The aim of this study was to evaluate the white matter (WM) volume change and its correlation with symptom severity in patients with schizophrenia using voxel-based morphometry. A total of 20 patients with schizophrenia and 20 age-matched healthy controls participated in this study. MR image data were processed using SPM8 software with diffeomorphic anatomical registration through an exponentiated Lie algebra (DARTEL) algorithm. The patients with schizophrenia showed significant decreases (P=0.042) in the WM volumes of the temporal lobe and superior frontal gyrus compared with the healthy controls. The WM volumes of the middle temporal gyrus were negatively correlated with the scores of both the Positive Subscale (Pearson's ρ=-0.68, P=0.001) and the Negative Subscale (ρ=-0.71, P=0.0005) in the Positive and Negative Syndrome Scale. In addition, the scores of the General Psychopathology Subscale were negatively correlated with the WM volumes of the superior frontal gyrus (ρ=-0.68, P=0.0009). This study evaluated the WM volume of patients with schizophrenia compared with healthy controls using DARTEI-based voxel-based morphometry and also assessed the correlation of the localized WM volume changes with the Positive and Negative Syndrome Scale. These findings will be useful to understand the neuropathology associated with WM abnormality in schizophrenia.

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

    PubMed

    Chou, Yen-Liang; Ihle, Thomas

    2015-02-01

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

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

    NASA Astrophysics Data System (ADS)

    Chou, Yen-Liang; Ihle, Thomas

    2015-02-01

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

  8. Association between waist circumference and gray matter volume in 2344 individuals from two adult community-based samples.

    PubMed

    Janowitz, Deborah; Wittfeld, Katharina; Terock, Jan; Freyberger, Harald Jürgen; Hegenscheid, Katrin; Völzke, Henry; Habes, Mohamad; Hosten, Norbert; Friedrich, Nele; Nauck, Matthias; Domanska, Grazyna; Grabe, Hans Jörgen

    2015-11-15

    We analyzed the putative association between abdominal obesity (measured in waist circumference) and gray matter volume (Study of Health in Pomerania: SHIP-2, N=758) adjusted for age and gender by applying volumetric analysis and voxel-based morphometry (VBM) with VBM8 to brain magnetic resonance (MR) imaging. We sought replication in a second, independent population sample (SHIP-TREND, N=1586). In a combined analysis (SHIP-2 and SHIP-TREND) we investigated the impact of hypertension, type II diabetes and blood lipids on the association between waist circumference and gray matter. Volumetric analysis revealed a significant inverse association between waist circumference and gray matter volume. VBM in SHIP-2 indicated distinct inverse associations in the following structures for both hemispheres: frontal lobe, temporal lobes, pre- and postcentral gyrus, supplementary motor area, supramarginal gyrus, insula, cingulate gyrus, caudate nucleus, olfactory sulcus, para-/hippocampus, gyrus rectus, amygdala, globus pallidus, putamen, cerebellum, fusiform and lingual gyrus, (pre-) cuneus and thalamus. These areas were replicated in SHIP-TREND. More than 76% of the voxels with significant gray matter volume reduction in SHIP-2 were also distinct in TREND. These brain areas are involved in cognition, attention to interoceptive signals as satiety or reward and control food intake. Due to our cross-sectional design we cannot clarify the causal direction of the association. However, previous studies described an association between subjects with higher waist circumference and future cognitive decline suggesting a progressive brain alteration in obese subjects. Pathomechanisms may involve chronic inflammation, increased oxidative stress or cellular autophagy associated with obesity.

  9. Improved source apportionment and speciation of low-volume particulate matter samples.

    PubMed

    Schauer, James J; Majestic, Brian J; Sheesley, Rebecca J; Shafer, Martin M; Deminter, Jeffrey T; Mieritz, Mark

    2010-12-01

    New chemical analysis methods for the characterization of atmospheric particulate matter (PM)* samples were developed and demonstrated in order to expand the number of such methods for use in future health studies involving PM. Three sets of methods were, developed, for the analysis (1) of organic tracer compounds in low-volume personal exposure samples (for source apportionment), (2) of trace metals and other trace elements in low-volume personal exposure samples, and (3) of the speciation of the oxidation states of water-soluble iron (Fe), manganese (Mn), and chromium (Cr) in PM samples. The development of the second set of methods built on previous work by the project team, which had in the past used similar methods in atmospheric source apportionment studies. The principal challenges in adapting these methods to the analysis of personal exposure samples were the improvement of detection limits (DLs) and control of the low-level contamination that can compromise personal exposure samples. A secondary goal of our development efforts was to reduce the cost and complexity of the three sets of methods in order to help facilitate their broader use in future health studies. The goals of the project were achieved, and the ability to integrate the methods into existing health studies was demonstrated by way of conducting two pilot studies. The first study involved analysis of trace elements in size-resolved PM samples that had been collected to represent study subjects' personal exposures along with simultaneous measures of indoor and outdoor PM concentrations. The second study involved analysis of the speciation of organic tracer compounds in personal exposure samples, indoor samples, and outdoor samples in order to understand the diesel PM exposure of study subjects in various job classifications in an occupational setting. Both pilot studies used existing samples from. large multi-year health studies and were intended to demonstrate the feasibility and value of using

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

    SciTech Connect

    Chen Famin; Wu Yongshi

    2010-11-15

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

  11. Grey-matter volume as a potential feature for the classification of Alzheimer's disease and mild cognitive impairment: an exploratory study.

    PubMed

    Guo, Yane; Zhang, Zengqiang; Zhou, Bo; Wang, Pan; Yao, Hongxiang; Yuan, Minshao; An, Ningyu; Dai, Haitao; Wang, Luning; Zhang, Xi; Liu, Yong

    2014-06-01

    Specific patterns of brain atrophy may be helpful in the diagnosis of Alzheimer's disease (AD). In the present study, we set out to evaluate the utility of grey-matter volume in the classification of AD and amnestic mild cognitive impairment (aMCI) compared to normal control (NC) individuals. Voxel-based morphometric analyses were performed on structural MRIs from 35 AD patients, 27 aMCI patients, and 27 NC participants. A two-sample two-tailed t-test was computed between the NC and AD groups to create a map of abnormal grey matter in AD. The brain areas with significant differences were extracted as regions of interest (ROIs), and the grey-matter volumes in the ROIs of the aMCI patients were included to evaluate the patterns of change across different disease severities. Next, correlation analyses between the grey-matter volumes in the ROIs and all clinical variables were performed in aMCI and AD patients to determine whether they varied with disease progression. The results revealed significantly decreased grey matter in the bilateral hippocampus/parahippocampus, the bilateral superior/middle temporal gyri, and the right precuneus in AD patients. The grey-matter volumes were positively correlated with clinical variables. Finally, we performed exploratory linear discriminative analyses to assess the classifying capacity of grey-matter volumes in the bilateral hippocampus and parahippocampus among AD, aMCI, and NC. Leave-one-out cross-validation analyses demonstrated that grey-matter volumes in hippocampus and parahippocampus accurately distinguished AD from NC. These findings indicate that grey-matter volumes are useful in the classification of AD.

  12. Abnormal gray matter volume and resting-state functional connectivity in former heroin-dependent individuals abstinent for multiple years.

    PubMed

    Wang, Lubin; Zou, Feng; Zhai, Tianye; Lei, Yu; Tan, Shuwen; Jin, Xiao; Ye, Enmao; Shao, Yongcong; Yang, Yihong; Yang, Zheng

    2016-05-01

    Previous studies have suggested that heroin addiction is associated with structural and functional brain abnormalities. However, it is largely unknown whether these characteristics of brain abnormalities would be persistent or restored after long periods of abstinence. Considering the very high rates of relapse, we hypothesized that there may exist some latent neural vulnerabilities in abstinent heroin users. In this study, structural and resting-state functional magnetic resonance imaging data were collected from 30 former heroin-dependent (FHD) subjects who were drug free for more than 3 years and 30 non-addicted control (CN) volunteers. Voxel-based morphometry was used to identify possible gray matter volume differences between the FHD and CN groups. Alterations in resting-state functional connectivity in FHD were examined using brain areas with gray matter deficits as seed regions. Significantly reduced gray matter volume was observed in FHD in an area surrounding the parieto-occipital sulcus, which included the precuneus and cuneus. Functional connectivity analyses revealed that the FHD subjects showed reduced positive correlation within the default mode network and visual network and decreased negative correlation between the default mode network, visual network and task positive network. Moreover, the altered functional connectivity was correlated with self-reported impulsivity scores in the FHD subjects. Our findings suggest that disruption of large-scale brain systems is present in former heroin users even after multi-year abstinence, which could serve as system-level neural underpinnings for behavioral dysfunctions associated with addiction.

  13. Volume Matters: Improved Outcomes for Patients Presenting to High-Volume Emergency Departments with Atrial Flutter and Fibrillation

    PubMed Central

    Graham, Michelle M.; Holroyd, Brian R.

    2016-01-01

    Objectives Clinical familiarity plays a role in health outcomes; the relationship between emergency department (ED) volume and outcomes for atrial fibrillation and flutter (AFF) are not clear. We compared ED presentation outcomes for AFF between high (HV) and low volume (LV) EDs in Alberta, Canada. Methods 45,372 AFF presentations for patients aged ≥ 35 years from all 104 EDs in Alberta during 1999 to 2011 using administrative health databases formed a retrospective cohort. EDs were grouped by annual AFF volume: 11 high (>100 presentations) or 93 low (≤100 presentations). Outcomes included hospital admission rate, return to ED for AFF within 30 and 90 days, and death within 30 and 90 days. Analyses included statistical tests and mixed effects modeling. Results Mean age at ED presentation was 69.8 years (52% male). HV ED presentations were associated with lower admissions (adjusted odds ratio [aOR] = 0.68, 95% confidence interval [CI] 0.64, 0.72; p-value [p]<0.001), ED returns at 90 (aOR = 0.81, 95% CI 0.73, 0.90; p<0.001) days, and a higher likelihood of specialist visits at 30 (aOR = 1.81, 95% CI 1.68, 1.94; p<0.001) and 90 (aOR = 1.82, 95% CI 1.76, 2.03; p<0.001) days. For admitted patients, there were fewer returns to HV EDs at 30 (aOR = 0.37, 95% CI 0.15, 0.87; p = 0.02) and 90 (aOR = 0.48, 95% CI 0.26, 0.89; p = 0.02) days after hospital discharge. There was no difference in death between the two groups. Conclusions AFF patients presenting to HV EDs experienced fewer admissions and AFF ED revisit and higher specialist referrals compared to LV EDs. PMID:27814387

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

    SciTech Connect

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

    2014-02-01

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

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

    PubMed

    Kim, Tae-Hoon; Kim, Seok-Kwun; Jeong, Gwang-Woo

    2015-12-16

    Several studies seem to support the hypothesis that brain anatomy is associated with transsexualism. However, these studies were still limited because few neuroanatomical findings have been obtained from female-to-male (FtM) transsexuals. This study compared the cerebral regional volumes of gray matter (GM) between FtM transsexuals and female controls using a voxel-based morphometry. Twelve FtM transsexuals who had undergone sex-reassignment surgery and 15 female controls participated in this study. Both groups were age matched and right-handed, with no history of neurological illness. Fifteen female controls were recruited to determine whether GM volumes in FtM transsexuals more closely resembled individuals who shared their biological sex. MRI data were processed using SPM 8 with the diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL). FtM transsexuals showed significantly larger volumes of the thalamus, hypothalamus, midbrain, gyrus rectus, head of caudate nucleus, precentral gyrus, and subcallosal area compared with the female controls. However, the female controls showed a significantly larger volume in the superior temporal gyrus including Heschl's gyrus and Rolandic operculum. These findings confirm that the volume difference in brain substructures in FtM transsexuals is likely to be associated with transsexualism and that transsexualism is probably associated with distinct cerebral structures, determining gender identity.

  16. Progressive Volume Loss and White Matter Degeneration in Cstb-Deficient Mice: A Diffusion Tensor and Longitudinal Volumetry MRI Study

    PubMed Central

    Manninen, Otto; Laitinen, Teemu; Lehtimäki, Kimmo K.; Tegelberg, Saara; Lehesjoki, Anna-Elina; Gröhn, Olli; Kopra, Outi

    2014-01-01

    Unverricht-Lundborg type progressive myoclonus epilepsy (EPM1, OMIM 254800) is an autosomal recessive disorder characterized by onset at the age of 6 to 16 years, incapacitating stimulus-sensitive myoclonus and tonic-clonic epileptic seizures. It is caused by mutations in the gene encoding cystatin B. Previously, widespread white matter changes and atrophy has been detected both in adult EPM1 patients and in 6-month-old cystatin B–deficient mice, a mouse model for the EPM1 disease. In order to elucidate the spatiotemporal dynamics of the brain atrophy and white matter changes in EPM1, we conducted longitudinal in vivo magnetic resonance imaging and ex vivo diffusion tensor imaging accompanied with tract-based spatial statistics analysis to compare volumetric changes and fractional anisotropy in the brains of 1 to 6 months of age cystatin B–deficient and control mice. The results reveal progressive but non-uniform volume loss of the cystatin B–deficient mouse brains, indicating that different neuronal populations possess distinct sensitivity to the damage caused by cystatin B deficiency. The diffusion tensor imaging data reveal early and progressive white matter alterations in cystatin B–deficient mice affecting all major tracts. The results also indicate that the white matter damage in the cystatin B–deficient brain is most likely secondary to glial activation and neurodegenerative events rather than a primary result of CSTB deficiency. The data also show that diffusion tensor imaging combined with TBSS analysis provides a feasible approach not only to follow white matter damage in neurodegenerative mouse models but also to detect fractional anisotropy changes related to normal white matter maturation and reorganisation. PMID:24603771

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

    PubMed

    Kleber, Boris; Veit, Ralf; Moll, Christina Valérie; Gaser, Christian; Birbaumer, Niels; Lotze, Martin

    2016-06-01

    In contrast to instrumental musicians, professional singers do not train on a specific instrument but perfect a motor system that has already been extensively trained during speech motor development. Previous functional imaging studies suggest that experience with singing is associated with enhanced somatosensory-based vocal motor control. However, experience-dependent structural plasticity in vocal musicians has rarely been studied. We investigated voxel-based morphometry (VBM) in 27 professional classical singers and compared gray matter volume in regions of the "singing-network" to an age-matched group of 28 healthy volunteers with no special singing experience. We found right hemispheric volume increases in professional singers in ventral primary somatosensory cortex (larynx S1) and adjacent rostral supramarginal gyrus (BA40), as well as in secondary somatosensory (S2) and primary auditory cortices (A1). Moreover, we found that earlier commencement with vocal training correlated with increased gray-matter volume in S1. However, in contrast to studies with instrumental musicians, this correlation only emerged in singers who began their formal training after the age of 14years, when speech motor development has reached its first plateau. Structural data thus confirm and extend previous functional reports suggesting a pivotal role of somatosensation in vocal motor control with increased experience in singing. Results furthermore indicate a sensitive period for developing additional vocal skills after speech motor coordination has matured.

  18. Neutron Matter at Next-to-Next-to-Next-to-Leading Order in Chiral Effective Field Theory

    NASA Astrophysics Data System (ADS)

    Tews, I.; Krüger, T.; Hebeler, K.; Schwenk, A.

    2013-01-01

    Neutron matter presents a unique system for chiral effective field theory because all many-body forces among neutrons are predicted to next-to-next-to-next-to-leading order (N3LO). We present the first complete N3LO calculation of the neutron matter energy. This includes the subleading three-nucleon forces for the first time and all leading four-nucleon forces. We find relatively large contributions from N3LO three-nucleon forces. Our results provide constraints for neutron-rich matter in astrophysics with controlled theoretical uncertainties.

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

    PubMed Central

    Cooke, Gillian E.; Wetter, Nathan C.; Banducci, Sarah E.; Mackenzie, Michael J.; Zuniga, Krystle E.; Awick, Elizabeth A.; Roberts, Sarah A.; Sutton, Brad P.; McAuley, Edward; Kramer, Arthur F.

    2016-01-01

    Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment. PMID:26915025

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

    PubMed

    Cooke, Gillian E; Wetter, Nathan C; Banducci, Sarah E; Mackenzie, Michael J; Zuniga, Krystle E; Awick, Elizabeth A; Roberts, Sarah A; Sutton, Brad P; McAuley, Edward; Kramer, Arthur F

    2016-01-01

    Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment.

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

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

    DOE PAGES

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

    2015-10-14

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

  3. Beyond the dark matter effective field theory and a simplified model approach at colliders

    NASA Astrophysics Data System (ADS)

    Baek, Seungwon; Ko, P.; Park, Myeonghun; Park, Wan-Il; Yu, Chaehyun

    2016-05-01

    Direct detection of and LHC search for the singlet fermion dark matter (SFDM) model with Higgs portal interaction are considered in a renormalizable model where the full Standard Model (SM) gauge symmetry is imposed by introducing a singlet scalar messenger. In this model, direct detection is described by an effective operator mq q bar q χ bar χ as usual, but the full amplitude for monojet + E̸T involves two intermediate scalar propagators, which cannot be seen within the effective field theory (EFT) or in the simplified model without the full SM gauge symmetry. We derive the collider bounds from the ATLAS monojet + E̸T as well as the CMS t t bar +E̸T data, finding out that the bounds and the interpretation of the results are completely different from those obtained within the EFT or simplified models. It is pointed out that it is important to respect unitarity, renormalizability and local gauge invariance of the SM.

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

    DOE PAGES

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

    2014-07-04

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

  5. WIMP capture by the Sun in the effective theory of dark matter self-interactions

    NASA Astrophysics Data System (ADS)

    Catena, Riccardo; Widmark, Axel

    2016-12-01

    We study the capture of WIMP dark matter by the Sun in the non-relativistic effective theory of dark matter self-interactions. The aim is to assess how self-interactions affect the expected neutrino flux coming from WIMP annihilation in the Sun, and to do so in a model independent manner. We consider all non-relativistic Galilean invariant self-interaction operators that can arise from the exchange of a heavy particle of spin less than or equal to 1 for WIMPs of spin equal to 0, 1/2 and 1. We show that for interaction operators depending at most linearly on the momentum transfer, the WIMP-induced neutrino flux can be enhanced by several orders of magnitude compared to the same flux in absence of self-interactions. This is true even for standard values of the thermally averaged annihilation cross-section. This conclusion impacts the analysis of present and future observations performed at neutrino telescopes.

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

    PubMed Central

    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. PMID:25720412

  7. Thermophysical Properties of Matter - The TPRC Data Series. Volume 7. Thermal Radiative Properties - Metallic Elements and Alloys

    DTIC Science & Technology

    1970-01-01

    alloys —stainless steels— aluminum — aluminum alloys - antimony— (continue on ravarse aide) 20. ABSTRACT fConHnu» on revrrt» »Id» II noetfmry mtd...Spectral Absorptance 883 2. BINARY ALLOYS Figure and/or Table No. Material and Sub-property Page 261 Aluminum ♦ Cobalt - Normal Spectral Reflectance...SHEET —— . THTin: *OV*HY31ZJ I 00 9 ^DP^HTIES OF MATTER Tha TPRC Data ^erlas VOLUME 7 THERMAL RADIATIVE Metallic Elements end Alloys J

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

    PubMed Central

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

    2014-01-01

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

  9. Association of polygenic risk for major psychiatric illness with subcortical volumes and white matter integrity in UK Biobank

    PubMed Central

    Reus, L. M.; Shen, X.; Gibson, J.; Wigmore, E.; Ligthart, L.; Adams, M. J.; Davies, G.; Cox, S. R.; Hagenaars, S. P.; Bastin, M. E.; Deary, I. J.; Whalley, H. C.; McIntosh, A. M.

    2017-01-01

    Major depressive disorder (MDD), schizophrenia (SCZ) and bipolar disorder (BP) are common, disabling and heritable psychiatric diseases with a complex overlapping polygenic architecture. Individuals with these disorders, as well as their unaffected relatives, show widespread structural differences in corticostriatal and limbic networks. Structural variation in many of these brain regions is also heritable and polygenic but whether their genetic architecture overlaps with that of major psychiatric disorders is unknown. We sought to address this issue by examining the impact of polygenic risk of MDD, SCZ, and BP on subcortical brain volumes and white matter (WM) microstructure in a large single sample of neuroimaging data; the UK Biobank Imaging study. The first release of UK Biobank imaging data comprised participants with overlapping genetic data and subcortical volumes (N = 978) and WM measures (N = 816). The calculation of polygenic risk scores was based on genome-wide association study results generated by the Psychiatric Genomics Consortium. Our findings indicated no statistically significant associations between either subcortical volumes or WM microstructure, and polygenic risk for MDD, SCZ or BP. These findings suggest that subcortical brain volumes and WM microstructure may not be closely linked to the genetic mechanisms of major psychiatric disorders. PMID:28186152

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

    PubMed Central

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

    2016-01-01

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

  11. A longitudinal study of the relationship between personality traits and the annual rate of volume changes in regional gray matter in healthy adults.

    PubMed

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

    2013-12-01

    To investigate whether personality traits affect the rate of decline of gray matter volume, we analyzed the relationships between personality traits and the annual rate of changes of gray matter volume in 274 healthy community dwelling subjects with a large age range by applying a longitudinal design over 6 years, using brain magnetic resonance images (MRI) and the Revised NEO Personality Inventory (NEO-PI-R) at baseline. Brain MRI data were processed using voxel-based morphometry with a custom template by applying the DARTEL diffeomorphic registration tool. For each subject, we used NEO-PI-R to evaluate the five major personality traits, including neuroticism, extraversion, openness, agreeableness, and conscientiousness. The results show that the annual rate of change in regional gray matter volume in the right inferior parietal lobule was correlated significantly and negatively with a personality of openness, which is known to be related to intellect, intellectual curiosity, and creativity adjusting for age, gender, and intracranial volume. This result indicates that subjects with a personality trait of less openness have an accelerated loss of gray matter volume in the right inferior parietal lobule, compared with subjects with a personality trait of more openness. Because the right inferior parietal lobule is involved in higher cognitive function such as working memory and creativity, a personality trait of openness is thought to be important for preserving gray matter volume and cognitive function of the right inferior parietal lobule in healthy adults.

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

    PubMed

    Cai, Yi; Liu, Jun; Zhang, Li; Liao, Mei; Zhang, Yan; Wang, Lifeng; Peng, Hongjun; He, Zhong; Li, Zexuan; Li, Weihui; Lu, Shaojia; Ding, Yuqiang; Li, Lingjiang

    2015-02-01

    Bipolar disorder and unipolar depressive disorder (UD) may be different in brain structure. In the present study, we performed voxel-based morphometry (VBM) to quantify the grey matter volumes in 23 patients with bipolar I depressive disorder (BP1) and 23 patients with UD, and 23 age-, gender-, and education-matched healthy controls (HCs) using magnetic resonance imaging. We found that compared with the HC and UD groups, the BP1 group showed reduced grey matter volumes in the right inferior frontal gyrus and middle cingulate gyrus, while the UD group showed reduced volume in the right inferior frontal gyrus compared to HCs. In addition, correlation analyses revealed that the grey matter volumes of these regions were negatively correlated with the Hamilton depression rating scores. Taken together, the results of our study suggest that decreased grey matter volume of the right inferior frontal gyrus is a common abnormality in BP1 and UD, and decreased grey matter volume in the right middle cingulate gyrus may be specific to BP1.

  13. Perturbations of matter fields in the second-order gauge-invariant cosmological perturbation theory

    NASA Astrophysics Data System (ADS)

    Nakamura, Kouji

    2009-12-01

    To show that the general framework of the second-order gauge-invariant perturbation theory developed by K. Nakamura [Prog. Theor. Phys. 110, 723 (2003)PTPKAV0033-068X10.1143/PTP.110.723; Prog. Theor. Phys. 113, 481 (2005)PTPKAV0033-068X10.1143/PTP.113.481] is applicable to a wide class of cosmological situations, some formulas for the perturbations of the matter fields are summarized within the framework of the second-order gauge-invariant cosmological perturbation theory in a four-dimensional homogeneous isotropic universe, which is developed in Prog. Theor. Phys. 117, 17 (2007)PTPKAV0033-068X10.1143/PTP.117.17. We derive the formulas for the perturbations of the energy-momentum tensors and equations of motion for a perfect fluid, an imperfect fluid, and a single scalar field, and show that all equations are derived in terms of gauge-invariant variables without any gauge fixing. Through these formulas, we may say that the decomposition formulas for the perturbations of any tensor field into gauge-invariant and gauge-variant parts, which are proposed in the above papers, are universal.

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

    SciTech Connect

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

    2013-10-01

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

  15. An improved thermodiffusion model for ternary mixtures using Fujita's free volume theory

    NASA Astrophysics Data System (ADS)

    Abbasi, Alireza; Saghir, M. Ziad; Kawaji, Masahiro

    2011-09-01

    Thermodiffusion along molecular diffusion is one of the major mechanisms of transport phenomena. They have an important role in displacement of hydrocarbon fluid components in an oil reservoir. Free volume controls the diffusivity of the molecule in diffusion-limited systems. It states that the transfer kinetics of molecules depends greatly on molecular size and shape as well as the concentration. A new proposed model based on Fujita-type model is used to predict the thermodiffusion coefficients in ternary mixtures such as n-dodecane (nC12), n-butane (nC4), methane (C1), n-dodecane (nC12), isobutylbenzene (IBB), tetrahydronaphtalene (THN) and n-octane (C8), n-decane (nC10), 1-methylnaphtalene (MN). The ratio of evaporation energy to activation energy required for estimating the thermodiffusion coefficients is calculated by the available free volume theory. In particular, the combination of available free volume theory and Shukla and Firoozabadi's model is applied to predict the thermodiffusion coefficient. The results show a good performance of the new approach in estimating the thermodiffusion coefficients.

  16. Excluded volume in solvation: sensitivity of scaled-particle theory to solvent size and density.

    PubMed Central

    Tang, K E; Bloomfield, V A

    2000-01-01

    Changes in solvent environment greatly affect macromolecular structure and stability. To investigate the role of excluded volume in solvation, scaled-particle theory is often used to calculate delta G(tr)(ev), the excluded-volume portion of the solute transfer free energy, delta G(tr). The inputs to SPT are the solvent radii and molarities. Real molecules are not spheres. Hence, molecular radii are not uniquely defined and vary for any given species. Since delta G(tr)(ev) is extremely sensitive to solvent radii, uncertainty in these radii causes a large uncertainty in delta G(tr)(ev)-several kcal/mol for amino acid solutes transferring from water to aqueous mixtures. This uncertainty is larger than the experimental delta G(tr) values. Also, delta G(tr)(ev) can be either positive or negative. Adding neutral crowding molecules may not necessarily reduce solubility. Lastly, delta G(tr)(ev) is very sensitive to solvent density, rho. A few percent error in rho may even cause qualitative deviations in delta G(tr)(ev). For example, if rho is calculated by assuming the hard-sphere pressure to be constant, then delta G(tr)(ev) values and uncertainties are now only tenths of a kcal/mol and are positive. Because delta G(tr)(ev) values calculated by scaled-particle theory are strongly sensitive to solvent radii and densities, determining the excluded-volume contribution to transfer free energies using SPT may be problematic. PMID:11053104

  17. Impact of spillover from white matter by partial volume effect on quantification of amyloid deposition with [(11)C]PiB PET.

    PubMed

    Matsubara, Keisuke; Ibaraki, Masanobu; Shimada, Hitoshi; Ikoma, Yoko; Suhara, Tetsuya; Kinoshita, Toshibumi; Itco, Hiroshi

    2016-12-01

    High non-specific uptake of [(11)C]Pittsburgh compound B ([(11)C]PiB) in white matter and signal spillover from white matter, due to partial volume effects, confound radioactivity measured in positron emission tomography (PET) with [(11)C]PiB. We aimed to reveal the partial volume effect in absolute values of kinetic parameters for [(11)C]PiB, in terms of spillover from white matter. Dynamic data acquired in [(11)C]PiB PET scans with five healthy volunteers and eight patients with Alzheimer's disease were corrected with region-based and voxel-based partial volume corrections. Binding potential (BPND) was estimated using the two-tissue compartment model analysis with a plasma input function. Partial volume corrections significantly decreased cortical BPND values. The degree of decrease in healthy volunteers (-52.7±5.8%) was larger than that in Alzheimer's disease patients (-11.9±4.2%). The simulation demonstrated that white matter spillover signals due to the partial volume effect resulted in an overestimation of cortical BPND, with a greater degree of overestimation for lower BPND values. Thus, an overestimation due to partial volume effects is more severe in healthy volunteers than in Alzheimer's disease patients. Partial volume corrections may be useful for accurately quantifying Aβ deposition in cortical regions.

  18. Association between regional white and gray matter volume and ambiguity tolerance: Evidence from voxel-based morphometry.

    PubMed

    Tong, Dandan; Yang, Wenjing; Zhang, Qinglin; Li, Wenfu; Wei, Dongtao; Che, Xianwei; Zhang, Meng; Hitchman, Glenn; Qiu, Jiang; Liu, Yijun; Cao, Guikang

    2015-08-01

    The concept of tolerance of ambiguity (AT) is defined as the way in which an individual tends to perceive and deal with confusing, vague, and unclear situations. AT is generally considered as an important personality trait, but the neural mechanisms underlying individual differences in AT have never been investigated. Using voxel-based morphometry and MSTAT-II scale, we investigated the correlations between AT and regional white matter volume (rWMV) and regional gray matter volume (rGMV) in 351 young healthy subjects. We found AT to be positively correlated with rGMV in the dorsolateral prefrontal cortex (DLPFC), and negatively correlated with rGMV in the precuneus. These results indicate that increased rGMV in the left DLPFC may lead to characteristics of ambiguous stimuli consideration from multiple contexts and risk taking. Decreased rGMV in the left precuneus may be associated with a high tolerance for ambiguity, which attributes uncertainty to self-related factors.

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

    PubMed

    Kaiser, Anelis; Eppenberger, Leila S; Smieskova, Renata; Borgwardt, Stefan; Kuenzli, Esther; Radue, Ernst-Wilhelm; Nitsch, Cordula; Bendfeldt, Kerstin

    2015-01-01

    Numerous structural studies have established that experience shapes and reshapes the brain throughout a lifetime. The impact of early development, however, is still a matter of debate. Further clues may come from studying multilinguals who acquired their second language at different ages. We investigated adult multilinguals who spoke three languages fluently, where the third language was learned in classroom settings, not before the age of 9 years. Multilinguals exposed to two languages simultaneously from birth (SiM) were contrasted with multinguals who acquired their first two languages successively (SuM). Whole brain voxel based morphometry revealed that, relative to SuM, SiM have significantly lower gray matter volume in several language-associated cortical areas in both hemispheres: bilaterally in medial and inferior frontal gyrus, in the right medial temporal gyrus and inferior posterior parietal gyrus, as well as in the left inferior temporal gyrus. Thus, as shown by others, successive language learning increases the volume of language-associated cortical areas. In brains exposed early on and simultaneously to more than one language, however, learning of additional languages seems to have less impact. We conclude that - at least with respect to language acquisition - early developmental influences are maintained and have an effect on experience-dependent plasticity well into adulthood.

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

    PubMed Central

    Kaiser, Anelis; Eppenberger, Leila S.; Smieskova, Renata; Borgwardt, Stefan; Kuenzli, Esther; Radue, Ernst-Wilhelm; Nitsch, Cordula; Bendfeldt, Kerstin

    2015-01-01

    Numerous structural studies have established that experience shapes and reshapes the brain throughout a lifetime. The impact of early development, however, is still a matter of debate. Further clues may come from studying multilinguals who acquired their second language at different ages. We investigated adult multilinguals who spoke three languages fluently, where the third language was learned in classroom settings, not before the age of 9 years. Multilinguals exposed to two languages simultaneously from birth (SiM) were contrasted with multinguals who acquired their first two languages successively (SuM). Whole brain voxel based morphometry revealed that, relative to SuM, SiM have significantly lower gray matter volume in several language-associated cortical areas in both hemispheres: bilaterally in medial and inferior frontal gyrus, in the right medial temporal gyrus and inferior posterior parietal gyrus, as well as in the left inferior temporal gyrus. Thus, as shown by others, successive language learning increases the volume of language-associated cortical areas. In brains exposed early on and simultaneously to more than one language, however, learning of additional languages seems to have less impact. We conclude that – at least with respect to language acquisition – early developmental influences are maintained and have an effect on experience-dependent plasticity well into adulthood. PMID:26106338

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

    SciTech Connect

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

    2010-05-21

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

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

    SciTech Connect

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

    1988-04-01

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

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

    DOE R&D Accomplishments Database

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

    1988-04-01

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

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

    PubMed

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

    2012-01-01

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

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

    PubMed

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

    2009-05-15

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

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

    SciTech Connect

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

    2014-12-01

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

  7. Linear and curvilinear correlations of brain gray matter volume and density with age using voxel-based morphometry with the Akaike information criterion in 291 healthy children.

    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

    2013-08-01

    We examined linear and curvilinear correlations of gray matter volume and density in cortical and subcortical gray matter with age using magnetic resonance images (MRI) in a large number of healthy children. We applied voxel-based morphometry (VBM) and region-of-interest (ROI) analyses with the Akaike information criterion (AIC), which was used to determine the best-fit model by selecting which predictor terms should be included. We collected data on brain structural MRI in 291 healthy children aged 5-18 years. Structural MRI data were segmented and normalized using a custom template by applying the diffeomorphic anatomical registration using exponentiated lie algebra (DARTEL) procedure. Next, we analyzed the correlations of gray matter volume and density with age in VBM with AIC by estimating linear, quadratic, and cubic polynomial functions. Several regions such as the prefrontal cortex, the precentral gyrus, and cerebellum showed significant linear or curvilinear correlations between gray matter volume and age on an increasing trajectory, and between gray matter density and age on a decreasing trajectory in VBM and ROI analyses with AIC. Because the trajectory of gray matter volume and density with age suggests the progress of brain maturation, our results may contribute to clarifying brain maturation in healthy children from the viewpoint of brain structure.

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

    SciTech Connect

    Angulo, Raul E.; Foreman, Simon; Senatore, Leonardo; Schmittfull, Marcel E-mail: sfore@stanford.edu E-mail: senatore@stanford.edu

    2015-10-01

    Given the importance of future large scale structure surveys for delivering new cosmological information, it is crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a manifestly convergent perturbative scheme to compute the clustering of dark matter in the weakly nonlinear regime in an expansion in k/k{sub NL}, where k is the wavenumber of interest and k{sub NL} is the wavenumber associated to the nonlinear scale. It has been recently shown that the EFTofLSS matches to 1% level the dark matter power spectrum at redshift zero up to k≅ 0.3 h Mpc{sup −1} and k≅ 0.6 h Mpc{sup −1} at one and two loops respectively, using only one counterterm that is fit to data. Similar results have been obtained for the momentum power spectrum at one loop. This is a remarkable improvement with respect to former analytical techniques. Here we study the prediction for the equal-time dark matter bispectrum at one loop. We find that at this order it is sufficient to consider the same counterterm that was measured in the power spectrum. Without any remaining free parameter, and in a cosmology for which k{sub NL} is smaller than in the previously considered cases (σ{sub 8}=0.9), we find that the prediction from the EFTofLSS agrees very well with N-body simulations up to k≅ 0.25 h Mpc{sup −1}, given the accuracy of the measurements, which is of order a few percent at the highest k's of interest. While the fit is very good on average up to k≅ 0.25 h Mpc{sup −1}, the fit performs slightly worse on equilateral configurations, in agreement with expectations that for a given maximum k, equilateral triangles are the most nonlinear.

  9. An Effective Field Theory Analysis of the First LUX Dark Matter Search

    NASA Astrophysics Data System (ADS)

    Larsen, Nicole A.

    A wealth of astrophysical research supports the existence of dark matter in the universe, yet the exact identity and nature of this unknown particle remain elusive. The Weakly Interacting Massive Particle (WIMP), one of the most promising dark matter candidates, is thought to interact with Standard Model particles only through the gravitational and weak nuclear forces. The Large Underground Xenon (LUX) experiment is one of a large number of experiments that seek to detect WIMPs through their rare but discernible scatters off of target nuclei. Specifically, LUX is a 370-kg dual-phase xenon-based time projection chamber (TPC) that operates by detecting light and ionization signals from particles incident upon a xenon target. The first part of this dissertation details the design of the LUX experiment and describes several novel hardware subsystems that allow LUX to detect extremely rare events with high precision. With the 2013 release of the world's first sub-zeptobarn spin-independent WIMP-nucleon cross section limit, the LUX (Large Underground Xenon) experiment has emerged as a frontrunner in the field of dark matter direct detection. However, tension between experiments and the absence of a definitive positive detection suggest it would be prudent to search for answers outside the standard spin-independent/spin-dependent analyses. hi particular, the standard analyses neglect momentum- and velocity-dependent interactions on the grounds that WIMP-nucleus collisions are nonrelativistic. At the parton level, this is not always the case, and moreover, models exist in which the standard spin-independent and spin-dependent interactions are subdominant to new kinds of interactions. Recent theoretical work has identified a complete set of 14 possible independent WIMP-nucleon interactions using basic symmetries and an effective field theory formulation. These interactions produce not only spin-independent and spin-dependent nuclear responses but also novel nuclear

  10. Extraction of hot QCD matter transport coefficients utilizing microscopic transport theory

    NASA Astrophysics Data System (ADS)

    Demir, Nasser Soliman

    Ultrarelativistic heavy-ion collisions at the Relativistic Heavy-Ion Collider (RHIC) are thought to have produced a state of matter called the Quark-Gluon-Plasma (QGP). The QGP forms when nuclear matter governed by Quantum Chromodynamics (QCD) reaches a temperature and baryochemical potential necessary to achieve the transition of hadrons (bound states of quarks and gluons) to deconfined quarks and gluons. Such conditions have been achieved at RHIC, and the resulting QGP created exhibits properties of a near perfect fluid. In particular, strong evidence shows that the QGP exhibits a very small shear viscosity to entropy density ratio eta/s, near the lower bound predicted for that quantity by Anti-deSitter space/Conformal Field Theory (AdS/CFT) methods of eta/s = ℎ4pkB , where h is Planck's constant and kB is Boltzmann's constant. As the produced matter expands and cools, it evolves through a phase described by a hadron gas with rapidly increasing eta/s. This thesis presents robust calculations of eta/s for hadronic and partonic media as a function of temperature using the Green-Kubo formalism. An analysis is performed for the behavior of eta/s to mimic situations of the hadronic media at RHIC evolving out of chemical equilibrium, and systematic uncertainties are assessed for our method. In addition, preliminary results are presented for the bulk viscosity to entropy density ratio zeta/s, whose behavior is not well-known in a relativistic heavy ion collisions. The diffusion coefficient for baryon number is investigated, and an algorithm is presented to improve upon the previous work of investigation of heavy quark diffusion in a thermal QGP. By combining the results of my investigations for eta/s from our microscopic transport models with what is currently known from the experimental results on elliptic flow from RHIC, I find that the trajectory of eta/s in a heavy ion collision has a rich structure, especially near the deconfinement transition temperature Tc. I

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

    SciTech Connect

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

    2015-10-14

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

  12. Impact of 5-Hz rTMS over the primary sensory cortex is related to white matter volume in individuals with chronic stroke.

    PubMed

    Brodie, Sonia M; Borich, Michael R; Boyd, Lara A

    2014-11-01

    Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that may facilitate mechanisms of motor learning. In a recent single-blind, pseudo-randomized study, we showed that 5-Hz rTMS over ipsilesional primary somatosensory cortex followed by practice of a skilled motor task enhanced motor learning compared with sham rTMS + practice in individuals with chronic stroke. However, the beneficial effect of stimulation was inconsistent. The current study examined how differences in sensorimotor cortex morphology might predict rTMS-related improvements in motor learning in these individuals. High-resolution T1-weighted magnetic resonance images were acquired and processed in FreeSurfer using a newly developed automated, whole brain parcellation technique. Gray matter and white matter volumes of the ipsilesional primary somatosensory and motor cortices were extracted. A significant positive association was observed between the volume of white matter in the primary somatosensory cortex and motor learning-related change, exclusively in the group that received active 5-Hz rTMS. A regression model with age, gray matter and white matter volumes as predictors was significant for predicting motor learning-related change in individuals who received active TMS. White matter volume predicted the greatest amount of variance (47.6%). The same model was non-significant when volumes of the primary motor cortex were considered. We conclude that white matter volume in the cortex underlying the TMS coil may be a novel predictor for behavioral response to 5-Hz rTMS over the ipsilesional primary somatosensory followed by motor practice.

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

    NASA Technical Reports Server (NTRS)

    Reuther, J.; Jameson, A.

    1994-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  15. Some considerations concerning volume-modulated arc therapy: a stepping stone towards a general theory

    NASA Astrophysics Data System (ADS)

    Webb, S.; McQuaid, D.

    2009-07-01

    In this paper it is formally shown that the dynamic multileaf collimator (MLC) IMRT delivery technique remains valid if the MLC is supported on a 1D moving platform. It is also shown that, in such circumstances, it is always time preferable to deliver overlapping modulating fields as a single swept field rather than as separate fields. The most general formulism is presented and then related to simpler equations in limiting cases. The paper explains in detail how a 'small-arc approximation' can be invoked to relate the 1D linear theory to the MLC-on-moving-platform-(gantry) delivery technique involving rotation therapy and known as volume-modulated arc therapy (VMAT). It is explained how volume-modulated arc therapy delivered with open unmodulated fields and which can deliver conformal dose distributions can be interpreted as an IMRT delivery. The (Elekta adopted) term VMAT will be used in a generic sense to include a similar (Varian) method known as RapidArc. Approximate expressions are derived for the 'amount of modulation' possible in a VMAT delivery. This paper does not discuss the actual VMAT planning but gives an insight at a deep level into VMAT delivery. No universal theory of VMAT is known in the sense that there is no theory that can predict precisely the performance of a VMAT delivery in terms of the free parameters available (variable gantry speed, variable fluence-delivery rate, set of MLC shapes, MLC orientation, number of arcs, coplanarity versus non-coplanarity, etc). This is in stark contrast to the situation with several other IMRT delivery techniques where such theoretical analyses are known. In this paper we do not provide such a theory; the material presented is a stepping stone on the path towards this.

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

    NASA Astrophysics Data System (ADS)

    Hernández, Pilar; Laine, Mikko

    2003-01-01

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

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

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  18. Solid-fluid equilibrium of fused-hard-sphere systems: Free-volume theories and simulation

    NASA Astrophysics Data System (ADS)

    Gay, Shawn Christian

    Historically, the theoretical investigation of solid-fluid phase equilibrium has largely focused on the freezing of hard spheres. Only relatively recently have theories begun to address the phase equilibria of systems of nonspherical molecules. This thesis details the application of various theoretical methods to predict the solid-fluid phase equilibria of systems of nonspherical molecules. The general approach is to first calculate the properties of systems of fused-hard-sphere molecules, and then model real systems by extending the fused-hard-sphere results using generalized van der Waals theory and perturbation theory to describe the effects of longer range interactions. Results of original research are presented that demonstrate the effectiveness of the theories, often by direct comparison with Monte Carlo simulation results and, where applicable, by comparison with experiment. We use a simple cell theory to calculate the free energy of the heteronuclear hard-dumbbell solid and an analytic equation of state to calculate the free energy of the fluid. Decreasing the ratio of the diameters of the spheres composing the dumbbell is found to increase the pressure at freezing. We have also calculated the distribution of free volumes in the solid phase of two-dimensional hard dumbbells. This information allows us to characterize a fluctuating cell theory as well as new statistical geometry relations for fused-hard-sphere systems presented in this thesis. Finally, we use simple cell theory results for hard dumbbells in a generalized van der Waals theory to calculate the solid-liquid phase transition for a system of dipolar hard dumbbells. Our model is chosen to approximate a methyl chloride molecule. Thermodynamic perturbation theory is used to include dipolar effects in the fluid equation of state, and static-lattice sums are used to approximate dipolar effects in the solid phase. We find that the presence of a dipole moment stabilizes a non-closepacking crystal

  19. Asymmetric nuclear matter and neutron star properties within the extended Brueckner theory

    NASA Astrophysics Data System (ADS)

    Hassaneen, Khaled S. A.

    2017-01-01

    Microscopically, the equation of state (EOS) and other properties of asymmetric nuclear matter at zero temperature have been investigated extensively by adopting the non-relativistic Brueckner-Hartree-Fock (BHF) and the extended BHF approaches by using the self-consistent Green's function approach or by including a phenomenological three-body force. Once three-body forces are introduced, the phenomenological saturation point is reproduced and the theory is applied to the study of neutron star properties. We can calculate the total mass and radius for neutron stars using various equations of state at high densities in β-equilibrium without hyperons. A comparison with other microscopic predictions based on non-relativistic and density-dependent relativistic mean-field calculations has been done. It is found that relativistic EOS yields however larger mass and radius for neutron star than predictions based on non-relativistic approaches. Also the three-body force plays a crucial role to deduce the theoretical value of the maximum mass of neutron stars in agreement with recent measurements of the neutron star mass.

  20. Functional Brain Networks and White Matter Underlying Theory-of-Mind in Autism

    PubMed Central

    Kana, Rajesh K.; Libero, Lauren E.; Hu, Christi P.; Deshpande, Hrishikesh D.; Colburn, Jeffrey S.

    2014-01-01

    Human beings constantly engage in attributing causal explanations to one’s own and to others’ actions, and theory-of-mind (ToM) is critical in making such inferences. Although children learn causal attribution early in development, children with autism spectrum disorders (ASDs) are known to have impairments in the development of intentional causality. This functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) study investigated the neural correlates of physical and intentional causal attribution in people with ASDs. In the fMRI scanner, 15 adolescents and adults with ASDs and 15 age- and IQ-matched typically developing peers made causal judgments about comic strips presented randomly in an event-related design. All participants showed robust activation in bilateral posterior superior temporal sulcus at the temporo-parietal junction (TPJ) in response to intentional causality. Participants with ASDs showed lower activation in TPJ, right inferior frontal gyrus and left premotor cortex. Significantly weaker functional connectivity was also found in the ASD group between TPJ and motor areas during intentional causality. DTI data revealed significantly reduced fractional anisotropy in ASD participants in white matter underlying the temporal lobe. In addition to underscoring the role of TPJ in ToM, this study found an interaction between motor simulation and mentalizing systems in intentional causal attribution and its possible discord in autism. PMID:22977198

  1. Implications of Poincaré symmetry for thermal field theories in finite-volume

    NASA Astrophysics Data System (ADS)

    Giusti, Leonardo; Meyer, Harvey B.

    2013-01-01

    The analytic continuation to an imaginary velocity i ξ of the canonical partition function of a thermal system expressed in a moving frame has a natural implementation in the Euclidean path-integral formulation in terms of shifted boundary conditions. Writing the Boltzmann factor as [InlineEquation not available: see fulltext.], the Poincaré invariance underlying a relativistic theory implies a dependence of the free-energy on L 0 and the shift ξ only through the combination [InlineEquation not available: see fulltext.]. This in turn implies a set of Ward identities, some of which were previously derived by us, among the correlators of the energy-momentum tensor. In the infinite-volume limit they lead to relations among the cumulants of the total energy distribution and those of the momentum, i.e. they connect the energy and the momentum distributions in the canonical ensemble. In finite volume the Poincaré symmetry translates into exact relations among partition functions and correlation functions defined with different sets of (generalized) periodic boundary conditions. They have interesting applications in lattice field theory. In particular, they offer Ward identities to renormalize non-perturbatively the energy-momentum tensor and novel ways to compute thermodynamic potentials. At fixed bare parameters they also provide a simple method to vary the temperature in much smaller steps than with the standard procedure.

  2. Thermophysical Properties of Matter-The TPRC Data Series. Volume 10. Thermal Diffusivity

    DTIC Science & Technology

    1974-01-01

    published data since the latest same degree of completeness. However, as additional edition. In this context, the TPRC Data Series departs data are...Preface xi for the Department of Defense as well as a component volume. I wish to take this opportunity to personally of the National Standard Reference...Gathered from the Literature," 18, 1-49, 1968. Department of Food Science, College of Agriculture and 43. Bornemann, K. and Sauerwald, F., "Density

  3. Generic van der Waals equation of state, modified free volume theory of diffusion, and viscosity of simple liquids.

    PubMed

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

    2005-03-31

    The shear viscosity formula derived by the density fluctuation theory in previous papers is computed for argon, krypton, and methane by using the self-diffusion coefficients derived in the modified free volume theory with the help of the generic van der Waals equation of state. In the temperature regime near or above the critical temperature, the density dependence of the shear viscosity can be accounted for by ab initio calculations with the self-diffusion coefficients provided by the modified free volume theory if the minimum (critical) free volume is set equal to the molecular volume and the volume overlap parameter (alpha) is taken about unity in the expression for the self-diffusion coefficient. In the subcritical temperature regime, if the density fluctuation range parameter is chosen appropriately at a temperature, then the resulting expression for the shear viscosity can well account for its density and temperature dependence over the ranges of density and temperature experimentally studied. In the sense that once the density fluctuation range is fixed at a temperature, the theory can account for the experimental data at other subcritical temperatures on the basis of the intermolecular force only; the theory is predictive even in the subcritical regime of temperature. Theory is successfully tested in comparison with experimental data for self-diffusion coefficients and shear viscosity for argon, krypton, and methane.

  4. Earth matter effects on supernova neutrinos in large-volume detectors

    NASA Astrophysics Data System (ADS)

    Borriello, Enrico

    2013-04-01

    Neutrino oscillations in the Earth matter may introduce peculiar modulations in the supernova (SN) neutrino spectra. The detection of this effect has been proposed as diagnostic tool for the neutrino mass hierarchy. We perform an updated study on the observability of this effect at large next-generation underground detectors (i.e., 0.4 Mton water Cherenkov, 50 kton scintillation and 100 kton liquid Argon detectors) based on neutrino fluxes from state-of-the-art SN simulations and accounting for statistical fluctuations via Montecarlo simulations. Since the average energies predicted by recent simulations are lower than previously expected and a tendency towards the equalization of the neutrino fluxes appears during the SN cooling phase, the detection of the Earth matter effect will be more challenging than expected from previous studies. We find that none of the proposed detectors shall be able to detect the Earth modulation for the neutrino signal of a typical galactic SN at 10 kpc. It should be observable in a 100 kton liquid Argon detector for a SN at few kpc and all three detectors would clearly see the Earth signature for very close-by stars only (d˜200 pc).

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

    NASA Astrophysics Data System (ADS)

    Logan, D. E.

    2005-02-01

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

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

    PubMed

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

    2015-12-01

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

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

    PubMed Central

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

    2015-01-01

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

  8. Sex Differences in Gray Matter Volume of the Right Anterior Hippocampus Explain Sex Differences in Three-Dimensional Mental Rotation

    PubMed Central

    Wei, Wei; Chen, Chuansheng; Dong, Qi; Zhou, Xinlin

    2016-01-01

    Behavioral studies have reported that males perform better than females in 3-dimensional (3D) mental rotation. Given the important role of the hippocampus in spatial processing, the present study investigated whether structural differences in the hippocampus could explain the sex difference in 3D mental rotation. Results showed that after controlling for brain size, males had a larger anterior hippocampus, whereas females had a larger posterior hippocampus. Gray matter volume (GMV) of the right anterior hippocampus was significantly correlated with 3D mental rotation score. After controlling GMV of the right anterior hippocampus, sex difference in 3D mental rotation was no longer significant. These results suggest that the structural difference between males’ and females’ right anterior hippocampus was a neurobiological substrate for the sex difference in 3D mental rotation. PMID:27895570

  9. Regional Gray Matter Volume Is Associated with Restrained Eating in Healthy Chinese Young Adults: Evidence from Voxel-Based Morphometry

    PubMed Central

    Su, Yanhua; Jackson, Todd; Wei, Dongtao; Qiu, Jiang; Chen, Hong

    2017-01-01

    Highlight Participants were non-clinical young adults with different restrained eating levels.We assessed relations of restrained eating (RE) with regional gray matter volume (rGMV).High RE scores were related to larger GMV in specific areas related to reward.High RE scores were also linked to less GMV in regions related to response inhibition. Objective: Dieting is a popular method of weight control. However, few dieters are able to maintain initial weight losses over an extended period of time. Why do most restrained dieters fail to lose weight? Alterations in brain structures associated with restrained eating (RE) represent one potentially important mechanism that contributes to difficulties in maintaining weight loss within this group. To evaluate this contention, we investigated associations between intentional, sustained restriction of food intake to lose or maintain body weight, and regional gray matter volume (rGMV) within a large non-clinical young adult, sample. Methods: Participants (150 women, 108 men) completed measures of RE and demographics prior to undergoing an MRI scan. Voxel-based morphometry (VBM) evaluated strengths of association between RE scores and rGMV. Results: Higher RE levels corresponded to more rGMV in regions linked to risk of overeating and binge-eating including the left insula and orbitofrontal cortex (OFC). Conversely, RE had significant negative correlations with rGMV in the left and right posterior cingulum gyrus, regions linked to inhibitory control and potential risk for future weight gain. Conclusions: Together, findings suggested individual differences in RE among young adults correspond to GMV variability in regions linked to overweight and obesity risk.

  10. Thermophysical Properties of Matter - the TPRC Data Series. Volume 5. Specific Heat - Nonmetallic Solids

    DTIC Science & Technology

    1970-01-01

    of the volume consists of the ate level may also use it as a teaching tool to point presentation of numerical data compiled over the out to his...46, Chemistry, Chap. X, Interscience, New York, 1959. 1966. 61. Skinner, H. A. (Editor), Experinental Thermochemistry , 47. Wallace, W. E., Craig, R. S...tMuel!er, E. F. and Rossini, F. D., "The Calory and the Joule in Thermodynamics and Thermochemistry ," Am. J. etc. Phys. 12(1), 1-7, 19,14. e. Number

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

    PubMed

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

    2016-06-01

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

  12. Effects of parental emotional warmth on the relationship between regional gray matter volume and depression-related personality traits.

    PubMed

    Yang, Junyi; Yin, Ping; Wei, Dongtao; Wang, Kangcheng; Li, Yongmei; Qiu, Jiang

    2017-06-01

    The depression-related personality trait is associated with the severity of patients' current depressive symptoms and with the vulnerability to depression within the nonclinical groups. However, little is known about the anatomical structure associated with the depression-related personality traits within the nonclinical sample. Parenting behavior is associated with the depression symptoms; however, whether or not parenting behavior influence the neural basis of the depression-related personality traits is unclear. Thus in current study, first, we used voxel-based morphometry to identify the brain regions underlying individual differences in depression-related personality traits, as measured by the revised Neuroticism-Extraversion-Openness Personality Inventory, in a large sample of young healthy adults. Second, we use mediation analysis to investigate the relationship between parenting behavior and neural basis of depression-related personality traits. The results revealed that depression-related personality traits were positively correlated with gray matter volume mainly in medial frontal gyrus (MFG) that is implicated in the self-referential processing and emotional regulation. Furthermore, parental emotional warmth acted as a mediational mechanism underlying the association between the MFG volume and the depression-related personality trait. Together, our findings suggested that the family environment might play an important role in the acquisition and process of the depression-related personality traits.

  13. Sex Matters: Hippocampal Volume Predicts Individual Differences in Associative Memory in Cognitively Normal Older Women but Not Men.

    PubMed

    Zheng, Zhiwei; Li, Rui; Xiao, Fengqiu; He, Rongqiao; Zhang, Shouzi; Li, Juan

    2017-01-01

    The hippocampus plays a prominent role in associative memory by supporting relational binding and recollection processes. Structural atrophy in the hippocampus is likely to induce associative memory deficits in older adults. Previous studies have primarily focused on average age-related differences in hippocampal structure and memory performance. To date, however, it remains unclear whether individual differences in hippocampal morphometry underlie differential associative memory performance, and whether there are sex differences in the structural correlates of associative memory in healthy older adults. Here, we used voxel-based morphometry (VBM) to examine the extent to which gray matter volume (GMV) of the hippocampus predicts associative memory performance in cognitively normal older adults. Seventy-one participants completed a cued recall paired-associative learning test (PALT), which consists of novel associations and semantically related associations, and underwent magnetic resonance imaging (MRI). We observed worse associative memory performance and larger variability for novel associations than for semantically related associations. The VBM results revealed that higher scores on associative memory for novel associations were related to greater hippocampal GMV across all older adults. When considering men and women separately, the correlation between hippocampal GMV and associative memory performance for novel associations reached significance only in older women. These findings suggest that hippocampal structural volumes may predict individual differences in novel associative memory in older women but not men.

  14. Sex Matters: Hippocampal Volume Predicts Individual Differences in Associative Memory in Cognitively Normal Older Women but Not Men

    PubMed Central

    Zheng, Zhiwei; Li, Rui; Xiao, Fengqiu; He, Rongqiao; Zhang, Shouzi; Li, Juan

    2017-01-01

    The hippocampus plays a prominent role in associative memory by supporting relational binding and recollection processes. Structural atrophy in the hippocampus is likely to induce associative memory deficits in older adults. Previous studies have primarily focused on average age-related differences in hippocampal structure and memory performance. To date, however, it remains unclear whether individual differences in hippocampal morphometry underlie differential associative memory performance, and whether there are sex differences in the structural correlates of associative memory in healthy older adults. Here, we used voxel-based morphometry (VBM) to examine the extent to which gray matter volume (GMV) of the hippocampus predicts associative memory performance in cognitively normal older adults. Seventy-one participants completed a cued recall paired-associative learning test (PALT), which consists of novel associations and semantically related associations, and underwent magnetic resonance imaging (MRI). We observed worse associative memory performance and larger variability for novel associations than for semantically related associations. The VBM results revealed that higher scores on associative memory for novel associations were related to greater hippocampal GMV across all older adults. When considering men and women separately, the correlation between hippocampal GMV and associative memory performance for novel associations reached significance only in older women. These findings suggest that hippocampal structural volumes may predict individual differences in novel associative memory in older women but not men. PMID:28321185

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

    NASA Astrophysics Data System (ADS)

    Glass, John O.; Mulhern, Raymond K.; White, Holly A.; Wilkinson, Gina M.; Reddick, Wilburn E.

    2003-05-01

    Quantitative assessment of MR examinations in 37 survivors of childhood cancer treated with central nervous system prophylaxis revealed that normal appearing white matter (NAWM) volume is associated with attention-related problems, localized specifically in the right prefrontal region. T1-, T2-, and PD-weighted images were segmented and divided into pre-frontal, frontal, parietal/temporal, and parietal/occipital regions for each hemisphere. These eight regions were analyzed in five slices centered at the level of the basal ganglia. The patient's age at diagnosis and time elapsed from diagnosis were used as covariates in the regressions. Attentional measures showed significant deficiency when compared to age and gender normative values. Total, frontal and/or prefrontal NAWM volumes from the range of slices examined were significantly associated with 5 of the 8 attentional measures. The frontal/prefrontal region of the brain is associated with executive functioning tasks and could potentially be spared as much as possible during therapy planning. The results of the present study further support the contention that NAWM is an important substrate for treatment-induced neurocognitive problems among survivors of malignant brain tumors of childhood.

  16. Research in the theory of condensed matter and elementary particles. (Progress report)

    SciTech Connect

    Not Available

    1985-01-01

    The proposed research is concerned with problems occupying the common ground between quantum field theory and statistical mechanics. The topics under investigation include: superconformal field theory in two dimensions, its relationship to two dimensional critical phenomena and its applications in string theory; the covariant formulation of the superstring theory; formation of large-scale structures and spatial chaos in dynamical systems; fermion-boson mass relations in BCS type theories; and properties of quantum field theories defined over galois fields. 37 refs.

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

    DOE PAGES

    Giedt, Joel

    2011-01-01

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

  18. Higher Adolescent Body Mass Index Is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality

    PubMed Central

    Kennedy, James T.; Collins, Paul F.; Luciana, Monica

    2016-01-01

    Adolescent obesity is associated with an increased chance of developing serious health risks later in life. Identifying the neurobiological and personality factors related to increases in adiposity is important to understanding what drives maladaptive consummatory and exercise behaviors that result in obesity. Previous research has largely focused on adults with few findings published on interactions among adiposity, brain structure, and personality. In this study, Voxel Based Morphometry (VBM) was used to identify associations between gray and white matter volumes and increasing adiposity, as measured by Body Mass Index percentile (BMI%), in 137 adolescents (age range: 9–20 years, BMI% range: 5.16–99.56). Variations in gray and white matter volume and BMI% were then linked to individual differences in personality measures from the Multidimensional Personality Questionnaire (MPQ). After controlling for age and other covariates, BMI% correlated negatively with gray matter volume in the bilateral caudate (right: partial r = −0.338, left: r = −0.404), medial prefrontal cortex (partial r = −0.339), anterior cingulate (partial r = −0.312), bilateral frontal pole (right: partial r = −0.368, left: r = −0.316), and uncus (partial r = −0.475) as well as white matter volume bilaterally in the anterior limb of the internal capsule (right: partial r = −0.34, left: r = −0.386), extending to the left middle frontal subgyral white matter. Agentic Positive Emotionality (PEM-AG) was correlated negatively with BMI% (partial r = −0.384). PEM-AG was correlated positively with gray matter volume in the right uncus (partial r = 0.329). These results suggest that higher levels of adiposity in adolescents are associated with lower trait levels in reward-related personality domains, as well as structural variations in brain regions associated with reward processing, control, and sensory integration. PMID:27660604

  19. Distribution function approach to redshift space distortions. Part IV: perturbation theory applied to dark matter

    SciTech Connect

    Vlah, Zvonimir; Seljak, Uroš; Baldauf, Tobias; McDonald, Patrick; Okumura, Teppei E-mail: seljak@physik.uzh.ch E-mail: teppei@ewha.ac.kr

    2012-11-01

    We develop a perturbative approach to redshift space distortions (RSD) using the phase space distribution function approach and apply it to the dark matter redshift space power spectrum and its moments. RSD can be written as a sum over density weighted velocity moments correlators, with the lowest order being density, momentum density and stress energy density. We use standard and extended perturbation theory (PT) to determine their auto and cross correlators, comparing them to N-body simulations. We show which of the terms can be modeled well with the standard PT and which need additional terms that include higher order corrections which cannot be modeled in PT. Most of these additional terms are related to the small scale velocity dispersion effects, the so called finger of god (FoG) effects, which affect some, but not all, of the terms in this expansion, and which can be approximately modeled using a simple physically motivated ansatz such as the halo model. We point out that there are several velocity dispersions that enter into the detailed RSD analysis with very different amplitudes, which can be approximately predicted by the halo model. In contrast to previous models our approach systematically includes all of the terms at a given order in PT and provides a physical interpretation for the small scale dispersion values. We investigate RSD power spectrum as a function of μ, the cosine of the angle between the Fourier mode and line of sight, focusing on the lowest order powers of μ and multipole moments which dominate the observable RSD power spectrum. Overall we find considerable success in modeling many, but not all, of the terms in this expansion. This is similar to the situation in real space, but predicting power spectrum in redshift space is more difficult because of the explicit influence of small scale dispersion type effects in RSD, which extend to very large scales.

  20. Neuroprotection after a first episode of mania: a randomized controlled maintenance trial comparing the effects of lithium and quetiapine on grey and white matter volume.

    PubMed

    Berk, M; Dandash, O; Daglas, R; Cotton, S M; Allott, K; Fornito, A; Suo, C; Klauser, P; Liberg, B; Henry, L; Macneil, C; Hasty, M; McGorry, P; Pantelis, Cs; Yücel, M

    2017-01-24

    Lithium and quetiapine are effective treatments for bipolar disorder, but their potential neuroprotective effects in humans remain unclear. A single blinded equivalence randomized controlled maintenance trial was conducted in a prospective cohort of first-episode mania (FEM) patients (n=26) to longitudinally compare the putative protective effects of lithium and quetapine on grey and white matter volume. A healthy control sample was also collected (n=20). Using structural MRI scans, voxel-wise grey and white matter volumes at baseline and changes over time in response to treatment were investigated. Patients were assessed at three time points (baseline, 3 and 12-month follow-up), whereas healthy controls were assessed at two time points (baseline and 12-month follow-up). Patients were randomized to lithium (serum level 0.6 mmol l(-1), n=20) or quetiapine (flexibly dosed up to 800 mg per day, n=19) monotherapy. At baseline, compared with healthy control subjects, patients with FEM showed reduced grey matter in the orbitofrontal cortex, anterior cingulate, inferior frontal gyrus and cerebellum. In addition, patients had reduced internal capsule white matter volume bilaterally (t1,66>3.20, P<0.01). Longitudinally, there was a significant treatment × time effect only in the white matter of the left internal capsule (F2,112=8.54, P<0.01). Post hoc testing showed that, compared with baseline, lithium was more effective than quetiapine in slowing the progression of white matter volume reduction after 12 months (t1,24=3.76, P<0.01). Our data support the role of lithium but not quetiapine therapy in limiting white matter reduction early in the illness course after FEM.

  1. Plane Symmetric Cosmological Model with Quark and Strange Quark Matter in f ( R, T) Theory of Gravity

    NASA Astrophysics Data System (ADS)

    Agrawal, P. K.; Pawar, D. D.

    2017-03-01

    We studied plane symmetric cosmological model in the presence of quark and strange quark matter with the help of f( R, T) theory. To decipher solutions of plane symmetric space-time, we used power law relation between scale factor and deceleration parameter. We considered the special law of variation of Hubble's parameter proposed by Berman ( Nuovo Cimento B74, 182, 1983) which yields constant deceleration parameter. We also discussed the physical behavior of the solutions by using some physical parameters.

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

    SciTech Connect

    Zaborszky, J.; Venkatasubramanian, V.

    1995-10-01

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

  3. Cognitive Deficits Post-Traumatic Brain Injury and Their Association with Injury Severity and Gray Matter Volumes.

    PubMed

    Livny, Abigail; Biegon, Anat; Kushnir, Tammar; Harnof, Sagi; Hoffmann, Chen; Fruchter, Eyal; Weiser, Mark

    2017-04-01

    Traumatic brain injury (TBI) is known to have a substantial though highly variable impact on cognitive abilities. Due to the wide range of cognitive abilities among healthy individuals, an objective assessment of TBI-related cognitive loss requires an accurate measurement of pre-morbid cognitive performance. To address this problem, we recruited 50 adults who sustained a TBI and had performed a cognitive baseline assessment in adolescence as part of the aptitude tests mandated by the Israeli Defense Forces. This group was matched with non-injured controls (n = 35). Pre- and post-injury cognitive assessments consisted of three domains-namely, verbal abstraction, mathematical reasoning, and non-verbal abstract reasoning (from the Wechsler Adult Intelligence Scale-Third Edition). The difference between post- and pre-injury scores was calculated as a measure of domain-specific cognitive decline. Voxel-based regression was used to correlate cognitive decline with modulated gray matter probability maps controlling for age, Glasgow Coma Scale, and total intracranial volume. Using objectively assessed cognitive scores, we found that abstract reasoning declined in both moderate-severe and mild TBI patients, whereas verbal abstraction declined only in the moderate-severe group. Mathematical reasoning was not affected by TBI. In the TBI patients, non-verbal abstract reasoning post-pre-injury change scores were negatively correlated with the volume of the insula. We conclude that access to pre-morbid neuropsychological data may have facilitated the discovery of the effects of mild TBI on abstract reasoning, as well as a significant correlation between TBI-related decline in this cognitive domain and the volume of the bilateral insula, both of which had not been appreciated in the past.

  4. Multistage Grading of Amnestic Mild Cognitive Impairment: The Associated Brain Gray Matter Volume and Cognitive Behavior Characterization

    PubMed Central

    Yang, Caishui; Sun, Xuan; Tao, Wuhai; Li, Xin; Zhang, Junying; Jia, Jianjun; Chen, Kewei; Zhang, Zhanjun

    2017-01-01

    Background and Purpose: It is well known that there is a wide range of different pathological stages related to Alzheimer's disease (AD) among patients with amnestic mild cognitive impairment (aMCI). Further refinement of the stages based on neuropsychological and neuroimaging methods is important for earlier disease detection, as well as for the development and evaluation of disease-modifying interventions. Materials and Methods: In this cross-sectional study, 125 aMCI patients were classified into declined progressively three stages of mild, moderate and severe, utilizing the extreme groups approach (EGA) based on their memory function. Fifty-two patients, in addition to 24 cognitively normal subjects, were included in further structural MRI analyses. Characteristics of cognitive functions and brain structures across these newly defined stages were explored through general linear models. Results: Almost all the non-memory cognitive functions showed progressive decline as memory function deteriorated. In addition, medial structures including the right hippocampus, right lingual and left fusiform gyrus, presented with greater gray matter (GM) atrophy during the later stages of aMCI (corrected p < 0.05). Correlations were found between GM volume of the lingual gyrus and processing speed (r = 0.419, p = 0.003) and between the fusiform gyrus and general cognitive function (r = 0.281, p = 0.046). Moreover, both cognitive function and GM volume presented non-linear trajectories over stages of aMCI. Conclusion: Our study characterized the cognitive profiles along with the degree of episodic memory impairment, and these three stages of aMCI showed non-linear progressive decline in cognitive functions and GM volumes. PMID:28119601

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

    PubMed Central

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

    2016-01-01

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

  6. Coherence in laser-driven electrons at the surface and in the volume of solid matter

    NASA Astrophysics Data System (ADS)

    Hommelhoff, Peter

    2017-01-01

    The femtosecond frequency comb allows controlling the carrier field of ultrashort laser pulses. We show two examples on how this control over fields oscillating with a few hundred terahertz can be utilized to control electrons at the surface and in the volume of solids. After a brief discussion of strong-field physics at metal needle tips, we show how ultrafast two-color laser pulses allow quantum path interference to dramatically alter the emission current from sharp tips, with an interference visibility of 94%. With carrier-envelope phase-controlled laser pulses, we show furthermore how light-field sensitive currents can be excited in monolayer graphene via an interplay of interband and intraband electron dynamics including multiple Landau-Zener transitions.

  7. Corrected thermodynamic description of adsorption via formalism of the theory of volume filling of micropores.

    PubMed

    Terzyk, Artur P; Gauden, Piotr A; Rychlicki, Gerhard

    2006-06-01

    Based on the series of benzene adsorption and related enthalpy of adsorption data measured on porous carbons that possess various porous structures, we show that the creation of a solidlike structure in pores depends on the average pore diameter of an adsorbent. Taking into account the solidlike adsorbed phase in the thermodynamic description of the adsorption process via the formalism of the theory of volume filling of micropores (TVFM) leads to very good agreement between the data measured experimentally and those calculated from TVFM. Finally we show that the boundary between solidlike and liquidlike structures of benzene molecules in carbon pores is located around the average pore diameter, close to ca. 2.1-2.4 nm.

  8. Microwave remote sensing: Active and passive. Volume 3 - From theory to applications

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T.; Moore, R. K.; Fung, A. K.

    1986-01-01

    Aspects of volume scattering and emission theory are discussed, taking into account a weakly scattering medium, the Born approximation, first-order renormalization, the radiative transfer method, and the matrix-doubling method. Other topics explored are related to scatterometers and probing systems, the passive microwave sensing of the atmosphere, the passive microwave sensing of the ocean, the passive microwave sensing of land, the active microwave sensing of land, and radar remote sensing applications. Attention is given to inversion techniques, atmospheric attenuation and emission, a temperature profile retrieval from ground-based observations, mapping rainfall rates, the apparent temperature of the sea, the emission behavior of bare soil surfaces, the emission behavior of vegetation canopies, the emission behavior of snow, wind-vector radar scatterometry, radar measurements of sea ice, and the back-scattering behavior of cultural vegetation canopies.

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

    SciTech Connect

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

    2012-07-19

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

  10. Children's Theory of God's Mind: Theory-of-Mind Studies and Why They Matter to Religious Education

    ERIC Educational Resources Information Center

    Wigger, J. Bradley

    2016-01-01

    Theory-of-mind research has been carried out for over three decades, examining the ways children understand the minds of others--their perspectives, intentions, desires, and knowledge. Since the early 21st century, theory-of-mind studies have begun exploring the ways in which children think and reason about the minds--not only of ordinary, visible…

  11. A new method for volume segmentation of PET images, based on possibility theory.

    PubMed

    Dewalle-Vignion, Anne-Sophie; Betrouni, Nacim; Lopes, Renaud; Huglo, Damien; Stute, Simon; Vermandel, Maximilien

    2011-02-01

    18F-fluorodeoxyglucose positron emission tomography (18FDG PET) has become an essential technique in oncology. Accurate segmentation and uptake quantification are crucial in order to enable objective follow-up, the optimization of radiotherapy planning, and therapeutic evaluation. We have designed and evaluated a new, nearly automatic and operator-independent segmentation approach. This incorporated possibility theory, in order to take into account the uncertainty and inaccuracy inherent in the image. The approach remained independent of PET facilities since it did not require any preliminary calibration. Good results were obtained from phantom images [percent error =18.38% (mean) ± 9.72% (standard deviation)]. Results on simulated and anatomopathological data sets were quantified using different similarity measures and showed the method was efficient (simulated images: Dice index =82.18% ± 13.53% for SUV =2.5 ). The approach could, therefore, be an efficient and robust tool for uptake volume segmentation, and lead to new indicators for measuring volume of interest activity.

  12. HPA-axis function and grey matter volume reductions: imaging the diathesis-stress model in individuals at ultra-high risk of psychosis

    PubMed Central

    Valli, I; Crossley, N A; Day, F; Stone, J; Tognin, S; Mondelli, V; Howes, O; Valmaggia, L; Pariante, C; McGuire, P

    2016-01-01

    The onset of psychosis is thought to involve interactions between environmental stressors and the brain, with cortisol as a putative mediator. We examined the relationship between the cortisol stress response and brain structure in subjects at ultra-high risk (UHR) for psychosis. Waking salivary cortisol was measured in 22 individuals at UHR for psychosis and 17 healthy controls. Grey matter volume was assessed using magnetic resonance imaging at 3 T. The relationship between the stress response and grey matter volume was investigated using voxel-based analyses. Our predictions of the topography of cortisol action as a structural brain modulator were informed by measures of brain glucocorticoid and mineralcorticoid receptor distribution obtained from the multimodal neuroanatomical and genetic Allen Brain Atlas. Across all subjects, reduced responsivity of the hypothalamus–pituitary–adrenal (HPA) axis was correlated with smaller grey matter volumes in the frontal, parietal and temporal cortex and in the hippocampus. This relationship was particularly marked in the UHR subjects in the right prefrontal, left parahippocampal/fusiform and parietal cortices. The subgroup that subsequently developed psychosis showed a significant blunting of HPA stress response, observed at trend level also in the whole UHR sample. Altered responses to stress in people at high risk of psychosis are related to reductions in grey matter volume in areas implicated in the vulnerability to psychotic disorders. These areas may represent the neural components of a stress vulnerability model. PMID:27138796

  13. HPA-axis function and grey matter volume reductions: imaging the diathesis-stress model in individuals at ultra-high risk of psychosis.

    PubMed

    Valli, I; Crossley, N A; Day, F; Stone, J; Tognin, S; Mondelli, V; Howes, O; Valmaggia, L; Pariante, C; McGuire, P

    2016-05-03

    The onset of psychosis is thought to involve interactions between environmental stressors and the brain, with cortisol as a putative mediator. We examined the relationship between the cortisol stress response and brain structure in subjects at ultra-high risk (UHR) for psychosis. Waking salivary cortisol was measured in 22 individuals at UHR for psychosis and 17 healthy controls. Grey matter volume was assessed using magnetic resonance imaging at 3 T. The relationship between the stress response and grey matter volume was investigated using voxel-based analyses. Our predictions of the topography of cortisol action as a structural brain modulator were informed by measures of brain glucocorticoid and mineralcorticoid receptor distribution obtained from the multimodal neuroanatomical and genetic Allen Brain Atlas. Across all subjects, reduced responsivity of the hypothalamus-pituitary-adrenal (HPA) axis was correlated with smaller grey matter volumes in the frontal, parietal and temporal cortex and in the hippocampus. This relationship was particularly marked in the UHR subjects in the right prefrontal, left parahippocampal/fusiform and parietal cortices. The subgroup that subsequently developed psychosis showed a significant blunting of HPA stress response, observed at trend level also in the whole UHR sample. Altered responses to stress in people at high risk of psychosis are related to reductions in grey matter volume in areas implicated in the vulnerability to psychotic disorders. These areas may represent the neural components of a stress vulnerability model.

  14. Gray Matter Volume in Adolescent Anxiety: An Impact of the Brain-Derived Neurotrophic Factor Val[superscript 66]Met Polymorphism?

    ERIC Educational Resources Information Center

    Mueller, Sven C.; Aouidad, Aveline; Gorodetsky, Elena; Goldman, David; Pine, Daniel S.; Ernst, Monique

    2013-01-01

    Objective: Minimal research links anxiety disorders in adolescents to regional gray matter volume (GMV) abnormalities and their modulation by genetic factors. Prior research suggests that a brain-derived neurotrophic factor (BNDF) Val[superscript 66]Met polymorphism may modulate such brain morphometry profiles. Method: Using voxel-based…

  15. Excluded volume effects in compressed polymer brushes: A density functional theory

    SciTech Connect

    Chen, Cangyi; Tang, Ping E-mail: fengqiu@fudan.edu.cn; Qiu, Feng E-mail: fengqiu@fudan.edu.cn; Shi, An-Chang

    2015-03-28

    A classical density functional theory (DFT) is applied to investigate the behavior of compressed polymer brushes composed of hard-sphere chains. The excluded volume interactions among the chain segments are explicitly treated. Two compression systems are used to study the behavior of brush-wall and brush-brush interactions. For the brush-brush systems, an obvious interpenetration zone has been observed. The extent of the interpenetration depends strongly on the grafting density. Furthermore, the repulsive force between the brush and wall or between the two brushes has been obtained as a function of the compression distance. Compared to the prediction of the analytic self-consistent field theory, such force increases more rapidly in the brush-wall compression with high polymer grafting densities or at higher compressions. In the brush-brush compression system, the interpenetration between the two compressed brushes creates a “softer” interaction. The influence of hard-sphere solvents on the behavior of compressed brushes is also discussed.

  16. Species, Diaspore Volume and Body Mass Matter in Gastropod Seed Feeding Behavior

    PubMed Central

    Türke, Manfred; Weisser, Wolfgang W.

    2013-01-01

    Background Seed dispersal of ant-dispersed plants (myrmecochores) is a well studied ecosystem function. Recently, slugs have been found to act as seed dispersers of myrmecochores. The aim of our study was to (1) further generalize the finding that gastropods feed on seeds of myrmecochores and hence may act as seed dispersers, (2) to test whether gastropod body mass and the volume of diaspores have an influence on the seed dispersal potential. Methodology and Principal Findings We assessed the seed dispersal potential of four slug and snail species with a set of seven myrmecochorous plant species from seven different plant families common to Central European beech forests. Diaspores differed in shape and size. Gastropods differed in their readiness to feed on diaspores and in the proportion of seeds that were swallowed as a whole, and this readiness generally decreased with increasing diaspore size. Smaller Arionid slugs (58 mm body length; mean) mostly fed on the elaiosome but also swallowed small diaspores and therefore not only act as elaiosome consumers, a nutrient rich appendage on myrmecochorous diaspores, but may also disperse seeds. Large Arionid slugs (>100 mm body length) swallowed diaspores of all sizes. Diaspores swallowed by gastropods were defecated without damage. Within-species variability in body size also affect seed dispersal potential, as larger individuals of the red slug (Arion rufus) swallowed more diaspores of wood anemone (Anemone nemorosa) than smaller ones. Conclusions and Significance Our results help to generalize the finding that gastropods consume and potentially disperse seeds of myrmecochores. The dispersal potential of gastropods is strongly influenced by diaspore size in relation to gastropod size. PMID:23844239

  17. Does Weather Matter? The Effect of Weather Patterns and Temporal Factors on Pediatric Orthopedic Trauma Volume

    PubMed Central

    Livingston, Kristin S.; Miller, Patricia E.; Lierhaus, Anneliese; Matheney, Travis H.; Mahan, Susan T.

    2016-01-01

    Objectives: Orthopaedists often speculate how weather and school schedule may influence pediatric orthopedic trauma volume, but few studies have examined this. This study aims to determine: how do weather patterns, day, month, season and public school schedule influence the daily frequency of pediatric orthopedic trauma consults and admissions? Methods: With IRB approval, orthopedic trauma data from a level 1 pediatric trauma center, including number of daily orthopedic trauma consults and admissions, were collected from July 2009 to March 2012. Historical weather data (high temperatures, precipitation and hours of daylight), along with local public school schedule data were collected for the same time period. Univariate and multivariate regression models were used to show the average number of orthopedic trauma consults and admissions as a function of weather and temporal variables. Results: High temperature, precipitation, month and day of the week significantly affected the number of daily consults and admissions. The number of consults and admissions increased by 1% for each degree increase in temperature (p=0.001 and p<0.001, respectively), and decreased by 21% for each inch of precipitation (p<0.001, p=0.006). Daily consults on snowy days decreased by an additional 16% compared to days with no precipitation. November had the lowest daily consult and admission rate, while September had the highest. Daily consult rate was lowest on Wednesdays and highest on Saturdays. Holiday schedule was not independently significant. Conclusion: Pediatric orthopedic trauma consultations and admissions are highly linked to temperature and precipitation, as well as day of the week and time of year. PMID:27990193

  18. Gray matter myelination of 1555 human brains using partial volume corrected MRI images

    PubMed Central

    Shafee, Rebecca; Buckner, Randy L.; Fischl, Bruce

    2014-01-01

    The myelin content of the cortex changes over the human lifetime and aberrant cortical myelination is associated with diseases such as schizophrenia and multiple sclerosis. Recently magnetic resonance imaging (MRI) techniques have shown potential in differentiating between myeloarchitectonically distinct cortical regions in vivo. Here we introduce a new algorithm for correcting partial volume effects present in mm-scale MRI images which was used to investigate the myelination pattern of the cerebral cortex in 1555 clinically normal subjects using the ratio of T1-weighted (T1w) and T2-weighted (T2w) MRI images. A significant linear cross-sectional age increase in T1w/T2w estimated myelin was detected across an 18 to 35 year age span (highest value of ~ 1%/year compared to mean T1w/T2w myelin value at 18 years). The cortex was divided at mid-thickness and the value of T1w/T2w myelin calculated for the inner and the outer layers separately. The increase in T1w/T2w estimated myelin occurs predominantly in the inner layer for most cortical regions. The ratio of the inner and outer layer T1w/T12w myelin was further validated using high-resolution in vivo MRI scans and also a high-resolution MRI scan of a postmortem brain. Additionally, the relationships between cortical thickness, curvature and T1w/T2w estimated myelin were found to be significant, although the relationships varied across the cortex. We discuss these observations as well as limitations of using the T1w/T2w ratio as an estimate of cortical myelin. PMID:25449739

  19. Gray-Matter Volume Estimate Score: A Novel Semi-Automatic Method Measuring Early Ischemic Change on CT

    PubMed Central

    Song, Dongbeom; Lee, Kijeong; Kim, Eun Hye; Kim, Young Dae; Lee, Hye Sun; Kim, Jinkwon; Song, Tae-Jin; Ahn, Sung Soo; Nam, Hyo Suk; Heo, Ji Hoe

    2016-01-01

    Background and Purpose We developed a novel method named Gray-matter Volume Estimate Score (GRAVES), measuring early ischemic changes on Computed Tomography (CT) semi-automatically by computer software. This study aimed to compare GRAVES and Alberta Stroke Program Early CT Score (ASPECTS) with regards to outcome prediction and inter-rater agreement. Methods This was a retrospective cohort study. Among consecutive patients with ischemic stroke in the anterior circulation who received intra-arterial therapy (IAT), those with a readable pretreatment CT were included. Two stroke neurologists independently measured both the GRAVES and ASPECTS. GRAVES was defined as the percentage of estimated hypodense lesion in the gray matter of the ipsilateral hemisphere. Spearman correlation analysis, receiver operating characteristic (ROC) comparison test, and intra-class correlation coefficient (ICC) comparison tests were performed between GRAVES and ASPECTS. Results Ninety-four subjects (age: 68.7±10.3; male: 54 [54.9%]) were enrolled. The mean GRAVES was 9.0±8.9 and the median ASPECTS was 8 (interquartile range, 6-9). Correlation between ASPECTS and GRAVES was good (Spearman’s rank correlation coefficient, 0.642; P<0.001). ROC comparison analysis showed that the predictive value of GRAVES for favorable outcome was not significantly different from that of ASPECTS (area under curve, 0.765 vs. 0.717; P=0.308). ICC comparison analysis revealed that inter-rater agreement of GRAVES was significantly better than that of ASPECTS (0.978 vs. 0.895; P<0.001). Conclusions GRAVES had a good correlation with ASPECTS. GRAVES was as good as ASPECTS in predicting a favorable clinical outcome, but was better than ASPECTS regarding inter-rater agreement. GRAVES may be used to predict the outcome of IAT. PMID:26467197

  20. Nuclear charge and neutron radii and nuclear matter: Trend analysis in Skyrme density-functional-theory approach

    NASA Astrophysics Data System (ADS)

    Reinhard, P.-G.; Nazarewicz, W.

    2016-05-01

    Background: Radii of charge and neutron distributions are fundamental nuclear properties. They depend on both nuclear interaction parameters related to the equation of state of infinite nuclear matter and on quantal shell effects, which are strongly impacted by the presence of nuclear surface. Purpose: In this work, by studying the correlation of charge and neutron radii, and neutron skin, with nuclear matter parameters, we assess different mechanisms that drive nuclear sizes. Method: We apply nuclear density functional theory using a family of Skyrme functionals obtained by means of optimization protocols, which do not include any radius information. By performing the Monte Carlo sampling of reasonable functionals around the optimal parametrization, we scan all correlations between nuclear matter properties and observables characterizing charge and neutron distributions of spherical closed-shell nuclei 48Ca,208Pb, and 298Fl. Results: By considering the influence of various nuclear matter properties on charge and neutron radii in a multidimensional parameter space of Skyrme functionals, we demonstrate the existence of two strong relationships: (i) between the nuclear charge radii and the saturation density of symmetric nuclear matter ρ0, and (ii) between the neutron skins and the slope of the symmetry energy L . The impact of other nuclear matter properties on nuclear radii is weak or nonexistent. For functionals optimized to experimental binding energies only, proton and neutron radii are found to be weakly correlated due to canceling trends from different nuclear matter characteristics. Conclusion: The existence of only two strong relations connecting nuclear radii with nuclear matter properties has important consequences. First, by requiring that the nuclear functional reproduces the empirical saturation point of symmetric nuclear matter practically fixes the charge (or proton) radii, and vice versa. This explains the recent results of ab initio calculations

  1. The Impact of the in utero and Early Postnatal Environments on Grey and White Matter Volume: A Study with Adolescent Monozygotic Twins.

    PubMed

    Levesque, Melissa L; Fahim, Cherine; Ismaylova, Elmira; Verner, Marie-Pier; Casey, Kevin F; Vitaro, Frank; Brendgen, Mara; Dionne, Ginette; Boivin, Michel; Tremblay, Richard E; Booij, Linda

    2015-01-01

    Prenatal and early postnatal adversities have been shown to be associated with brain development. However, we do not know how much of this association is confounded by genetics, nor whether the postnatal environment can moderate the impact of in utero adversity. This study used a monozygotic (MZ) twin design to assess (1) the association between birth weight (BW) and brain volume in adolescence, (2) the association between within-twin-pair BW discordance and brain volume discordance in adolescence, and (3) whether the association between BW and brain volume in adolescence is mediated or moderated by early negative maternal parenting behaviours. These associations were assessed in a sample of 108 MZ twins followed longitudinally since birth and scanned at age 15. The total grey matter (GM) and white matter (WM) volumes were obtained using the Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) toolbox in the Statistical Parametric Mapping version 8 (SPM8). We found that the BW was significantly associated with the total GM and WM volumes, particularly in the superior frontal gyrus and thalamus. Within-twin-pair discordance in BW was also significantly associated with within-pair discordance in both the GM and the WM volumes, supporting the hypothesis that the specific in utero environment is associated with brain development independently of genetics. Early maternal hostile parenting behaviours and depressive symptoms were associated with total GM volume but not WM volume. Finally, greater early maternal hostility may moderate the association between the BW and GM volume in adolescence, since the positive association between the BW and total GM volume appeared stronger at higher levels of maternal hostility (trend). Together, these findings support the importance of the in utero and early environments for brain development.

  2. Contributions of organic and inorganic matter to sediment volume and accretion in tidal wetlands at steady state

    PubMed Central

    Barber, Donald C.; Callaway, John C.; Chambers, Randy; Hagen, Scott C.; Hopkinson, Charles S.; Johnson, Beverly J.; Megonigal, Patrick; Neubauer, Scott C.; Troxler, Tiffany; Wigand, Cathleen

    2016-01-01

    Abstract A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self‐packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1‐LOI)/k2], where k1 and k2 are the self‐packing densities of the pure organic and inorganic components, respectively. The model explained 78% of the variability in total BD when fitted to 5075 measurements drawn from 33 wetlands distributed around the conterminous United States. The values of k1 and k2 were estimated to be 0.085 ± 0.0007 g cm−3 and 1.99 ± 0.028 g cm−3, respectively. Based on the fitted organic density (k1) and constrained by primary production, the model suggests that the maximum steady state accretion arising from the sequestration of refractory organic matter is ≤ 0.3 cm yr−1. Thus, tidal peatlands are unlikely to indefinitely survive a higher rate of sea‐level rise in the absence of a significant source of mineral sediment. Application of k2 to a mineral sediment load typical of East and eastern Gulf Coast estuaries gives a vertical accretion rate from inorganic sediment of 0.2 cm yr−1. Total steady state accretion is the sum of the parts and therefore should not be greater than 0.5 cm yr−1 under the assumptions of the model. Accretion rates could deviate from this value depending on variation in plant productivity, root:shoot ratio, suspended sediment concentration, sediment‐capture efficiency, and episodic events. PMID:27819012

  3. ZNF804A variants confer risk for heroin addiction and affect decision making and gray matter volume in heroin abusers.

    PubMed

    Sun, Yan; Zhao, Li-Yan; Wang, Gui-Bin; Yue, Wei-Hua; He, Yong; Shu, Ni; Lin, Qi-Xiang; Wang, Fan; Li, Jia-Li; Chen, Na; Wang, Hui-Min; Kosten, Thomas R; Feng, Jia-Jia; Wang, Jun; Tang, Yu-De; Liu, Shu-Xue; Deng, Gui-Fa; Diao, Gan-Huan; Tan, Yun-Long; Han, Hong-Bin; Lin, Lu; Shi, Jie

    2016-05-01

    Drug addiction shares common neurobiological pathways and risk genes with other psychiatric diseases, including psychosis. One of the commonly identified risk genes associated with broad psychosis has been ZNF804A. We sought to test whether psychosis risk variants in ZNF804A increase the risk of heroin addiction by modulating neurocognitive performance and gray matter volume (GMV) in heroin addiction. Using case-control genetic analysis, we compared the distribution of ZNF804A variants (genotype and haplotype) in 1035 heroin abusers and 2887 healthy subjects. We also compared neurocognitive performance (impulsivity, global cognitive ability and decision-making ability) in 224 subjects and GMV in 154 subjects based on the ZNF804A variants. We found significant differences in the distribution of ZNF804A intronic variants (rs1344706 and rs7597593) allele and haplotype frequencies between the heroin and control groups. Decision-making impairment was worse in heroin abusers who carried the ZNF804A risk allele and haplotype. Subjects who carried more risk alleles and haplotypes of ZNF804A had greater GMV in the bilateral insular cortex, right temporal cortex and superior parietal cortex. The interaction between heroin addiction and ZNF804A variants affected GMV in the left sensorimotor cortex. Our findings revealed several ZNF804A variants that were significantly associated with the risk of heroin addiction, and these variants affected decision making and GMV in heroin abusers compared with controls. The precise neural mechanisms that underlie these associations are unknown, which requires future investigations of the effects of ZNF804A on both dopamine neurotransmission and the relative increases in the volume of various brain areas.

  4. Contributions of organic and inorganic matter to sediment volume and accretion in tidal wetlands at steady state.

    PubMed

    Morris, James T; Barber, Donald C; Callaway, John C; Chambers, Randy; Hagen, Scott C; Hopkinson, Charles S; Johnson, Beverly J; Megonigal, Patrick; Neubauer, Scott C; Troxler, Tiffany; Wigand, Cathleen

    2016-04-01

    A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 and k2 are the self-packing densities of the pure organic and inorganic components, respectively. The model explained 78% of the variability in total BD when fitted to 5075 measurements drawn from 33 wetlands distributed around the conterminous United States. The values of k1 and k2 were estimated to be 0.085 ± 0.0007 g cm(-3) and 1.99 ± 0.028 g cm(-3), respectively. Based on the fitted organic density (k1) and constrained by primary production, the model suggests that the maximum steady state accretion arising from the sequestration of refractory organic matter is ≤ 0.3 cm yr(-1). Thus, tidal peatlands are unlikely to indefinitely survive a higher rate of sea-level rise in the absence of a significant source of mineral sediment. Application of k2 to a mineral sediment load typical of East and eastern Gulf Coast estuaries gives a vertical accretion rate from inorganic sediment of 0.2 cm yr(-1). Total steady state accretion is the sum of the parts and therefore should not be greater than 0.5 cm yr(-1) under the assumptions of the model. Accretion rates could deviate from this value depending on variation in plant productivity, root:shoot ratio, suspended sediment concentration, sediment-capture efficiency, and episodic events.

  5. Contributions of organic and inorganic matter to sediment volume and accretion in tidal wetlands at steady state

    NASA Astrophysics Data System (ADS)

    Morris, James T.; Barber, Donald C.; Callaway, John C.; Chambers, Randy; Hagen, Scott C.; Hopkinson, Charles S.; Johnson, Beverly J.; Megonigal, Patrick; Neubauer, Scott C.; Troxler, Tiffany; Wigand, Cathleen

    2016-04-01

    A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes that the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 and k2 are the self-packing densities of the pure organic and inorganic components, respectively. The model explained 78% of the variability in total BD when fitted to 5075 measurements drawn from 33 wetlands distributed around the conterminous United States. The values of k1 and k2 were estimated to be 0.085 ± 0.0007 g cm-3 and 1.99 ± 0.028 g cm-3, respectively. Based on the fitted organic density (k1) and constrained by primary production, the model suggests that the maximum steady state accretion arising from the sequestration of refractory organic matter is ≤ 0.3 cm yr-1. Thus, tidal peatlands are unlikely to indefinitely survive a higher rate of sea-level rise in the absence of a significant source of mineral sediment. Application of k2 to a mineral sediment load typical of East and eastern Gulf Coast estuaries gives a vertical accretion rate from inorganic sediment of 0.2 cm yr-1. Total steady state accretion is the sum of the parts and therefore should not be greater than 0.5 cm yr-1 under the assumptions of the model. Accretion rates could deviate from this value depending on variation in plant productivity, root:shoot ratio, suspended sediment concentration, sediment-capture efficiency, and episodic events.

  6. Empowerment Theory for the Professional School Counselor: A Manifesto for What Really Matters

    ERIC Educational Resources Information Center

    Hipolito-Delgado, Carlos P.; Lee, Courtland C.

    2007-01-01

    Borrowing from the legacy of feminist and multicultural theories, various counseling fields have applied portions of empowerment theory to their work with oppressed clients. This article examines the main concepts associated with empowerment theory and provides important implications for professional school counselors.

  7. Translating Theory into Practice: Implications of Japanese Management Theory for Student Personnel Administrators. NASPA Monograph Series Volume 3. First Edition.

    ERIC Educational Resources Information Center

    Deegan, William L.; And Others

    Japanese management theory was studied to identify specific models for consideration by student personnel administrators. The report is organized into three sections: major components of Japanese management theory, potential implications for student personnel administration, and three models, based on components of Japanese management theory, for…

  8. Lower total and regional grey matter brain volumes in youth with perinatally-acquired HIV infection: Associations with HIV disease severity, substance use, and cognition.

    PubMed

    Lewis-de Los Angeles, C Paula; Williams, Paige L; Huo, Yanling; Wang, Shirlene D; Uban, Kristina A; Herting, Megan M; Malee, Kathleen; Yogev, Ram; Csernansky, John G; Nichols, Sharon; Van Dyke, Russell B; Sowell, Elizabeth R; Wang, Lei

    2017-05-01

    Despite improved survival due to combination antiretroviral therapy (cART), youth with perinatally-acquired HIV (PHIV) show cognitive deficits and developmental delay at increased rates. HIV affects the brain during critical periods of development, and the brain may be a persistent reservoir for HIV due to suboptimal blood brain barrier penetration of cART. We conducted structural magnetic resonance imaging (sMRI) and cognitive testing in 40 PHIV youth (mean age=16.7years) recruited from the NIH Pediatric HIV/AIDS Cohort Study (PHACS) who are part of the first generation of PHIV youth surviving into adulthood. Historical and current HIV disease severity and substance use measures were also collected. Total and regional cortical grey matter brain volumes were compared to a group of 334 typically-developing, HIV-unexposed and uninfected youth (frequency-matched for age and sex) from the Pediatric Imaging, Neurocognition, and Genetics (PING) study (mean age=16.1years). PHIV youth had smaller (2.8-5.1%) total and regional grey matter volumes than HIV-unexposed and uninfected youth, with smallest volumes seen among PHIV youth with higher past peak viral load (VL) and recent unsuppressed VL. In PHIV youth, worse cognitive performance correlated with smaller volumes. This pattern of smaller grey matter volumes suggests that PHIV infection may influence brain development and underlie cognitive dysfunction seen in this population. Among PHIV youth, smaller volumes were also linked to substance use (alcohol use: 9.0-13.4%; marijuana use: 10.1-16.0%). In this study, collection of substance use information was limited to the PHIV cohort; future studies should also collect substance use information in controls to further address interactions between HIV and substance use on brain volume.

  9. Emotional intelligence moderates the relationship between regional gray matter volume in the bilateral temporal pole and critical thinking disposition.

    PubMed

    Yao, Xiaonan; Yuan, Shuge; Yang, Wenjing; Chen, Qunlin; Wei, Dongtao; Hou, Yuling; Zhang, Lijie; Qiu, Jiang; Yang, Dong

    2017-03-29

    Critical thinking enables people to form sound beliefs and provides a basis for emotional life. Research has indicated that individuals with better critical thinking disposition can better recognize and regulate their emotions, though the neuroanatomical mechanisms involved in this process remain to be elucidated. Further, the influence of emotional intelligence on the relationship between brain structure and critical thinking disposition has not been examined. The present study utilized voxel-based morphometry (VBM) to investigate the neural structures underlying critical thinking disposition in a large sample of college students (N = 296). Regional gray matter volume (rGMV) in the bilateral temporal pole, which reflects an individual's ability to process social and emotional information, was negatively correlated with critical thinking disposition. In addition, rGMV in bilateral para hippocampal regions -regions involved in contextual association/emotional regulation-exhibited negative correlation with critical thinking disposition. Further analysis revealed that emotional intelligence moderated the relationship between rGMV of the temporal pole and critical thinking disposition. Specifically, critical thinking disposition was associated with decreased GMV of the temporal pole for individuals who have relatively higher emotional intelligence rather than lower emotional intelligence. The results of the present study indicate that people who have higher emotional intelligence exhibit more effective and automatic processing of emotional information and tend to be strong critical thinkers.

  10. Free D-aspartate regulates neuronal dendritic morphology, synaptic plasticity, gray matter volume and brain activity in mammals

    PubMed Central

    Errico, F; Nisticò, R; Di Giorgio, A; Squillace, M; Vitucci, D; Galbusera, A; Piccinin, S; Mango, D; Fazio, L; Middei, S; Trizio, S; Mercuri, N B; Teule, M A; Centonze, D; Gozzi, A; Blasi, G; Bertolino, A; Usiello, A

    2014-01-01

    D-aspartate (D-Asp) is an atypical amino acid, which is especially abundant in the developing mammalian brain, and can bind to and activate N-methyl-D-Aspartate receptors (NMDARs). In line with its pharmacological features, we find that mice chronically treated with D-Asp show enhanced NMDAR-mediated miniature excitatory postsynaptic currents and basal cerebral blood volume in fronto-hippocampal areas. In addition, we show that both chronic administration of D-Asp and deletion of the gene coding for the catabolic enzyme D-aspartate oxidase (DDO) trigger plastic modifications of neuronal cytoarchitecture in the prefrontal cortex and CA1 subfield of the hippocampus and promote a cytochalasin D-sensitive form of synaptic plasticity in adult mouse brains. To translate these findings in humans and consistent with the experiments using Ddo gene targeting in animals, we performed a hierarchical stepwise translational genetic approach. Specifically, we investigated the association of variation in the gene coding for DDO with complex human prefrontal phenotypes. We demonstrate that genetic variation predicting reduced expression of DDO in postmortem human prefrontal cortex is mapped on greater prefrontal gray matter and activity during working memory as measured with MRI. In conclusion our results identify novel NMDAR-dependent effects of D-Asp on plasticity and physiology in rodents, which also map to prefrontal phenotypes in humans. PMID:25072322

  11. Foundations of Education, Volume I: History and Theory of Teaching Children and Youths with Visual Impairments. Second Edition.

    ERIC Educational Resources Information Center

    Holbrook, M. Cay, Ed.; Koenig, Alan J., Ed.

    This text, one of two volumes on the instruction of students with visual impairments, focuses on the history and theory of teaching such students. The following chapters are included: (1) "Historical Perspectives" (Phil Hatlen) with emphasis on the last 50 years; (2) "Visual Impairment" (Kathleen M. Huebner) which provides general information…

  12. A review on the relativistic effective field theory with parameterized couplings for nuclear matter and neutron stars

    NASA Astrophysics Data System (ADS)

    Vasconcellos, C. A. Zen

    2015-12-01

    Nuclear science has developed many excellent theoretical models for many-body systems in the domain of the baryon-meson strong interaction for the nucleus and nuclear matter at low, medium and high densities. However, a full microscopic understanding of nuclear systems in the extreme density domain of compact stars is still lacking. The aim of this contribution is to shed some light on open questions facing the nuclear many-body problem at the very high density domain. Here we focus our attention on the conceptual issue of naturalness and its role in shaping the baryon-meson phase space dynamics in the description of the equation of state (EoS) of nuclear matter and neutrons stars. In particular, in order to stimulate possible new directions of research, we discuss relevant aspects of a recently developed relativistic effective theory for nuclear matter within Quantum Hadrodynamics (QHD) with genuine many-body forces and derivative natural parametric couplings. Among other topics we discuss in this work the connection of this theory with other known effective QHD models of the literature and its potentiality in describing a new physics for dense matter. The model with parameterized couplings exhausts the whole fundamental baryon octet (n, p, Σ-, Σ0, Σ+, Λ, Ξ-, Ξ0) and simulates n-order corrections to the minimal Yukawa baryon couplings by considering nonlinear self-couplings of meson fields and meson-meson interaction terms coupled to the baryon fields involving scalar-isoscalar (σ, σ∗), vector-isoscalar (ω, ɸ), vector-isovector (ϱ) and scalar-isovector (δ) virtual sectors. Following recent experimental results, we consider in our calculations the extreme case where the Σ- experiences such a strong repulsion that its influence in the nuclear structure of a neutron star is excluded at all. A few examples of calculations of properties of neutron stars are shown and prospects for the future are discussed.

  13. COMT Val158Met × SLC6A4 5-HTTLPR interaction impacts on gray matter volume of regions supporting emotion processing

    PubMed Central

    El-Hage, Wissam; Monté, Gemma C.; Gohier, Benedicte; Tropeano, Maria; Phillips, Mary L.; Surguladze, Simon A.

    2014-01-01

    There have been several reports on the association between the Val158Met genetic polymorphism of the catechol-O-methyltransferase (COMT) gene, as well as the serotonin transporter-linked polymorphic region (5-HTTLPR) of the serotonin transporter gene (SLC6A4), and frontolimbic region volumes, which have been suggested to underlie individual differences in emotion processing or susceptibility to emotional disorders. However, findings have been somewhat inconsistent. This study used diffeomorphic anatomic registration through exponentiated Lie algebra (DARTEL) whole-brain voxel-based morphometry to study the genetic effects of COMT Val158Met and SLC6A4 5-HTTLPR, as well as their interaction, on the regional gray matter volumes of a sample of 91 healthy volunteers. An interaction of COMT Val158Met × SLC6A4 5-HTTLPR genotypes with gray matter volume was found in bilateral parahippocampal gyrus, amygdala, hippocampus, vermis of cerebellum and right putamen/insula. In particular, the gray matter volume in these regions was smaller in individuals who were both COMT-Met and 5-HTTLPR-S carriers, or both COMT-Val and 5-HTTLPR-L homozygotes, as compared with individuals with intermediate combinations of alleles. The interaction of COMT Val158Met and SLC6A4 5-HTTLPR adds to the understanding of individual differences in emotion processing. PMID:23748501

  14. White matter maturation is associated with the emergence of Theory of Mind in early childhood

    PubMed Central

    Grosse Wiesmann, Charlotte; Schreiber, Jan; Singer, Tania; Steinbeis, Nikolaus; Friederici, Angela D.

    2017-01-01

    The ability to attribute mental states to other individuals is crucial for human cognition. A milestone of this ability is reached around the age of 4, when children start understanding that others can have false beliefs about the world. The neural basis supporting this critical step is currently unknown. Here, we relate this behavioural change to the maturation of white matter structure in 3- and 4-year-old children. Tract-based spatial statistics and probabilistic tractography show that the developmental breakthrough in false belief understanding is associated with age-related changes in local white matter structure in temporoparietal regions, the precuneus and medial prefrontal cortex, and with increased dorsal white matter connectivity between temporoparietal and inferior frontal regions. These effects are independent of co-developing cognitive abilities. Our findings show that the emergence of mental state representation is related to the maturation of core belief processing regions and their connection to the prefrontal cortex. PMID:28322222

  15. White matter maturation is associated with the emergence of Theory of Mind in early childhood.

    PubMed

    Grosse Wiesmann, Charlotte; Schreiber, Jan; Singer, Tania; Steinbeis, Nikolaus; Friederici, Angela D

    2017-03-21

    The ability to attribute mental states to other individuals is crucial for human cognition. A milestone of this ability is reached around the age of 4, when children start understanding that others can have false beliefs about the world. The neural basis supporting this critical step is currently unknown. Here, we relate this behavioural change to the maturation of white matter structure in 3- and 4-year-old children. Tract-based spatial statistics and probabilistic tractography show that the developmental breakthrough in false belief understanding is associated with age-related changes in local white matter structure in temporoparietal regions, the precuneus and medial prefrontal cortex, and with increased dorsal white matter connectivity between temporoparietal and inferior frontal regions. These effects are independent of co-developing cognitive abilities. Our findings show that the emergence of mental state representation is related to the maturation of core belief processing regions and their connection to the prefrontal cortex.

  16. (Research in the theory of condensed matter and elementary particles. ) Progress report

    SciTech Connect

    Not Available

    1986-01-01

    Progress is summarized in these areas: a new formulation of two dimensional critical phenomena and string theory, supersymmetric critical phenomena and string compactification, conformal field theory on orbifolds, Gaussian models with twisted boundary conditions, modular invariance and supersymmetric critical phenomena, critical indices, conformal invariance, and current algebra, renormalization group fixed points and the string equation of motion, fermionic string field theory, N = 2 super Riemann surfaces, the spinor field in covariant superstring theory, covariant quantization of superstrings, models of aggregation, and quasi-supersymmetry in the BCS mechanism. Further work is proposed in the areas of two dimensional critical phenomena, two dimensional conformal field theory and string theory, the physics of computation, models of aggregation, and the many vortex Aharonov-Bohm problem. 57 refs. (LEW)

  17. Effective theory of WIMP dark matter supplemented by simplified models: Singlet-like Majorana fermion case

    NASA Astrophysics Data System (ADS)

    Matsumoto, Shigeki; Mukhopadhyay, Satyanarayan; Tsai, Yue-Lin Sming

    2016-09-01

    We enumerate the set of simplified models which match onto the complete set of gauge invariant effective operators up to dimension six describing interactions of a singlet-like Majorana fermion dark matter with the standard model. Tree-level matching conditions for each case are worked out in the large mediator mass limit, defining a one-to-one correspondence between the effective operator coefficients and the simplified model parameters for weakly interacting models. Utilizing such a mapping, we compute the dark matter annihilation rate in the early universe, as well as other low-energy observables like nuclear recoil rates using the effective operators, while the simplified models are used to compute the dark matter production rates at high-energy colliders like LEP, LHC and future lepton colliders. Combining all relevant constraints with a profile-likelihood analysis, we then discuss the currently allowed parameter regions and prospects for future searches in terms of the effective operator parameters, reducing the model dependence to a minimal level. In the parameter region where such a model-independent analysis is applicable, and leaving aside the special dark matter mass regions where the annihilation proceeds through an s -channel Z or Higgs boson pole, the current constraints allow effective operator suppression scales (Λ ) of the order of a few hundred GeV for dark matter masses mχ>20 GeV at 95% C.L., while the maximum allowed scale is around 3 TeV for mχ˜O (1 TeV ) . An estimate of the future reach of ton-scale direct detection experiments and planned electron-positron colliders show that most of the remaining regions can be probed, apart from dark matter masses near half of the Z -boson mass (with 500 GeV <Λ <2 TeV ) and those beyond the kinematic reach of the future lepton colliders.

  18. The QCD vacuum, hadrons and superdense matter

    SciTech Connect

    Shuryak, E.

    1986-01-01

    This is probably the only textbook available that gathers QCD, many-body theory and phase transitions in one volume. The presentation is pedagogical and readable. Contents: The QCD Vacuum: Introduction; QCD on the Lattice Topological Effects in Gauges Theories. Correlation Functions and Microscopic Excitations: Introduction; Operator Product Expansion; The Sum Rules beyond OPE; Nonpower Contributions to Correlators and Instantons; Hadronic Spectroscopy on the Lattice. Dense Matter: Hadronic Matter; Asymptotically Dense Quark-Gluon Plasma; Instantons in Matter; Lattice Calculations at Finite Temperature; Phase Transitions; Macroscopic Excitations and Experiments: General Properties of High Energy Collisions; ''Barometers'', ''Thermometers'', Interferometric ''Microscope''; Experimental Perspectives.

  19. Life Goals Matter to Happiness: A Revision of Set-Point Theory

    ERIC Educational Resources Information Center

    Headey, Bruce

    2008-01-01

    Using data from the long-running German Socio-Economic Panel Survey (SOEP), this paper provides evidence that life goals matter substantially to subjective well-being (SWB). Non-zero sum goals, which include commitment to family, friends and social and political involvement, promote life satisfaction. Zero sum goals, including commitment to career…

  20. Mind-Sets Matter: A Meta-Analytic Review of Implicit Theories and Self-Regulation

    ERIC Educational Resources Information Center

    Burnette, Jeni L.; O'Boyle, Ernest H.; VanEpps, Eric M.; Pollack, Jeffrey M.; Finkel, Eli J.

    2013-01-01

    This review builds on self-control theory (Carver & Scheier, 1998) to develop a theoretical framework for investigating associations of implicit theories with self-regulation. This framework conceptualizes self-regulation in terms of 3 crucial processes: goal setting, goal operating, and goal monitoring. In this meta-analysis, we included…

  1. Mind-sets matter: a meta-analytic review of implicit theories and self-regulation.

    PubMed

    Burnette, Jeni L; O'Boyle, Ernest H; VanEpps, Eric M; Pollack, Jeffrey M; Finkel, Eli J

    2013-05-01

    This review builds on self-control theory (Carver & Scheier, 1998) to develop a theoretical framework for investigating associations of implicit theories with self-regulation. This framework conceptualizes self-regulation in terms of 3 crucial processes: goal setting, goal operating, and goal monitoring. In this meta-analysis, we included articles that reported a quantifiable assessment of implicit theories and at least 1 self-regulatory process or outcome. With a random effects approach used, meta-analytic results (total unique N = 28,217; k = 113) across diverse achievement domains (68% academic) and populations (age range = 5-42; 10 different nationalities; 58% from United States; 44% female) demonstrated that implicit theories predict distinct self-regulatory processes, which, in turn, predict goal achievement. Incremental theories, which, in contrast to entity theories, are characterized by the belief that human attributes are malleable rather than fixed, significantly predicted goal setting (performance goals, r = -.151; learning goals, r = .187), goal operating (helpless-oriented strategies, r = -.238; mastery-oriented strategies, r = .227), and goal monitoring (negative emotions, r = -.233; expectations, r = .157). The effects for goal setting and goal operating were stronger in the presence (vs. absence) of ego threats such as failure feedback. Discussion emphasizes how the present theoretical analysis merges an implicit theory perspective with self-control theory to advance scholarship and unlock major new directions for basic and applied research.

  2. Burning odor-elicited anxiety in OEF/OIF combat veterans: Inverse relationship to gray matter volume in olfactory cortex.

    PubMed

    Cortese, Bernadette M; McConnell, Patrick A; Froeliger, Brett; Leslie, Kimberly; Uhde, Thomas W

    2015-11-01

    Despite the anatomical overlap between the brain's fear/threat and olfactory systems, a very limited number of investigations have considered the role of odors and the central olfactory system in the pathophysiology of PTSD. The goal of the present study was to assess structural differences in primary and secondary olfactory cortex between combat veterans with and without PTSD (CV + PTSD, CV-PTSD, respectively). An additional goal was to determine the relationship between gray matter volume (GMV) in olfactory cortex and the distressing properties of burning-related odors. A region of interest voxel-based morphometric (VBM) approach was used to measure GMV in olfactory cortex in a well-characterized group of CV + PTSD (n = 20) and CV-PTSD (n = 25). Prior to the MRI exam, combat-related (i.e., burning rubber) and control odors were systematically sampled and rated according to their potential for eliciting PTSD symptoms. Results showed that CV + PTSD exhibited significantly reduced GMV in anterior piriform (primary olfactory) and orbitofrontal (secondary olfactory) cortices compared to CV-PTSD (both p < .01). For the entire group, GMV in bilateral anterior piriform cortex was inversely related to burning rubber odor-elicited memories of trauma (p < .05). GMV in orbitofrontal cortex was inversely related to both clinical and laboratory measures of PTSD symptoms (all p < .05). In addition to replicating an established inverse relationship between GMV in anxiety-associated brain structures and PTSD symptomatology, the present study extends those findings by being the first report of volumetric decreases in olfactory cortex that are inversely related to odor-elicited PTSD symptoms. Potential mechanisms underlying these findings are discussed.

  3. Reduced visual cortex gray matter volume and thickness in young adults who witnessed domestic violence during childhood.

    PubMed

    Tomoda, Akemi; Polcari, Ann; Anderson, Carl M; Teicher, Martin H

    2012-01-01

    Exposure to interparental violence is associated with negative outcomes, such as depression, post-traumatic stress disorder and reduced cognitive abilities. However, little is known about the potential effects of witnessing domestic violence during childhood on gray matter volume (GMV) or cortical thickness. High-resolution 3.0 T volumetric scans (Siemens Trio Scanner) were obtained on 52 subjects (18-25 years) including 22 (6 males/16 females) with a history of visually witnessing episodes of domestic violence, and 30 (8 males/22 females) unexposed control subjects, with neither a current nor past DSM-IV Axis I or II disorder. Potential confounding effects of age, gender, level of parental verbal aggression, parental education, financial stress, full scale IQ, and total GMV, or average thickness were modeled using voxel based morphometry and FreeSurfer. Witnessing domestic violence subjects had a 6.1% GMV reduction in the right lingual gyrus (BA18) (P = 0.029, False Discovery Rate corrected peak level). Thickness in this region was also reduced, as was thickness in V2 bilaterally and left occipital pole. Theses regions were maximally sensitive to exposure to witnessing domestic violence between 11-13 years of age. Regional reductions in GMV and thickness were observed in both susceptible and resilient witnessing domestic violence subjects. Results in subjects witnessing domestic violence were similar to previously reported results in subjects with childhood sexual abuse, as the primary region affected was visual cortex. Brain regions that process and convey the adverse sensory input of the abuse may be specifically modified by this experience, particularly in subjects exposed to a single type of maltreatment. Exposure to multiple types of maltreatment is more commonly associated with morphological alterations in corticolimbic regions. These findings fit with preclinical studies showing that visual cortex is a highly plastic structure.

  4. White matter integrity, hippocampal volume, and cognitive performance of a world-famous nonagenarian track-and-field athlete.

    PubMed

    Burzynska, A Z; Wong, C N; Chaddock-Heyman, L; Olson, E A; Gothe, N P; Knecht, A; Voss, M W; McAuley, E; Kramer, A F

    2016-01-01

    Physical activity (PA) and cardiorespiratory fitness (CRF) are associated with successful brain and cognitive aging. However, little is known about the effects of PA, CRF, and exercise on the brain in the oldest-old. Here we examined white matter (WM) integrity, measured as fractional anisotropy (FA) and WM hyperintensity (WMH) burden, and hippocampal (HIPP) volume of Olga Kotelko (1919-2014). Olga began training for competitions at age of 77 and as of June 2014 held over 30 world records in her age category in track-and-field. We found that Olga's WMH burden was larger and the HIPP was smaller than in the reference sample (58 healthy low-active women 60-78 years old), and her FA was consistently lower in the regions overlapping with WMH. Olga's FA in many normal-appearing WM regions, however, did not differ or was greater than in the reference sample. In particular, FA in her genu corpus callosum was higher than any FA value observed in the reference sample. We speculate that her relatively high FA may be related to both successful aging and the beneficial effects of exercise in old age. In addition, Olga had lower scores on memory, reasoning and speed tasks than the younger reference sample, but outperformed typical adults of age 90-95 on speed and memory. Together, our findings open the possibility of old-age benefits of increasing PA on WM microstructure and cognition despite age-related increase in WMH burden and HIPP shrinkage, and add to the still scarce neuroimaging data of the healthy oldest-old (>90 years) adults.

  5. Lattice calculation of thermal properties of low-density neutron matter with pionless NN effective field theory

    SciTech Connect

    Abe, T.; Seki, R.

    2009-05-15

    Thermal properties of low-density neutron matter are investigated by determinantal quantum Monte Carlo lattice calculations on 3+1 dimensional cubic lattices. Nuclear effective field theory (EFT) is applied using the pionless single- and two-parameter neutron-neutron interactions, determined from the {sup 1}S{sub 0} scattering length and effective range. The determination of the interactions and the calculations of neutron matter are carried out consistently by applying EFT power counting rules. The thermodynamic limit is taken by the method of finite-size scaling, and the continuum limit is examined in the vanishing lattice filling limit. The {sup 1}S{sub 0} pairing gap at T{approx_equal}0 is computed directly from the off-diagonal long-range order of the spin pair-pair correlation function and is found to be approximately 30% smaller than BCS calculations with the conventional nucleon-nucleon potentials. The critical temperature T{sub c} of the normal-to-superfluid phase transition and the pairing temperature scale T* are determined, and the temperature-density phase diagram is constructed. The physics of low-density neutron matter is clearly identified as being a BCS-Bose-Einstein condensation crossover.

  6. Common and distinct patterns of grey-matter volume alteration in major depression and bipolar disorder: evidence from voxel-based meta-analysis.

    PubMed

    Wise, T; Radua, J; Via, E; Cardoner, N; Abe, O; Adams, T M; Amico, F; Cheng, Y; Cole, J H; de Azevedo Marques Périco, C; Dickstein, D P; Farrow, T F D; Frodl, T; Wagner, G; Gotlib, I H; Gruber, O; Ham, B J; Job, D E; Kempton, M J; Kim, M J; Koolschijn, P C M P; Malhi, G S; Mataix-Cols, D; McIntosh, A M; Nugent, A C; O'Brien, J T; Pezzoli, S; Phillips, M L; Sachdev, P S; Salvadore, G; Selvaraj, S; Stanfield, A C; Thomas, A J; van Tol, M J; van der Wee, N J A; Veltman, D J; Young, A H; Fu, C H; Cleare, A J; Arnone, D

    2016-05-24

    Finding robust brain substrates of mood disorders is an important target for research. The degree to which major depression (MDD) and bipolar disorder (BD) are associated with common and/or distinct patterns of volumetric changes is nevertheless unclear. Furthermore, the extant literature is heterogeneous with respect to the nature of these changes. We report a meta-analysis of voxel-based morphometry (VBM) studies in MDD and BD. We identified studies published up to January 2015 that compared grey matter in MDD (50 data sets including 4101 individuals) and BD (36 data sets including 2407 individuals) using whole-brain VBM. We used statistical maps from the studies included where available and reported peak coordinates otherwise. Group comparisons and conjunction analyses identified regions in which the disorders showed common and distinct patterns of volumetric alteration. Both disorders were associated with lower grey-matter volume relative to healthy individuals in a number of areas. Conjunction analysis showed smaller volumes in both disorders in clusters in the dorsomedial and ventromedial prefrontal cortex, including the anterior cingulate cortex and bilateral insula. Group comparisons indicated that findings of smaller grey-matter volumes relative to controls in the right dorsolateral prefrontal cortex and left hippocampus, along with cerebellar, temporal and parietal regions were more substantial in major depression. These results suggest that MDD and BD are characterised by both common and distinct patterns of grey-matter volume changes. This combination of differences and similarities has the potential to inform the development of diagnostic biomarkers for these conditions.Molecular Psychiatry advance online publication, 24 May 2016; doi:10.1038/mp.2016.72.

  7. Altered relationship between electrophysiological response to errors and gray matter volumes in an extended network for error-processing in pediatric obsessive-compulsive disorder.

    PubMed

    Liu, Yanni; Hanna, Gregory L; Carrasco, Melisa; Gehring, William J; Fitzgerald, Kate D

    2014-04-01

    Pediatric patients with obsessive-compulsive disorder (OCD) show an increased electrophysiological response to errors that is thought to be localized to the posterior medial prefrontal cortex (pMFC). However, the relation of this response, the error-related negativity (ERN), to underlying brain structures remains unknown. In an examination of 20 pediatric OCD patients and 20 healthy youth, we found that more negative ERN amplitude was correlated with lower gray matter (GM) density in pMFC and orbital frontal cortex. The association of the ERN with pMFC gray matter volume was driven by the patient group. In addition, a group difference in the association of ERN with gray matter in right insula was observed, showing an association of these measures in healthy youth (more negative ERN amplitude was associated with lower GM density in insula), but not in patients. These findings provide preliminary evidence linking gray matter volumes in an extended network for error processing to the ERN, and suggest that structural alterations in this network may underlie exaggeration of the ERN in pediatric OCD.

  8. The diphoton and diboson excesses in a left-right symmetric theory of dark matter

    NASA Astrophysics Data System (ADS)

    Berlin, Asher

    We explore the possibility that the recently reported diphoton excess at ATLAS and CMS can be accommodated within a minimal extension of a left-right symmetric model. Our setup is able to simultaneously explain the Run 2 diphoton and Run 1 diboson excesses, while providing a standard thermal freeze-out of weak-scale dark matter. In this scenario, the 750 GeV neutral right-handed Higgs triplet is responsible for the diphoton excess. Interactions of this state with the neutral and charged components of dark matter multiplets provide the dominant mechanisms for production and decay. A striking signature of this model is the additional presence of missing energy in the diphoton channel.

  9. Diphoton and diboson excesses in a left-right symmetric theory of dark matter

    NASA Astrophysics Data System (ADS)

    Berlin, Asher

    2016-03-01

    We explore the possibility that the recently reported diphoton excess at ATLAS and CMS can be accommodated within a minimal extension of a left-right symmetric model. Our setup is able to simultaneously explain the Run 2 diphoton and Run 1 diboson excesses, while providing a standard thermal freeze-out of weak-scale dark matter. In this scenario, the 750 GeV neutral right-handed Higgs triplet is responsible for the diphoton excess. Interactions of this state with the neutral and charged components of dark matter multiplets provide the dominant mechanisms for production and decay. A striking signature of this model is the additional presence of missing energy in the diphoton channel.

  10. Chiral symmetry and effective field theories for hadronic, nuclear and stellar matter

    NASA Astrophysics Data System (ADS)

    Holt, Jeremy W.; Rho, Mannque; Weise, Wolfram

    2016-03-01

    Chiral symmetry, first entering in nuclear physics in the 1970s for which Gerry Brown played a seminal role, has led to a stunningly successful framework for describing strongly-correlated nuclear dynamics both in finite and infinite systems. We review how the early, germinal idea conceived with the soft-pion theorems in the pre-QCD era has evolved into a highly predictive theoretical framework for nuclear physics, aptly assessed by Steven Weinberg: "it (chiral effective field theory) allows one to show in a fairly convincing way that what they (nuclear physicists) have been doing all along... is the correct first step in a consistent approximation scheme". Our review recounts both how the theory presently fares in confronting Nature and how one can understand its extremely intricate workings in terms of the multifaceted aspects of chiral symmetry, namely, chiral perturbation theory, skyrmions, Landau Fermi-liquid theory, the Cheshire cat phenomenon, and hidden local and mended symmetries.

  11. BRST formulation of Chern-Simons gauge theory coupled to matter fields

    SciTech Connect

    Shin, H.; Kim, W.; Kim, J. ); Park, Y. )

    1992-09-15

    We study the Abelian Chern-Simons gauge theory coupled to a complex scalar field in the covariant gauge. By introducing the Becchi-Rouet-Stora-Tyutin formulation, it is shown that fractional spin also appears in the covariant gauge.

  12. Digital Quantum Simulation of Z2 Lattice Gauge Theories with Dynamical Fermionic Matter

    NASA Astrophysics Data System (ADS)

    Zohar, Erez; Farace, Alessandro; Reznik, Benni; Cirac, J. Ignacio

    2017-02-01

    We propose a scheme for digital quantum simulation of lattice gauge theories with dynamical fermions. Using a layered optical lattice with ancilla atoms that can move and interact with the other atoms (simulating the physical degrees of freedom), we obtain a stroboscopic dynamics which yields the four-body plaquette interactions, arising in models with (2 +1 ) and higher dimensions, without the use of perturbation theory. As an example we show how to simulate a Z2 model in (2 +1 ) dimensions.

  13. Integrating caring theory with nursing practice and education: connecting with what matters.

    PubMed

    Dyess, Susan; Boykin, Anne; Rigg, Connie

    2010-11-01

    Theory-based nursing practice positively influences many outcomes in healthcare organizations. As a response to limited human and economic resources, a college of nursing and a for-profit healthcare organization worked in partnership to develop a project that focused on developing and demonstrating the value of a dedicated education unit grounded in caring theory. The authors describe the development of the project, initial outcomes, and the relevance to nursing administration.

  14. A Matter of Principle: The Principles of Quantum Theory, Dirac's Equation, and Quantum Information

    NASA Astrophysics Data System (ADS)

    Plotnitsky, Arkady

    2015-10-01

    This article is concerned with the role of fundamental principles in theoretical physics, especially quantum theory. The fundamental principles of relativity will be addressed as well, in view of their role in quantum electrodynamics and quantum field theory, specifically Dirac's work, which, in particular Dirac's derivation of his relativistic equation of the electron from the principles of relativity and quantum theory, is the main focus of this article. I shall also consider Heisenberg's earlier work leading him to the discovery of quantum mechanics, which inspired Dirac's work. I argue that Heisenberg's and Dirac's work was guided by their adherence to and their confidence in the fundamental principles of quantum theory. The final section of the article discusses the recent work by D'Ariano and coworkers on the principles of quantum information theory, which extend quantum theory and its principles in a new direction. This extension enabled them to offer a new derivation of Dirac's equations from these principles alone, without using the principles of relativity.

  15. Rotary-wing aerodynamics. Volume 1: Basic theories of rotor aerodynamics with application to helicopters. [momentum, vortices, and potential theory

    NASA Technical Reports Server (NTRS)

    Stepniewski, W. Z.

    1979-01-01

    The concept of rotary-wing aircraft in general is defined. The energy effectiveness of helicopters is compared with that of other static thrust generators in hover, as well as with various air and ground vehicles in forward translation. The most important aspects of rotor-blade dynamics and rotor control are reviewed. The simple physicomathematical model of the rotor offered by the momentum theory is introduced and its usefulness and limitations are assessed. The combined blade-element and momentum theory approach, which provides greater accuracy in performance predictions, is described as well as the vortex theory which models a rotor blade by means of a vortex filament or vorticity surface. The application of the velocity and acceleration potential theory to the determination of flow fields around three dimensional, non-rotating bodies as well as to rotor aerodynamic problems is described. Airfoil sections suitable for rotors are also considered.

  16. Alabama Children: A Matter of Commitment and Priority. Special Report to Governor Fob James and the Alabama Legislature. Volume I and Volume II.

    ERIC Educational Resources Information Center

    Ames, Bobbie H.

    This report in two volumes is the product of a year-long needs assessment undertaken by the Governor of Alabama's Commission for the Alabama Year of the Child. Volume I, which contains an overview and recommendations to the governor and the legislature, includes position papers and letters from the commission and interested citizens. These…

  17. Integer, fractional, and anomalous quantum Hall effects explained with Eyring's rate process theory and free volume concept.

    PubMed

    Hao, Tian

    2017-02-22

    The Hall effects, especially the integer, fractional and anomalous quantum Hall effects, have been addressed using Eyring's rate process theory and free volume concept. The basic assumptions are that the conduction process is a common rate controlled "reaction" process that can be described with Eyring's absolute rate process theory; the mobility of electrons should be dependent on the free volume available for conduction electrons. The obtained Hall conductivity is clearly quantized as with prefactors related to both the magnetic flux quantum number and the magnetic quantum number via the azimuthal quantum number, with and without an externally applied magnetic field. This article focuses on two dimensional (2D) systems, but the approaches developed in this article can be extended to 3D systems.

  18. Grey matter volumes in treatment naïve vs. chronically treated children with attention deficit/hyperactivity disorder: a combined approach.

    PubMed

    Villemonteix, Thomas; De Brito, Stéphane A; Kavec, Martin; Balériaux, Danielle; Metens, Thierry; Slama, Hichem; Baijot, Simon; Mary, Alison; Peigneux, Philippe; Massat, Isabelle

    2015-08-01

    Psychostimulants are the first-line treatment in attention deficit/hyperactivity disorder (ADHD), but their effects on brain development remain poorly understood. In particular, previous structural magnetic resonance imaging (sMRI) studies only investigated treatment effects on grey matter (GM) volumes in selected regions of interest (ROIs). In this study, voxel-based morphometry (VBM) was used to assess medication-related GM volume differences across the entire brain. Automated tracing measurements of selected ROIs were also obtained. Three groups (77 participants aged 7-to-13 year old) underwent MRI scans and were compared: never-medicated children with ADHD (n=33), medicated (methylphenidate) children with ADHD (n=20) and typically developing children (TD; n=24). Optimised VBM was used to investigate regional GM volumes, controlling for age and gender. Automated tracing procedures were also used to assess the average volume of the caudate nucleus, the amygdala and the nucleus accumbens. When compared to both medicated children with ADHD and TD children, never-medicated children with ADHD exhibited decreased GM volume in the insula and in the middle temporal gyrus. When compared to TD children, medicated children with ADHD had decreased GM volume in the middle frontal gyrus and in the precentral gyrus. Finally, ROI analyses revealed a significant association between duration of treatment and GM volume of the left nucleus accumbens in medicated children with ADHD. In conclusion, this study documents potential methylphenidate-related GM volume normalization and deviation in previously unexplored brain structures, and reports a positive association between treatment history and GM volume in the nucleus accumbens, a key region for reward-processing.

  19. A matter of timing: developmental theories of romantic involvement and psychosocial adjustment.

    PubMed

    Furman, Wyndol; Collibee, Charlene

    2014-11-01

    The present study compared two theories of the association between romantic involvement and adjustment: a social timetable theory and a developmental task theory. We examined seven waves of longitudinal data on a community based sample of 200 participants (Wave 1 mean age = 15 years, 10 months). In each wave, multiple measures of substance use, externalizing symptoms, and internalizing symptoms were gathered, typically from multiple reporters. Multilevel modeling revealed that greater levels of romantic involvement in adolescence were associated with higher levels of substance use and externalizing symptoms but became associated with lower levels in adulthood. Having a romantic partner was associated with greater levels of substance use, externalizing symptoms, and internalizing symptoms in adolescence but was associated with lower levels in young adulthood. The findings were not consistent with a social timetable theory, which predicts that nonnormative involvement is associated with poor adjustment. Instead, the findings are consistent with a developmental task theory, which predicts that precocious romantic involvement undermines development and adaptation, but when romantic involvement becomes a salient developmental task in adulthood, it is associated with positive adjustment. Discussion focuses on the processes that may underlie the changing nature of the association between romantic involvement and adjustment.

  20. Instanton effects in three-dimensional supersymmetric gauge theories with matter

    NASA Astrophysics Data System (ADS)

    Dorey, Nick; Tong, David; Vandoren, Stefan

    1998-04-01

    Using standard field theory techniques we compute perturbative and instanton contributions to the Coulomb branch of three-dimensional supersymmetric QCD with N = 2 and N = 4 supersymmetry and gauge group SU(2). For the N = 4 theory with one massless flavor, we confirm the proposal of Seiberg and Witten that the Coulomb branch is the double-cover of the centered moduli space of two BPS monopoles constructed by Atiyah and Hitchin. Introducing a hypermultiplet mass term, we show that the asymptotic metric on the Coulomb branch coincides with the metric on Dancer's deformation of the monopole moduli space. For the N = 2 theory with Nf flavors, we compute the one-loop corrections to the metric and complex structure on the Coulomb branch. We then determine the superpotential including one-loop effects around the instanton background. These calculations provide an explicit check of several results previously obtained by symmetry and holomorphy arguments.

  1. Continuous Theory of Active Matter Systems with Metric-Free Interactions

    NASA Astrophysics Data System (ADS)

    Peshkov, Anton; Ngo, Sandrine; Bertin, Eric; Chaté, Hugues; Ginelli, Francesco

    2012-08-01

    We derive a hydrodynamic description of metric-free active matter: starting from self-propelled particles aligning with neighbors defined by “topological” rules, not metric zones—a situation advocated recently to be relevant for bird flocks, fish schools, and crowds—we use a kinetic approach to obtain well-controlled nonlinear field equations. We show that the density-independent collision rate per particle characteristic of topological interactions suppresses the linear instability of the homogeneous ordered phase and the nonlinear density segregation generically present near threshold in metric models, in agreement with microscopic simulations.

  2. A review on the relativistic effective field theory with parameterized couplings for nuclear matter and neutron stars

    SciTech Connect

    Vasconcellos, C. A. Zen

    2015-12-17

    Nuclear science has developed many excellent theoretical models for many-body systems in the domain of the baryon-meson strong interaction for the nucleus and nuclear matter at low, medium and high densities. However, a full microscopic understanding of nuclear systems in the extreme density domain of compact stars is still lacking. The aim of this contribution is to shed some light on open questions facing the nuclear many-body problem at the very high density domain. Here we focus our attention on the conceptual issue of naturalness and its role in shaping the baryon-meson phase space dynamics in the description of the equation of state (EoS) of nuclear matter and neutrons stars. In particular, in order to stimulate possible new directions of research, we discuss relevant aspects of a recently developed relativistic effective theory for nuclear matter within Quantum Hadrodynamics (QHD) with genuine many-body forces and derivative natural parametric couplings. Among other topics we discuss in this work the connection of this theory with other known effective QHD models of the literature and its potentiality in describing a new physics for dense matter. The model with parameterized couplings exhausts the whole fundamental baryon octet (n, p, Σ{sup −}, Σ{sup 0}, Σ{sup +}, Λ, Ξ{sup −}, Ξ{sup 0}) and simulates n-order corrections to the minimal Yukawa baryon couplings by considering nonlinear self-couplings of meson fields and meson-meson interaction terms coupled to the baryon fields involving scalar-isoscalar (σ, σ∗), vector-isoscalar (ω, Φ), vector-isovector (ϱ) and scalar-isovector (δ) virtual sectors. Following recent experimental results, we consider in our calculations the extreme case where the Σ{sup −} experiences such a strong repulsion that its influence in the nuclear structure of a neutron star is excluded at all. A few examples of calculations of properties of neutron stars are shown and prospects for the future are discussed.

  3. Non-Gaussian covariance of the matter power spectrum in the effective field theory of large scale structure

    NASA Astrophysics Data System (ADS)

    Bertolini, Daniele; Schutz, Katelin; Solon, Mikhail P.; Walsh, Jonathan R.; Zurek, Kathryn M.

    2016-06-01

    We compute the non-Gaussian contribution to the covariance of the matter power spectrum at one-loop order in standard perturbation theory (SPT), using the framework of the effective field theory (EFT) of large scale structure (LSS). The complete one-loop contributions are evaluated for the first time, including the leading EFT corrections that involve seven independent operators, of which four appear in the power spectrum and bispectrum. We compare the non-Gaussian part of the one-loop covariance computed with both SPT and EFT of LSS to two separate simulations. In one simulation, we find that the one-loop prediction from SPT reproduces the simulation well to ki+kj˜0.25 h /Mpc , while in the other simulation we find a substantial improvement of EFT of LSS (with one free parameter) over SPT, more than doubling the range of k where the theory accurately reproduces the simulation. The disagreement between these two simulations points to unaccounted for systematics, highlighting the need for improved numerical and analytic understanding of the covariance.

  4. Auxiliary-field quantum Monte Carlo simulations of neutron matter in chiral effective field theory.

    PubMed

    Wlazłowski, G; Holt, J W; Moroz, S; Bulgac, A; Roche, K J

    2014-10-31

    We present variational Monte Carlo calculations of the neutron matter equation of state using chiral nuclear forces. The ground-state wave function of neutron matter, containing nonperturbative many-body correlations, is obtained from auxiliary-field quantum Monte Carlo simulations of up to about 340 neutrons interacting on a 10(3) discretized lattice. The evolution Hamiltonian is chosen to be attractive and spin independent in order to avoid the fermion sign problem and is constructed to best reproduce broad features of the chiral nuclear force. This is facilitated by choosing a lattice spacing of 1.5 fm, corresponding to a momentum-space cutoff of Λ=414  MeV/c, a resolution scale at which strongly repulsive features of nuclear two-body forces are suppressed. Differences between the evolution potential and the full chiral nuclear interaction (Entem and Machleidt Λ=414  MeV [L. Coraggio et al., Phys. Rev. C 87, 014322 (2013).

  5. Using Multiple Representations to Promote Grade 11 Students' Scientific Understanding of the Particle Theory of Matter

    ERIC Educational Resources Information Center

    Adadan, Emine

    2013-01-01

    This study explored two groups of Grade 11 (age 16-17) students' conceptual understandings about aspects of particle theory before, immediately after, and 3 months after instruction with multiple representations (IMR) and instruction with verbal representations (IVR). Data sources included open-ended questionnaires, interviews, and student…

  6. The Theory of Multiple Intelligences: A Case of Missing Cognitive Matter.

    ERIC Educational Resources Information Center

    Allix, Nicholas M.

    2000-01-01

    Argues that although Gardner's conception of human cognition, characterized by a set of multiple and distinct cognitive capabilities, is an advance over the narrow conception of IQ, it runs into fundamental difficulties of a methodological kind and is based on a discredited empiricist theory of knowledge which work with artificial neural networks…

  7. Approaches to Teaching the Particulate Theory of Matter. Children's Learning in Science Project.

    ERIC Educational Resources Information Center

    Leeds Univ. (England). Centre for Studies in Science and Mathematics Education.

    During the period 1984-1986, over 30 teachers from the Yorkshire (England) region have worked in collaboration with the Children's Learning in Science Project (CLIS) developing and testing teaching schemes in the areas of energy, particle theory, and plant nutrition. The project is based upon the constructivist approach to teaching. This guide…

  8. A Test and Extension of Objectification Theory as It Predicts Disordered Eating: Does Women's Age Matter?

    ERIC Educational Resources Information Center

    Augustus-Horvath, Casey L.; Tylka, Tracy L.

    2009-01-01

    When predicting disordered eating, models incorporating several of objectification theory's (B. L. Fredrickson & T. A. Roberts, 1997) core constructs (i.e., sexual objectification, self-objectification, body shame, poor interoceptive awareness) have been empirically supported with women of traditional undergraduate age who are consistent in…

  9. Zero-Range Effective Field Theory for Resonant Wino Dark Matter

    NASA Astrophysics Data System (ADS)

    Johnson, Evan; Braaten, Eric; Zhang, Hong

    2017-01-01

    The most dramatic ``Sommerfeld enhancements'' of neutral-wino-pair annihilation occur when the wino mass is tuned to near critical values where there is a zero-energy S-wave resonance at the neutral-wino-pair threshold. If the wino mass is larger than the critical value, the resonance is a wino-pair bound state. If the wino mass is near a critical value, low-energy winos can be described by a zero-range effective field theory in which the winos interact nonperturbatively through a contact interaction. The parameters of the zero-range effective field theory can be determined by matching wino scattering amplitudes calculated by solving the Schrödinger equation for a nonrelativistic effective field theory in which the winos interact nonperturbatively through a potential due to the exchange of weak gauge bosons. The power of the zero-range effective field theory is illustrated by calculating the rate for formation of the bound state in the collision of two neutral winos through the emission of two soft photons. Supported in part by DOE grant DE-FG02-05ER15715.

  10. SPAR thermal analysis processors reference manual, system level 16. Volume 1: Program executive. Volume 2: Theory. Volume 3: Demonstration problems. Volume 4: Experimental thermal element capability. Volume 5: Programmer reference

    NASA Technical Reports Server (NTRS)

    Marlowe, M. B.; Moore, R. A.; Whetstone, W. D.

    1979-01-01

    User instructions are given for performing linear and nonlinear steady state and transient thermal analyses with SPAR thermal analysis processors TGEO, SSTA, and TRTA. It is assumed that the user is familiar with basic SPAR operations and basic heat transfer theory.

  11. Green Ocean Amazon 2014/15 High-Volume Filter Sampling: Atmospheric Particulate Matter of an Amazon Tropical City and its Relationship to Population Health Field Campaign Report

    SciTech Connect

    Machado, C. M.; Santos, Erickson O.; Fernandes, Karenn S.; Neto, J. L.; Souza, Rodrigo A.

    2016-08-01

    Manaus, the capital of the Brazilian state of Amazonas, is developing very rapidly. Its pollution plume contains aerosols from fossil fuel combustion mainly due to vehicular emission, industrial activity, and a thermal power plant. Soil resuspension is probably a secondary source of atmospheric particles. The plume transports from Manaus to the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility ARM site at Manacapuru urban pollutants as well as pollutants from pottery factories along the route of the plume. Considering the effects of particulate matter on health, atmospheric particulate matter was evaluated at this site as part of the ARM Facility’s Green Ocean Amazon 2014/15 (GoAmazon 2014/15) field campaign. Aerosol or particulate matter (PM) is typically defined by size, with the smaller particles having more health impact. Total suspended particulate (TSP) are particles smaller than 100 μm; particles smaller than 2.5 μm are called PM2.5. In this work, the PM2.5 levels were obtained from March to December of 2015, totaling 34 samples and TSP levels from October to December of 2015, totaling 17 samples. Sampling was conducted with PM2.5 and TSP high-volume samplers using quartz filters (Figure 1). Filters were stored during 24 hours in a room with temperature (21,1ºC) and humidity (44,3 %) control, in order to do gravimetric analyses by weighing before and after sampling. This procedure followed the recommendations of the Brazilian Association for Technical Standards local norm (NBR 9547:1997). Mass concentrations of particulate matter were obtained from the ratio between the weighted sample and the volume of air collected. Defining a relationship between particulate matter (PM2.5 and TSP) and respiratory diseases of the local population is an important goal of this project, since no information exists on that topic.

  12. Habitual 'sleep credit' is associated with greater grey matter volume of the medial prefrontal cortex, higher emotional intelligence and better mental health.

    PubMed

    Weber, Mareen; Webb, Christian A; Deldonno, Sophie R; Kipman, Maia; Schwab, Zachary J; Weiner, Melissa R; Killgore, William D S

    2013-10-01

    In modern society, people often fail to obtain the amount of sleep that experts recommend for good health and performance. Insufficient sleep can lead to degraded cognitive performance and alterations in emotional functioning. However, most people also acknowledge that on a regular basis they obtain more sleep than they subjectively perceive they need at a minimum to stave off performance decrements, a construct we describe as subjective 'sleep credit'. Few people would contest the notion that getting more sleep is better, but data on both behavioural and neuroanatomical correlates of 'sleep credit' are surprisingly limited. We conducted a voxel-based morphometric study to assess cerebral grey matter correlates of habitually sleeping more than one's subjective requirements. We further tested whether these structural correlates are associated with perceived emotional intelligence and indices of psychopathology while controlling for age, gender, and total intracranial volume. In a sample of 55 healthy adults aged 18-45 years (28 males, 27 females), whole-brain multiple regression showed that habitual subjective 'sleep credit' was correlated positively with grey matter volume within regions of the left medial prefrontal cortex and right orbitofrontal gyrus. Volumes were extracted and regressed against self-report emotion and psychopathology indices. Only grey matter volume of the medial prefrontal cortex cluster correlated with greater emotional intelligence and lower scores on several indices of psychopathology. Findings converge with previous evidence of the role of the medial prefrontal cortex in the relationship between sleep and emotional functioning, and suggest that behaviour and brain structure vary with habitual 'sleep credit'.

  13. Does Dirac-Born-Infeld modification of quadratic theories really matter?

    SciTech Connect

    Quiros, Israel; Urena-Lopez, L. Arturo

    2010-08-15

    We study the consequences of further modification of f(R,R{sub {mu}{nu}R}{sup {mu}{nu}},R{sub {mu}{nu}{sigma}{rho}R}{sup {mu}{nu}{sigma}{rho}})/f(R) theories by means of the Dirac-Born-Infeld procedure, which is the replacement of f by {lambda}({radical}(1+2f/{lambda})-1) (the free parameter {lambda} fixes an additional energy scale). We pay special attention to the definition of masses of the linearized propagating degrees of freedom because they are important to judge the stability of the linearization around vacuum background spaces. In this context we discuss the subtleties associated with expanding f(R,R{sub {mu}{nu}R}{sup {mu}{nu}},R{sub {mu}{nu}{sigma}{rho}R}{sup {mu}{nu}{sigma}{rho}}) Lagrangians around maximally symmetric spaces of constant curvature, as well as with equivalence of the linearized Lagrangian to a scalar-tensor theory. Investigation of the consequences of applying the Dirac-Born-Infeld (DBI) strategy to further modify quadratic theories on the stability of de Sitter vacuum, as well as its impact on the cosmological dynamics, are the main concern of this paper. We show that (i) although the DBI deformation does not affect the Ostrogradski stability, other important instabilities such as the Ricci and scalar-tachyon ones, may be indeed surmounted (sometimes at the cost of renouncing to the original motivation of the DBI strategy, to avoid singularities), and (ii) DBI transforming the original theory broadens its possibilities to do cosmology since the asymptotic structure of the DBI-dual theory is richer than in the standard case. In particular, either the dimension of the phase space is increased, or there appear bifurcations in the control-parameter space.

  14. On the validity of the effective field theory for dark matter searches at the LHC part III: analysis for the t-channel

    NASA Astrophysics Data System (ADS)

    Busoni, Giorgio; De Simone, Andrea; Jacques, Thomas; Morgante, Enrico; Riotto, Antonio

    2014-09-01

    We extend our recent analysis of the limitations of the effective field theory approach to studying dark matter at the LHC, by investigating the case in which Dirac dark matter couples to standard model quarks via t-channel exchange of a heavy scalar mediator. We provide analytical results for the validity of the effective field theory description, for both √s = 8 TeV and 14 TeV. We make use of a MonteCarlo event generator to assess the validity of our analytical conclusions. We also point out the general trend that in the regions where the effective field theory is valid, the dark matter relic abundance is typically large.

  15. Towards a Realization of the Condensed-Matter-Gravity Correspondence in String Theory via Consistent Abelian Truncation of the Aharony-Bergman-Jafferis-Maldacena Model

    NASA Astrophysics Data System (ADS)

    Mohammed, Asadig; Murugan, Jeff; Nastase, Horatiu

    2012-11-01

    We present an embedding of the three-dimensional relativistic Landau-Ginzburg model for condensed matter systems in an N=6, U(N)×U(N) Chern-Simons-matter theory [the Aharony-Bergman-Jafferis-Maldacena model] by consistently truncating the latter to an Abelian effective field theory encoding the collective dynamics of O(N) of the O(N2) modes. In fact, depending on the vacuum expectation value on one of the Aharony-Bergman-Jafferis-Maldacena scalars, a mass deformation parameter μ and the Chern-Simons level number k, our Abelianization prescription allows us to interpolate between the Abelian Higgs model with its usual multivortex solutions and a ϕ4 theory. We sketch a simple condensed matter model that reproduces all the salient features of the Abelianization. In this context, the Abelianization can be interpreted as giving a dimensional reduction from four dimensions.

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

    PubMed

    Mohammed, Asadig; Murugan, Jeff; Nastase, Horatiu

    2012-11-02

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

  17. Self-consistent field theory of tethered polymers: One dimensional, three dimensional, strong stretching theories and the effects of excluded-volume-only interactions

    SciTech Connect

    Suo, Tongchuan Whitmore, Mark D.

    2014-11-28

    We examine end-tethered polymers in good solvents, using one- and three-dimensional self-consistent field theory, and strong stretching theories. We also discuss different tethering scenarios, namely, mobile tethers, fixed but random ones, and fixed but ordered ones, and the effects and important limitations of including only binary interactions (excluded volume terms). We find that there is a “mushroom” regime in which the layer thickness is independent of the tethering density, σ, for systems with ordered tethers, but we argue that there is no such plateau for mobile or disordered anchors, nor is there one in the 1D theory. In the other limit of brushes, all approaches predict that the layer thickness scales linearly with N. However, the σ{sup 1/3} scaling is a result of keeping only excluded volume interactions: when the full potential is included, the dependence is faster and more complicated than σ{sup 1/3}. In fact, there does not appear to be any regime in which the layer thickness scales in the combination Nσ{sup 1/3}. We also compare the results for two different solvents with each other, and with earlier Θ solvent results.

  18. Theory of excluded volume equation of state: higher approximations and new generation of equations of state for entire density range.

    PubMed

    Rusanov, Anatoly I

    2004-07-22

    A novel theory of an equation of state based on excluded volume and formulated in two preceding papers for gases and gaseous mixtures is extended to the entire density range by considering higher (beginning from the third) approximations of the theory. The algorithm of constructing higher approximations is elaborated. Equations of state are deduced using the requirement of maximum simplicity and contain a single free parameter to be chosen by reason of convenience or simplicity or to be used as a fitting parameter with respect to the computer simulation database. In this way, precise equations of state are derived for the hard-sphere fluid in the entire density range. On the side, the theory reproduces most known earlier equations of state for hard spheres and determines their place in the hierarchy of approximations. Equations of state for van der Waals fluids are also presented, and their critical parameters are estimated.

  19. Muon flux limits for Majorana dark matter from strong coupling theories

    SciTech Connect

    Belotsky, Konstantin; Khlopov, Maxim; Kouvaris, Chris

    2009-04-15

    We analyze the effects of the capture of dark matter (DM) particles, with successive annihilations, predicted in the minimal walking technicolor model (MWT) by the Sun and the Earth. We show that the Super-Kamiokande upper limit on excessive muon flux disfavors the mass interval between 100 and 200 GeV for MWT DM with a suppressed standard model interaction (due to a mixing angle), and the mass interval between 0 and 1500 GeV for MWT DM without such suppression, upon making the standard assumption about the value of the local DM distribution. In the first case, the exclusion interval is found to be very sensitive to the DM distribution parameters and can vanish at the extreme of the acceptable values.

  20. Supersymmetric U( N) Chern-Simons-Matter Theory and Phase Transitions

    NASA Astrophysics Data System (ADS)

    Russo, Jorge G.; Silva, Guillermo A.; Tierz, Miguel

    2015-09-01

    We study supersymmetric U( N) Chern-Simons with fundamental and antifundamental chiral multiplets of mass m in the parameter space spanned by ( g, m, N, N f ), where g denotes the coupling constant. In particular, we analyze the matrix model description of its partition function, both at finite N using the method of orthogonal polynomials together with Mordell integrals and, at large N with fixed g, using the theory of Toeplitz determinants. We show for the massless case that there is an explicit realization of the Giveon-Kutasov duality. For finite N, with , three regimes that exactly correspond to the known three large N phases of the theory are identified and characterized.

  1. Theory and applications of light-matter interactions in quantum dot nanowire photonic crystal systems

    NASA Astrophysics Data System (ADS)

    Angelatos, Gerasimos

    Photonic crystal slabs coupled with quantum dipole emitters allow one to control quantum light-matter interactions and are a promising platform for quantum information science technologies; however their development has been hindered by inherent fabrication issues. Inspired by recent nanowire growth techniques and opportunities in fundamental quantum nanophotonics, in this thesis we theoretically investigate light-matter interactions in nanowire photonic crystal structures with embedded quantum dots, a novel engineered quantum system, for applications in quantum optics. We develop designs for currently fabricable structures, including finite-size effects and radiative loss, and investigate their fundamental properties using photonic band structure calculations, finite-difference time-domain computations, and a rigorous photonic Green function technique. We study and engineer realistic nanowire photonic crystal waveguides for single photon applications whose performance can exceed that of state-of-the-art slab photonic crystals, and design a directed single photon source. We then develop a powerful quantum optical formalism using master equation techniques and the photonic Green function to understand the quantum dynamics of these exotic structures in open and lossy photonic environments. This is used to explore the coupling of a pair of quantum dots in a nanowire photonic crystal waveguide, demonstrating long-lived entangled states and a system with a completely controllable Hamiltonian capable of simulating a wide variety of quantum systems and entering a unique regime of cavity quantum electrodynamics characterized by strong exchange-splitting. Lastly, we propose and study a "metamaterial" polariton waveguide comprised of a nanowire photonic crystal waveguide with an embedded quantum dot in each unit cell, and explain the properties of both infinite and finite-sized structures using a Green function approach. We show that an external quantum dot can be strongly

  2. Constraints on cold dark matter theories from observations of massive x-ray-luminous clusters of galaxies at high redshift

    NASA Technical Reports Server (NTRS)

    Luppino, G. A.; Gioia, I. M.

    1995-01-01

    During the course of a gravitational lensing survey of distant, X-ray selected Einstein Observatory Extended Medium Sensitivity Survey (EMSS) clusters of galaxies, we have studied six X-ray-luminous (L(sub x) greater than 5 x 10(exp 44)(h(sub 50)(exp -2))ergs/sec) clusters at redshifts exceeding z = 0.5. All of these clusters are apparently massive. In addition to their high X-ray luminosity, two of the clusters at z approximately 0.6 exhibit gravitationally lensed arcs. Furthermore, the highest redshift cluster in our sample, MS 1054-0321 at z = 0.826, is both extremely X-ray luminous (L(sub 0.3-3.5keV)=9.3 x 10(exp 44)(h(sub 50)(exp -2))ergs/sec) and exceedingly rich with an optical richness comparable to an Abell Richness Class 4 cluster. In this Letter, we discuss the cosmological implications of the very existence of these clusters for hierarchical structure formation theories such as standard Omega = 1 CDM (cold dark matter), hybrid Omega = 1 C + HDM (hot dark matter), and flat, low-density Lambda + CDM models.

  3. Resting-State Functional Connectivity Bias of Middle Temporal Gyrus and Caudate with Altered Gray Matter Volume in Major Depression

    PubMed Central

    Ma, Chaoqiong; Ding, Jurong; Li, Jun; Guo, Wenbin; Long, Zhiliang; Liu, Feng; Gao, Qing; Zeng, Ling; Zhao, Jingping; Chen, Huafu

    2012-01-01

    Magnetic resonance imaging (MRI) studies have indicated that the structure deficits and resting-state functional connectivity (FC) imbalances in cortico-limbic circuitry might underline the pathophysiology of MDD. Using structure and functional MRI, our aim is to investigate gray matter abnormalities in patients with treatment-resistant depression (TRD) and treatment-responsive depression (TSD), and test whether the altered gray matter is associated with altered FC. Voxel-based morphometry was used to investigate the regions with gray matter abnormality and FC analysis was further conducted between each gray matter abnormal region and the remaining voxels in the brain. Using one-way analysis of variance, we found significant gray matter abnormalities in the right middle temporal cortex (MTG) and bilateral caudate among the TRD, TSD and healthy controls. For the FC of the right MTG, we found that both the patients with TRD and TSD showed altered connectivity mainly in the default-mode network (DMN). For the FC of the right caudate, both patient groups showed altered connectivity in the frontal regions. Our results revealed the gray matter reduction of right MTG and bilateral caudate, and disrupted functional connection to widely distributed circuitry in DMN and frontal regions, respectively. These results suggest that the abnormal DMN and reward circuit activity might be biomarkers of depression trait. PMID:23028892

  4. The effect of skull volume and density on differentiating gray and white matter on routine computed tomography scans of the head.

    PubMed

    Craddock, Carter; Chen, Michael Y; Dixon, Robert L; Schlarb, Christopher A; Williams, Daniel W

    2006-01-01

    Increased volume and density of the skull makes computed tomography differentiation of gray and white matter (GM and WM, respectively) more difficult. The purpose of this investigation was to study the effects of skull volume and bone density on GM and WM differentiation. A total of 21 patients with thick skulls and 22 controls were included in this study. Three consecutive slices from the computed tomography scan were analyzed. The basal ganglia had to be visualized on at least 1 slice. Calvarial volume measurement, mean pixel value in each slice, and Hounsfield unit difference between WM and GM, were compared between the thick-skulled and control groups. The mean bone volume of each slice in the thick-skulled group was 55.7, 54.3, and 56 mL, whereas the mean volume of each slice in the normal group was 39.3, 38.5, and 39.9 mL (P < 0.001). In our series, patients with thick skulls had 41% more bone volume than the normal group. The mean skull pixel value in each slice was 935.9 in patients with thick skulls and 987 in patients in the normal group. There was no difference between right and left sides of the same group of patients. Patients with larger volumes of skull have significant decrease in the Hounsfield unit of the GM and WM compared with the control group. As a result, diagnosing any low-contrast brain abnormality including early/subtle infarction in subjects with a thicker calvarium may be more difficult.

  5. Contributions of organic and inorganic matter to sediment volume and accretion in tidal wetlands at steady state

    EPA Science Inventory

    A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function of loss on ignition (LOI). The model assumes the bulk volume of sediment equates to the sum of self-packing volumes of organic and mineral components or BD =...

  6. Finding Freedom in the Classroom: A Practical Introduction to Critical Theory. Counterpoints, Volume 24.

    ERIC Educational Resources Information Center

    Hinchey, Patricia H.

    This book introduces critical theory, providing a practical starting point for teachers interested in exploring alternatives for creating a new kind of classroom experience, both for themselves and their students. Critical theory offers most educators an approach to education that is radically different from the norm. This book provides the…

  7. Abnormal brain white matter network in young smokers: a graph theory analysis study.

    PubMed

    Zhang, Yajuan; Li, Min; Wang, Ruonan; Bi, Yanzhi; Li, Yangding; Yi, Zhang; Liu, Jixin; Yu, Dahua; Yuan, Kai

    2017-03-13

    Previous diffusion tensor imaging (DTI) studies had investigated the white matter (WM) integrity abnormalities in some specific fiber bundles in smokers. However, little is known about the changes in topological organization of WM structural network in young smokers. In current study, we acquired DTI datasets from 58 male young smokers and 51 matched nonsmokers and constructed the WM networks by the deterministic fiber tracking approach. Graph theoretical analysis was used to compare the topological parameters of WM network (global and nodal) and the inter-regional fractional anisotropy (FA) weighted WM connections between groups. The results demonstrated that both young smokers and nonsmokers had small-world topology in WM network. Further analysis revealed that the young smokers exhibited the abnormal topological organization, i.e., increased network strength, global efficiency, and decreased shortest path length. In addition, the increased nodal efficiency predominately was located in frontal cortex, striatum and anterior cingulate gyrus (ACG) in smokers. Moreover, based on network-based statistic (NBS) approach, the significant increased FA-weighted WM connections were mainly found in the PFC, ACG and supplementary motor area (SMA) regions. Meanwhile, the network parameters were correlated with the nicotine dependence severity (FTND) scores, and the nodal efficiency of orbitofrontal cortex was positive correlation with the cigarette per day (CPD) in young smokers. We revealed the abnormal topological organization of WM network in young smokers, which may improve our understanding of the neural mechanism of young smokers form WM topological organization level.

  8. International Conference on Mathematical Methods in Electromagnetic Theory (MMET 2000), Volume 1 Held in Kharkov, Ukraine on September 12-15, 2000

    DTIC Science & Technology

    2000-09-01

    Conference Proceedings 2000 International Conference on MATHEMATICAL METHODS IN ELECTROMAGNETIC THEORY MMkT 2000 Volume 1 Kharkov. Ukraine September...Final 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS International Conference on Mathematical Methods In Electromagnetic Theory F61775-00-WF084 (MMET 2000...Maximum 200 words) This is Volume I of the final Conference Proceedings of the 8th International Conference on Mathematical Methods in Electromagnetic

  9. Oxidative mitochondrial DNA damage in peripheral blood mononuclear cells is associated with reduced volumes of hippocampus and subcortical gray matter in chronically HIV-infected patients

    PubMed Central

    Kallianpur, Kalpana J.; Gerschenson, Mariana; Mitchell, Brooks I.; LiButti, Daniel E.; Umaki, Tracie M.; Ndhlovu, Lishomwa C.; Nakamoto, Beau K.; Chow, Dominic C.; Shikuma, Cecilia M.

    2016-01-01

    Cross-sectional relationships were examined between regional brain volumes and mitochondrial DNA (mtDNA) 8-hydroxy-2-deoxyguanosine (8-oxo-dG) in peripheral blood mononuclear cells (PBMCs) of 47 HIV patients [mean age 51 years; 81% with HIV RNA ≤50 copies/mL] on combination antiretroviral therapy. The gene-specific DNA damage and repair assay measured mtDNA 8-oxo-dG break frequency. Magnetic resonance imaging was performed at 3 T. Higher mtDNA 8-oxo-dG was associated with lateral ventricular enlargement and with decreased volumes of hippocampus, pallidum, and total subcortical gray matter, suggesting the involvement of systemic mitochondrial-specific oxidative stress in chronic HIV-related structural brain changes and cognitive difficulties. Clarification of the mechanism may provide potential therapeutic targets. PMID:26923169

  10. International journal of quantum chemistry. Quantum Chemistry Symposium Number 27: Proceedings of the International Symposium on Atomic, Molecular, and Condensed Matter Theory and Computational Methods

    NASA Astrophysics Data System (ADS)

    Lowdin, Per-Olov; Ohrn, N. Y.; Sabin, John R.; Zerner, Michael C.

    1993-03-01

    The topics covered at the 33rd annual Sanibel Symposium, organized by the faculty and staff of the Quantum Theory Project of the University of Florida, and held March 13 - 20, 1993, include advanced scientific computing, interaction of photons and matter, quantum molecular dynamics, electronic structure methods, polymeric systems, and quantum chemical methods for extended systems.

  11. Prefrontal-Parietal White Matter Volumes in Healthy Elderlies Are Decreased in Proportion to the Degree of Cardiovascular Risk and Related to Inhibitory Control Deficits

    PubMed Central

    Santos, Pedro P.; Silveira, Paula S. Da; Souza-Duran, Fabio L.; Tamashiro-Duran, Jaqueline H.; Scazufca, Márcia; Menezes, Paulo R.; Leite, Claudia Da Costa; Lotufo, Paulo A.; Vallada, Homero; Wajngarten, Maurício; De Toledo Ferraz Alves, Tânia C.; Rzezak, Patricia; Busatto, Geraldo F.

    2017-01-01

    Cardiovascular risk (CVR) factors may be associated with poor cognitive functioning in elderlies and impairments in brain structure. Using MRI and voxel-based morphometry (VBM), we assessed regional white matter (WM) volumes in a population-based sample of individuals aged 65–75 years (n = 156), subdivided in three CVR subgroups using the Framingham Risk Score. Cognition was assessed using the Short Cognitive Performance Test. In high-risk subjects, we detected significantly reduced WM volume in the right juxtacortical dorsolateral prefrontal region compared to both low and intermediate CVR subgroups. Findings remained significant after accounting for the presence of the APOEε4 allele. Inhibitory control performance was negatively related to right prefrontal WM volume, proportionally to the degree of CVR. Significantly reduced deep parietal WM was also detected bilaterally in the high CVR subgroup. This is the first large study documenting the topography of CVR-related WM brain volume deficits. The significant association regarding poor response inhibition indicates that prefrontal WM deficits related to CVR are clinically meaningful, since inhibitory control is known to rely on prefrontal integrity. PMID:28184203

  12. Gray Matter Volumes in Obsessive-Compulsive Disorder Before and After Fluoxetine or Cognitive-Behavior Therapy: A Randomized Clinical Trial

    PubMed Central

    Hoexter, Marcelo Queiroz; de Souza Duran, Fábio Luis; D'Alcante, Carina Chaubet; Dougherty, Darin Dean; Shavitt, Roseli Gedanke; Lopes, Antonio Carlos; Diniz, Juliana Belo; Deckersbach, Thilo; Batistuzzo, Marcelo Camargo; Bressan, Rodrigo Affonseca; Miguel, Euripedes Constantino; Busatto, Geraldo Filho

    2012-01-01

    Serotonin reuptake inhibitors and cognitive-behavior therapy (CBT) are considered first-line treatments for obsessive-compulsive disorder (OCD). However, little is known about their modulatory effects on regional brain morphology in OCD patients. We sought to document structural brain abnormalities in treatment-naive OCD patients and to determine the effects of pharmacological and cognitive-behavioral treatments on regional brain volumes. Treatment-naive patients with OCD (n=38) underwent structural magnetic resonance imaging scan before and after a 12-week randomized clinical trial with either fluoxetine or group CBT. Matched-healthy controls (n=36) were also scanned at baseline. Voxel-based morphometry was used to compare regional gray matter (GM) volumes of regions of interest (ROIs) placed in the orbitofrontal, anterior cingulate and temporolimbic cortices, striatum, and thalamus. Treatment-naive OCD patients presented smaller GM volume in the left putamen, bilateral medial orbitofrontal, and left anterior cingulate cortices than did controls (p<0.05, corrected for multiple comparisons). After treatment with either fluoxetine or CBT (n=26), GM volume abnormalities in the left putamen were no longer detectable relative to controls. ROI-based within-group comparisons revealed that GM volume in the left putamen significantly increased (p<0.012) in fluoxetine-treated patients (n=13), whereas no significant GM volume changes were observed in CBT-treated patients (n=13). This study supports the involvement of orbitofronto/cingulo-striatal loops in the pathophysiology of OCD and suggests that fluoxetine and CBT may have distinct neurobiological mechanisms of action. PMID:22030709

  13. ATLAS, an integrated structural analysis and design system. Volume 6: Design module theory

    NASA Technical Reports Server (NTRS)

    Backman, B. F.

    1979-01-01

    The automated design theory underlying the operation of the ATLAS Design Module is decribed. The methods, applications and limitations associated with the fully stressed design, the thermal fully stressed design and a regional optimization algorithm are presented. A discussion of the convergence characteristics of the fully stressed design is also included. Derivations and concepts specific to the ATLAS design theory are shown, while conventional terminology and established methods are identified by references.

  14. Research in Lattice Gauge Theory and in the Phenomenology of Neutrinos and Dark Matter

    SciTech Connect

    Meurice, Yannick L; Reno, Mary Hall

    2016-06-23

    Research in theoretical elementary particle physics was performed by the PI Yannick Meurice and co-PI Mary Hall Reno. New techniques designed for precision calculations of strong interaction physics were developed using the tensor renormalization group method. Large-scale Monte Carlo simulations with dynamical quarks were performed for candidate models for Higgs compositeness. Ab-initio lattice gauge theory calculations of semileptonic decays of B-mesons observed in collider experiments and relevant to test the validity of the standard model were performed with the Fermilab/MILC collaboration. The phenomenology of strong interaction physics was applied to new predictions for physics processes in accelerator physics experiments and to cosmic ray production and interactions. A research focus has been on heavy quark production and their decays to neutrinos. The heavy quark contributions to atmospheric neutrino and muon fluxes have been evaluated, as have the neutrino fluxes from accelerator beams incident on heavy targets. Results are applicable to current and future particle physics experiments and to astrophysical neutrino detectors such as the IceCube Neutrino Observatory.

  15. Writing as a Learning Tool: Integrating Theory and Practice. Studies in Writing, Volume 7.

    ERIC Educational Resources Information Center

    Tynjala, Paivi, Ed.; Mason, Lucia, Ed.; Lonka, Kirsti, Ed.

    This book, the seventh volume in the Studies in Writing International Series on the Research of Learning and Instruction of Writing, is an account of the current state of using writing as a tool for learning. The book presents psychological and educational foundations of the writing across the curriculum movement and describes writing-to-learn…

  16. Health Occupations Curriculum. Skills and Theory for Health Assistant. Volume I, Units 1-4.

    ERIC Educational Resources Information Center

    Arizona State Dept. of Education, Phoenix.

    This volume consists of the first four units of a basic core curriculum that is intended for all health workers. The units deal with the following topics: (1) the health care facility, the long-term care facility, the health team, and the nursing team; (2) verbal and nonverbal communication, written communication, human behavior, ethical behavior,…

  17. SOURCE SAMPLING FINE PARTICULATE MATTER: A KRAFT PROCESS RECOVERY BOILER AT A PULP AND PAPER FACILITY, VOLUMES 1 AND 2

    EPA Science Inventory

    Fine particulate matter of aerodynamic diameter 2.5 m or less (PM-2.5) has been found harmful to human health, and a National Ambient Air Quality Standard for PM-2.5 was promulgated by the U.S. Environmental Protection Agency in July 1997. A national network of ambient monitorin...

  18. Middle School Matters: Improving the Life Course of Black Boys. Policy Notes. Volume 20, Number 4, Winter 2012

    ERIC Educational Resources Information Center

    Yaffe, Deborah

    2012-01-01

    This issue of ETS Policy Notes (Vol. 20, No. 4) provides highlights from the symposium, "Middle School Matters: Improving the Life Course of Black Boys" held on July 23-24, 2012. The second in a series of four symposia co-sponsored by ETS and the Children's Defense Fund (CDF), the seminar examined the education and status of…

  19. Radiation Therapy After Breast-Conserving Surgery: Does Hospital Surgical Volume Matter? A Population-Based Study in Taiwan

    SciTech Connect

    Chien, Chun-Ru; Pan, I-Wen; Tsai, Yi-Wen; Tsai, Teressa; Liang, Ji-An; Buchholz, Thomas A.; Shih, Ya-Chen Tina

    2012-01-01

    Purpose: To examine the association between hospital surgical volume and the use of radiation therapy (RT) after breast-conserving surgery (BCS) in Taiwan. Methods and Materials: We used claims data from the National Health Insurance program in Taiwan (1997-2005) in this retrospective population-based study. We identified patients with breast cancer, receipt of BCS, use of radiation, and the factors that could potentially associated with the use of RT from enrollment records, and the ICD-9 and billing codes in claims. We conducted logistic regression to examine factors associated with RT use after BCS, and performed subgroup analyses to examine whether the association differs by medical center status or hospital volumes. Results: Among 5,094 patients with newly diagnosed invasive breast cancer who underwent BCS, the rate of RT was significantly lower in low-volume hospitals (74% vs. 82%, p < 0.01). Patients treated in low-volume hospitals were less likely to receive RT after BCS (odds ratio = 0.72, 95% confidence interval = 0.62-0.83). In addition, patients treated after the implementation of the voluntary pay-for-performance policy in 2001 were more likely to receive RT (odds ratio = 1.23; 95% confidence interval = 1.05-1.45). Subgroup analyses indicated that the high-volume effect was limited to hospitals accredited as non-medical centers, and that the effect of the pay-for-performance policy was most pronounced among low-volume hospitals. Conclusions: Using population-based data from Taiwan, our study concluded that hospital surgical volume and pay-for-performance policy are positively associated with RT use after BCS.

  20. Chern-Simons theories with fundamental matter: A brief review of large N results including Fermi-Bose duality and the S-matrix

    NASA Astrophysics Data System (ADS)

    Wadia, Spenta R.

    2016-10-01

    We begin with a few words about Salam’s contribution to the growth of String Theory in India. In the technical talk we review results in SU(N) Chern-Simons plus vector matter theories in 2+1 dim in the large N limit. The dressing of charged matter by Chern-Simons gauge fields leads to anyons that interpolate between fermions and bosons and lead to a duality symmetry between fermionic and bosonic theories. The S-matrix (defined in the large N limit) besides exhibiting this duality, also exhibits novel properties due to the presence of anyons. The S-matrix is not analytic, like in Aharonov-Bohm scattering, and satisfies modified crossing symmetry relations.

  1. The Quantum Theory of Fields

    NASA Astrophysics Data System (ADS)

    Weinberg, Steven

    1996-08-01

    In this second volume of The Quantum Theory of Fields, available for the first time in paperback, Nobel Laureate Steven Weinberg continues his masterly expoistion of quantum theory. Volume 2 provides an up-to-date and self-contained account of the methods of quantum field theory, and how they have led to an understanding of the weak, strong, and electromagnetic interactions of the elementary particles. The presentation of modern mathematical methods is throughout interwoven with accounts of the problems of elementary particle physics and condensed matter physics to which they have been applied. Exercises are included at the end of each chapter.

  2. Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 1: Noise Sources

    NASA Technical Reports Server (NTRS)

    Hubbard, Harvey H. (Editor)

    1991-01-01

    Methodology recommended to evaluate aeroacoustic related problems is provided, and approaches to their solutions are suggested without extensive tables, nomographs, and derivations. Orientation is toward flight vehicles and emphasis is on underlying physical concepts. Theoretical, experimental, and applied aspects are covered, including the main formulations and comparisons of theory and experiment. The topics covered include: propeller and propfan noise, rotor noise, turbomachinery noise, jet noise classical theory and experiments, noise from turbulent shear flows, jet noise generated by large-scale coherent motion, airframe noise, propulsive lift noise, combustion and core noise, and sonic booms.

  3. Toward order-by-order calculations of the nuclear and neutron matter equations of state in chiral effective field theory

    NASA Astrophysics Data System (ADS)

    Sammarruca, F.; Coraggio, L.; Holt, J. W.; Itaco, N.; Machleidt, R.; Marcucci, L. E.

    2015-05-01

    We calculate the nuclear and neutron matter equations of state from microscopic nuclear forces at different orders in chiral effective field theory and with varying momentum-space cutoff scales. We focus attention on how the order-by-order convergence depends on the choice of resolution scale and the implications for theoretical uncertainty estimates on the isospin asymmetry energy. Specifically we study the equations of state using consistent NLO and N2LO (next-to-next-to-leading order) chiral potentials where the low-energy constants cD and cE associated with contact vertices in the N2LO chiral three-nucleon force are fitted to reproduce the binding energies of H3 and He3 as well as the beta-decay lifetime of H3 . At these low orders in the chiral expansion there is little sign of convergence, while an exploratory study employing the N3LO two-nucleon force together with the N2LO three-nucleon force give first indications for (slow) convergence with low-cutoff potentials and poor convergence with higher-cutoff potentials. The consistent NLO and N2LO potentials described in the present work provide the basis for estimating theoretical uncertainties associated with the order-by-order convergence of nuclear many-body calculations in chiral effective field theory.

  4. Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 2: Noise Control

    NASA Technical Reports Server (NTRS)

    Hubbard, Harvey H. (Editor)

    1991-01-01

    Flight vehicles and the underlying concepts of noise generation, noise propagation, noise prediction, and noise control are studied. This volume includes those chapters that relate to flight vehicle noise control and operations: human response to aircraft noise; atmospheric propagation; theoretical models for duct acoustic propagation and radiation; design and performance of duct acoustic treatment; jet noise suppression; interior noise; flyover noise measurement and prediction; and quiet aircraft design and operational characteristics.

  5. Coupled 2-dimensional cascade theory for noise an d unsteady aerodynamics of blade row interaction in turbofans. Volume 2: Documentation for computer code CUP2D

    NASA Technical Reports Server (NTRS)

    Hanson, Donald B.

    1994-01-01

    A two dimensional linear aeroacoustic theory for rotor/stator interaction with unsteady coupling was derived and explored in Volume 1 of this report. Computer program CUP2D has been written in FORTRAN embodying the theoretical equations. This volume (Volume 2) describes the structure of the code, installation and running, preparation of the input file, and interpretation of the output. A sample case is provided with printouts of the input and output. The source code is included with comments linking it closely to the theoretical equations in Volume 1.

  6. Student Assessment System. Domain Referenced Tests. Allied Health Occupations/Practical Nursing. Volume II: Theory.

    ERIC Educational Resources Information Center

    Campbell, Gene, Comp.; Simpson, Bruce, Comp.

    These written domain referenced tests (DRTs) for the area of allied health occupations/practical nursing test cognitive abilities or knowledge of theory. Introductory materials describe domain referenced testing and test development. Each multiple choice test includes a domain statement, describing the behavior and content of the domain, and a…

  7. Teaching Together, Learning Together. Counterpoints, Studies in the Postmodern Theory of Education Volume 294

    ERIC Educational Resources Information Center

    Roth, Wolff-Michael, Ed.; Tobin, Kenneth, Ed.

    2005-01-01

    Coteaching and cogenerative dialoguing are ways of learning to teach that truly bridge the gap between theory and praxis, as new teachers learn to teach alongside peers and more experienced teachers. These practices are also means of overcoming teacher isolation and burnout. Through cogenerative dialogue sessions, new and experienced teachers,…

  8. RIKEN BNL RESEARCH CENTER WORKSHOP ON GAUGE-INVARIANT VARIABLES IN GAUGE THEORIES, VOLUME 20

    SciTech Connect

    VAN BAAL,P.; ORLAND,P.; PISARSKI,R.

    2000-06-01

    This four-day workshop focused on the wide variety of approaches to the non-perturbative physics of QCD. The main topic was the formulation of non-Abelian gauge theory in orbit space, but some other ideas were discussed, in particular the possible extension of the Maldacena conjecture to nonsupersymmetric gauge theories. The idea was to involve most of the participants in general discussions on the problem. Panel discussions were organized to further encourage debate and understanding. Most of the talks roughly fell into three categories: (1) Variational methods in field theory; (2) Anti-de Sitter space ideas; (3) The fundamental domain, gauge fixing, Gribov copies and topological objects (both in the continuum and on a lattice). In particular some remarkable progress in three-dimensional gauge theories was presented, from the analytic side by V.P. Nair and mostly from the numerical side by O. Philipsen. This work may ultimately have important implications for RHIC experiments on the high-temperature quark-gluon plasma.

  9. Temperament: Theory and Practice. Brunner/Mazel Basic Principles into Practice Series, Volume 12.

    ERIC Educational Resources Information Center

    Chess, Stella; Thomas, Alexander

    This book outlines the basic tenets and applications of the theory of temperament based on the findings of the New York Longitudinal Study begun in 1956. It describes the concept and definition of temperament, reviews studies that support and expand on the definition, and explores temperament and its impact across various practice settings and…

  10. Transformative Leadership: A Reader. Counterpoints: Studies in the Postmodern Theory of Education. Volume 409

    ERIC Educational Resources Information Center

    Shields, Carolyn M., Ed.

    2011-01-01

    This important, timely, and thought-provoking reader is a collection of original chapters by authors from five different countries, each of whom explores a facet of transformative leadership. Transformative leadership is fundamentally a critical approach to leadership that goes well beyond the tenets of most current leadership theories to focus on…

  11. One Month of Oral Morphine Decreases Gray Matter Volume in the Right Amygdala of Individuals with Low Back Pain: Confirmation of Previously Reported Magnetic Resonance Imaging Results

    PubMed Central

    Chu, Larry F.; Stringer, Elizabeth Ann; Baker, Katharine S.; Sayyid, Zahra N.; Sun, John; Campbell, Kelsey A.; Younger, Jarred W.

    2016-01-01

    Objective. Prolonged exposure to opioids is known to produce neuroplastic changes in animals; however, few studies have investigated the effects of short-term prescription opioid use in humans. A previous study from our laboratory demonstrated a dosage-correlated volumetric decrease in the right amygdala of participants administered oral morphine daily for 1 month. The purpose of this current study was to replicate and extend the initial findings. Methods. Twenty-one participants with chronic low back pain were enrolled in this double-blind, placebo-controlled study. Participants were randomized to receive daily morphine (n = 11) or a matched placebo (n = 10) for 1 month. High-resolution anatomical images were acquired immediately before and after the treatment administration period. Morphological gray matter changes were investigated using tensor-based morphometry, and significant regions were subsequently tested for correlation with morphine dosage. Results. Decreased gray matter volume was observed in several reward- and pain-related regions in the morphine group, including the bilateral amygdala, left inferior orbitofrontal cortex, and bilateral pre-supplementary motor areas. Morphine administration was also associated with significant gray matter increases in cingulate regions, including the mid cingulate, dorsal anterior cingulate, and ventral posterior cingulate. Conclusions. Many of the volumetric increases and decreases overlapped spatially with the previously reported changes. Individuals taking placebo for 1 month showed neither gray matter increases nor decreases. The results corroborate previous reports that rapid alterations occur in reward-related networks following short-term prescription opioid use. PMID:26814280

  12. Telomere Length and CCL11 Levels are Associated With Gray Matter Volume and Episodic Memory Performance in Schizophrenia: Evidence of Pathological Accelerated Aging.

    PubMed

    Czepielewski, Leticia Sanguinetti; Massuda, Raffael; Panizzutti, Bruna; Grun, Lucas Kich; Barbé-Tuana, Florencia María; Teixeira, Antonio Lucio; Barch, Deanna M; Gama, Clarissa S

    2017-02-22

    Schizophrenia (SZ) is associated with increased somatic morbidity and mortality, in addition to cognitive impairments similar to those seen in normal aging, which may suggest that pathological accelerated aging occurs in SZ. Therefore, we aim to evaluate the relationships of age, telomere length (TL), and CCL11 (aging and inflammatory biomarkers, respectively), gray matter (GM) volume and episodic memory performance in individuals with SZ compared to healthy controls (HC). One hundred twelve participants (48 SZ and 64 HC) underwent clinical and memory assessments, structural MRI, and had their peripheral blood drawn for biomarkers analysis. Comparisons of group means and correlations were performed. Participants with SZ had decreased TL and GM volume, increased CCL11, and worse memory performance compared to HC. In SZ, shorter TL was related to increased CCL11, and both biomarkers were related to reduced GM volume, all of which were related to worse memory performance. Older age was only associated with reduced GM, but longer duration of illness was related with all the aforementioned variables. Younger age of disease onset was associated with increased CCL11 levels and worse memory performance. In HC, there were no significant correlations except between memory and GM. Our results are consistent with the hypothesis of accelerated aging in SZ. These results may indicate that it is not age itself, but the impact of the disease associated with a pathological accelerated aging that leads to impaired outcomes in SZ.

  13. White matter volume in the brainstem and inferior parietal lobule is related to motor performance in children with autism spectrum disorder: A voxel-based morphometry study.

    PubMed

    Hanaie, Ryuzo; Mohri, Ikuko; Kagitani-Shimono, Kuriko; Tachibana, Masaya; Matsuzaki, Junko; Hirata, Ikuko; Nagatani, Fumiyo; Watanabe, Yoshiyuki; Fujita, Norihiko; Taniike, Masako

    2016-09-01

    Many studies have reported poor motor performance in autism spectrum disorder (ASD); however, the underlying brain mechanisms remain unclear. Recent neuroimaging studies have suggested that abnormalities of the white matter (WM) are related to the features of ASD. In this study, we used voxel-based morphometry (VBM) to investigate which WM regions correlate with motor performance in children with ASD, and whether the WM volume in those brain regions differed between children with ASD and typically developing (TD) children. The subjects included 19 children with ASD and 20 TD controls. Motor performance was assessed using the Movement Assessment Battery for Children 2 (M-ABC 2). Children with ASD showed poorer motor performance than did the controls. There was a significant positive correlation between the total test score on the M-ABC 2 and the volume of WM in the brainstem and WM adjacent to the left supramarginal gyrus (SMG). In addition, compared with the TD controls, children with ASD had a decreased volume of WM in the brainstem and adjacent to the left intraparietal sulcus, which is close to the SMG. These findings suggest that structural changes in the WM in the brainstem and left inferior parietal lobule may contribute to poor motor performance in children with ASD. Autism Res 2016, 9: 981-992. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  14. MAIL LOG, program theory, volume 1. [Scout project automatic data system

    NASA Technical Reports Server (NTRS)

    Harris, D. K.

    1979-01-01

    The program theory used to obtain the software package, MAIL LOG, developed for the Scout Project Automatic Data System, SPADS, is described. The program is written in FORTRAN for the PRIME 300 computer system. The MAIL LOG data base consists of three main subfiles: (1) incoming and outgoing mail correspondence; (2) design information releases and reports; and (3) drawings and engineering orders. All subroutine descriptions, flowcharts, and MAIL LOG outputs are given and the data base design is described.

  15. Becoming a Teacher: Using Narrative as Reflective Practice. A Cross-Disciplinary Approach. Counterpoints: Studies in the Postmodern Theory of Education. Volume 411

    ERIC Educational Resources Information Center

    Blake, Robert W., Jr., Ed.; Blake, Brett Elizabeth, Ed.

    2012-01-01

    "Becoming a Teacher" revisits the concept of Teacher Lore (Schubert and Ayers, 1992), by providing a cross-disciplinary approach linking elements of narrative theory to all aspects of pre- and in-service teaching. In essence, it embraces the notion that what teachers say matters. The rationale behind this text is the idea that narrative can not…

  16. Form--a matter of generation: the relation of generation, form, and function in the epigenetic theory of Caspar F. Wolff.

    PubMed

    Witt, Elke

    2008-12-01

    The question, how organisms obtain their specific complex and functional forms, was widely discussed during the eighteenth century. The theory of preformation, which was the dominant theory of generation, was challenged by different alternative epigenetic theories. By the end of the century it was the vitalist approach most famously advocated by Johann Friedrich Blumenbach that prevailed. Yet the alternative theory of generation brought forward by Caspar Friedrich Wolff was an important contribution to the treatment of this question. He turned his attention from the properties of matter and the forces acting on it towards the level of the processes of generation in order to explain the constitution of organismic forms. By regarding organic structures and forms to be the result of the lawfulness of ongoing processes, he opened up the possibility of a functional but non-teleological explanation of generation, and thereby provided an important complement to materialist and vitalist approaches.

  17. Desperately seeking grey matter volume changes in sleep apnea: A methodological review of magnetic resonance brain voxel-based morphometry studies.

    PubMed

    Celle, Sébastien; Delon-Martin, Chantal; Roche, Frédéric; Barthélémy, Jean-Claude; Pépin, Jean-Louis; Dojat, Michel

    2016-02-01

    Cognitive impairment related to obstructive sleep apnea might be explained by subtle changes in brain anatomy. This has been mainly investigated using magnetic resonance brain scans coupled with a voxel-based morphometry analysis. However, this approach is prone to several methodological pitfalls that may explain the large discrepancy in the results reported in the literature. We critically reviewed twelve papers addressing grey matter volume modifications in association with obstructive sleep apnea. Finally, based on strict methodological criteria, only three studies reported robust, but conflicting, results. No clear evidence has emerged and exploring brain alteration due to obstructive sleep apnea should thus be considered as an open field. We provide recommendations for designing additional robust voxel-based morphometry studies, notably the use of larger cohorts, which is the only way to solve the underpowered issue and the underestimated role of confounders in neuroimaging studies.

  18. Amyloid burden in the hippocampus and default mode network: relationships with gray matter volume and cognitive performance in mild stage Alzheimer disease.

    PubMed

    Chang, Ya-Ting; Huang, Chi-Wei; Chang, Yen-Hsiang; Chen, Nai-Ching; Lin, Kun-Ju; Yan, Tzu-Chen; Chang, Wen-Neng; Chen, Sz-Fan; Lui, Chun-Chung; Lin, Pin-Hsuan; Chang, Chiung-Chih

    2015-04-01

    Amyloid load, as measured by florbetapir positron emission tomography (PET) standardized uptake value ratio (SUVr), has high specificity in the diagnosis of Alzheimer disease (AD). As the posterior cingulate cortex (PCC) represents densely amyloid-affected regions early in AD, we hypothesized that amyloid load within the key hubs of the default mode networks (DMN) may result in local or distant interconnected gray matter (GM) volume atrophy, thereby affecting cognitive performance. Thirty AD patients with a clinical dementia rating sum of box score ≤2 were enrolled and underwent cognitive evaluation, 3-dimensional T1-weighted imaging and florbetapir PET. Volumes of interest (VOIs) included the hippocampus, lateral temporal region, and key hubs of the DMN [anterior cingulate cortex (ACC), PCC, posterior parietal, and precuneus]. The SUVr was calculated by florbetapir standard uptake value (SUV) within the T1-weighted image segmented GM VOIs divided by the cerebellar GM SUV. Our results suggested inverse correlations between ACC (ρ = -0.444, P = 0.016) and PCC SUVr (ρ = -0.443, P = 0.016) with PCC GM volume. In stepwise regression, the orientation scores were associated with PCC SUVr (β = 2.584, P = 0.02) and posterior parietal volume (β = -0.446, P = 0.04), whereas the word recall score was related to hippocampal volume (β = -0.391, P = 0.04). After removing the patients with a hippocampal VOI below the lowest tertile and adjusting for age, an inverse correlation was found between hippocampal volume and SUVr in the ACC (partial σ = -0.639, P = 0.002), precuneus (partial σ = -0.692, P = 0.002), and lateral temporal SUVr (partial σ = -0.604, P = 0.005). Our results suggest that amyloid burden within the key DMN regions may contribute to local and distant GM atrophy, and that this may explain the cognitive scores.

  19. A voxel-based morphometry (VBM) analysis of regional grey and white matter volume abnormalities within the speech production network of children who stutter.

    PubMed

    Beal, Deryk S; Gracco, Vincent L; Brettschneider, Jane; Kroll, Robert M; De Nil, Luc F

    2013-09-01

    It is well documented that neuroanatomical differences exist between adults who stutter and their fluently speaking peers. Specifically, adults who stutter have been found to have more grey matter volume (GMV) in speech relevant regions including inferior frontal gyrus, insula and superior temporal gyrus (Beal et al., 2007; Song et al., 2007). Despite stuttering having its onset in childhood only one study has investigated the neuroanatomical differences between children who do and do not stutter. Chang et al. (2008) reported children who stutter had less GMV in the bilateral inferior frontal gyri and middle temporal gyrus relative to fluently speaking children. Thus it appears that children who stutter present with unique neuroanatomical abnormalities as compared to those of adults who stutter. In order to better understand the neuroanatomical correlates of stuttering earlier in its development, near the time of onset, we used voxel-based morphometry to examine volumetric differences between 11 children who stutter and 11 fluent children. Children who stutter had less GMV in the bilateral inferior frontal gyri and left putamen but more GMV in right Rolandic operculum and superior temporal gyrus relative to fluent children. Children who stutter also had less white matter volume bilaterally in the forceps minor of the corpus callosum. We discuss our findings of widespread anatomic abnormalities throughout the cortical network for speech motor control within the context of the speech motor skill limitations identified in people who stutter (Namasivayam and van Lieshout, 2008; Smits-Bandstra et al., 2006).

  20. Tap density equations of granular powders based on the rate process theory and the free volume concept.

    PubMed

    Hao, Tian

    2015-02-28

    The tap density of a granular powder is often linked to the flowability via the Carr index that measures how tight a powder can be packed, under an assumption that more easily packed powders usually flow poorly. Understanding how particles are packed is important for revealing why a powder flows better than others. There are two types of empirical equations that were proposed to fit the experimental data of packing fractions vs. numbers of taps in the literature: the inverse logarithmic and the stretched exponential. Using the rate process theory and the free volume concept under the assumption that particles will obey similar thermodynamic laws during the tapping process if the "granular temperature" is defined in a different way, we obtain the tap density equations, and they are reducible to the two empirical equations currently widely used in literature. Our equations could potentially fit experimental data better with an additional adjustable parameter. The tapping amplitude and frequency, the weight of the granular materials, and the environmental temperature are grouped into this parameter that weighs the pace of the packing process. The current results, in conjunction with our previous findings, may imply that both "dry" (granular) and "wet" (colloidal and polymeric) particle systems are governed by the same physical mechanisms in term of the role of the free volume and how particles behave (a rate controlled process).

  1. Capillary forces between two spheres with a fixed volume liquid bridge: theory and experiment.

    PubMed

    Rabinovich, Yakov I; Esayanur, Madhavan S; Moudgil, Brij M

    2005-11-22

    Capillary forces are commonly encountered in nature because of the spontaneous condensation of liquid from surrounding vapor, leading to the formation of a liquid bridge. In most cases, the advent of capillary forces by condensation leads to undesirable events such as an increase in the strength of granules, which leads to flow problems and/or caking of powder samples. The prediction and control of the magnitude of capillary forces is necessary for eliminating or minimizing these undesirable events. The capillary force as a function of the separation distance, for a liquid bridge with a fixed volume in a sphere/plate geometry, was calculated using different expressions reported previously. These relationships were developed earlier, either on the basis of the total energy of two solid surfaces interacting through the liquid and the ambient vapor or by direct calculation of the force as a result of the differential gas pressure across the liquid bridge. It is shown that the results obtained using these methodologies (total energy or differential pressure) agree, confirming that a total-energy-based approach is applicable, despite the thermodynamic nonequilibrium conditions of a fixed volume bridge rupture process. On the basis of the formulas for the capillary force between a sphere and a plane surface, equations for the calculation of the capillary force between two spheres are derived in this study. Experimental measurements using an atomic force microscope (AFM) validate the formulas developed. The most common approach for transforming interaction force or energy from that of sphere/plate geometry to that of sphere/sphere geometry is the Derjaguin approximation. However, a comparison of the theoretical formulas derived in this study for the interaction of two spheres with those for sphere/plate geometry shows that the Derjaguin approximation is only valid at zero separation distance. This study attempts to explain the inapplicability of the Derjaguin

  2. Constraining the particle nature of dark matter: Model-independent tests from the intersection of theory and observation

    NASA Astrophysics Data System (ADS)

    Mack, Gregory Daniel

    Dark matter is one of the greatest mysteries of modern astrophysics. It comprises about 83% of the matter density in the Universe and approximately 22% of the total energy density, yet its identity and particle properties are unknown. Gravitational interactions reveal its presence, but it does not readily interact with light or normal matter. The purpose of this dissertation is to provide insight into the particle properties of this exotic type of matter in a model-independent fashion. Dark matter is expected to be its own antiparticle, but the strength of its self-annihilation is not known. It is often assumed to be consistent with that which gives the correct abundance if dark matter were produced as a thermal relic in the early Universe, but that has not been proven. Constraints on the dark matter self-annihilation cross section are found over a wide range of masses, both for the separate cases of monoenergetic neutrino and monoenergetic photon production, and the corresponding limits on the total self-annihilation cross section. This is done by comparing the theoretical flux from a region of annihilating dark matter to observational data of that region. While larger than the thermal relic value, the resulting upper bounds are surprisingly stringent and among the first model-independent limits of their kind. A specific application of residual dark matter annihilations during the time of Big Bang Nucleosynthesis is analyzed, adding a lower limit to the value of the annihilation cross section for a certain mass range to couple with the calculated upper bounds mentioned above. The interaction strength of dark matter with normal matter is constrained by the case of dark matter capture in Earth and the resulting heat flow from annihilation in the core. When compared to observation, the analysis rules out many possible interaction strengths between dark matter and normal matter, showing that the interaction, as measured by the interaction cross section, must be truly

  3. STICAP: A linear circuit analysis program with stiff systems capability. Volume 1: Theory manual. [network analysis

    NASA Technical Reports Server (NTRS)

    Cooke, C. H.

    1975-01-01

    STICAP (Stiff Circuit Analysis Program) is a FORTRAN 4 computer program written for the CDC-6400-6600 computer series and SCOPE 3.0 operating system. It provides the circuit analyst a tool for automatically computing the transient responses and frequency responses of large linear time invariant networks, both stiff and nonstiff (algorithms and numerical integration techniques are described). The circuit description and user's program input language is engineer-oriented, making simple the task of using the program. Engineering theories underlying STICAP are examined. A user's manual is included which explains user interaction with the program and gives results of typical circuit design applications. Also, the program structure from a systems programmer's viewpoint is depicted and flow charts and other software documentation are given.

  4. SCDAP/RELAP5/MOD 3.1 code manual: Damage progression model theory. Volume 2

    SciTech Connect

    Davis, K.L.; Allison, C.M.; Berna, G.A.

    1995-06-01

    The SCDAP/RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during a severe accident. The code models the coupled behavior of the reactor coolant system, the core, fission products released during a severe accident transient as well as large and small break loss of coolant accidents, operational transients such as anticipated transient without SCRAM, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits as much of a particular system to be modeled as necessary. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater conditioning systems. This volume contains detailed descriptions of the severe accident models and correlations. It provides the user with the underlying assumptions and simplifications used to generate and implement the basic equations into the code, so an intelligent assessment of the applicability and accuracy of the resulting calculation can be made.

  5. Yoga meditation practitioners exhibit greater gray matter volume and fewer reported cognitive failures: results of a preliminary voxel-based morphometric analysis.

    PubMed

    Froeliger, Brett; Garland, Eric L; McClernon, F Joseph

    2012-01-01

    Hatha yoga techniques, including physical postures (asanas), breathing exercises (pranayama), and meditation, involve the practice of mindfulness. In turn, yoga meditation practices may induce the state of mindfulness, which, when evoked recurrently through repeated practice, may accrue into trait or dispositional mindfulness. Putatively, these changes may be mediated by experience-dependent neuroplastic changes. Though prior studies have identified differences in gray matter volume (GMV) between long-term mindfulness practitioners and controls, no studies to date have reported on whether yoga meditation is associated with GMV differences. The present study investigated GMV differences between yoga meditation practitioners (YMP) and a matched control group (CG). The YMP group exhibited greater GM volume in frontal, limbic, temporal, occipital, and cerebellar regions; whereas the CG had no greater regional greater GMV. In addition, the YMP group reported significantly fewer cognitive failures on the Cognitive Failures Questionnaire (CFQ), the magnitude of which was positively correlated with GMV in numerous regions identified in the primary analysis. Lastly, GMV was positively correlated with the duration of yoga practice. Results from this preliminary study suggest that hatha yoga practice may be associated with the promotion of neuroplastic changes in executive brain systems, which may confer therapeutic benefits that accrue with repeated practice.

  6. Yoga Meditation Practitioners Exhibit Greater Gray Matter Volume and Fewer Reported Cognitive Failures: Results of a Preliminary Voxel-Based Morphometric Analysis

    PubMed Central

    Froeliger, Brett; Garland, Eric L.; McClernon, F. Joseph

    2012-01-01

    Hatha yoga techniques, including physical postures (asanas), breathing exercises (pranayama), and meditation, involve the practice of mindfulness. In turn, yoga meditation practices may induce the state of mindfulness, which, when evoked recurrently through repeated practice, may accrue into trait or dispositional mindfulness. Putatively, these changes may be mediated by experience-dependent neuroplastic changes. Though prior studies have identified differences in gray matter volume (GMV) between long-term mindfulness practitioners and controls, no studies to date have reported on whether yoga meditation is associated with GMV differences. The present study investigated GMV differences between yoga meditation practitioners (YMP) and a matched control group (CG). The YMP group exhibited greater GM volume in frontal, limbic, temporal, occipital, and cerebellar regions; whereas the CG had no greater regional greater GMV. In addition, the YMP group reported significantly fewer cognitive failures on the Cognitive Failures Questionnaire (CFQ), the magnitude of which was positively correlated with GMV in numerous regions identified in the primary analysis. Lastly, GMV was positively correlated with the duration of yoga practice. Results from this preliminary study suggest that hatha yoga practice may be associated with the promotion of neuroplastic changes in executive brain systems, which may confer therapeutic benefits that accrue with repeated practice. PMID:23304217

  7. Somatosensory Brain Function and Gray Matter Regional Volumes Differ According to Exercise History: Evidence from Monozygotic Twins.

    PubMed

    Hautasaari, Pekka; Savić, Andrej M; Loberg, Otto; Niskanen, Eini; Kaprio, Jaakko; Kujala, Urho M; Tarkka, Ina M

    2017-01-01

    Associations between long-term physical activity and cortical function and brain structure are poorly known. Our aim was to assess whether brain functional and/or structural modulation associated with long-term physical activity is detectable using a discordant monozygotic male twin pair design. Nine monozygotic male twin pairs were carefully selected for an intrapair difference in their leisure-time physical activity of at least three years duration (mean age 34 ± 1 years). We registered somatosensory mismatch response (SMMR) in EEG to electrical stimulation of fingers and whole brain MR images. We obtained exercise history and measured physical fitness and body composition. Equivalent electrical dipole sources of SMMR as well as gray matter (GM) voxel counts in regions of interest indicated by source analysis were evaluated. SMMR dipolar source strengths differed between active and inactive twins within twin pairs in postcentral gyrus, medial frontal gyrus and superior temporal gyrus and in anterior cingulate (AC) GM voxel counts differed similarly. Compared to active twins, their inactive twin brothers showed greater dipole strengths in short periods of the deviant-elicited SMMR and larger AC GM voxel counts. Stronger activation in early unattended cortical processing of the deviant sensory signals in inactive co-twins may imply less effective gating of somatosensory information in inactive twins compared to their active brothers. Present findings indicate that already in 30's long-term physical activity pattern is linked with specific brain indices, both in functional and structural domains.

  8. Proceedings of RIKEN BNL Research Center Workshop: The Approach to Equilibrium in Strongly Interacting Matter. Volume 118

    SciTech Connect

    Liao, J.; Venugopalan, R.; Berges, J.; Blaizot, J. -P.; Gelis, F.

    2014-04-09

    The RIKEN BNL Research Center (RBRC) was established in April 1997 at Brookhaven National Laboratory*. It is funded by the ''Rikagaku Kenkyusho'' (RIKEN, The Institute of Physical and Chemical Research) of Japan and the U. S. Department of Energy’s Office of Science. The RBRC is dedicated to the study of strong interactions, including spin physics, lattice QCD, and RHIC physics through the nurturing of a new generation of young physicists. The RBRC has theory, lattice gauge computing and experimental components. It is presently exploring the possibility of an astrophysics component being added to the program. The purpose of this Workshop is to critically review the recent progress on the theory and phenomenology of early time dynamics in relativistic heavy ion collisions from RHIC to LHC energies, to examine the various approaches on thermalization and existing issues, and to formulate new research efforts for the future. Topics slated to be covered include Experimental evidence for equilibration/isotropization, comparison of various approaches, dependence on the initial conditions and couplings, and turbulent cascades and Bose-Einstein condensatio