Two-dimensional conductors with interactions and disorder from particle-vortex duality

DOE PAGES

Goldman, H.; Mulligan, M.; Raghu, S.; ...

2017-12-27

Here, we study Dirac fermions in two spatial dimensions (2D) coupled to strongly fluctuating U(1) gauge fields in the presence of quenched disorder. Such systems are dual to theories of free Dirac fermions, which are vortices of the original theory. In analogy to superconductivity, when these fermionic vortices localize, the original system becomes a perfect conductor, and when the vortices possess a finite conductivity, the original fermions do as well. We provide several realizations of this principle and thereby introduce examples of strongly interacting 2D metals that evade Anderson localization.

Two-dimensional conductors with interactions and disorder from particle-vortex duality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldman, H.; Mulligan, M.; Raghu, S.

Here, we study Dirac fermions in two spatial dimensions (2D) coupled to strongly fluctuating U(1) gauge fields in the presence of quenched disorder. Such systems are dual to theories of free Dirac fermions, which are vortices of the original theory. In analogy to superconductivity, when these fermionic vortices localize, the original system becomes a perfect conductor, and when the vortices possess a finite conductivity, the original fermions do as well. We provide several realizations of this principle and thereby introduce examples of strongly interacting 2D metals that evade Anderson localization.

Epidemiologic Insights into Stone Disease as a Systemic Disorder

NASA Astrophysics Data System (ADS)

Curhan, Gary C.

2007-04-01

Examining the epidemiology of stone disease can provide insight into etiology. There is a growing body of evidence that stone disease is not simply a disorder of the kidney. In fact, nephrolithiasis is clearly a systemic disorder. Conditions associated with stone disease include the classic ones such as inflammatory bowel disease and primary hyperparathyroidism. More recent studies have demonstrated strong associations with obesity, gout, diabetes and hypertension. Future studies will help uncover the underlying common pathophysiologic abnormalities.

Transport in a disordered ν = 2 / 3 fractional quantum Hall junction

NASA Astrophysics Data System (ADS)

Protopopov, I. V.; Gefen, Yuval; Mirlin, A. D.

2017-10-01

Electric and thermal transport properties of a ν = 2 / 3 fractional quantum Hall junction are analyzed. We investigate the evolution of the electric and thermal two-terminal conductances, G and GQ, with system size L and temperature T. This is done both for the case of strong interaction between the 1 and 1/ 3 modes (when the low-temperature physics of the interacting segment of the device is controlled by the vicinity of the strong-disorder Kane-Fisher-Polchinski fixed point) and for relatively weak interaction, for which the disorder is irrelevant at T = 0 in the renormalization-group sense. The transport properties in both cases are similar in several respects. In particular, G(L) is close to 4/3 (in units of e2 / h) and GQ to 2 (in units of πT / 6 ħ) for small L, independently of the interaction strength. For large L the system is in an incoherent regime, with G given by 2/3 and GQ showing the Ohmic scaling, GQ ∝ 1 / L, again for any interaction strength. The hallmark of the strong-disorder fixed point is the emergence of an intermediate range of L, in which the electric conductance shows strong mesoscopic fluctuations and the thermal conductance is GQ = 1. The analysis is extended also to a device with floating 1/3 mode, as studied in a recent experiment (Grivnin et al. 2014).

The Dopamine Receptor D4 Gene ("DRD4") Moderates Family Environmental Effects on ADHD

ERIC Educational Resources Information Center

Martel, Michelle M.; Nikolas, Molly; Jernigan, Katherine; Friderici, Karen; Waldman, Irwin; Nigg, Joel T.

2011-01-01

Attention-Deficit/Hyperactivity Disorder (ADHD) is a prime candidate for exploration of gene-by-environment interaction (i.e., G x E), particularly in relation to dopamine system genes, due to strong evidence that dopamine systems are dysregulated in the disorder. Using a G x E design, we examined whether the "DRD4" promoter 120-bp tandem repeat…

Disordered artificial spin ices: Avalanches and criticality (invited)

NASA Astrophysics Data System (ADS)

Reichhardt, Cynthia J. Olson; Chern, Gia-Wei; Libál, Andras; Reichhardt, Charles

2015-05-01

We show that square and kagome artificial spin ices with disconnected islands exhibit disorder-induced nonequilibrium phase transitions. The critical point of the transition is characterized by a diverging length scale and the effective spin reconfiguration avalanche sizes are power-law distributed. For weak disorder, the magnetization reversal is dominated by system-spanning avalanche events characteristic of a supercritical regime, while at strong disorder, the avalanche distributions have subcritical behavior and are cut off above a length scale that decreases with increasing disorder. The different type of geometrical frustration in the two lattices produces distinct forms of critical avalanche behavior. Avalanches in the square ice consist of the propagation of locally stable domain walls separating the two polarized ground states, and we find a scaling collapse consistent with an interface depinning mechanism. In the fully frustrated kagome ice, however, the avalanches branch strongly in a manner reminiscent of directed percolation. We also observe an interesting crossover in the power-law scaling of the kagome ice avalanches at low disorder. Our results show that artificial spin ices are ideal systems in which to study a variety of nonequilibrium critical point phenomena as the microscopic degrees of freedom can be accessed directly in experiments.

Disordered artificial spin ices: Avalanches and criticality (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reichhardt, Cynthia J. Olson, E-mail: cjrx@lanl.gov; Chern, Gia-Wei; Reichhardt, Charles

2015-05-07

We show that square and kagome artificial spin ices with disconnected islands exhibit disorder-induced nonequilibrium phase transitions. The critical point of the transition is characterized by a diverging length scale and the effective spin reconfiguration avalanche sizes are power-law distributed. For weak disorder, the magnetization reversal is dominated by system-spanning avalanche events characteristic of a supercritical regime, while at strong disorder, the avalanche distributions have subcritical behavior and are cut off above a length scale that decreases with increasing disorder. The different type of geometrical frustration in the two lattices produces distinct forms of critical avalanche behavior. Avalanches in themore » square ice consist of the propagation of locally stable domain walls separating the two polarized ground states, and we find a scaling collapse consistent with an interface depinning mechanism. In the fully frustrated kagome ice, however, the avalanches branch strongly in a manner reminiscent of directed percolation. We also observe an interesting crossover in the power-law scaling of the kagome ice avalanches at low disorder. Our results show that artificial spin ices are ideal systems in which to study a variety of nonequilibrium critical point phenomena as the microscopic degrees of freedom can be accessed directly in experiments.« less

Step Density Profiles in Localized Chains

NASA Astrophysics Data System (ADS)

De Roeck, Wojciech; Dhar, Abhishek; Huveneers, François; Schütz, Marius

2017-06-01

We consider two types of strongly disordered one-dimensional Hamiltonian systems coupled to baths (energy or particle reservoirs) at the boundaries: strongly disordered quantum spin chains and disordered classical harmonic oscillators. These systems are believed to exhibit localization, implying in particular that the conductivity decays exponentially in the chain length L. We ask however for the profile of the (very slowly) transported quantity in the steady state. We find that this profile is a step-function, jumping in the middle of the chain from the value set by the left bath to the value set by the right bath. This is confirmed by numerics on a disordered quantum spin chain of 9 spins and on much longer chains of harmonic oscillators. From theoretical arguments, we find that the width of the step grows not faster than √{L}, and we confirm this numerically for harmonic oscillators. In this case, we also observe a drastic breakdown of local equilibrium at the step, resulting in a heavily oscillating temperature profile.

Effect of strong disorder on three-dimensional chiral topological insulators: Phase diagrams, maps of the bulk invariant, and existence of topological extended bulk states

NASA Astrophysics Data System (ADS)

Song, Juntao; Fine, Carolyn; Prodan, Emil

2014-11-01

The effect of strong disorder on chiral-symmetric three-dimensional lattice models is investigated via analytical and numerical methods. The phase diagrams of the models are computed using the noncommutative winding number, as functions of disorder strength and model's parameters. The localized/delocalized characteristic of the quantum states is probed with level statistics analysis. Our study reconfirms the accurate quantization of the noncommutative winding number in the presence of strong disorder, and its effectiveness as a numerical tool. Extended bulk states are detected above and below the Fermi level, which are observed to undergo the so-called "levitation and pair annihilation" process when the system is driven through a topological transition. This suggests that the bulk invariant is carried by these extended states, in stark contrast with the one-dimensional case where the extended states are completely absent and the bulk invariant is carried by the localized states.

From Genes to Environment: Using integrative genomics to build a “systems level” understanding of autism spectrum disorders

PubMed Central

Hu, Valerie W.

2012-01-01

Autism spectrum disorders (ASD) are pervasive neurodevelopmental disorders that affect an estimated 1 in 110 individuals. Although there is a strong genetic component associated with these disorders, this review focuses on the multi-factorial nature of ASD and how different genome-wide (genomic) approaches contribute to our understanding of autism. Emphasis is placed on the need to study defined ASD phenotypes as well as to integrate large-scale ‘omics’ data in order to develop a “systems level” perspective of ASD which, in turn, is necessary to allow predictions regarding responses to specific perturbations and interventions. PMID:22497667

Disorder-induced transitions in resonantly driven Floquet topological insulators

NASA Astrophysics Data System (ADS)

Titum, Paraj; Lindner, Netanel H.; Refael, Gil

2017-08-01

We investigate the effects of disorder in Floquet topological insulators (FTIs) occurring in semiconductor quantum wells. Such FTIs are induced by resonantly driving a transition between the valence and conduction bands. We show that when disorder is added, the topological nature of such FTIs persists as long as there is a mobility gap at the resonant quasienergy. For strong enough disorder, this gap closes and all the states become localized as the system undergoes a transition to a trivial insulator. Interestingly, the effects of disorder are not necessarily adverse: we show that in the same quantum well, disorder can also induce a transition from a trivial to a topological system, thereby establishing a Floquet topological Anderson insulator (FTAI). We identify the conditions on the driving field necessary for observing such a transition.

[Facts visualized through job support activities for mentally disordered persons--what is the objective of medical treatment for mental disorder?].

PubMed

Tagawa, Seiji

2014-01-01

According to a recent investigation by the Public Employment Security Office, the rate of employing mentally disordered persons is increasing. In the report, it was predicted that the number of employed mentally disordered persons will exceed the number of physically disordered persons within a few years, and will become the highest of the main three disabled types. Despite the strong desire of mentally disordered persons to work, supporting systems have been inadequate. In 2007, mental clinic doctors in Osaka took the lead and established the NPO Osaka Job Support Network for Mentally Disordered Persons (JSN) to support their employment persons. We aimed to establish a support system for mentally disordered persons who have a strong will to work, stating "I would like to work" to their family doctors, who introduce JSN to the patients, and then the family doctors and JSN cooperate to support the patients to realize the desire to "work". Since April 2013, 49 persons have found a job and "graduated" from JSN. Over 6 years until the end of March, 2013, a total of 154 persons found jobs and "graduated" from JSN. From now on, it is expected that around 50 persons will find jobs and "graduate" from JSN every year. It is definitely insufficient just to repeat "temporary" medical treatment for mental disorders with a long course like schizophrenia. A care management view that values the hopes and dreams of patients is required in psychiatric treatment.

Metallic phases from disordered (2+1)-dimensional quantum electrodynamics

DOE PAGES

Goswami, Pallab; Goldman, Hart; Raghu, S.

2017-06-15

Metallic phases have been observed in several disordered two-dimensional (2D) systems, including thin films near superconductor-insulator transitions and quantum Hall systems near plateau transitions. The existence of 2D metallic phases at zero temperature generally requires an interplay of disorder and interaction effects. Consequently, experimental observations of 2D metallic behavior have largely defied explanation. We formulate a general stability criterion for strongly interacting, massless Dirac fermions against disorder, which describe metallic ground states with vanishing density of states. We show that (2+1)-dimensional quantum electrodynamics (QED 3) with a large, even number of fermion flavors remains metallic in the presence of weakmore » scalar potential disorder due to the dynamic screening of disorder by gauge fluctuations. In conclusion, we also show that QED 3 with weak mass disorder exhibits a stable, dirty metallic phase in which both interactions and disorder play important roles.« less

Metallic phases from disordered (2+1)-dimensional quantum electrodynamics

NASA Astrophysics Data System (ADS)

Goswami, Pallab; Goldman, Hart; Raghu, S.

2017-06-01

Metallic phases have been observed in several disordered two-dimensional (2D) systems, including thin films near superconductor-insulator transitions and quantum Hall systems near plateau transitions. The existence of 2D metallic phases at zero temperature generally requires an interplay of disorder and interaction effects. Consequently, experimental observations of 2D metallic behavior have largely defied explanation. We formulate a general stability criterion for strongly interacting, massless Dirac fermions against disorder, which describe metallic ground states with vanishing density of states. We show that (2+1)-dimensional quantum electrodynamics (QED3) with a large, even number of fermion flavors remains metallic in the presence of weak scalar potential disorder due to the dynamic screening of disorder by gauge fluctuations. We also show that QED3 with weak mass disorder exhibits a stable, dirty metallic phase in which both interactions and disorder play important roles.

Mott-Hubbard transition and Anderson localization: A generalized dynamical mean-field theory approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuchinskii, E. Z.; Nekrasov, I. A.; Sadovskii, M. V.

The DOS, the dynamic (optical) conductivity, and the phase diagram of a strongly correlated and strongly disordered paramagnetic Anderson-Hubbard model are analyzed within the generalized dynamical mean field theory (DMFT + {sigma} approximation). Strong correlations are taken into account by the DMFT, and disorder is taken into account via an appropriate generalization of the self-consistent theory of localization. The DMFT effective single-impurity problem is solved by a numerical renormalization group (NRG); we consider the three-dimensional system with a semielliptic DOS. The correlated metal, Mott insulator, and correlated Anderson insulator phases are identified via the evolution of the DOS and dynamicmore » conductivity, demonstrating both the Mott-Hubbard and Anderson metal-insulator transition and allowing the construction of the complete zero-temperature phase diagram of the Anderson-Hubbard model. Rather unusual is the possibility of a disorder-induced Mott insulator-to-metal transition.« less

Localization and delocalization of a one-dimensional system coupled with the environment

NASA Astrophysics Data System (ADS)

Zhu, Hong-Jun; Xiong, Shi-Jie

2010-03-01

We investigate several models of a one-dimensional chain coupling with surrounding atoms to elucidate disorder-induced delocalization in quantum wires, a peculiar behaviour against common wisdom. We show that the localization length is enhanced by disorder of side sites in the case of strong disorder, but in the case of weak disorder there is a plateau in this dependence. The above behaviour is the conjunct influence of the coupling to the surrounding atoms and the antiresonant effect. We also discuss different effects and their physical origin of different types of disorder in such systems. The numerical results show that coupling with the surrounding atoms can induce either the localization or delocalization effect depending on the values of parameters.

Screening and transport in 2D semiconductor systems at low temperatures

PubMed Central

Das Sarma, S.; Hwang, E. H.

2015-01-01

Low temperature carrier transport properties in 2D semiconductor systems can be theoretically well-understood within RPA-Boltzmann theory as being limited by scattering from screened Coulomb disorder arising from random quenched charged impurities in the environment. In this work, we derive a number of analytical formula, supported by realistic numerical calculations, for the relevant density, mobility, and temperature range where 2D transport should manifest strong intrinsic (i.e., arising purely from electronic effects) metallic temperature dependence in different semiconductor materials arising entirely from the 2D screening properties, thus providing an explanation for why the strong temperature dependence of the 2D resistivity can only be observed in high-quality and low-disorder 2D samples and also why some high-quality 2D materials manifest much weaker metallicity than other materials. We also discuss effects of interaction and disorder on the 2D screening properties in this context as well as compare 2D and 3D screening functions to comment why such a strong intrinsic temperature dependence arising from screening cannot occur in 3D metallic carrier transport. Experimentally verifiable predictions are made about the quantitative magnitude of the maximum possible low-temperature metallicity in 2D systems and the scaling behavior of the temperature scale controlling the quantum to classical crossover. PMID:26572738

Different phases of a system of hard rods on three dimensional cubic lattice

NASA Astrophysics Data System (ADS)

Vigneshwar, N.; Dhar, Deepak; Rajesh, R.

2017-11-01

We study the different phases of a system of monodispersed hard rods of length k on a cubic lattice, using an efficient cluster algorithm able to simulate densities close to the fully-packed limit. For k≤slant 4 , the system is disordered at all densities. For k=5, 6 , we find a single density-driven transition, from a disordered phase to high density layered-disordered phase, in which the density of rods of one orientation is strongly suppressed, breaking the system into weakly coupled layers. Within a layer, the system is disordered. For k ≥slant 7 , three density-driven transitions are observed numerically: isotropic to nematic to layered-nematic to layered-disordered. In the layered-nematic phase, the system breaks up into layers, with nematic order in each layer, but very weak correlation between the ordering directions of different layers. We argue that the layered-nematic phase is a finite-size effect, and in the thermodynamic limit, the nematic phase will have higher entropy per site. We expect the systems of rods in four and higher dimensions will have a qualitatively similar phase diagram.

Emergent quasicrystals in strongly correlated systems

NASA Astrophysics Data System (ADS)

Sagi, Eran; Nussinov, Zohar

2016-07-01

Commensurability is of paramount importance in numerous strongly interacting electronic systems. In the fractional quantum Hall effect, a rich cascade of increasingly narrow plateaux appear at larger denominator filling fractions. Rich commensurate structures also emerge, at certain filling fractions, in high temperature superconductors and other electronic systems. A natural question concerns the character of these and other electronic systems at irrational filling fractions. Here we demonstrate that quasicrystalline structures naturally emerge in these situations, and trigger behaviors not typically expected of periodic systems. We first show that irrationally filled quantum Hall systems cross over into quasiperiodically ordered configuration in the thin-torus limit. Using known properties of quasicrystals, we argue that these states are unstable against the effects of disorder, in agreement with the existence of quantum Hall plateaux. We then study analogous physical situations in a system of cold Rydberg atoms placed on an optical lattice. Such an experimental setup is generally disorder free, and can therefore be used to detect the emergent quasicrystals we predict. We discuss similar situations in the Falicov-Kimball model, where known exact results can be used to establish quasicrystalline structures in one and two dimensions. We briefly speculate on possible relations between our theoretical findings and the existence of glassy dynamics and other features of strongly correlated electronic systems.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goswami, Pallab; Goldman, Hart; Raghu, S.

Metallic phases have been observed in several disordered two-dimensional (2D) systems, including thin films near superconductor-insulator transitions and quantum Hall systems near plateau transitions. The existence of 2D metallic phases at zero temperature generally requires an interplay of disorder and interaction effects. Consequently, experimental observations of 2D metallic behavior have largely defied explanation. We formulate a general stability criterion for strongly interacting, massless Dirac fermions against disorder, which describe metallic ground states with vanishing density of states. We show that (2+1)-dimensional quantum electrodynamics (QED 3) with a large, even number of fermion flavors remains metallic in the presence of weakmore » scalar potential disorder due to the dynamic screening of disorder by gauge fluctuations. In conclusion, we also show that QED 3 with weak mass disorder exhibits a stable, dirty metallic phase in which both interactions and disorder play important roles.« less

Discrete time-crystalline order in black diamond

NASA Astrophysics Data System (ADS)

Zhou, Hengyun; Choi, Soonwon; Choi, Joonhee; Landig, Renate; Kucsko, Georg; Isoya, Junichi; Jelezko, Fedor; Onoda, Shinobu; Sumiya, Hitoshi; Khemani, Vedika; von Keyserlingk, Curt; Yao, Norman; Demler, Eugene; Lukin, Mikhail D.

2017-04-01

The interplay of periodic driving, disorder, and strong interactions has recently been predicted to result in exotic ``time-crystalline'' phases, which spontaneously break the discrete time-translation symmetry of the underlying drive. Here, we report the experimental observation of such discrete time-crystalline order in a driven, disordered ensemble of 106 dipolar spin impurities in diamond at room-temperature. We observe long-lived temporal correlations at integer multiples of the fundamental driving period, experimentally identify the phase boundary and find that the temporal order is protected by strong interactions; this order is remarkably stable against perturbations, even in the presence of slow thermalization. Our work opens the door to exploring dynamical phases of matter and controlling interacting, disordered many-body systems.

Emergence of nanoscale inhomogeneity in the superconducting state of a homogeneously disordered conventional superconductor

PubMed Central

Kamlapure, Anand; Das, Tanmay; Ganguli, Somesh Chandra; Parmar, Jayesh B.; Bhattacharyya, Somnath; Raychaudhuri, Pratap

2013-01-01

The notion of spontaneous formation of an inhomogeneous superconducting state is at the heart of most theories attempting to understand the superconducting state in the presence of strong disorder. Using scanning tunneling spectroscopy and high resolution scanning transmission electron microscopy, we experimentally demonstrate that under the competing effects of strong homogeneous disorder and superconducting correlations, the superconducting state of a conventional superconductor, NbN, spontaneously segregates into domains. Tracking these domains as a function of temperature we observe that the superconducting domains persist across the bulk superconducting transition, Tc, and disappear close to the pseudogap temperature, T*, where signatures of superconducting correlations disappear from the tunneling spectrum and the superfluid response of the system. PMID:24132046

Emergence of nanoscale inhomogeneity in the superconducting state of a homogeneously disordered conventional superconductor.

PubMed

Kamlapure, Anand; Das, Tanmay; Ganguli, Somesh Chandra; Parmar, Jayesh B; Bhattacharyya, Somnath; Raychaudhuri, Pratap

2013-10-17

The notion of spontaneous formation of an inhomogeneous superconducting state is at the heart of most theories attempting to understand the superconducting state in the presence of strong disorder. Using scanning tunneling spectroscopy and high resolution scanning transmission electron microscopy, we experimentally demonstrate that under the competing effects of strong homogeneous disorder and superconducting correlations, the superconducting state of a conventional superconductor, NbN, spontaneously segregates into domains. Tracking these domains as a function of temperature we observe that the superconducting domains persist across the bulk superconducting transition, Tc, and disappear close to the pseudogap temperature, T*, where signatures of superconducting correlations disappear from the tunneling spectrum and the superfluid response of the system.

Annual Research Review: The neurobehavioral development of multiple memory systems: implications for childhood and adolescent psychiatric disorders

PubMed Central

Goodman, Jarid; Marsh, Rachel; Peterson, Bradley S.; Packard, Mark G.

2014-01-01

Extensive evidence indicates that mammalian memory is organized into multiple brains systems, including a “cognitive” memory system that depends upon the hippocampus and a stimulus-response “habit” memory system that depends upon the dorsolateral striatum. Dorsal striatal-dependent habit memory may in part influence the development and expression of some human psychopathologies, particularly those characterized by strong habit-like behavioral features. The present review considers this hypothesis as it pertains to psychopathologies that typically emerge during childhood and adolescence. These disorders include Tourette syndrome, attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, eating disorders, and autism spectrum disorders. Human and nonhuman animal research shows that the typical development of memory systems comprises the early maturation of striatal-dependent habit memory and the relatively late maturation of hippocampal-dependent cognitive memory. We speculate that the differing rates of development of these memory systems may in part contribute to the early emergence of habit-like symptoms in childhood and adolescence. In addition, abnormalities in hippocampal and striatal brain regions have been observed consistently in youth with these disorders, suggesting that the aberrant development of memory systems may also contribute to the emergence of habit-like symptoms as core pathological features of these illnesses. Considering these disorders within the context of multiple memory systems may help elucidate the pathogenesis of habit-like symptoms in childhood and adolescence, and lead to novel treatments that lessen the habit-like behavioral features of these disorders. PMID:24286520

Fate of superconductivity in three-dimensional disordered Luttinger semimetals

NASA Astrophysics Data System (ADS)

Mandal, Ipsita

2018-05-01

Superconducting instability can occur in three-dimensional quadratic band crossing semimetals only at a finite coupling strength due to the vanishing of density of states at the quadratic band touching point. Since realistic materials are always disordered to some extent, we study the effect of short-ranged-correlated disorder on this superconducting quantum critical point using a controlled loop-expansion applying dimensional regularization. The renormalization group (RG) scheme allows us to determine the RG flows of the various interaction strengths and shows that disorder destroys the superconducting quantum critical point. In fact, the system exhibits a runaway flow to strong disorder.

Opening-assisted coherent transport in the semiclassical regime

NASA Astrophysics Data System (ADS)

Zhang, Yang; Celardo, G. Luca; Borgonovi, Fausto; Kaplan, Lev

2017-02-01

We study quantum enhancement of transport in open systems in the presence of disorder and dephasing. Quantum coherence effects may significantly enhance transport in open systems even in the semiclassical regime (where the decoherence rate is greater than the intersite hopping amplitude), as long as the disorder is sufficiently strong. When the strengths of disorder and dephasing are fixed, there is an optimal opening strength at which the coherent transport enhancement is optimized. Analytic results are obtained in two simple paradigmatic tight-binding models of large systems: the linear chain and the fully connected network. The physical behavior is also reflected in the Fenna-Matthews-Olson (FMO) photosynthetic complex, which may be viewed as intermediate between these paradigmatic models.

Three-Dimensional Localized-Delocalized Anderson Transition in the Time Domain

NASA Astrophysics Data System (ADS)

Delande, Dominique; Morales-Molina, Luis; Sacha, Krzysztof

2017-12-01

Systems which can spontaneously reveal periodic evolution are dubbed time crystals. This is in analogy with space crystals that display periodic behavior in configuration space. While space crystals are modeled with the help of space periodic potentials, crystalline phenomena in time can be modeled by periodically driven systems. Disorder in the periodic driving can lead to Anderson localization in time: the probability for detecting a system at a fixed point of configuration space becomes exponentially localized around a certain moment in time. We here show that a three-dimensional system exposed to a properly disordered pseudoperiodic driving may display a localized-delocalized Anderson transition in the time domain, in strong analogy with the usual three-dimensional Anderson transition in disordered systems. Such a transition could be experimentally observed with ultracold atomic gases.

Dynamics of the Random Field Ising Model

NASA Astrophysics Data System (ADS)

Xu, Jian

The Random Field Ising Model (RFIM) is a general tool to study disordered systems. Crackling noise is generated when disordered systems are driven by external forces, spanning a broad range of sizes. Systems with different microscopic structures such as disordered mag- nets and Earth's crust have been studied under the RFIM. In this thesis, we investigated the domain dynamics and critical behavior in two dipole-coupled Ising ferromagnets Nd2Fe14B and LiHoxY 1-xF4. With Tc well above room temperature, Nd2Fe14B has shown reversible disorder when exposed to an external transverse field and crosses between two universality classes in the strong and weak disorder limits. Besides tunable disorder, LiHoxY1-xF4 has shown quantum tunneling effects arising from quantum fluctuations, providing another mechanism for domain reversal. Universality within and beyond power law dependence on avalanche size and energy were studied in LiHo0.65Y0.35 F4.

Overview and Analysis of the Behaviourist Criticism of the "Diagnostic and Statistical Manual of Mental Disorders (DSM)"

ERIC Educational Resources Information Center

Andersson, Gerhard; Ghaderi, Ata

2006-01-01

While a majority of cognitive behavioural researchers and clinicians adhere to the classification system provided in the "Diagnostic and Statistical Manual of Mental Disorders (DSM-IV)," strong objections have been voiced among behaviourists who find the dichotomous allocation of patients into psychiatric diagnoses incompatible with the philosophy…

Computational studies of model disordered and strongly correlated electronic systems

NASA Astrophysics Data System (ADS)

Johri, Sonika

The theory of non-interacting electrons in perfect crystals was completed soon after the advent of quantum mechanics. Though capable of describing electron behaviour in most simple solid state physics systems, this approach falls woefully short of describing condensed matter systems of interest today, and designing the quantum devices of the future. The reason is that nature is never free of disorder, and emergent properties arising from interactions can be clearly seen in the pure, low-dimensional materials that can be engineered today. In this thesis, I address some salient problems in disordered and correlated electronic systems using modern numerical techniques like sparse matrix diagonalization, density matrix renormalization group (DMRG), and large disorder renormalization group (LDRG) methods. The pioneering work of P. W. Anderson, in 1958, led to an understanding of how an electron can stop diffusing and become localized in a region of space when a crystal is sufficiently disordered. Thus disorder can lead to metal-insulator transitions, for instance, in doped semiconductors. Theoretical research on the Anderson disorder model since then has mostly focused on the localization-delocalization phase transition. The localized phase in itself was not thought to exhibit any interesting physics. Our work has uncovered a new singularity in the disorder-averaged inverse participation ratio of wavefunctions within the localized phase, arising from resonant states. The effects of system size, dimension and disorder distribution on the singularity have been studied. A novel wavefunction-based LDRG technique has been designed for the Anderson model which captures the singular behaviour. While localization is well established for a single electron in a disordered potential, the situation is less clear in the case of many interacting particles. Most studies of a many-body localized phase are restricted to a system which is isolated from its environment. Such a condition cannot be achieved perfectly in experiments. A chapter of this thesis is devoted to studying signatures of incomplete localization in a disordered system with interacting particles which is coupled to a bath. . Strongly interacting particles can also give rise to topological phases of matter that have exotic emergent properties, such as quasiparticles with fractional charges and anyonic, or perhaps even non-Abelian statistics. In addition to their intrinsic novelty, these particles (e.g. Majorana fermions) may be the building blocks of future quantum computers. The third part of my thesis focuses on the best experimentally known realizations of such systems - the fractional quantum Hall effect (FQHE) which occurs in two-dimensional electron gases in a strong perpendicular magnetic field. It has been observed in systems such as semiconductor heterostructures and, more recently, graphene. I have developed software for exact diagonalization of the many-body FQHE problem on the surface of a cylinder, a hitherto unstudied type of geometry. This geometry turns out to be optimal for the DMRG algorithm. Using this new geometry, I have studied properties of various fractionally-filled states, computing the overlap between exact ground states and model wavefunctions, their edge excitations, and entanglement spectra. I have calculated the sizes and tunneling amplitudes of quasiparticles, information which is needed to design the interferometers used to experimentally measure their Aharanov-Bohm phase. I have also designed numerical probes of the recently discovered geometric degree of freedom of FQHE states.

Study of multiband disordered systems using the typical medium dynamical cluster approximation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yi; Terletska, Hanna; Moore, C.

We generalize the typical medium dynamical cluster approximation to multiband disordered systems. Using our extended formalism, we perform a systematic study of the nonlocal correlation effects induced by disorder on the density of states and the mobility edge of the three-dimensional two-band Anderson model. We include interband and intraband hopping and an intraband disorder potential. Our results are consistent with those obtained by the transfer matrix and the kernel polynomial methods. We also apply the method to K xFe 2-ySe 2 with Fe vacancies. Despite the strong vacancy disorder and anisotropy, we find the material is not an Anderson insulator.more » Moreover our results demonstrate the application of the typical medium dynamical cluster approximation method to study Anderson localization in real materials.« less

Study of multiband disordered systems using the typical medium dynamical cluster approximation

DOE PAGES

Zhang, Yi; Terletska, Hanna; Moore, C.; ...

2015-11-06

We generalize the typical medium dynamical cluster approximation to multiband disordered systems. Using our extended formalism, we perform a systematic study of the nonlocal correlation effects induced by disorder on the density of states and the mobility edge of the three-dimensional two-band Anderson model. We include interband and intraband hopping and an intraband disorder potential. Our results are consistent with those obtained by the transfer matrix and the kernel polynomial methods. We also apply the method to K xFe 2-ySe 2 with Fe vacancies. Despite the strong vacancy disorder and anisotropy, we find the material is not an Anderson insulator.more » Moreover our results demonstrate the application of the typical medium dynamical cluster approximation method to study Anderson localization in real materials.« less

Slow Relaxation in Anderson Critical Systems

NASA Astrophysics Data System (ADS)

Choi, Soonwon; Yao, Norman; Choi, Joonhee; Kucsko, Georg; Lukin, Mikhail

2016-05-01

We study the single particle dynamics in disordered systems with long range hopping, focusing on the critical cases, i.e., the hopping amplitude decays as 1 /rd in d-dimension. We show that with strong on-site potential disorder, the return probability of the particle decays as power-law in time. As on-site potential disorder decreases, the temporal profile smoothly changes from a simple power-law to the sum of multiple power-laws with exponents ranged from 0 to νmax. We analytically compute the decay exponents using a simple resonance counting argument, which quantitatively agrees with exact numerical results. Our result implies that the dynamics in Anderson Critical systems are dominated by resonances. Harvard-MIT CUA, Kwanjeong Educational Fellowship, AFOSR MURI, Samsung Scholarship.

Cytomegalovirus Retinitis as a Presenting Feature of Multisystem Disorder: Dyskeratosis Congenita.

PubMed

Parchand, Swapnil; Barwad, Adarsh

2017-01-01

Cytomegalovirus (CMV) retinitis is an opportunistic infection commonly seen in disorders that affect the immune system of the body such as acquired immunodeficiency syndrome and hematological malignancies such as leukemia/lymphoma or organ transplantation. The occurrence of CMV retinitis in the absence of such condition should be thoroughly investigated, as it is a strong indicator of poor immune competence. We here report an interesting case of CMV retinitis as a presenting feature of rare multisystem disorde r "Dyskeratosis congenita."

Emergent large mechanical damping in ferroelastic-martensitic systems driven by disorder

NASA Astrophysics Data System (ADS)

Ni, Yan; Zhang, Zhen; Fang, Minxia; Hao, Yanshuang; Ding, Xiangdong; Otsuka, Kazuhiro; Ren, Xiaobing

2018-05-01

Disorders and point defects strongly interplay with the phase transition and alter the properties of ferroelastic-martensitic systems. Unusual static and quasistatic behaviors, such as time-dependent phase transitions, are discovered when disorders are introduced. However, the role of disorders on the ferroelastic system in vibrational environments at moderate frequency is rarely known, investigation of which could further shed light on their application as mechanical damping materials. Here we present the emergence of large damping capacity in ferroelastic-martensitic systems [including both the T i50 -xN i50 +x alloy and (C a1 -xS rx) Ti O3 ceramics] by introducing disorder (i.e., substitutional Ni and Sr, respectively). As the level disorder increases, the damping capacity of both systems raises and eventually reaches a maximum when long-range-ordered martensite tends to vanish. Moreover, near the disorder-induced phase boundary, we observe a large mechanical damping in ferroelastic ceramics (C a1 -xS rx) Ti O3 with a figure of merit ˜2 GP a1 /2 . Microscopic and dynamic investigations indicate that such damping plateau could result from the competing evolution of density and mobility of domain boundaries when disorder is introduced. Our work provides a degree of freedom to develop ferroelastic damping materials and a potential way to tune domain-boundary-mediated functionalities for other ferroic materials.

Neuro-Cardio Mechanisms in Huntington's Disease and Other Neurodegenerative Disorders.

PubMed

Critchley, Bethan J; Isalan, Mark; Mielcarek, Michal

2018-01-01

Although Huntington's disease is generally considered to be a neurological disorder, there is mounting evidence that heart malfunction plays an important role in disease progression. This is perhaps not unexpected since both cardiovascular and nervous systems are strongly connected - both developmentally and subsequently in health and disease. This connection occurs through a system of central and peripheral neurons that control cardiovascular performance, while in return the cardiovascular system works as a sensor for the nervous system to react to physiological events. Hence, given their permanent interconnectivity, any pathological events occurring in one system might affect the second. In addition, some pathological signals from Huntington's disease might occur simultaneously in both the cardiovascular and nervous systems, since mutant huntingtin protein is expressed in both. Here we aim to review the source of HD-related cardiomyopathy in the light of recently published studies, and to identify similarities between HD-related cardiomyopathy and other neuro-cardio disorders.

Finite-temperature behavior of a classical spin-orbit-coupled model for YbMgGaO4 with and without bond disorder

NASA Astrophysics Data System (ADS)

Parker, Edward; Balents, Leon

2018-05-01

We present the results of finite-temperature classical Monte Carlo simulations of a strongly spin-orbit-coupled nearest-neighbor triangular-lattice model for the candidate U (1 ) quantum spin liquid YbMgGaO4 at large system sizes. We find a single continuous finite-temperature stripe-ordering transition with slowly diverging heat capacity that completely breaks the sixfold ground-state degeneracy, despite the absence of a known conformal field theory describing such a transition. We also simulate the effect of random-bond disorder in the model, and find that even weak bond disorder destroys the transition by fragmenting the system into very large domains—possibly explaining the lack of observed ordering in the real material. The Imry-Ma argument only partially explains this fragility to disorder, and we extend the argument with a physical explanation for the preservation of our system's time-reversal symmetry even under a disorder model that preserves the same symmetry.

Finite-temperature fluid–insulator transition of strongly interacting 1D disordered bosons

PubMed Central

Michal, Vincent P.; Aleiner, Igor L.; Altshuler, Boris L.; Shlyapnikov, Georgy V.

2016-01-01

We consider the many-body localization–delocalization transition for strongly interacting one-dimensional disordered bosons and construct the full picture of finite temperature behavior of this system. This picture shows two insulator–fluid transitions at any finite temperature when varying the interaction strength. At weak interactions, an increase in the interaction strength leads to insulator → fluid transition, and, for large interactions, there is a reentrance to the insulator regime. It is feasible to experimentally verify these predictions by tuning the interaction strength with the use of Feshbach or confinement-induced resonances, for example, in 7Li or 39K. PMID:27436894

Two-dimensional Anderson-Hubbard model in the DMFT + {Sigma} approximation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuchinskii, E. Z., E-mail: kuchinsk@iep.uran.ru; Kuleeva, N. A.; Nekrasov, I. A.

The density of states, the dynamic (optical) conductivity, and the phase diagram of the paramagnetic two-dimensional Anderson-Hubbard model with strong correlations and disorder are analyzed within the generalized dynamical mean field theory (DMFT + {Sigma} approximation). Strong correlations are accounted by the DMFT, while disorder is taken into account via the appropriate generalization of the self-consistent theory of localization. We consider the two-dimensional system with the rectangular 'bare' density of states (DOS). The DMFT effective single-impurity problem is solved by numerical renormalization group (NRG). The 'correlated metal,' Mott insulator, and correlated Anderson insulator phases are identified from the evolution ofmore » the density of states, optical conductivity, and localization length, demonstrating both Mott-Hubbard and Anderson metal-insulator transitions in two-dimensional systems of finite size, allowing us to construct the complete zero-temperature phase diagram of the paramagnetic Anderson-Hubbard model. The localization length in our approximation is practically independent of the strength of Hubbard correlations. But the divergence of the localization length in a finite-size two-dimensional system at small disorder signifies the existence of an effective Anderson transition.« less

Cluster-Glass Phase in Pyrochlore X Y Antiferromagnets with Quenched Disorder

NASA Astrophysics Data System (ADS)

Andrade, Eric C.; Hoyos, José A.; Rachel, Stephan; Vojta, Matthias

2018-03-01

We study the impact of quenched disorder (random exchange couplings or site dilution) on easy-plane pyrochlore antiferromagnets. In the clean system, order by disorder selects a magnetically ordered state from a classically degenerate manifold. In the presence of randomness, however, different orders can be chosen locally depending on details of the disorder configuration. Using a combination of analytical considerations and classical Monte Carlo simulations, we argue that any long-range-ordered magnetic state is destroyed beyond a critical level of randomness where the system breaks into magnetic domains due to random exchange anisotropies, becoming, therefore, a glass of spin clusters, in accordance with the available experimental data. These random anisotropies originate from off-diagonal exchange couplings in the microscopic Hamiltonian, establishing their relevance to other magnets with strong spin-orbit coupling.

Dynamic phases of active matter systems with quenched disorder

DOE PAGES

Sandor, Csand; Libal, Andras; Reichhardt, Charles; ...

2017-03-16

Depinning and nonequilibrium transitions within sliding states in systems driven over quenched disorder arise across a wide spectrum of size scales ranging from atomic friction at the nanoscale, flux motion in type II superconductors at the mesoscale, colloidal motion in disordered media at the microscale, and plate tectonics at geological length scales. Here we show that active matter or self-propelled particles interacting with quenched disorder under an external drive represents a class of system that can also exhibit pinning-depinning phenomena, plastic flow phases, and nonequilibrium sliding transitions that are correlated with distinct morphologies and velocity-force curve signatures. When interactions withmore » the substrate are strong, a homogeneous pinned liquid phase forms that depins plastically into a uniform disordered phase and then dynamically transitions first into a moving stripe coexisting with a pinned liquid and then into a moving phase-separated state at higher drives. We numerically map the resulting dynamical phase diagrams as a function of external drive, substrate interaction strength, and self-propulsion correlation length. These phases can be observed for active matter moving through random disorder. Lastly, our results indicate that intrinsically nonequilibrium systems can exhibit additional nonequilibrium transitions when subjected to an external drive.« less

Dynamic phases of active matter systems with quenched disorder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandor, Csand; Libal, Andras; Reichhardt, Charles

Depinning and nonequilibrium transitions within sliding states in systems driven over quenched disorder arise across a wide spectrum of size scales ranging from atomic friction at the nanoscale, flux motion in type II superconductors at the mesoscale, colloidal motion in disordered media at the microscale, and plate tectonics at geological length scales. Here we show that active matter or self-propelled particles interacting with quenched disorder under an external drive represents a class of system that can also exhibit pinning-depinning phenomena, plastic flow phases, and nonequilibrium sliding transitions that are correlated with distinct morphologies and velocity-force curve signatures. When interactions withmore » the substrate are strong, a homogeneous pinned liquid phase forms that depins plastically into a uniform disordered phase and then dynamically transitions first into a moving stripe coexisting with a pinned liquid and then into a moving phase-separated state at higher drives. We numerically map the resulting dynamical phase diagrams as a function of external drive, substrate interaction strength, and self-propulsion correlation length. These phases can be observed for active matter moving through random disorder. Lastly, our results indicate that intrinsically nonequilibrium systems can exhibit additional nonequilibrium transitions when subjected to an external drive.« less

Exploring one-particle orbitals in large many-body localized systems

NASA Astrophysics Data System (ADS)

Villalonga, Benjamin; Yu, Xiongjie; Luitz, David J.; Clark, Bryan K.

2018-03-01

Strong disorder in interacting quantum systems can give rise to the phenomenon of many-body localization (MBL), which defies thermalization due to the formation of an extensive number of quasilocal integrals of motion. The one-particle operator content of these integrals of motion is related to the one-particle orbitals (OPOs) of the one-particle density matrix and shows a strong signature across the MBL transition as recently pointed out by Bera et al. [Phys. Rev. Lett. 115, 046603 (2015), 10.1103/PhysRevLett.115.046603; Ann. Phys. 529, 1600356 (2017), 10.1002/andp.201600356]. We study the properties of the OPOs of many-body eigenstates of an MBL system in one dimension. Using shift-and-invert MPS, a matrix product state method to target highly excited many-body eigenstates introduced previously [Phys. Rev. Lett. 118, 017201 (2017), 10.1103/PhysRevLett.118.017201], we are able to obtain accurate results for large systems of sizes up to L =64 . We find that the OPOs drawn from eigenstates at different energy densities have high overlap and their occupations are correlated with the energy of the eigenstates. Moreover, the standard deviation of the inverse participation ratio of these orbitals is maximal at the nose of the mobility edge. Also, the OPOs decay exponentially in real space, with a correlation length that increases at low disorder. In addition, we find that the probability distribution of the strength of the large-range coupling constants of the number operators generated by the OPOs approach a log-uniform distribution at strong disorder.

Autonomic and inflammatory consequences of posttraumatic stress disorder and the link to cardiovascular disease.

PubMed

Brudey, Chevelle; Park, Jeanie; Wiaderkiewicz, Jan; Kobayashi, Ihori; Mellman, Thomas A; Marvar, Paul J

2015-08-15

Stress- and anxiety-related disorders are on the rise in both military and general populations. Over the next decade, it is predicted that treatment of these conditions, in particular, posttraumatic stress disorder (PTSD), along with its associated long-term comorbidities, will challenge the health care system. Multiple organ systems are adversely affected by PTSD, and PTSD is linked to cancer, arthritis, digestive disease, and cardiovascular disease. Evidence for a strong link between PTSD and cardiovascular disease is compelling, and this review describes current clinical data linking PTSD to cardiovascular disease, via inflammation, autonomic dysfunction, and the renin-angiotensin system. Recent clinical and preclinical evidence regarding the role of the renin-angiotensin system in the extinction of fear memory and relevance in PTSD-related immune and autonomic dysfunction is also addressed. Copyright © 2015 the American Physiological Society.

Attractive Hubbard model with disorder and the generalized Anderson theorem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuchinskii, E. Z., E-mail: kuchinsk@iep.uran.ru; Kuleeva, N. A., E-mail: strigina@iep.uran.ru; Sadovskii, M. V., E-mail: sadovski@iep.uran.ru

Using the generalized DMFT+Σ approach, we study the influence of disorder on single-particle properties of the normal phase and the superconducting transition temperature in the attractive Hubbard model. A wide range of attractive potentials U is studied, from the weak coupling region, where both the instability of the normal phase and superconductivity are well described by the BCS model, to the strong-coupling region, where the superconducting transition is due to Bose-Einstein condensation (BEC) of compact Cooper pairs, formed at temperatures much higher than the superconducting transition temperature. We study two typical models of the conduction band with semi-elliptic and flatmore » densities of states, respectively appropriate for three-dimensional and two-dimensional systems. For the semi-elliptic density of states, the disorder influence on all single-particle properties (e.g., density of states) is universal for an arbitrary strength of electronic correlations and disorder and is due to only the general disorder widening of the conduction band. In the case of a flat density of states, universality is absent in the general case, but still the disorder influence is mainly due to band widening, and the universal behavior is restored for large enough disorder. Using the combination of DMFT+Σ and Nozieres-Schmitt-Rink approximations, we study the disorder influence on the superconducting transition temperature T{sub c} for a range of characteristic values of U and disorder, including the BCS-BEC crossover region and the limit of strong-coupling. Disorder can either suppress T{sub c} (in the weak-coupling region) or significantly increase T{sub c} (in the strong-coupling region). However, in all cases, the generalized Anderson theorem is valid and all changes of the superconducting critical temperature are essentially due to only the general disorder widening of the conduction band.« less

Quantum glassiness in strongly correlated clean systems: an example of topological overprotection.

PubMed

Chamon, Claudio

2005-02-04

This Letter presents solvable examples of quantum many-body Hamiltonians of systems that are unable to reach their ground states as the environment temperature is lowered to absolute zero. These examples, three-dimensional generalizations of quantum Hamiltonians proposed for topological quantum computing, (1) have no quenched disorder, (2) have solely local interactions, (3) have an exactly solvable spectrum, (4) have topologically ordered ground states, and (5) have slow dynamical relaxation rates akin to those of strong structural glasses.

Quantum Glassiness in Strongly Correlated Clean Systems: An Example of Topological Overprotection

NASA Astrophysics Data System (ADS)

Chamon, Claudio

2005-01-01

This Letter presents solvable examples of quantum many-body Hamiltonians of systems that are unable to reach their ground states as the environment temperature is lowered to absolute zero. These examples, three-dimensional generalizations of quantum Hamiltonians proposed for topological quantum computing, (1)have no quenched disorder, (2)have solely local interactions, (3)have an exactly solvable spectrum, (4)have topologically ordered ground states, and (5)have slow dynamical relaxation rates akin to those of strong structural glasses.

Contribution of Dynorphin and Orexin Neuropeptide Systems to the Motivational Effects of Alcohol.

PubMed

Anderson, Rachel I; Moorman, David E; Becker, Howard C

2018-03-11

Understanding the neural systems that drive alcohol motivation and are disrupted in alcohol use disorders is of critical importance in developing novel treatments. The dynorphin and orexin/hypocretin neuropeptide systems are particularly relevant with respect to alcohol use and misuse. Both systems are strongly associated with alcohol-seeking behaviors, particularly in cases of high levels of alcohol use as seen in dependence. Furthermore, both systems also play a role in stress and anxiety, indicating that disruption of these systems may underlie long-term homeostatic dysregulation seen in alcohol use disorders. These systems are also closely interrelated with one another - dynorphin/kappa opioid receptors and orexin/hypocretin receptors are found in similar regions and hypocretin/orexin neurons also express dynorphin - suggesting that these two systems may work together in the regulation of alcohol seeking and may be mutually disrupted in alcohol use disorders. This chapter reviews studies demonstrating a role for each of these systems in motivated behavior, with a focus on their roles in regulating alcohol-seeking and self-administration behaviors. Consideration is also given to evidence indicating that these neuropeptide systems may be viable targets for the development of potential treatments for alcohol use disorders.

Dimensional assessment of personality in an out-patient sample: relations of the systems of Millon and Cloninger.

PubMed

Bayon, C; Hill, K; Svrakic, D M; Przybeck, T R; Cloninger, C R

1996-01-01

The Cloninger Temperament and Character Inventory (TCI) and the Millon Clinical Multiaxial Inventory (MCMI-II) are both self-report inventories that can be used to assess personality reliably in clinical samples. Both instruments were administered to 103 consecutive psychiatric out-patients with or without personality disorders. The goals were to assess the convergent validity of the two instruments, to replicate the findings of Svrakic et al. (1993) Archives of General Psychiatry, 50, 991-999, about the differential diagnosis of Axis II disorders, and to analyse the relations of Millon's measures of Axis I disorders with Cloninger's measures. We observed a strong convergent validity between the instruments; the seven dimensions of the TCI accounted for most of the variance in MCMI-II measures of both Axis 1 and Axis 2 disorders. As reported by Svrakic et al. (1993) Archives of General Psychiatry, 50, 991-999, in in-patients, low self-directedness and low cooperativeness were confirmed to be the essential features of all personality disorders in out-patients. In addition, self-transcendence, the third of Cloninger's character dimensions, was observed to be a strong correlate of severe Axis-1 psychopathology, including manic and delusional disorders.

Disordered animal multilayer reflectors and the localization of light

PubMed Central

Jordan, T. M.; Partridge, J. C.; Roberts, N. W.

2014-01-01

Multilayer optical reflectors constructed from ‘stacks’ of alternating layers of high and low refractive index dielectric materials are present in many animals. For example, stacks of guanine crystals with cytoplasm gaps occur within the skin and scales of fish, and stacks of protein platelets with cytoplasm gaps occur within the iridophores of cephalopods. Common to all these animal multilayer reflectors are different degrees of random variation in the thicknesses of the individual layers in the stack, ranging from highly periodic structures to strongly disordered systems. However, previous discussions of the optical effects of such thickness disorder have been made without quantitative reference to the propagation of light within the reflector. Here, we demonstrate that Anderson localization provides a general theoretical framework to explain the common coherent interference and optical properties of these biological reflectors. Firstly, we illustrate how the localization length enables the spectral properties of the reflections from more weakly disordered ‘coloured’ and more strongly disordered ‘silvery’ reflectors to be explained by the same physical process. Secondly, we show how the polarization properties of reflection can be controlled within guanine–cytoplasm reflectors, with an interplay of birefringence and thickness disorder explaining the origin of broadband polarization-insensitive reflectivity. PMID:25339688

Anti-levitation in integer quantum Hall systems

NASA Astrophysics Data System (ADS)

Wang, C.; Avishai, Y.; Meir, Yigal; Wang, X. R.

2014-01-01

The evolution of extended states of two-dimensional electron gas with white-noise randomness and field is numerically investigated by using the Anderson model on square lattices. Focusing on the lowest Landau band we establish an anti-levitation scenario of the extended states: As either the disorder strength W increases or the magnetic field strength B decreases, the energies of the extended states move below the Landau energies pertaining to a clean system. Moreover, for strong enough disorder, there is a disorder-dependent critical magnetic field Bc(W) below which there are no extended states at all. A general phase diagram in the W-1/B plane is suggested with a line separating domains of localized and delocalized states.

Quasiparticle density of states, localization, and distributed disorder in the cuprate superconductors

NASA Astrophysics Data System (ADS)

Sulangi, Miguel Antonio; Zaanen, Jan

2018-04-01

We explore the effects of various kinds of random disorder on the quasiparticle density of states of two-dimensional d -wave superconductors using an exact real-space method, incorporating realistic details known about the cuprates. Random on-site energy and pointlike unitary impurity models are found to give rise to a vanishing DOS at the Fermi energy for narrow distributions and low concentrations, respectively, and lead to a finite, but suppressed, DOS at unrealistically large levels of disorder. Smooth disorder arising from impurities located away from the copper-oxide planes meanwhile gives rise to a finite DOS at realistic impurity concentrations. For the case of smooth disorder whose average potential is zero, a resonance is found at zero energy for the quasiparticle DOS at large impurity concentrations. We discuss the implications of these results on the computed low-temperature specific heat, the behavior of which we find is strongly affected by the amount of disorder present in the system. We also compute the localization length as a function of disorder strength for various types of disorder and find that intermediate- and high-energy states are quasiextended for low disorder, and that states near the Fermi energy are strongly localized and have a localization length that exhibits an unusual dependence on the amount of disorder. We comment on the origin of disorder in the cuprates and provide constraints on these based on known results from scanning tunneling spectroscopy and specific heat experiments.

Superconductivity drives magnetism in δ -doped La2CuO4

NASA Astrophysics Data System (ADS)

Suter, A.; Logvenov, G.; Boris, A. V.; Baiutti, F.; Wrobel, F.; Howald, L.; Stilp, E.; Salman, Z.; Prokscha, T.; Keimer, B.

2018-04-01

Understanding the interplay between different orders in a solid is a key challenge in highly correlated electronic systems. In real systems this is even more difficult since disorder can have strong influence on the subtle balance between these orders and thus can obscure the interpretation of the observed physical properties. Here we present a study on δ -doped La2CuO4 (δ -LCON ) superlattices. By means of molecular beam epitaxy whole LaO2 layers were periodically replaced by SrO2 layers, providing a charge reservoir yet reducing the level of disorder typically present in doped cuprates to an absolute minimum. The induced superconductivity and its interplay with the antiferromagnetic order is studied by means of low-energy muon spin rotation. We find a quasi-two-dimensional superconducting state which couples to the antiferromagnetic order in a nontrivial way. Below the superconducting transition temperature, the magnetic volume fraction increases strongly. The reason could be a charge redistribution of the free carriers due to the opening of the superconducting gap which is possible due to the close proximity and low disorder between the different ordered regions.

Field-induced cluster spin glass and inverse symmetry breaking enhanced by frustration

NASA Astrophysics Data System (ADS)

Schmidt, M.; Zimmer, F. M.; Magalhaes, S. G.

2018-03-01

We consider a cluster disordered model to study the interplay between short- and long-range interactions in geometrically frustrated spin systems under an external magnetic field (h). In our approach, the intercluster long-range disorder (J) is analytically treated to get an effective cluster model that is computed exactly. The clusters follow a checkerboard lattice with first-neighbor (J1) and second-neighbor (J2) interactions. We find a reentrant transition from the cluster spin-glass (CSG) state to a paramagnetic (PM) phase as the temperature decreases for a certain range of h. This inverse symmetry breaking (ISB) appears as a consequence of both quenched disorder with frustration and h, that introduce a CSG state with higher entropy than the polarized PM phase. The competitive scenario introduced by antiferromagnetic (AF) short-range interactions increases the CSG state entropy, leading to continuous ISB transitions and enhancing the ISB regions, mainly in the geometrically frustrated case (J1 =J2). Remarkably, when strong AF intracluster couplings are present, field-induced CSG phases can be found. These CSG regions are strongly related to the magnetization plateaus observed in this cluster disordered system. In fact, it is found that each field-induced magnetization jump brings a CSG region. We notice that geometrical frustration, as well as cluster size, play an important role in the magnetization plateaus and, therefore, are also relevant in the field-induced glassy states. Our findings suggest that competing interactions support ISB and field-induced CSG phases in disordered cluster systems under an external magnetic field.

A disorder-enhanced quasi-one-dimensional superconductor

PubMed Central

Petrović, A. P.; Ansermet, D.; Chernyshov, D.; Hoesch, M.; Salloum, D.; Gougeon, P.; Potel, M.; Boeri, L.; Panagopoulos, C.

2016-01-01

A powerful approach to analysing quantum systems with dimensionality d>1 involves adding a weak coupling to an array of one-dimensional (1D) chains. The resultant quasi-1D (q1D) systems can exhibit long-range order at low temperature, but are heavily influenced by interactions and disorder due to their large anisotropies. Real q1D materials are therefore ideal candidates not only to provoke, test and refine theories of strongly correlated matter, but also to search for unusual emergent electronic phases. Here we report the unprecedented enhancement of a superconducting instability by disorder in single crystals of Na2−δMo6Se6, a q1D superconductor comprising MoSe chains weakly coupled by Na atoms. We argue that disorder-enhanced Coulomb pair-breaking (which usually destroys superconductivity) may be averted due to a screened long-range Coulomb repulsion intrinsic to disordered q1D materials. Our results illustrate the capability of disorder to tune and induce new correlated electron physics in low-dimensional materials. PMID:27448209

A disorder-enhanced quasi-one-dimensional superconductor.

PubMed

Petrović, A P; Ansermet, D; Chernyshov, D; Hoesch, M; Salloum, D; Gougeon, P; Potel, M; Boeri, L; Panagopoulos, C

2016-07-22

A powerful approach to analysing quantum systems with dimensionality d>1 involves adding a weak coupling to an array of one-dimensional (1D) chains. The resultant quasi-1D (q1D) systems can exhibit long-range order at low temperature, but are heavily influenced by interactions and disorder due to their large anisotropies. Real q1D materials are therefore ideal candidates not only to provoke, test and refine theories of strongly correlated matter, but also to search for unusual emergent electronic phases. Here we report the unprecedented enhancement of a superconducting instability by disorder in single crystals of Na2-δMo6Se6, a q1D superconductor comprising MoSe chains weakly coupled by Na atoms. We argue that disorder-enhanced Coulomb pair-breaking (which usually destroys superconductivity) may be averted due to a screened long-range Coulomb repulsion intrinsic to disordered q1D materials. Our results illustrate the capability of disorder to tune and induce new correlated electron physics in low-dimensional materials.

Synchronization of chaotic and nonchaotic oscillators: Application to bipolar disorder

NASA Astrophysics Data System (ADS)

Nono Dueyou Buckjohn, C.; Siewe Siewe, M.; Tchawoua, C.; Kofane, T. C.

2010-08-01

In this Letter, we use a synchronization scheme on two bipolar disorder models consisting of a strong nonlinear system with multiplicative excitation and a nonlinear oscillator without parametric harmonic forcing. The stability condition following our control function is analytically demonstrated using the Lyapunov theory and Routh-Hurwitz criteria, we then have the condition for the existence of a feedback gain matrix. A convenient demonstration of the accuracy of the method is complemented by the numerical simulations from which we illustrate the synchronized dynamics between the two non-identical bipolar disorder patients.

Quantum critical fluctuations in disordered d-wave superconductors.

PubMed

Meyer, Julia S; Gornyi, Igor V; Altland, Alexander

2003-03-14

To explain the strong quasiparticle damping in the cuprates, Sachdev and collaborators proposed to couple the system to a critically fluctuating id(xy)- or is-order parameter mode. Here we generalize the approach to the presence of static disorder. In the id case, the order parameter dynamics becomes diffusive, but otherwise much of the phenomenology of the clean case remains intact. In contrast, the interplay of disorder and is-order parameter fluctuations leads to a secondary superconductor transition, with a critical temperature exponentially sensitive to the impurity concentration.

Lifshitz phase: the microscopic structure of aqueous and ethanol mixtures of 1,n-diols.

PubMed

Požar, Martina; Perera, Aurélien

2017-06-14

We study binary mixtures of ethylene glycol and 1,3-propandiol with water or ethanol using computer simulations. Despite strong hydrogen bonding tendencies between all these molecules, we find that these mixtures are surprisingly homogeneous, in contrast to the strong micro-heterogeneity found in aqueous ethanol mixtures. The aqueous diol mixtures are found to be close to ideal mixtures, with near-ideal Kirkwood-Buff integrals. Ethanol-diol mixtures show weak non-ideality. The origin of this unexpected randomness is due to the fact that the two hydrogen bonding hydroxyl groups of the 1,n-diol are bound by the neutral alkyl bond, which prevents the micro-segregation of the different types of hydroxyl groups. These findings suggest that random disorder can arise in the presence of strong interactions - in contrast to the usual picture of random disorder due to weak interactions between the components. They point to the important role of molecular topology in tuning concentration fluctuations in complex liquids. We propose and justify herein the name of Lifshitz phases to designate such types of disordered systems.

Strong-coupling induced damping of spin-echo modulations in magic-angle-spinning NMR: Implications for J coupling measurements in disordered solids

NASA Astrophysics Data System (ADS)

Guerry, Paul; Brown, Steven P.; Smith, Mark E.

2017-10-01

In the context of improving J coupling measurements in disordered solids, strong coupling effects have been investigated in the spin-echo and refocused INADEQUATE spin-echo (REINE) modulations of three- and four-spin systems under magic-angle-spinning (MAS), using density matrix simulations and solid-state NMR experiments on a cadmium phosphate glass. Analytical models are developed for the different modulation regimes, which are shown to be distinguishable in practice using Akaike's information criterion. REINE modulations are shown to be free of the damping that occurs for spin-echo modulations when the observed spin has the same isotropic chemical shift as its neighbour. Damping also occurs when the observed spin is bonded to a strongly-coupled pair. For mid-chain units, the presence of both direct and relayed damping makes both REINE and spin-echo modulations impossible to interpret quantitatively. We nonetheless outline how a qualitative comparison of the modulation curves can provide valuable information on disordered networks, possibly also pertaining to dynamic effects therein.

Substance Abuse and Trauma.

PubMed

Simmons, Shannon; Suárez, Liza

2016-10-01

There is a strong, bidirectional link between substance abuse and traumatic experiences. Teens with cooccurring substance use disorders (SUDs) and posttraumatic stress disorder (PTSD) have significant functional and psychosocial impairment. Common neurobiological foundations point to the reinforcing cycle of trauma symptoms, substance withdrawal, and substance use. Treatment of teens with these issues should include a systemic and integrated approach to both the SUD and the PTSD. Copyright © 2016 Elsevier Inc. All rights reserved.

Oxytocin for the treatment of drug and alcohol use disorders.

PubMed

Lee, Mary R; Weerts, Elise M

2016-12-01

There is growing interest in the use of oxytocin (OT) as a potential treatment for alcohol and other substance-use disorders. OT is a neuropeptide that modulates adaptive processes associated with addiction including reward, tolerance, associative learning, memory, and stress responses. OT exerts its effects through interactions with the hypothalamic-pituitary-adrenal axis and multiple neurotransmitter systems including the dopamine mesolimbic reward and corticotrophin-releasing factor stress systems. The effects of OT on stress systems are of high interest, given the strong link between stress, drug use and relapse, and known dysregulation of hypothalamic-pituitary-adrenal-axis activity associated with substance-use disorders. At the same time, the OT system is itself altered by acute or chronic drug exposure. This review summarizes the preclinical and clinical literature on the OT system and its relevance to drug and alcohol addiction. In addition, findings from recent clinical trials conducted in participants with cocaine, cannabis, or alcohol use disorder are included and evidence that OT may help to normalize blunted stress responses, and attenuate withdrawal-associated hypercortisolism, negative mood, and withdrawal symptoms is summarized.

Anomalous Hooke’s law in disordered graphene

NASA Astrophysics Data System (ADS)

Gornyi, I. V.; Kachorovskii, V. Yu; Mirlin, A. D.

2017-03-01

The discovery of graphene, a single monolayer of graphite, has provided an experimental demonstration of stability of 2D crystals. Although thermal fluctuations of such crystals tend to destroy the long-range order in the system, the crystal can be stabilized by strong anharmonicity effects. This competition is the central issue of the crumpling transition, i.e., a transition between flat and crumpled phases. We show that anharmonicity-controlled fluctuations of a graphene membrane around equilibrium flat phase lead to unusual elastic properties. In particular, we demonstrate that stretching ξ of a flake of graphene is a nonlinear function of the applied tension at small tension: ξ \\propto {σ }η /(2-η ) and ξ \\propto {σ }η /(8-η ) for clean and strongly disordered graphene, respectively. Conventional linear Hooke’s law, ξ \\propto σ , is realized at sufficiently large tensions: σ \\gg {σ }* , where {σ }* depends both on temperature and on the disorder strength.

Temperature Dependence of the Upper Critical Field in Disordered Hubbard Model with Attraction

NASA Astrophysics Data System (ADS)

Kuchinskii, E. Z.; Kuleeva, N. A.; Sadovskii, M. V.

2017-12-01

We study disorder effects upon the temperature behavior of the upper critical magnetic field in an attractive Hubbard model within the generalized DMFT+Σ approach. We consider the wide range of attraction potentials U—from the weak coupling limit, where superconductivity is described by BCS model, up to the strong coupling limit, where superconducting transition is related to Bose-Einstein condensation (BEC) of compact Cooper pairs, formed at temperatures significantly higher than superconducting transition temperature, as well as the wide range of disorder—from weak to strong, when the system is in the vicinity of Anderson transition. The growth of coupling strength leads to the rapid growth of H c2( T), especially at low temperatures. In BEC limit and in the region of BCS-BEC crossover H c2( T), dependence becomes practically linear. Disordering also leads to the general growth of H c2( T). In BCS limit of weak coupling increasing disorder lead both to the growth of the slope of the upper critical field in the vicinity of the transition point and to the increase of H c2( T) in the low temperature region. In the limit of strong disorder in the vicinity of the Anderson transition localization corrections lead to the additional growth of H c2( T) at low temperatures, so that the H c2( T) dependence becomes concave. In BCS-BEC crossover region and in BEC limit disorder only slightly influences the slope of the upper critical field close to T c . However, in the low temperature region H c2 ( T may significantly grow with disorder in the vicinity of the Anderson transition, where localization corrections notably increase H c2 ( T = 0) also making H c2( T) dependence concave.

Variable-Range Hopping through Marginally Localized Phonons

NASA Astrophysics Data System (ADS)

Banerjee, Sumilan; Altman, Ehud

2016-03-01

We investigate the effect of coupling Anderson localized particles in one dimension to a system of marginally localized phonons having a symmetry protected delocalized mode at zero frequency. This situation is naturally realized for electrons coupled to phonons in a disordered nanowire as well as for ultracold fermions coupled to phonons of a superfluid in a one-dimensional disordered trap. To determine if the coupled system can be many-body localized we analyze the phonon-mediated hopping transport for both the weak and strong coupling regimes. We show that the usual variable-range hopping mechanism involving a low-order phonon process is ineffective at low temperature due to discreteness of the bath at the required energy. Instead, the system thermalizes through a many-body process involving exchange of a diverging number n ∝-log T of phonons in the low temperature limit. This effect leads to a highly singular prefactor to Mott's well-known formula and strongly suppresses the variable range hopping rate. Finally, we comment on possible implications of this physics in higher dimensional electron-phonon coupled systems.

Entanglement dynamics in random media

NASA Astrophysics Data System (ADS)

Menezes, G.; Svaiter, N. F.; Zarro, C. A. D.

2017-12-01

We study how the entanglement dynamics between two-level atoms is impacted by random fluctuations of the light cone. In our model the two-atom system is envisaged as an open system coupled with an electromagnetic field in the vacuum state. We employ the quantum master equation in the Born-Markov approximation in order to describe the completely positive time evolution of the atomic system. We restrict our investigations to the situation in which the atoms are coupled individually to two spatially separated cavities, one of which displays the emergence of light-cone fluctuations. In such a disordered cavity, we assume that the coefficients of the Klein-Gordon equation are random functions of the spatial coordinates. The disordered medium is modeled by a centered, stationary, and Gaussian process. We demonstrate that disorder has the effect of slowing down the entanglement decay. We conjecture that in a strong-disorder environment the mean life of entangled states can be enhanced in such a way as to almost completely suppress quantum nonlocal decoherence.

Psychological Co-morbidity in Functional Gastrointestinal Disorders: Epidemiology, Mechanisms and Management

PubMed Central

2012-01-01

Functional gastrointestinal disorder (FGID) is one of the commonest digestive diseases worldwide and leads to significant morbidity and burden on healthcare resource. The putative bio-psycho-social pathophysiological model for FGID underscores the importance of psychological distress in the pathogenesis of FGID. Concomitant psychological disorders, notably anxiety and depressive disorders, are strongly associated with FGID and these psychological co-morbidities correlate with severity of FGID symptoms. Early life adversity such as sexual and physical abuse is more commonly reported in patients with FGID. There is mounting evidence showing that psychological disorders are commonly associated with abnormal central processing of visceral noxious stimuli. The possible causal link between psychological disorders and FGID involves functional abnormalities in various components of the brain-gut axis, which include hypothalamic-pituitary-adrenal system, sympathetic and parasympathetic nervous system, serotonergic and endocannabinoid systems. Moreover, recent studies have also shown that psychological distress may alter the systemic and gut immunity, which is increasingly recognized as a pathophysiologic feature of FGID. Psychotropic agent, in particular antidepressant, and psychological intervention such as cognitive behavioral therapy and meditation have been reported to be effective for alleviation of gastrointestinal symptoms and quality of life in FGID patients. Further studies are needed to evaluate the impact of early detection and management of co-morbid psychological disorders on the long-term clinical outcome and disease course of FGID. PMID:22323984

Coding of time-dependent stimuli in homogeneous and heterogeneous neural populations.

PubMed

Beiran, Manuel; Kruscha, Alexandra; Benda, Jan; Lindner, Benjamin

2018-04-01

We compare the information transmission of a time-dependent signal by two types of uncoupled neuron populations that differ in their sources of variability: i) a homogeneous population whose units receive independent noise and ii) a deterministic heterogeneous population, where each unit exhibits a different baseline firing rate ('disorder'). Our criterion for making both sources of variability quantitatively comparable is that the interspike-interval distributions are identical for both systems. Numerical simulations using leaky integrate-and-fire neurons unveil that a non-zero amount of both noise or disorder maximizes the encoding efficiency of the homogeneous and heterogeneous system, respectively, as a particular case of suprathreshold stochastic resonance. Our findings thus illustrate that heterogeneity can render similarly profitable effects for neuronal populations as dynamic noise. The optimal noise/disorder depends on the system size and the properties of the stimulus such as its intensity or cutoff frequency. We find that weak stimuli are better encoded by a noiseless heterogeneous population, whereas for strong stimuli a homogeneous population outperforms an equivalent heterogeneous system up to a moderate noise level. Furthermore, we derive analytical expressions of the coherence function for the cases of very strong noise and of vanishing intrinsic noise or heterogeneity, which predict the existence of an optimal noise intensity. Our results show that, depending on the type of signal, noise as well as heterogeneity can enhance the encoding performance of neuronal populations.

Interplay between short-range correlated disorder and Coulomb interaction in nodal-line semimetals

NASA Astrophysics Data System (ADS)

Wang, Yuxuan; Nandkishore, Rahul M.

2017-09-01

In nodal-line semimetals, Coulomb interactions and short-range correlated disorder are both marginal perturbations to the clean noninteracting Hamiltonian. We analyze their interplay using a weak-coupling renormalization group approach. In the clean case, the Coulomb interaction has been found to be marginally irrelevant, leading to Fermi liquid behavior. We extend the analysis to incorporate the effects of disorder. The nodal line structure gives rise to kinematical constraints similar to that for a two-dimensional Fermi surface, which plays a crucial role in the one-loop renormalization of the disorder couplings. For a twofold degenerate nodal loop (Weyl loop), we show that disorder flows to strong coupling along a unique fixed trajectory in the space of symmetry inequivalent disorder couplings. Along this fixed trajectory, all symmetry inequivalent disorder strengths become equal. For a fourfold degenerate nodal loop (Dirac loop), disorder also flows to strong coupling, however, the strengths of symmetry inequivalent disorder couplings remain different. We show that feedback from disorder reverses the sign of the beta function for the Coulomb interaction, causing the Coulomb interaction to flow to strong coupling as well. However, the Coulomb interaction flows to strong coupling asymptotically more slowly than disorder. Extrapolating our results to strong coupling, we conjecture that at low energies nodal line semimetals should be described by a noninteracting nonlinear sigma model. We discuss the relation of our results with possible many-body localization at zero temperatures in such materials.

A new phase of disordered phonons modelled by random matrices

NASA Astrophysics Data System (ADS)

Schmittner, Sebastian; Zirnbauer, Martin

2015-03-01

Starting from the clean harmonic crystal and not invoking two-level systems, we propose a model for phonons in a disordered solid. In this model the strength of mass and spring constant disorder can be increased separately. Both types of disorder are modelled by random matrices that couple the degrees of freedom locally. Treated in coherent potential approximation (CPA), the speed of sound decreases with increasing disorder until it reaches zero at finite disorder strength. There, a critical transition to a strong disorder phase occurs. In this novel phase, we find the density of states at zero energy in three dimensions to be finite, leading to a linear temperature dependence of the heat capacity, as observed experimentally for vitreous systems. For any disorder strength, our model is stable, i.e. masses and spring constants are positive, and there are no runaway dynamics. This is ensured by using appropriate probability distributions, inspired by Wishart ensembles, for the random matrices. The CPA self-consistency equations are derived in a very accessible way using planar diagrams. The talk focuses on the model and the results. The first author acknowledges financial support by the Deutsche Telekom Stiftung.

Reentrant Resistive Behavior and Dimensional Crossover in Disordered Superconducting TiN Films.

PubMed

Postolova, Svetlana V; Mironov, Alexey Yu; Baklanov, Mikhail R; Vinokur, Valerii M; Baturina, Tatyana I

2017-05-11

A reentrant temperature dependence of the normal state resistance often referred to as the N-shaped temperature dependence, is omnipresent in disordered superconductors - ranging from high-temperature cuprates to ultrathin superconducting films - that experience superconductor-to-insulator transition. Yet, despite the ubiquity of this phenomenon its origin still remains a subject of debate. Here we investigate strongly disordered superconducting TiN films and demonstrate universality of the reentrant behavior. We offer a quantitative description of the N-shaped resistance curve. We show that upon cooling down the resistance first decreases linearly with temperature and then passes through the minimum that marks the 3D-2D crossover in the system. In the 2D temperature range the resistance first grows with decreasing temperature due to quantum contributions and eventually drops to zero as the system falls into a superconducting state. Our findings demonstrate the prime importance of disorder in dimensional crossover effects.

Mind and body: how the health of the body impacts on neuropsychiatry

PubMed Central

Renoir, Thibault; Hasebe, Kyoko; Gray, Laura

2013-01-01

It has long been established in traditional forms of medicine and in anecdotal knowledge that the health of the body and the mind are inextricably linked. Strong and continually developing evidence now suggests a link between disorders which involve Hypothalamic-Pituitary-Adrenal axis (HPA) dysregulation and the risk of developing psychiatric disease. For instance, adverse or excessive responses to stressful experiences are built into the diagnostic criteria for several psychiatric disorders, including depression and anxiety disorders. Interestingly, peripheral disorders such as metabolic disorders and cardiovascular diseases are also associated with HPA changes. Furthermore, many other systemic disorders associated with a higher incidence of psychiatric disease involve a significant inflammatory component. In fact, inflammatory and endocrine pathways seem to interact in both the periphery and the central nervous system (CNS) to potentiate states of psychiatric dysfunction. This review synthesizes clinical and animal data looking at interactions between peripheral and central factors, developing an understanding at the molecular and cellular level of how processes in the entire body can impact on mental state and psychiatric health. PMID:24385966

Role of tandospirone, a 5-HT1A receptor partial agonist, in the treatment of central nervous system disorders and the underlying mechanisms.

PubMed

Huang, Xuefei; Yang, Jing; Yang, Sijin; Cao, Shousong; Qin, Dalian; Zhou, Ya; Li, Xiaoli; Ye, Yun; Wu, Jianming

2017-11-24

5-hydroxytryptamine (5-HT, serotonin) is an important neurotransmitter in the modulation of the cognitive, behavioral and psychological functions in animals and humans. Among the fourteen subtypes of 5-HT receptor, 5-HT1A receptor has been extensively studied. Tandospirone, an azapirone derivative with strong and selective agonist effect on 5-HT1A receptor, has been used for the treatment of anxiety disorders especially generalized anxiety disorder for decades. Recently, tandospirone showed the efficacy in relieving the syndromes of social anxiety disorder and post-traumatic stress disorder as well as in potentiating the effect of antidepressants in the treatment of depression in both preclinical and clinical studies. More impressively, the beneficial effect of tandospirone has been revealed on improvement of motor dysfunction of Parkinson's disease and cognitive deficits of schizophrenia either in monotherapy or in combination with other drugs. This review discusses the superiority of tandospirone in the treatment of the disorders and associated mechanisms in central nervous system from the literature.

The role of ion irradiation in activating silent Raman modes via tuning in plasmonic behaviour and surface disorder of Au/ZnO/Pt NFG system

NASA Astrophysics Data System (ADS)

Singh, Udai B.; Gautam, Subodh K.; Kumar, Sunil; Ojha, Sunil; Ghosh, Santanu; Singh, Fouran

2017-09-01

The perceptible progression of Raman modes of zinc oxide (ZnO) is studied in nanostructures film gap (Au (10 nm)/ZnO (70 nm)/Pt (50 nm)) system with 1.2 MeV Xe ion irradiation. Unattainable silent Raman modes of ZnO turn out to be strongly visible after ion irradiation. The creation of ion-beam-induced lattice disorder, defects, and impurities in a ZnO layer leads to breakdown the translational crystal symmetry that results in the origin of silent modes. The formation of hot-spots in the ZnO layer of the NFG system also supports the enhancement of the intensity of Raman modes. Overall results are attributed to combined effects of lattice disorder, defects, and impurities along with plasmonic effect and explained in the framework of elastic-thermal-spike formation.

Anderson Localization from the Berry-Curvature Interchange in Quantum Anomalous Hall Systems

NASA Astrophysics Data System (ADS)

Qiao, Zhenhua; Han, Yulei; Zhang, Lei; Wang, Ke; Deng, Xinzhou; Jiang, Hua; Yang, Shengyuan A.; Wang, Jian; Niu, Qian

2016-07-01

We theoretically investigate the localization mechanism of the quantum anomalous Hall effect (QAHE) in the presence of spin-flip disorders. We show that the QAHE stays quantized at weak disorders, then enters a Berry-curvature mediated metallic phase at moderate disorders, and finally goes into the Anderson insulating phase at strong disorders. From the phase diagram, we find that at the charge neutrality point although the QAHE is most robust against disorders, the corresponding metallic phase is much easier to be localized into the Anderson insulating phase due to the interchange of Berry curvatures carried, respectively, by the conduction and valence bands. In the end, we provide a phenomenological picture related to the topological charges to better understand the underlying physical origin of the QAHE Anderson localization.

Anderson Localization from the Berry-Curvature Interchange in Quantum Anomalous Hall Systems

NASA Astrophysics Data System (ADS)

Han, Yulei; Qiao, Zhenhua

In this talk, we theoretically investigate the localization mechanism of the quantum anomalous Hall effect (QAHE) in the presence of spin-flip disorders. We show that the QAHE stays quantized at weak disorders, then enters a Berry-curvature mediated metallic phase at moderate disorders, and finally goes into the Anderson insulating phase at strong disorders. From the phase diagram, we find that at the charge neutrality point although the QAHE is most robust against disorders, the corresponding metallic phase is much easier to be localized into the Anderson insulating phase due to the interchange of Berry curvatures carried, respectively, by the conduction and valence bands. In the end, we provide a phenomenological picture related to the topological charges to better understand the underlying physical origin of the QAHE Anderson localization.

Condensation with two constraints and disorder

NASA Astrophysics Data System (ADS)

Barré, J.; Mangeolle, L.

2018-04-01

We consider a set of positive random variables obeying two additive constraints, a linear and a quadratic one; these constraints mimic the conservation laws of a dynamical system. In the simplest setting, without disorder, it is known that such a system may undergo a ‘condensation’ transition, whereby one random variable becomes much larger than the others; this transition has been related to the spontaneous appearance of non linear localized excitations in certain nonlinear chains, called breathers. Motivated by the study of breathers in a disordered discrete nonlinear Schrödinger equation, we study different instances of this problem in presence of a quenched disorder. Unless the disorder is too strong, the phase diagram looks like the one without disorder, with a transition separating a fluid phase, where all variables have the same order of magnitude, and a condensed phase, where one variable is much larger than the others. We then show that the condensed phase exhibits various degrees of ‘intermediate symmetry breaking’: the site hosting the condensate is chosen neither uniformly at random, nor is it fixed by the disorder realization. Throughout the article, our heuristic arguments are complemented with direct Monte Carlo simulations.

Burke-Fahn-Marsden dystonia severity, Gross Motor, Manual Ability, and Communication Function Classification scales in childhood hyperkinetic movement disorders including cerebral palsy: a 'Rosetta Stone' study.

PubMed

Elze, Markus C; Gimeno, Hortensia; Tustin, Kylee; Baker, Lesley; Lumsden, Daniel E; Hutton, Jane L; Lin, Jean-Pierre S-M

2016-02-01

Hyperkinetic movement disorders (HMDs) can be assessed using impairment-based scales or functional classifications. The Burke-Fahn-Marsden Dystonia Rating Scale-movement (BFM-M) evaluates dystonia impairment, but may not reflect functional ability. The Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS), and Communication Function Classification System (CFCS) are widely used in the literature on cerebral palsy to classify functional ability, but not in childhood movement disorders. We explore the concordance of these three functional scales in a large sample of paediatric HMDs and the impact of dystonia severity on these scales. Children with HMDs (n=161; median age 10y 3mo, range 2y 6mo-21y) were assessed using the BFM-M, GMFCS, MACS, and CFCS from 2007 to 2013. This cross-sectional study contrasts the information provided by these scales. All four scales were strongly associated (all Spearman's rank correlation coefficient rs >0.72, p<0.001), with worse dystonia severity implying worse function. Secondary dystonias had worse dystonia and less function than primary dystonias (p<0.001). A longer proportion of life lived with dystonia is associated with more severe dystonia (rs =0.42, p<0.001). The BFM-M is strongly linked with the GMFCS, MACS, and CFCS, irrespective of aetiology. Each scale offers interrelated but complementary information and is applicable to all aetiologies. Movement disorders including cerebral palsy can be effectively evaluated using these scales. © 2015 Mac Keith Press.

Sample dimensionality: a predictor of order-disorder in component peak distribution in multidimensional separation.

PubMed

Giddings, J C

1995-05-26

While the use of multiple dimensions in separation systems can create very high peak capacities, the effectiveness of the enhanced peak capacity in resolving large numbers of components depends strongly on whether the distribution of component peaks is ordered or disordered. Peak overlap is common in disordered distributions, even with a very high peak capacity. It is therefore of great importance to understand the origin of peak order/disorder in multidimensional separations and to address the question of whether any control can be exerted over observed levels of order and disorder and thus separation efficacy. It is postulated here that the underlying difference between ordered and disordered distributions of component peaks in separation systems is related to sample complexity as measured by a newly defined parameter, the sample dimensionality s, and by the derivative dimensionality s'. It is concluded that the type and degree of order and disorder is determined by the relationship of s (or s') to the dimensionality n of the separation system employed. Thus for some relatively simple samples (defined as having small s values), increased order and a consequent enhancement of resolution can be realized by increasing n. The resolution enhancement is in addition to the normal gain in resolving power resulting from the increased peak capacity of multidimensional systems. However, for other samples (having even smaller s values), an increase in n provides no additional benefit in enhancing component separability.

Quantum simulation of strongly correlated condensed matter systems

NASA Astrophysics Data System (ADS)

Hofstetter, W.; Qin, T.

2018-04-01

We review recent experimental and theoretical progress in realizing and simulating many-body phases of ultracold atoms in optical lattices, which gives access to analog quantum simulations of fundamental model Hamiltonians for strongly correlated condensed matter systems, such as the Hubbard model. After a general introduction to quantum gases in optical lattices, their preparation and cooling, and measurement techniques for relevant observables, we focus on several examples, where quantum simulations of this type have been performed successfully during the past years: Mott-insulator states, itinerant quantum magnetism, disorder-induced localization and its interplay with interactions, and topological quantum states in synthetic gauge fields.

Gait disorder rehabilitation using vision and non-vision based sensors: A systematic review

PubMed Central

Ali, Asraf; Sundaraj, Kenneth; Ahmad, Badlishah; Ahamed, Nizam; Islam, Anamul

2012-01-01

Even though the amount of rehabilitation guidelines has never been greater, uncertainty continues to arise regarding the efficiency and effectiveness of the rehabilitation of gait disorders. This question has been hindered by the lack of information on accurate measurements of gait disorders. Thus, this article reviews the rehabilitation systems for gait disorder using vision and non-vision sensor technologies, as well as the combination of these. All papers published in the English language between 1990 and June, 2012 that had the phrases “gait disorder” “rehabilitation”, “vision sensor”, or “non vision sensor” in the title, abstract, or keywords were identified from the SpringerLink, ELSEVIER, PubMed, and IEEE databases. Some synonyms of these phrases and the logical words “and” “or” and “not” were also used in the article searching procedure. Out of the 91 published articles found, this review identified 84 articles that described the rehabilitation of gait disorders using different types of sensor technologies. This literature set presented strong evidence for the development of rehabilitation systems using a markerless vision-based sensor technology. We therefore believe that the information contained in this review paper will assist the progress of the development of rehabilitation systems for human gait disorders. PMID:22938548

Superconductivity-localization interplay and fluctuation magnetoresistance in epitaxial BaPb1 -xBixO3 thin films

NASA Astrophysics Data System (ADS)

Harris, D. T.; Campbell, N.; Uecker, R.; Brützam, M.; Schlom, D. G.; Levchenko, A.; Rzchowski, M. S.; Eom, C.-B.

2018-04-01

BaPb1 -xBixO3 is a superconductor, with transition temperature Tc=11 K, whose parent compound BaBiO3 possesses a charge ordering phase and perovskite crystal structure reminiscent of the cuprates. The lack of magnetism simplifies the BaPb1 -xBixO3 phase diagram, making this system an ideal platform for contrasting high-Tc systems with isotropic superconductors. Here we use high-quality epitaxial thin films and magnetotransport to demonstrate superconducting fluctuations that extend well beyond Tc. For the thickest films (thickness above ˜100 nm ) this region extends to ˜27 K , well above the bulk Tc and remarkably close to the higher Tc of Ba1 -xKxBiO3 (Tc=31 K). We drive the system through a superconductor-insulator transition by decreasing thickness and find the observed Tc correlates strongly with disorder. This material manifests strong fluctuations across a wide range of thicknesses, temperatures, and disorder presenting new opportunities for understanding the precursor of superconductivity near the 2D-3D dimensionality crossover.

Low-Energy Theory of Disordered Graphene

NASA Astrophysics Data System (ADS)

Altland, Alexander

2006-12-01

At low values of external doping, graphene displays a wealth of unconventional transport properties. Perhaps most strikingly, it supports a robust “metallic” regime, with universal conductance of the order of the conductance quantum. We here apply a combination of mean-field and bosonization methods to explore the large scale transport properties of the system. We find that, irrespective of the doping level, disordered graphene is subject to the common mechanisms of Anderson localization. However, at low doping a number of renormalization mechanisms conspire to protect the conductivity of the system, to an extend that strong localization may not be seen even at temperatures much smaller than those underlying present experimental work.

Development of Antisocial Personality Disorder in Detained Youth: The Predictive Value of Mental Disorders

PubMed Central

Washburn, Jason J.; Romero, Erin Gregory; Welty, Leah J.; Abram, Karen M.; Teplin, Linda A.; McClelland, Gary M.; Paskar, Leah D.

2009-01-01

Antisocial personality disorder (APD) is a serious public and mental health concern. Understanding how well conduct disorder (CD) and other mental disorders predict the development of APD among youth involved in the juvenile justice system is critical for prevention. This study used a stratified random sample of 1112 detained youth to examine the development of APD at a three-year follow-up interview. Nearly one fifth of male juvenile detainees later developed APD; approximately one quarter of male juvenile detainees with CD at baseline later developed APD. Significantly more males than females developed APD; no differences were found by race/ethnicity. Having five or more symptoms of CD, dysthymia, alcohol use disorder, or generalized anxiety disorder was significantly associated with developing modified APD (M-APD; APD without the CD requirement). Some disorders were strong predictors of APD; however, none were adequate screeners for identifying which detainees would later develop M-APD. The findings of this study have implications for interventions and further research in developmental psychopathology. PMID:17469880

Understanding disordered systems through numerical simulation and algorithm development

NASA Astrophysics Data System (ADS)

Sweeney, Sean Michael

Disordered systems arise in many physical contexts. Not all matter is uniform, and impurities or heterogeneities can be modeled by fixed random disorder. Numerous complex networks also possess fixed disorder, leading to applications in transportation systems, telecommunications, social networks, and epidemic modeling, to name a few. Due to their random nature and power law critical behavior, disordered systems are difficult to study analytically. Numerical simulation can help overcome this hurdle by allowing for the rapid computation of system states. In order to get precise statistics and extrapolate to the thermodynamic limit, large systems must be studied over many realizations. Thus, innovative algorithm development is essential in order reduce memory or running time requirements of simulations. This thesis presents a review of disordered systems, as well as a thorough study of two particular systems through numerical simulation, algorithm development and optimization, and careful statistical analysis of scaling properties. Chapter 1 provides a thorough overview of disordered systems, the history of their study in the physics community, and the development of techniques used to study them. Topics of quenched disorder, phase transitions, the renormalization group, criticality, and scale invariance are discussed. Several prominent models of disordered systems are also explained. Lastly, analysis techniques used in studying disordered systems are covered. In Chapter 2, minimal spanning trees on critical percolation clusters are studied, motivated in part by an analytic perturbation expansion by Jackson and Read that I check against numerical calculations. This system has a direct mapping to the ground state of the strongly disordered spin glass. We compute the path length fractal dimension of these trees in dimensions d = {2, 3, 4, 5} and find our results to be compatible with the analytic results suggested by Jackson and Read. In Chapter 3, the random bond Ising ferromagnet is studied, which is especially useful since it serves as a prototype for more complicated disordered systems such as the random field Ising model and spin glasses. We investigate the effect that changing boundary spins has on the locations of domain walls in the interior of the random ferromagnet system. We provide an analytic proof that ground state domain walls in the two dimensional system are decomposable, and we map these domain walls to a shortest paths problem. By implementing a multiple-source shortest paths algorithm developed by Philip Klein, we are able to efficiently probe domain wall locations for all possible configurations of boundary spins. We consider lattices with uncorrelated dis- order, as well as disorder that is spatially correlated according to a power law. We present numerical results for the scaling exponent governing the probability that a domain wall can be induced that passes through a particular location in the system's interior, and we compare these results to previous results on the directed polymer problem.

Phase fluctuations in a strongly disordered s-wave NbN superconductor close to the metal-insulator transition.

PubMed

Mondal, Mintu; Kamlapure, Anand; Chand, Madhavi; Saraswat, Garima; Kumar, Sanjeev; Jesudasan, John; Benfatto, L; Tripathi, Vikram; Raychaudhuri, Pratap

2011-01-28

We explore the role of phase fluctuations in a three-dimensional s-wave superconductor, NbN, as we approach the critical disorder for destruction of the superconducting state. Close to critical disorder, we observe a finite gap in the electronic spectrum which persists at temperatures well above T(c). The superfluid density is strongly suppressed at low temperatures and evolves towards a linear-T variation at higher temperatures. These observations provide strong evidence that phase fluctuations play a central role in the formation of a pseudogap state in a disordered s-wave superconductor.

Quantum glassiness in clean strongly correlated systems: an example of topological overprotection

NASA Astrophysics Data System (ADS)

Chamon, Claudio

2005-03-01

Describing matter at near absolute zero temperature requires understanding a system's quantum ground state and the low energy excitations around it, the quasiparticles, which are thermally populated by the system's contact to a heat bath. However, this paradigm breaks down if thermal equilibration is obstructed. I present solvable examples of quantum many-body Hamiltonians of systems that are unable to reach their ground states as the environment temperature is lowered to absolute zero. These examples, three dimensional generalizations of quantum Hamiltonians proposed for topological quantum computing, 1) have no quenched disorder, 2) have solely local interactions, 3) have an exactly solvable spectrum, 4) have topologically ordered ground states, and 5) have slow dynamical relaxation rates akin to those of strong structural glasses.

Enhancement of the finite-frequency superfluid response in the pseudogap regime of strongly disordered superconducting films

PubMed Central

Mondal, Mintu; Kamlapure, Anand; Ganguli, Somesh Chandra; Jesudasan, John; Bagwe, Vivas; Benfatto, Lara; Raychaudhuri, Pratap

2013-01-01

The persistence of a soft gap in the density of states above the superconducting transition temperature Tc, the pseudogap, has long been thought to be a hallmark of unconventional high-temperature superconductors. However, in the last few years this paradigm has been strongly revised by increasing experimental evidence for the emergence of a pseudogap state in strongly-disordered conventional superconductors. Nonetheless, the nature of this state, probed primarily through scanning tunneling spectroscopy (STS) measurements, remains partly elusive. Here we show that the dynamic response above Tc, obtained from the complex ac conductivity, is highly modified in the pseudogap regime of strongly disordered NbN films. Below the pseudogap temperature, T*, the superfluid stiffness acquires a strong frequency dependence associated with a marked slowing down of critical fluctuations. When translated into the length-scale of fluctuations, our results suggest a scenario of thermal phase fluctuations between superconducting domains in a strongly disordered s-wave superconductor. PMID:23446946

Enhancement of the finite-frequency superfluid response in the pseudogap regime of strongly disordered superconducting films.

PubMed

Mondal, Mintu; Kamlapure, Anand; Ganguli, Somesh Chandra; Jesudasan, John; Bagwe, Vivas; Benfatto, Lara; Raychaudhuri, Pratap

2013-01-01

The persistence of a soft gap in the density of states above the superconducting transition temperature Tc, the pseudogap, has long been thought to be a hallmark of unconventional high-temperature superconductors. However, in the last few years this paradigm has been strongly revised by increasing experimental evidence for the emergence of a pseudogap state in strongly-disordered conventional superconductors. Nonetheless, the nature of this state, probed primarily through scanning tunneling spectroscopy (STS) measurements, remains partly elusive. Here we show that the dynamic response above Tc, obtained from the complex ac conductivity, is highly modified in the pseudogap regime of strongly disordered NbN films. Below the pseudogap temperature, T*, the superfluid stiffness acquires a strong frequency dependence associated with a marked slowing down of critical fluctuations. When translated into the length-scale of fluctuations, our results suggest a scenario of thermal phase fluctuations between superconducting domains in a strongly disordered s-wave superconductor.

Disordered Kitaev chains with long-range pairing.

PubMed

Cai, Xiaoming

2017-03-22

We study the competition of disorder and superconductivity for a generalized Kitaev model in incommensurate potentials. The generalized Kitaev model describes one dimensional spinless fermions with long-range p-wave superconducting pairing, which decays with distance l as a power law  ∼[Formula: see text]. We focus on the transition from the topological superconducting phase to the topologically trivial Anderson localized phase, and effects of the exponent α on this phase transition. In the topological superconducting phase, for a system under open boundary condition the amplitude of zero-mode Majorana fermion has a hybrid exponential-algebraic decay as the distance increases from the edge. In the Anderson localized phase, some single-particle states remain critical for very strong disorders and the number of critical states increases as α decreases. In addition, except for critical disorders, the correlation function always has an exponential decay at the short range and an algebraic decay at the long range. Phase transition points are also numerically determined and the topological phase transition happens earlier at a smaller disorder strength for a system with smaller α.

Interparticle interactions effects on the magnetic order in surface of FeO4 nanoparticles.

PubMed

Lima, E; Vargas, J M; Rechenberg, H R; Zysler, R D

2008-11-01

We report interparticle interactions effects on the magnetic structure of the surface region in Fe3O4 nanoparticles. For that, we have studied a desirable system composed by Fe3O4 nanoparticles with (d) = 9.3 nm and a narrow size distribution. These particles present an interesting morphology constituted by a crystalline core and a broad (approximately 50% vol.) disordered superficial shell. Two samples were prepared with distinct concentrations of the particles: weakly-interacting particles dispersed in a polymer and strongly-dipolar-interacting particles in a powder sample. M(H, T) measurements clearly show that strong dipolar interparticle interaction modifies the magnetic structure of the structurally disordered superficial shell. Consequently, we have observed drastically distinct thermal behaviours of magnetization and susceptibility comparing weakly- and strongly-interacting samples for the temperature range 2 K < T < 300 K. We have also observed a temperature-field dependence of the hysteresis loops of the dispersed sample that is not observed in the hysteresis loops of the powder one.

Depression and smoking: a 5-year prospective study of patients with major depressive disorder.

PubMed

Holma, Irina A K; Holma, K Mikael; Melartin, Tarja K; Ketokivi, Mikko; Isometsä, Erkki T

2013-06-01

Major depressive disorder (MDD) and smoking are major public health problems and epidemiologically strongly associated. However, the relationship between smoking and depression and whether this is influenced by common confounding factors remain unclear, in part due to limited longitudinal data on covariation. In the Vantaa Depression Study, psychiatric out- and inpatients with DSM-IV MDD and aged 20-59 years at were followed from baseline to 6 months, 18 months, and 5 years. We investigated course of depression, smoking, and comorbid alcohol-use disorders among the 214 patients (79.6% of 269) participating at least three time points; differences between smoking versus nonsmoking patients, and covariation of MDD, smoking, and alcohol-use disorders. Overall, 31.3% of the patients smoked regularly, 41.1% intermittently, and 27.6% never. Smokers were younger, had more alcohol-use disorders and Cluster B and C personality disorder symptoms, a higher frequency of lifetime suicide attempts, higher neuroticism, smaller social networks, and lower perceived social support than never smokers. Smoking and depression had limited longitudinal covariation. Depression, smoking, and alcohol-use disorders all exhibited strong autoregressive tendencies. Among adult psychiatric MDD patients, smoking is strongly associated with substance-use and personality disorders, which may confound research on the impact of smoking. Rather than depression or smoking covarying or predicting each other, depression, smoking, and alcohol-use disorders each have strong autoregressive tendencies. These findings are more consistent with common factors causing their association than either of the conditions strongly predisposing to the other. © 2013 Wiley Periodicals, Inc.

The role of the opioid system in binge eating disorder.

PubMed

Giuliano, Chiara; Cottone, Pietro

2015-12-01

Binge eating disorder is characterized by excessive, uncontrollable consumption of palatable food within brief periods of time. Excessive intake of palatable food is thought to be driven by hedonic, rather than energy homeostatic, mechanisms. However, reward processing does not only comprise consummatory actions; a key component is represented by the anticipatory phase directed at procuring the reward. This phase is highly influenced by environmental food-associated stimuli, which can robustly enhance the desire to eat even in the absence of physiological needs. The opioid system (endogenous peptides and their receptors) has been strongly linked to the rewarding aspects of palatable food intake, and perhaps represents the key system involved in hedonic overeating. Here we review evidence suggesting that the opioid system can also be regarded as one of the systems that regulates the anticipatory incentive processes preceding binge eating hedonic episodes.

Suffering in silence: why a developmental psychopathology perspective on selective mutism is needed.

PubMed

Cohan, Sharon L; Price, Joseph M; Stein, Murray B

2006-08-01

A developmental psychopathology perspective is offered in an effort to organize the existing literature regarding the etiology of selective mutism (SM), a relatively rare disorder in which a child consistently fails to speak in 1 or more social settings (e.g., school) despite speaking normally in other settings (e.g., home). Following a brief description of the history, prevalence, and course of the disorder, multiple pathways to the development of SM are discussed, with a focus on the various genetic, temperamental, psychological, and social/environmental systems that may be important in conceptualizing this unusual childhood disorder. The authors propose that SM develops due to a series of complex interactions among the various systems reviewed (e.g., a strong genetic loading for anxiety interacts with an existing communication disorder, resulting in heightened sensitivity to verbal interactions and mutism in some settings). Suggestions are provided for future longitudinal, twin/adoption, molecular genetic, and neuroimaging studies that would be particularly helpful in testing the pathways perspective on SM.

Reentrant resistive behavior and dimensional crossover in disordered superconducting TiN films

DOE PAGES

Postolova, Svetlana V.; Mironov, Alexey Yu.; Baklanov, Mikhail R.; ...

2017-05-11

A reentrant temperature dependence of the normal state resistance often referred to as the N-shaped temperature dependence, is omnipresent in disordered superconductors – ranging from high-temperature cuprates to ultrathin superconducting films – that experience superconductor-to-insulator transition. Yet, despite the ubiquity of this phenomenon its origin still remains a subject of debate. Here we investigate strongly disordered superconducting TiN films and demonstrate universality of the reentrant behavior. We offer a quantitative description of the N-shaped resistance curve. We show that upon cooling down the resistance first decreases linearly with temperature and then passes through the minimum that marks the 3D-2D crossovermore » in the system. In the 2D temperature range the resistance first grows with decreasing temperature due to quantum contributions and eventually drops to zero as the system falls into a superconducting state. As a result, our findings demonstrate the prime importance of disorder in dimensional crossover effects.« less

Neural substrates of trait impulsivity, anhedonia, and irritability: Mechanisms of heterotypic comorbidity between externalizing disorders and unipolar depression.

PubMed

Zisner, Aimee; Beauchaine, Theodore P

2016-11-01

Trait impulsivity, which is often defined as a strong preference for immediate over delayed rewards and results in behaviors that are socially inappropriate, maladaptive, and short-sighted, is a predisposing vulnerability to all externalizing spectrum disorders. In contrast, anhedonia is characterized by chronically low motivation and reduced capacity to experience pleasure, and is common to depressive disorders. Although externalizing and depressive disorders have virtually nonoverlapping diagnostic criteria in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, heterotypic comorbidity between them is common. Here, we review common neural substrates of trait impulsivity, anhedonia, and irritability, which include both low tonic mesolimbic dopamine activity and low phasic mesolimbic dopamine responding to incentives during reward anticipation and associative learning. We also consider how other neural networks, including bottom-up emotion generation systems and top-down emotion regulation systems, interact with mesolimbic dysfunction to result in alternative manifestations of psychiatric illness. Finally, we present a model that emphasizes a translational, transdiagnostic approach to understanding externalizing/depression comorbidity. This model should refine ways in which internalizing and externalizing disorders are studied, classified, and treated.

Reconciling Local Structure Disorder and the Relaxor State in (Bi1/2Na1/2)TiO3-BaTiO3

NASA Astrophysics Data System (ADS)

Groszewicz, Pedro B.; Gröting, Melanie; Breitzke, Hergen; Jo, Wook; Albe, Karsten; Buntkowsky, Gerd; Rödel, Jürgen

2016-08-01

Lead-based relaxor ferroelectrics are key functional materials indispensable for the production of multilayer ceramic capacitors and piezoelectric transducers. Currently there are strong efforts to develop novel environmentally benign lead-free relaxor materials. The structural origins of the relaxor state and the role of composition modifications in these lead-free materials are still not well understood. In the present contribution, the solid-solution (100-x)(Bi1/2Na1/2)TiO3-xBaTiO3 (BNT-xBT), a prototypic lead-free relaxor is studied by the combination of solid-state nuclear magnetic resonance (NMR) spectroscopy, dielectric measurements and ab-initio density functional theory (DFT). For the first time it is shown that the peculiar composition dependence of the EFG distribution width (ΔQISwidth) correlates strongly to the dispersion in dielectric permittivity, a fingerprint of the relaxor state. Significant disorder is found in the local structure of BNT-xBT, as indicated by the analysis of the electric field gradient (EFG) in 23Na 3QMAS NMR spectra. Aided by DFT calculations, this disorder is attributed to a continuous unimodal distribution of octahedral tilting. These results contrast strongly to the previously proposed coexistence of two octahedral tilt systems in BNT-xBT. Based on these results, we propose that considerable octahedral tilt disorder may be a general feature of these oxides and essential for their relaxor properties.

Strong correlation induced charge localization in antiferromagnets

PubMed Central

Zhu, Zheng; Jiang, Hong-Chen; Qi, Yang; Tian, Chushun; Weng, Zheng-Yu

2013-01-01

The fate of a hole injected in an antiferromagnet is an outstanding issue of strongly correlated physics. It provides important insights into doped Mott insulators closely related to high-temperature superconductivity. Here, we report a systematic numerical study of t-J ladder systems based on the density matrix renormalization group. It reveals a surprising result for the single hole's motion in an otherwise well-understood undoped system. Specifically, we find that the common belief of quasiparticle picture is invalidated by the self-localization of the doped hole. In contrast to Anderson localization caused by disorders, the charge localization discovered here is an entirely new phenomenon purely of strong correlation origin. It results from destructive quantum interference of novel signs picked up by the hole, and since the same effect is of a generic feature of doped Mott physics, our findings unveil a new paradigm which may go beyond the single hole doped system. PMID:24002668

Prospects of Anderson's theorem for disordered cuprate superconductors

NASA Astrophysics Data System (ADS)

Ghosal, Amit; Chakraborty, Debmalya; Kaushal, Nitin

2018-05-01

We develop a simple pairing theory of superconductivity in strongly correlated d-wave superconductors for up to a moderate strength of disorder. Our description implements the key ideas of Anderson, originally proposed for disordered s-wave superconductors, but in addition takes care of the inherent strong electronic repulsion in these compounds, as well as the inhomogeneities. We first obtain the self-consistent one-particle states, that capture the effects of disorder exactly, and strong correlations using Gutzwiller approximation. These 'normal states' (at zero temperature) when coupled through BCS-type pairing attractions, produces results which are nearly identical to those from a more sophisticated Gutzwiller augmented Bogoliubov-de Gennes analysis.

Effect of systemic acid-base disorders on colonic intracellular pH and ion transport.

PubMed

Wagner, J D; Kurtin, P; Charney, A N

1985-07-01

We have previously reported that changes in colonic net Na and Cl absorption correlate with arterial CO2 partial pressure (PCO2) and that changes in colonic net Cl absorption and HCO3 secretion correlate with the plasma HCO3 concentration during the systemic acid-base disorders. To determine whether changes in intracellular pH (pHi) and HCO3 concentration [( HCO3]i) mediate these effects, we measured pHi and calculated [HCO3] in the distal colonic mucosa of anesthetized, mechanically ventilated Sprague-Dawley rats using 5,5-[14C]dimethyloxazolidine-2,4-dione and [3H]inulin. Rats were studied during normocapnia, acute respiratory acidosis and alkalosis, and uncompensated and pH-compensated acute metabolic acidosis and alkalosis. When animals in all groups were considered, there were strong correlations between mucosal pHi and both arterial PCO2 (r = -0.76) and pH (r = 0.82) and between mucosal [HCO3]i and both arterial PCO2 (r = 0.98) and HCO3 concentration (r = 0.77). When we considered the rates of colonic electrolyte transport that characterized these acid-base disorders [A. N. Charney and L. P. Haskell. Am. J. Physiol. 246 (Gastrointest. Liver Physiol. 9): G159-G165, 1984], we found strong correlations between mucosal pHi and net Na absorption (r = -0.86) and between mucosal [HCO3]i and both net Cl absorption (r = 0.98) and net HCO3 secretion (r = 0.83). These findings suggest that the systemic acid-base disorders cause changes in colonic mucosal pHi and [HCO3]i as a consequence of altered arterial PCO2 and HCO3 concentration. In addition, the effects of these disorders on colonic electrolyte transport may be mediated by changes in mucosal pHi and [HCO3]i.

Weak- versus strong-disorder superfluid—Bose glass transition in one dimension

NASA Astrophysics Data System (ADS)

Doggen, Elmer V. H.; Lemarié, Gabriel; Capponi, Sylvain; Laflorencie, Nicolas

2017-11-01

Using large-scale simulations based on matrix product state and quantum Monte Carlo techniques, we study the superfluid to Bose glass transition for one-dimensional attractive hard-core bosons at zero temperature, across the full regime from weak to strong disorder. As a function of interaction and disorder strength, we identify a Berezinskii-Kosterlitz-Thouless critical line with two different regimes. At small attraction where critical disorder is weak compared to the bandwidth, the critical Luttinger parameter Kc takes its universal Giamarchi-Schulz value Kc=3 /2 . Conversely, a nonuniversal Kc>3 /2 emerges for stronger attraction where weak-link physics is relevant. In this strong-disorder regime, the transition is characterized by self-similar power-law-distributed weak links with a continuously varying characteristic exponent α .

Tuning and Freezing Disorder in Photonic Crystals using Percolation Lithography.

PubMed

Burgess, Ian B; Abedzadeh, Navid; Kay, Theresa M; Shneidman, Anna V; Cranshaw, Derek J; Lončar, Marko; Aizenberg, Joanna

2016-01-21

Although common in biological systems, synthetic self-assembly routes to complex 3D photonic structures with tailored degrees of disorder remain elusive. Here we show how liquids can be used to finely control disorder in porous 3D photonic crystals, leading to complex and hierarchical geometries. In these optofluidic crystals, dynamically tunable disorder is superimposed onto the periodic optical structure through partial wetting or evaporation. In both cases, macroscopic symmetry breaking is driven by subtle sub-wavelength variations in the pore geometry. These variations direct site-selective infiltration of liquids through capillary interactions. Incorporating cross-linkable resins into our liquids, we developed methods to freeze in place the filling patterns at arbitrary degrees of partial wetting and intermediate stages of drying. These percolation lithography techniques produced permanent photonic structures with adjustable disorder. By coupling strong changes in optical properties to subtle differences in fluid behavior, optofluidic crystals may also prove useful in rapid analysis of liquids.

Sleep Disturbances Associated with Parkinson's Disease

PubMed Central

Suzuki, Keisuke; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Iwanami, Masaoki; Hirata, Koichi

2011-01-01

Sleep disturbances are common problems affecting the quality life of Parkinson's disease (PD) patients and are often underestimated. The causes of sleep disturbances are multifactorial and include nocturnal motor disturbances, nocturia, depressive symptoms, and medication use. Comorbidity of PD with sleep apnea syndrome, restless legs syndrome, rapid eye movement sleep behavior disorder, or circadian cycle disruption also results in impaired sleep. In addition, the involvement of serotoninergic, noradrenergic, and cholinergic neurons in the brainstem as a disease-related change contributes to impaired sleep structures. Excessive daytime sleepiness is not only secondary to nocturnal disturbances or dopaminergic medication but may also be due to independent mechanisms related to impairments in ascending arousal system and the orexin system. Notably, several recent lines of evidence suggest a strong link between rapid eye movement sleep behavior disorder and the risk of neurodegenerative diseases such as PD. In the present paper, we review the current literature concerning sleep disorders in PD. PMID:21876839

Theory of activated transport in bilayer quantum Hall systems.

PubMed

Roostaei, B; Mullen, K J; Fertig, H A; Simon, S H

2008-07-25

We analyze the transport properties of bilayer quantum Hall systems at total filling factor nu=1 in drag geometries as a function of interlayer bias, in the limit where the disorder is sufficiently strong to unbind meron-antimeron pairs, the charged topological defects of the system. We compute the typical energy barrier for these objects to cross incompressible regions within the disordered system using a Hartree-Fock approach, and show how this leads to multiple activation energies when the system is biased. We then demonstrate using a bosonic Chern-Simons theory that in drag geometries current in a single layer directly leads to forces on only two of the four types of merons, inducing dissipation only in the drive layer. Dissipation in the drag layer results from interactions among the merons, resulting in very different temperature dependences for the drag and drive layers, in qualitative agreement with experiment.

Photovoltaic concepts inspired by coherence effects in photosynthetic systems

NASA Astrophysics Data System (ADS)

Brédas, Jean-Luc; Sargent, Edward H.; Scholes, Gregory D.

2017-01-01

The past decade has seen rapid advances in our understanding of how coherent and vibronic phenomena in biological photosynthetic systems aid in the efficient transport of energy from light-harvesting antennas to photosynthetic reaction centres. Such coherence effects suggest strategies to increase transport lengths even in the presence of structural disorder. Here we explore how these principles could be exploited in making improved solar cells. We investigate in depth the case of organic materials, systems in which energy and charge transport stand to be improved by overcoming challenges that arise from the effects of static and dynamic disorder -- structural and energetic -- and from inherently strong electron-vibration couplings. We discuss how solar-cell device architectures can evolve to use coherence-exploiting materials, and we speculate as to the prospects for a coherent energy conversion system. We conclude with a survey of the impacts of coherence and bioinspiration on diverse solar-energy harvesting solutions, including artificial photosynthetic systems.

Peculiar spectral statistics of ensembles of trees and star-like graphs

NASA Astrophysics Data System (ADS)

Kovaleva, V.; Maximov, Yu; Nechaev, S.; Valba, O.

2017-07-01

In this paper we investigate the eigenvalue statistics of exponentially weighted ensembles of full binary trees and p-branching star graphs. We show that spectral densities of corresponding adjacency matrices demonstrate peculiar ultrametric structure inherent to sparse systems. In particular, the tails of the distribution for binary trees share the ‘Lifshitz singularity’ emerging in the one-dimensional localization, while the spectral statistics of p-branching star-like graphs is less universal, being strongly dependent on p. The hierarchical structure of spectra of adjacency matrices is interpreted as sets of resonance frequencies, that emerge in ensembles of fully branched tree-like systems, known as dendrimers. However, the relaxational spectrum is not determined by the cluster topology, but has rather the number-theoretic origin, reflecting the peculiarities of the rare-event statistics typical for one-dimensional systems with a quenched structural disorder. The similarity of spectral densities of an individual dendrimer and of an ensemble of linear chains with exponential distribution in lengths, demonstrates that dendrimers could be served as simple disorder-less toy models of one-dimensional systems with quenched disorder.

Peculiar spectral statistics of ensembles of trees and star-like graphs

DOE PAGES

Kovaleva, V.; Maximov, Yu; Nechaev, S.; ...

2017-07-11

In this paper we investigate the eigenvalue statistics of exponentially weighted ensembles of full binary trees and p-branching star graphs. We show that spectral densities of corresponding adjacency matrices demonstrate peculiar ultrametric structure inherent to sparse systems. In particular, the tails of the distribution for binary trees share the \\Lifshitz singularity" emerging in the onedimensional localization, while the spectral statistics of p-branching star-like graphs is less universal, being strongly dependent on p. The hierarchical structure of spectra of adjacency matrices is interpreted as sets of resonance frequencies, that emerge in ensembles of fully branched tree-like systems, known as dendrimers. However,more » the relaxational spectrum is not determined by the cluster topology, but has rather the number-theoretic origin, re ecting the peculiarities of the rare-event statistics typical for one-dimensional systems with a quenched structural disorder. The similarity of spectral densities of an individual dendrimer and of ensemble of linear chains with exponential distribution in lengths, demonstrates that dendrimers could be served as simple disorder-less toy models of one-dimensional systems with quenched disorder.« less

Decoding the contribution of dopaminergic genes and pathways to autism spectrum disorder (ASD).

PubMed

Nguyen, Michael; Roth, Andrew; Kyzar, Evan J; Poudel, Manoj K; Wong, Keith; Stewart, Adam Michael; Kalueff, Allan V

2014-01-01

Autism spectrum disorder (ASD) is a debilitating brain illness causing social deficits, delayed development and repetitive behaviors. ASD is a heritable neurodevelopmental disorder with poorly understood and complex etiology. The central dopaminergic system is strongly implicated in ASD pathogenesis. Genes encoding various elements of this system (including dopamine receptors, the dopamine transporter or enzymes of synthesis and catabolism) have been linked to ASD. Here, we comprehensively evaluate known molecular interactors of dopaminergic genes, and identify their potential molecular partners within up/down-steam signaling pathways associated with dopamine. These in silico analyses allowed us to construct a map of molecular pathways, regulated by dopamine and involved in ASD. Clustering these pathways reveals groups of genes associated with dopamine metabolism, encoding proteins that control dopamine neurotransmission, cytoskeletal processes, synaptic release, Ca(2+) signaling, as well as the adenosine, glutamatergic and gamma-aminobutyric systems. Overall, our analyses emphasize the important role of the dopaminergic system in ASD, and implicate several cellular signaling processes in its pathogenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Peculiar spectral statistics of ensembles of trees and star-like graphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovaleva, V.; Maximov, Yu; Nechaev, S.

In this paper we investigate the eigenvalue statistics of exponentially weighted ensembles of full binary trees and p-branching star graphs. We show that spectral densities of corresponding adjacency matrices demonstrate peculiar ultrametric structure inherent to sparse systems. In particular, the tails of the distribution for binary trees share the \\Lifshitz singularity" emerging in the onedimensional localization, while the spectral statistics of p-branching star-like graphs is less universal, being strongly dependent on p. The hierarchical structure of spectra of adjacency matrices is interpreted as sets of resonance frequencies, that emerge in ensembles of fully branched tree-like systems, known as dendrimers. However,more » the relaxational spectrum is not determined by the cluster topology, but has rather the number-theoretic origin, re ecting the peculiarities of the rare-event statistics typical for one-dimensional systems with a quenched structural disorder. The similarity of spectral densities of an individual dendrimer and of ensemble of linear chains with exponential distribution in lengths, demonstrates that dendrimers could be served as simple disorder-less toy models of one-dimensional systems with quenched disorder.« less

Disorder effects in topological states: Brief review of the recent developments

NASA Astrophysics Data System (ADS)

Wu, Binglan; Song, Juntao; Zhou, Jiaojiao; Jiang, Hua

2016-11-01

Disorder inevitably exists in realistic samples, manifesting itself in various exotic properties for the topological states. In this paper, we summarize and briefly review the work completed over the last few years, including our own, regarding recent developments in several topics about disorder effects in topological states. For weak disorder, the robustness of topological states is demonstrated, especially for both quantum spin Hall states with Z 2 = 1 and size induced nontrivial topological insulators with Z 2 = 0. For moderate disorder, by increasing the randomness of both the impurity distribution and the impurity induced potential, the topological insulator states can be created from normal metallic or insulating states. These phenomena and their mechanisms are summarized. For strong disorder, the disorder causes a metal-insulator transition. Due to their topological nature, the phase diagrams are much richer in topological state systems. Finally, the trends in these areas of disorder research are discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 11374219, 11474085, and 11534001) and the Natural Science Foundation of Jiangsu Province, China (Grant No BK20160007).

Development of antisocial personality disorder in detained youths: the predictive value of mental disorders.

PubMed

Washburn, Jason J; Romero, Erin Gregory; Welty, Leah J; Abram, Karen M; Teplin, Linda A; McClelland, Gary M; Paskar, Leah D

2007-04-01

Antisocial personality disorder (APD) is a serious public and mental health concern. Understanding how well conduct disorder (CD) and other mental disorders predict the development of APD among youths involved in the juvenile justice system is critical for prevention. The authors used a stratified random sample of 1,112 detained youths to examine the development of APD at a 3-year follow-up interview. Nearly one fifth of male juvenile detainees later developed APD; approximately one quarter of male juvenile detainees with CD at baseline later developed APD. Significantly more males than females developed APD; no differences were found by race/ethnicity. Having 5 or more symptoms of CD, dysthymia, alcohol use disorder, or generalized anxiety disorder was significantly associated with developing modified APD (M-APD; APD without the CD requirement). Some disorders were strong predictors of APD; however, none were adequate screeners for identifying which detainees would later develop M-APD. The findings of this study have implications for interventions and further research in developmental psychopathology. Copyright 2007 APA, all rights reserved.

Altered Circadian Timing System-Mediated Non-Dipping Pattern of Blood Pressure and Associated Cardiovascular Disorders in Metabolic and Kidney Diseases

PubMed Central

Nishiyama, Akira

2018-01-01

The morning surge in blood pressure (BP) coincides with increased cardiovascular (CV) events. This strongly suggests that an altered circadian rhythm of BP plays a crucial role in the development of CV disease (CVD). A disrupted circadian rhythm of BP, such as the non-dipping type of hypertension (i.e., absence of nocturnal BP decline), is frequently observed in metabolic disorders and chronic kidney disease (CKD). The circadian timing system, controlled by the central clock in the suprachiasmatic nucleus of the hypothalamus and/or by peripheral clocks in the heart, vasculature, and kidneys, modulates the 24 h oscillation of BP. However, little information is available regarding the molecular and cellular mechanisms of an altered circadian timing system-mediated disrupted dipping pattern of BP in metabolic disorders and CKD that can lead to the development of CV events. A more thorough understanding of this pathogenesis could provide novel therapeutic strategies for the management of CVD. This short review will address our and others’ recent findings on the molecular mechanisms that may affect the dipping pattern of BP in metabolic dysfunction and kidney disease and its association with CV disorders. PMID:29385702

Motor-based bodily self is selectively impaired in eating disorders.

PubMed

Campione, Giovanna Cristina; Mansi, Gianluigi; Fumagalli, Alessandra; Fumagalli, Beatrice; Sottocornola, Simona; Molteni, Massimo; Micali, Nadia

2017-01-01

Body representation disturbances in body schema (i.e. unconscious sensorimotor body representations for action) have been frequently reported in eating disorders. Recently, it has been proposed that body schema relies on adequate functioning of the motor system, which is strongly implicated in discriminating between one's own and someone else's body. The present study aimed to investigate the motor-based bodily self in eating disorders and controls, in order to examine the role of the motor system in body representation disturbances at the body schema level. Female outpatients diagnosed with eating disorders (N = 15), and healthy controls (N = 18) underwent a hand laterality task, in which their own (self-stimuli) and someone else's hands (other-stimuli) were displayed at different orientations. Participants had to mentally rotate their own hand in order to provide a laterality judgement. Group differences in motor-based bodily self-recognition-i.e. whether a general advantage occurred when implicitly processing self- vs. other-stimuli - were evaluated, by analyzing response times and accuracy by means of mixed ANOVAs. Patients with eating disorders did not show a temporal advantage when mentally rotating self-stimuli compared to other-stimuli, as opposed to controls (F(1, 31) = 5.6, p = 0.02; eating disorders-other = 1092 ±256 msec, eating disorders-self = 1097±254 msec; healthy controls-other = 1239±233 msec, healthy controls -self = 1192±232 msec). This study provides initial indication that high-level motor functions might be compromised as part of body schema disturbances in eating disorders. Further larger investigations are required to test motor system abnormalities in the context of body schema disturbance in eating disorders.

Housing First Reduces Re-offending among Formerly Homeless Adults with Mental Disorders: Results of a Randomized Controlled Trial

PubMed Central

Somers, Julian M.; Rezansoff, Stefanie N.; Moniruzzaman, Akm; Palepu, Anita; Patterson, Michelle

2013-01-01

Background Homelessness and mental illness have a strong association with public disorder and criminality. Experimental evidence indicates that Housing First (HF) increases housing stability and perceived choice among those experiencing chronic homelessness and mental disorders. HF is also associated with lower residential costs than common alternative approaches. Few studies have examined the effect of HF on criminal behavior. Methods Individuals meeting criteria for homelessness and a current mental disorder were randomized to one of three conditions treatment as usual (reference); scattered site HF; and congregate HF. Administrative data concerning justice system events were linked in order to study prior histories of offending and to test the relationship between housing status and offending following randomization for up to two years. Results The majority of the sample (67%) was involved with the justice system, with a mean of 8.07 convictions per person in the ten years prior to recruitment. The most common category of crime was “property offences” (mean = 4.09). Following randomization, the scattered site HF condition was associated with significantly lower numbers of sentences than treatment as usual (Adjusted IRR = 0.29; 95% CI 0.12–0.72). Congregate HF was associated with a marginally significant reduction in sentences compared to treatment as usual (Adjusted IRR = 0.55; 95% CI: 0.26–1.14). Conclusions This study is the first randomized controlled trial to demonstrate benefits of HF among a homeless sample with mental illness in the domain of public safety and crime. Our sample was frequently involved with the justice system, with great personal and societal costs. Further implementation of HF is strongly indicated, particularly in the scattered site format. Research examining interdependencies between housing, health, and the justice system is indicated. Trial registration ISRCTN57595077 PMID:24023796

Childhood adversities and first onset of psychiatric disorders in a national sample of adolescents

PubMed Central

McLaughlin, Katie A.; Green, Jennifer Greif; Gruber, Michael J.; Sampson, Nancy A.; Zaslavsky, Alan M.; Kessler, Ronald C.

2012-01-01

Context Although childhood adversities (CAs) are known to be highly co-occurring, most research examines their associations with mental disorders one at a time. Recent evidence from adult studies suggests, though, that the associations of multiple CAs with mental disorders are non-additive, arguing for the importance of multivariate analysis of multiple CAs. No attempt has yet been made to carry out a similar kind of analysis among children or adolescents. Objective To examine the multivariate associations of 12 CAs with first onset of mental disorders in a national sample of US adolescents. Design US national survey of adolescents (ages 13–17) assessing DSM-IV anxiety, mood, behavior, and substance disorders and CAs. The CAs include parental loss (death, divorce, other separations), maltreatment (physical, sexual, and emotional abuse, neglect), parental maladjustment (psychopathology, substance abuse, criminality, violence) and economic adversity. Setting Dual-frame household-school samples. Participants 6,483 adolescents-parent pairs. Main outcome measure Lifetime DSM-IV disorders assessed with the WHO Composite International Diagnostic Interview. Results 58.3% of adolescents reported at least one CA, among whom 59.7% reported multiple CAs. CAs reflecting maladaptive family functioning (MFF) were more strongly associated than other CAs with disorder onsets. The best-fitting model included terms for type and number of CAs and distinguished between MFF and Other CAs. CAs predicted behavior disorders most strongly and fear disorders least strongly. The joint associations of multiple CAs were sub-additive. The population-attributable risk proportions for disorder classes ranged from 15.7% for fear disorders to 40.7% for behavior disorders. CAs were associated with 28.2% of all onsets. Conclusions CAs are common, highly co-occurring, and strongly associated with onset of mental disorders among US adolescents. The sub-additive multivariate associations of CAs with disorder onsets have implications for targeting interventions to reduce exposure to CAs and to mitigate the harmful effects of CAs to improve population mental health. PMID:23117636

STM studies of topological phase transition in (Bi,In)2Se3

NASA Astrophysics Data System (ADS)

Zhang, Wenhan; Wang, Xueyun; Cheong, Sang-Wook; Wu, Weida; Weida Wu Team; Sang-Wook Cheong Collaboration

Topological insulators (TI) are a class of materials with insulating bulk and metallic surface state, which is the result of band inversion induced by strong spin-orbit coupling (SOC). The transition from topological phase to non-topological phase is of great significance. In theory, topological phase transition is realized by tuning SOC strength. It is characterized by the process of gap closing and reopening. Experimentally it was observed in two systems: TlBi(S1-xSex)2 and (Bi1-xInx)2 Se3 where the transition is realized by varying isovalent elements doping concentration. However, none of the previous studies addressed the impact of disorder, which is inevitable in doped systems. Here, we present a systematic scanning tunneling microscopy/spectroscopy study on (Bi1-xInx)2 Se3 single crystals with different In concentrations across the transition. Our results reveal an electronic inhomogeneity due to the random distribution of In defects which locally suppress the topological surface states. Our study provides a new angle of understanding the topological transition in the presence of strong disorders. This work is supported by NSF DMR-1506618.

Engineered disorder and light propagation in a planar photonic glass

PubMed Central

Romanov, Sergei G.; Orlov, Sergej; Ploss, Daniel; Weiss, Clemens K.; Vogel, Nicolas; Peschel, Ulf

2016-01-01

The interaction of light with matter strongly depends on the structure of the latter at wavelength scale. Ordered systems interact with light via collective modes, giving rise to diffraction. In contrast, completely disordered systems are dominated by Mie resonances of individual particles and random scattering. However, less clear is the transition regime in between these two extremes, where diffraction, Mie resonances and near-field interaction between individual scatterers interplay. Here, we probe this transitional regime by creating colloidal crystals with controlled disorder from two-dimensional self-assembly of bidisperse spheres. Choosing the particle size in a way that the small particles are transparent in the spectral region of interest enables us to probe in detail the effect of increasing positional disorder on the optical properties of the large spheres. With increasing disorder a transition from a collective optical response characterized by diffractive resonances to single particles scattering represented by Mie resonances occurs. In between these extremes, we identify an intermediate, hopping-like light transport regime mediated by resonant interactions between individual spheres. These results suggest that different levels of disorder, characterized not only by absence of long range order but also by differences in short-range correlation and interparticle distance, exist in colloidal glasses. PMID:27277521

Childhood adversity, mental disorder comorbidity, and suicidal behavior in schizotypal personality disorder.

PubMed

Lentz, Vanessa; Robinson, Jennifer; Bolton, James M

2010-11-01

Schizotypal personality disorder (SPD) is a serious and relatively common psychiatric disorder, yet remains understudied among the personality disorders. The current study examines the psychiatric correlates of SPD in a representative epidemiologic sample, utilizing data from the National Epidemiological Survey on Alcohol and Related Conditions (N = 34,653). Multiple logistic regression compared people with SPD to the general population across a broad range of childhood adversities, comorbid psychiatric disorders, and suicidal behavior. SPD was strongly associated with many adverse childhood experiences. After adjusting for confounding factors, SPD was independently associated with major depression and several anxiety disorders, including post-traumatic stress disorder. Interestingly, SPD was more strongly associated with borderline and narcissistic personality disorders than cluster A personality disorders. Individuals with SPD were also more likely to attempt suicide. As a whole, these results suggest that individuals with SPD experience significant morbidity and may be at increased risk of mortality.

Weakly-coupled quasi-1D helical modes in disordered 3D topological insulator quantum wires

NASA Astrophysics Data System (ADS)

Dufouleur, J.; Veyrat, L.; Dassonneville, B.; Xypakis, E.; Bardarson, J. H.; Nowka, C.; Hampel, S.; Schumann, J.; Eichler, B.; Schmidt, O. G.; Büchner, B.; Giraud, R.

2017-04-01

Disorder remains a key limitation in the search for robust signatures of topological superconductivity in condensed matter. Whereas clean semiconducting quantum wires gave promising results discussed in terms of Majorana bound states, disorder makes the interpretation more complex. Quantum wires of 3D topological insulators offer a serious alternative due to their perfectly-transmitted mode. An important aspect to consider is the mixing of quasi-1D surface modes due to the strong degree of disorder typical for such materials. Here, we reveal that the energy broadening γ of such modes is much smaller than their energy spacing Δ, an unusual result for highly-disordered mesoscopic nanostructures. This is evidenced by non-universal conductance fluctuations in highly-doped and disordered Bi2Se3 and Bi2Te3 nanowires. Theory shows that such a unique behavior is specific to spin-helical Dirac fermions with strong quantum confinement, which retain ballistic properties over an unusually large energy scale due to their spin texture. Our result confirms their potential to investigate topological superconductivity without ambiguity despite strong disorder.

Weakly-coupled quasi-1D helical modes in disordered 3D topological insulator quantum wires

PubMed Central

Dufouleur, J.; Veyrat, L.; Dassonneville, B.; Xypakis, E.; Bardarson, J. H.; Nowka, C.; Hampel, S.; Schumann, J.; Eichler, B.; Schmidt, O. G.; Büchner, B.; Giraud, R.

2017-01-01

Disorder remains a key limitation in the search for robust signatures of topological superconductivity in condensed matter. Whereas clean semiconducting quantum wires gave promising results discussed in terms of Majorana bound states, disorder makes the interpretation more complex. Quantum wires of 3D topological insulators offer a serious alternative due to their perfectly-transmitted mode. An important aspect to consider is the mixing of quasi-1D surface modes due to the strong degree of disorder typical for such materials. Here, we reveal that the energy broadening γ of such modes is much smaller than their energy spacing Δ, an unusual result for highly-disordered mesoscopic nanostructures. This is evidenced by non-universal conductance fluctuations in highly-doped and disordered Bi2Se3 and Bi2Te3 nanowires. Theory shows that such a unique behavior is specific to spin-helical Dirac fermions with strong quantum confinement, which retain ballistic properties over an unusually large energy scale due to their spin texture. Our result confirms their potential to investigate topological superconductivity without ambiguity despite strong disorder. PMID:28374744

Weakly-coupled quasi-1D helical modes in disordered 3D topological insulator quantum wires.

PubMed

Dufouleur, J; Veyrat, L; Dassonneville, B; Xypakis, E; Bardarson, J H; Nowka, C; Hampel, S; Schumann, J; Eichler, B; Schmidt, O G; Büchner, B; Giraud, R

2017-04-04

Disorder remains a key limitation in the search for robust signatures of topological superconductivity in condensed matter. Whereas clean semiconducting quantum wires gave promising results discussed in terms of Majorana bound states, disorder makes the interpretation more complex. Quantum wires of 3D topological insulators offer a serious alternative due to their perfectly-transmitted mode. An important aspect to consider is the mixing of quasi-1D surface modes due to the strong degree of disorder typical for such materials. Here, we reveal that the energy broadening γ of such modes is much smaller than their energy spacing Δ, an unusual result for highly-disordered mesoscopic nanostructures. This is evidenced by non-universal conductance fluctuations in highly-doped and disordered Bi2Se3 and Bi 2 Te 3 nanowires. Theory shows that such a unique behavior is specific to spin-helical Dirac fermions with strong quantum confinement, which retain ballistic properties over an unusually large energy scale due to their spin texture. Our result confirms their potential to investigate topological superconductivity without ambiguity despite strong disorder.

[Effects of diabetes and obesity on the higher brain functions in rodents].

PubMed

Asato, Megumi; Ikeda, Hiroko; Kamei, Junzo

2012-11-01

Metabolic disorders, such as diabetes and obesity, have been indicated to disturb the function of the central nervous system (CNS) as well as several peripheral organs. Clinically, it is well recognized that the prevalence of anxiety and depression is higher in diabetic and obesity patients than in the general population. We have recently indicated that streptozotocin-induced diabetic and diet-induced obesity mice have enhanced fear memory and higher anxiety-like behavior in several tests such as the conditioned fear, tail-suspension, hole-board and elevated open-platform tests. The changes in fear memory and anxiety-like behavior of diabetic and obese mice are due to the dysfunction of central glutamatergic and monoaminergic systems, which is mediated by the changes of intracellular signaling. These results suggest that metabolic disorders strongly affect the function of the CNS and disturb the higher brain functions. These dysfunctions of the CNS in diabetes and obesity are involved in the increased prevalence of anxiety disorders and depression. Normalization of these dysfunctions in the CNS will be a new attractive target to treat the metabolic disorders and their complications.

Gait impairment in neurological disorders: a new technological approach.

PubMed

Semprini, Roberta; Sale, Patrizio; Foti, Calogero; Fini, Massimo; Franceschini, Marco

2009-01-01

Gait recovery is considered one of the main objectives of rehabilitation interventions in neurological disabilities, as restricted movement can significantly reduce an individual's ability to take part in normal activities of daily living. Locomotor training has been shown to improve gait rehabilitation. Studies have recently been published on the use of robots and other devices in patients with gait disabilities, particularly in the rehabilitation of the lower limbs. However, analysis of the recent literature reveals a relative paucity of strong methodological studies. The evidence that is available, while strong, is not yet sufficient to allow definite conclusions to be drawn regarding the efficacy of these devices. From these considerations, it is clear that validated and standardized methods need to be adopted for each of the different systems available. This would help to clarify the indications for and correct use of robotic devices in the different neurological disorders.

Entanglement Properties and Quantum Phases for a Fermionic Disordered One-Dimensional Wire with Attractive Interactions.

PubMed

Berkovits, Richard

2015-11-13

A fermionic disordered one-dimensional wire in the presence of attractive interactions is known to have two distinct phases, a localized and superconducting, depending on the strength of interaction and disorder. The localized region may also exhibit a metallic behavior if the system size is shorter than the localization length. Here we show that the superconducting phase has a distribution of the entanglement entropy distinct from the metallic regime. The entanglement entropy distribution is strongly asymmetric with a Lévy α-stable distribution (compared to the Gaussian metallic distribution), as is seen also for the second Rényi entropy distribution. Thus, entanglement properties may reveal properties which cannot be detected by other methods.

Functional network dysfunction in anxiety and anxiety disorders

PubMed Central

Sylvester, C.M.; Corbetta, M.; Raichle, M.E.; Rodebaugh, T.; Schlaggar, B.L.; Sheline, Y.I.; Zorumski, C.F.; Lenze, E.J.

2012-01-01

A recent paradigm shift in systems neuroscience is the division of the human brain into functional networks. Functional networks are collections of brain regions with strongly correlated activity both at rest and during cognitive tasks, and each network is believed to implement a different aspect of cognition. Here, we propose that anxiety disorders and high trait anxiety are associated with a particular pattern of functional network dysfunction: increased functioning of the cingulo-opercular and ventral attention networks as well as decreased functioning of the fronto-parietal and default mode networks. This functional network model can be used to differentiate the pathology of anxiety disorders from other psychiatric illnesses such as major depression and provides targets for novel treatment strategies. PMID:22658924

Complex dynamics induced by strong confinement - From tracer diffusion in strongly heterogeneous media to glassy relaxation of dense fluids in narrow slits

NASA Astrophysics Data System (ADS)

Mandal, Suvendu; Spanner-Denzer, Markus; Leitmann, Sebastian; Franosch, Thomas

2017-08-01

We provide an overview of recent advances of the complex dynamics of particles in strong confinements. The first paradigm is the Lorentz model where tracers explore a quenched disordered host structure. Such systems naturally occur as limiting cases of binary glass-forming systems if the dynamics of one component is much faster than the other. For a certain critical density of the host structure the tracers undergo a localization transition which constitutes a critical phenomenon. A series of predictions in the vicinity of the transition have been elaborated and tested versus computer simulations. Analytical progress is achieved for small obstacle densities. The second paradigm is a dense strongly interacting liquid confined to a narrow slab. Then the glass transition depends nonmonotonically on the separation of the plates due to an interplay of local packing and layering. Very small slab widths allow to address certain features of the statics and dynamics analytically.

Confirmation of prior evidence of genetic susceptibility to alcoholism in a genome-wide association study of comorbid alcoholism and bipolar disorder.

PubMed

Lydall, Gregory John; Bass, Nicholas J; McQuillin, Andrew; Lawrence, Jacob; Anjorin, Adebayo; Kandaswamy, Radhika; Pereira, Ana; Guerrini, Irene; Curtis, David; Vine, Anna E; Sklar, Pamela; Purcell, Shaun M; Gurling, Hugh Malcolm Douglas

2011-12-01

Alcoholism and affective disorders are both strongly comorbid and heritable. We have investigated the genetic comorbidity between bipolar affective disorder and alcoholism. A genome-wide allelic association study of 506 patients from the University College London bipolar disorder case-control sample and 510 ancestrally matched supernormal controls. One hundred forty-three of the bipolar patients fulfilled the Research Diagnostic Criteria diagnosis of alcoholism. A total of 372 193 single nucleotide polymorphisms (SNPs) were genotyped. Genes previously shown to be associated with alcoholism and addiction phenotypes were then tested for association in the bipolar alcoholic sample using gene-wise permutation tests of all SNPs genotyped within a 50-kb region flanking each gene. Several central nervous system genes showed significant (P<0.05) gene-wise evidence of association with bipolar alcoholism. The genes implicated, which replicated genes previously shown to be associated with alcoholism were: cadherin 11, collagen type 11 α2, neuromedin U receptor 2, exportin7, and semaphorin-associated protein 5A. The SNPs most strongly implicated in bipolar alcoholism, but, which did not meet conventional genome-wide significance criteria were the insulin-like growth factor-binding protein 7, carboxypeptidase O, cerebellin 2, and the cadherin 12 genes. We have confirmed the role of some genes previously shown to be associated with alcoholism in the comorbid bipolar alcoholism subgroup. In this subgroup, bipolar disorder may lower the threshold for the phenotypic expression of these alcoholism susceptibility genes. We also show that some genes may independently increase susceptibility to affective disorder and alcoholism.

The Neurobiology of Bipolar Disorder: An Integrated Approach

PubMed Central

2016-01-01

Bipolar disorder is a heterogeneous condition with myriad clinical manifestations and many comorbidities leading to severe disabilities in the biopsychosocial realm. The objective of this review article was to underline recent advances in knowledge regarding the neurobiology of bipolar disorder. A further aim was to draw attention to new therapeutic targets in the treatment of bipolar disorder. To accomplish these goals, an electronic search was undertaken of the PubMed database in August 2015 of literature published during the last 10 years on the pathophysiology of bipolar disorder. A wide-ranging evaluation of the existing work was done with search terms such as "mood disorders and biology," "bipolar disorder and HPA axis," "bipolar disorder and cytokines," "mood disorders and circadian rhythm," "bipolar disorder and oxidative stress," etc. This endeavor showed that bipolar disorder is a diverse condition sharing neurobiological mechanisms with major depressive disorder and psychotic spectrum disorders. There is convincing evidence of crosstalk between different biological systems that act in a deleterious manner causing expression of the disease in genetically predisposed individuals. Inflammatory mediators act in concert with oxidative stress to dysregulate hormonal, metabolic, and circadian homeostasis in precipitating and perpetuating the illness. Stress, whether biologically or psychologically mediated, is responsible for the initiation and progression of the diathesis. Bipolar spectrum disorders have a strong genetic component; severe life stresses acting through various paths cause the illness phenotype. PMID:26865997

Mood, anxiety, and alcohol use disorders and later cause-specific sick leave in young adult employees.

PubMed

Torvik, Fartein Ask; Reichborn-Kjennerud, Ted; Gjerde, Line C; Knudsen, Gun Peggy; Ystrom, Eivind; Tambs, Kristian; Røysamb, Espen; Østby, Kristian; Ørstavik, Ragnhild

2016-08-03

Mental disorders strongly influence work capability in young adults, but it is not clear which disorders that are most strongly associated with sick leave, and which diagnoses that are stated on the sick leave certificates. Better knowledge of the impairments associated with different mental disorders is needed for optimal planning of interventions and prioritization of health services. In the current study, we investigate the prospective associations between eight mood, anxiety, and alcohol use disorders, and later sick leave granted for mental, somatic, or any disorder. Lifetime mental disorders were assessed by structured diagnostic interviews in 2,178 young adults followed for eight years with registry data on sick leave. Relative risk ratios were estimated for the associations between each mental disorder and the different forms of sick leave. All included diagnoses were associated with later sick leave. In adjusted analyses, major depressive disorder and generalized anxiety disorder were the strongest predictors of sick leave granted for mental disorders, whereas social anxiety disorder and specific phobia were the strongest predictors of sick leave granted for somatic disorders. Specific phobia and major depressive disorder had the highest attributable fractions for all-cause sick leave. Mood and anxiety disorders constituted independent risk factors for all cause sick leave, whereas alcohol use disorders seemed to be of less importance in young adulthood. Disorders characterised by distress were most strongly associated with sick leave granted for mental disorders, whereas disorders characterised by fear primarily predicted sick leave granted for somatic conditions. A large part of all sick leave is related to specific phobia, due to the high prevalence of this disorder. The impairment associated with this common disorder may be under-acknowledged, and it could decrease work capacity among individuals with somatic disorders. This disorder has good treatment response and may be overlooked as a target for interventions aimed at prevention of sick leave.

A link between perianal strep and pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS).

PubMed

Toufexis, Megan; Deoleo, Caroline; Elia, Josephine; Murphy, Tanya K

2014-04-01

Perianal streptococcal dermatitis is an infection caused by group A streptococcus (GAS). Children with a pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS) phenotype may have tics or obsessive compulsive symptoms secondary to a systemic immune activation by GAS infecting perianal areas. In this retrospective case series, the authors describe three children with symptoms consistent with PANDAS and a confirmed perianal streptococcal dermatitis as the likely infectious trigger. Concomitant perianal dermatitis and new-onset obsessive-compulsive symptoms and/or tics are strong indications for perianal culture and rapid antigen detection test in young children.

Gaplessness and the Coulomb anomaly in the strongly disordered films of molybdenum carbide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulkarni, P., E-mail: prasanna1609@gmail.com; Szabo, P.; Zemlicka, M.

2016-05-23

Gaplessness was observed in the disordered films of MoC close to the superconductor to insulator transition. The transition temperature decreases and the superconducting gap tends to close as the film thickness is reduced to 3 nm from 20 nm. The gaplessness is attributed to the enhanced Coulomb interactions due to the loss of screening in the presence of strong disorder in the films.

Atom-Pair Kinetics with Strong Electric-Dipole Interactions.

PubMed

Thaicharoen, N; Gonçalves, L F; Raithel, G

2016-05-27

Rydberg-atom ensembles are switched from a weakly to a strongly interacting regime via adiabatic transformation of the atoms from an approximately nonpolar into a highly dipolar quantum state. The resultant electric dipole-dipole forces are probed using a device akin to a field ion microscope. Ion imaging and pair-correlation analysis reveal the kinetics of the interacting atoms. Dumbbell-shaped pair-correlation images demonstrate the anisotropy of the binary dipolar force. The dipolar C_{3} coefficient, derived from the time dependence of the images, agrees with the value calculated from the permanent electric-dipole moment of the atoms. The results indicate many-body dynamics akin to disorder-induced heating in strongly coupled particle systems.

Drosophila and experimental neurology in the post-genomic era.

PubMed

Shulman, Joshua M

2015-12-01

For decades, the fruit fly, Drosophila melanogaster, has been among the premiere genetic model systems for probing fundamental neurobiology, including elucidation of mechanisms responsible for human neurologic disorders. Flies continue to offer virtually unparalleled versatility and speed for genetic manipulation, strong genomic conservation, and a nervous system that recapitulates a range of cellular and network properties relevant to human disease. I focus here on four critical challenges emerging from recent advances in our understanding of the genomic basis of human neurologic disorders where innovative experimental strategies are urgently needed: (1) pinpointing causal genes from associated genomic loci; (2) confirming the functional impact of allelic variants; (3) elucidating nervous system roles for novel or poorly studied genes; and (4) probing network interactions within implicated regulatory pathways. Drosophila genetic approaches are ideally suited to address each of these potential translational roadblocks, and will therefore contribute to mechanistic insights and potential breakthrough therapies for complex genetic disorders in the coming years. Strategic collaboration between neurologists, human geneticists, and the Drosophila research community holds great promise to accelerate progress in the post-genomic era. Copyright © 2015 Elsevier Inc. All rights reserved.

Drude weight fluctuations in many-body localized systems

NASA Astrophysics Data System (ADS)

Filippone, Michele; Brouwer, Piet W.; Eisert, Jens; von Oppen, Felix

2016-11-01

We numerically investigate the distribution of Drude weights D of many-body states in disordered one-dimensional interacting electron systems across the transition to a many-body localized phase. Drude weights are proportional to the spectral curvatures induced by magnetic fluxes in mesoscopic rings. They offer a method to relate the transition to the many-body localized phase to transport properties. In the delocalized regime, we find that the Drude weight distribution at a fixed disorder configuration agrees well with the random-matrix-theory prediction P (D ) ∝(γ2+D2) -3 /2 , although the distribution width γ strongly fluctuates between disorder realizations. A crossover is observed towards a distribution with different large-D asymptotics deep in the many-body localized phase, which however differs from the commonly expected Cauchy distribution. We show that the average distribution width <γ >, rescaled by L Δ ,Δ being the average level spacing in the middle of the spectrum and L the systems size, is an efficient probe of the many-body localization transition, as it increases (vanishes) exponentially in the delocalized (localized) phase.

The DSM-5 Levels of Personality Functioning and Severity of Iranian Patients With Antisocial and Borderline Personality Disorders.

PubMed

Amini, Mehdi; Pourshahbaz, Abbas; Mohammadkhani, Parvaneh; Khodaie Ardakani, Mohammad Reza; Lotfi, Mozhgan

2015-08-01

Fundamental problems with Personality Disorders (PD) diagnostic system in the previous version of DSM, led to the revision of DSM. Therefore, a multidimensional system has been proposed for diagnosis of personality disorder features in DSM-5. In the dimensional approach of DSM-5, personality disorders diagnosis is based on levels of personality functioning (Criteria A) and personality trait domains (Criteria B). The purpose of this study was firstly, to examine the DSM-5 levels of personality functioning in antisocial and borderline personality disorders, and second, to explore which levels of personality functioning in patients with antisocial and borderline personality disorders can better predicted severity than others. This study had a cross sectional design. The participants consisted of 252 individuals with antisocial (n = 122) and borderline personality disorders (n = 130). They were recruited from Tehran prisoners, and clinical psychology and psychiatry centers of Razi and Taleghani Hospitals, Tehran, Iran. The sample was selected based on judgmental sampling. The SCID-II-PQ, SCID-II and DSM-5 levels of personality functioning were used to diagnose and assess personality disorders. The data were analyzed by correlation and multiple regression analysis. All statistical analyses were performed using the SPSS 16 software. Firstly, it was found that DSM-5 levels of personality functioning have a strong correlation with antisocial and borderline personality symptoms, specially intimacy and self-directedness (P < 0.001). Secondly, the findings showed that identity, intimacy and self-directedness significantly predicted antisocial personality disorder severity (P < 0.0001). The results showed that intimacy and empathy were good predictors of borderline personality disorder severity, as well (P < 0.0001). Overall, our findings showed that levels of personality functioning are a significant predictor of personality disorders severity. The results partially confirm existing studies.

Universality from disorder in the random-bond Blume-Capel model

NASA Astrophysics Data System (ADS)

Fytas, N. G.; Zierenberg, J.; Theodorakis, P. E.; Weigel, M.; Janke, W.; Malakis, A.

2018-04-01

Using high-precision Monte Carlo simulations and finite-size scaling we study the effect of quenched disorder in the exchange couplings on the Blume-Capel model on the square lattice. The first-order transition for large crystal-field coupling is softened to become continuous, with a divergent correlation length. An analysis of the scaling of the correlation length as well as the susceptibility and specific heat reveals that it belongs to the universality class of the Ising model with additional logarithmic corrections which is also observed for the Ising model itself if coupled to weak disorder. While the leading scaling behavior of the disordered system is therefore identical between the second-order and first-order segments of the phase diagram of the pure model, the finite-size scaling in the ex-first-order regime is affected by strong transient effects with a crossover length scale L*≈32 for the chosen parameters.

Nitric Oxide Synthase Inhibitors as Antidepressants

PubMed Central

Wegener, Gregers; Volke, Vallo

2010-01-01

Affective and anxiety disorders are widely distributed disorders with severe social and economic effects. Evidence is emphatic that effective treatment helps to restore function and quality of life. Due to the action of most modern antidepressant drugs, serotonergic mechanisms have traditionally been suggested to play major roles in the pathophysiology of mood and stress-related disorders. However, a few clinical and several pre-clinical studies, strongly suggest involvement of the nitric oxide (NO) signaling pathway in these disorders. Moreover, several of the conventional neurotransmitters, including serotonin, glutamate and GABA, are intimately regulated by NO, and distinct classes of antidepressants have been found to modulate the hippocampal NO level in vivo. The NO system is therefore a potential target for antidepressant and anxiolytic drug action in acute therapy as well as in prophylaxis. This paper reviews the effect of drugs modulating NO synthesis in anxiety and depression. PMID:27713253

Tuning and Freezing Disorder in Photonic Crystals using Percolation Lithography

PubMed Central

Burgess, Ian B.; Abedzadeh, Navid; Kay, Theresa M.; Shneidman, Anna V.; Cranshaw, Derek J.; Lončar, Marko; Aizenberg, Joanna

2016-01-01

Although common in biological systems, synthetic self-assembly routes to complex 3D photonic structures with tailored degrees of disorder remain elusive. Here we show how liquids can be used to finely control disorder in porous 3D photonic crystals, leading to complex and hierarchical geometries. In these optofluidic crystals, dynamically tunable disorder is superimposed onto the periodic optical structure through partial wetting or evaporation. In both cases, macroscopic symmetry breaking is driven by subtle sub-wavelength variations in the pore geometry. These variations direct site-selective infiltration of liquids through capillary interactions. Incorporating cross-linkable resins into our liquids, we developed methods to freeze in place the filling patterns at arbitrary degrees of partial wetting and intermediate stages of drying. These percolation lithography techniques produced permanent photonic structures with adjustable disorder. By coupling strong changes in optical properties to subtle differences in fluid behavior, optofluidic crystals may also prove useful in rapid analysis of liquids. PMID:26790372

Toward a complex system understanding of bipolar disorder: A chaotic model of abnormal circadian activity rhythms in euthymic bipolar disorder.

PubMed

Hadaeghi, Fatemeh; Hashemi Golpayegani, Mohammad Reza; Jafari, Sajad; Murray, Greg

2016-08-01

In the absence of a comprehensive neural model to explain the underlying mechanisms of disturbed circadian function in bipolar disorder, mathematical modeling is a helpful tool. Here, circadian activity as a response to exogenous daily cycles is proposed to be the product of interactions between neuronal networks in cortical (cognitive processing) and subcortical (pacemaker) areas of the brain. To investigate the dynamical aspects of the link between disturbed circadian activity rhythms and abnormalities of neurotransmitter functioning in frontal areas of the brain, we developed a novel mathematical model of a chaotic system which represents fluctuations in circadian activity in bipolar disorder as changes in the model's parameters. A novel map-based chaotic system was developed to capture disturbances in circadian activity across the two extreme mood states of bipolar disorder. The model uses chaos theory to characterize interplay between neurotransmitter functions and rhythm generation; it aims to illuminate key activity phenomenology in bipolar disorder, including prolonged sleep intervals, decreased total activity and attenuated amplitude of the diurnal activity rhythm. To test our new cortical-circadian mathematical model of bipolar disorder, we utilized previously collected locomotor activity data recorded from normal subjects and bipolar patients by wrist-worn actigraphs. All control parameters in the proposed model have an important role in replicating the different aspects of circadian activity rhythm generation in the brain. The model can successfully replicate deviations in sleep/wake time intervals corresponding to manic and depressive episodes of bipolar disorder, in which one of the excitatory or inhibitory pathways is abnormally dominant. Although neuroimaging research has strongly implicated a reciprocal interaction between cortical and subcortical regions as pathogenic in bipolar disorder, this is the first model to mathematically represent this multilevel explanation of the phenomena of bipolar disorder. © The Royal Australian and New Zealand College of Psychiatrists 2016.

Thouless energy and multifractality across the many-body localization transition

NASA Astrophysics Data System (ADS)

Serbyn, Maksym; Papić, Z.; Abanin, Dmitry A.

2017-09-01

Thermal and many-body localized phases are separated by a dynamical phase transition of a new kind. We analyze the distribution of off-diagonal matrix elements of local operators across this transition in two different models of disordered spin chains. We show that the behavior of matrix elements can be used to characterize the breakdown of thermalization and to extract the many-body Thouless energy. We find that upon increasing the disorder strength the system enters a critical region around the many-body localization transition. The properties of the system in this region are: (i) the Thouless energy becomes smaller than the level spacing, (ii) the matrix elements show critical dependence on the energy difference, and (iii) the matrix elements, viewed as amplitudes of a fictitious wave function, exhibit strong multifractality. This critical region decreases with the system size, which we interpret as evidence for a diverging correlation length at the many-body localization transition. Our findings show that the correlation length becomes larger than the accessible system sizes in a broad range of disorder strength values and shed light on the critical behavior near the many-body localization transition.

Multipoint entanglement in disordered systems

NASA Astrophysics Data System (ADS)

Magán, Javier M.; Paganelli, Simone; Oganesyan, Vadim

2017-02-01

We develop an approach to characterize excited states of disordered many-body systems using spatially resolved structures of entanglement. We show that the behavior of the mutual information (MI) between two parties of a many-body system can signal a qualitative difference between thermal and localized phases - MI is finite in insulators while it approaches zero in the thermodynamic limit in the ergodic phase. Related quantities, such as the recently introduced Codification Volume (CV), are shown to be suitable to quantify the correlation length of the system. These ideas are illustrated using prototypical non-interacting wavefunctions of localized and extended particles and then applied to characterize states of strongly excited interacting spin chains. We especially focus on evolution of spatial structure of quantum information between high temperature diffusive and many-body localized (MBL) phases believed to exist in these models. We study MI as a function of disorder strength both averaged over the eigenstates and in time-evolved product states drawn from continuously deformed family of initial states realizable experimentally. As expected, spectral and time-evolved averages coincide inside the ergodic phase and differ significantly outside. We also highlight dispersion among the initial states within the localized phase - some of these show considerable generation and delocalization of quantum information.

Neighborhood and housing disorder, parenting, and youth adjustment in low-income urban families.

PubMed

Jocson, Rosanne M; McLoyd, Vonnie C

2015-06-01

Using two waves of data, this study examined relations among neighborhood and housing disorder, parents' psychological distress, parenting behaviors, and subsequent youth adjustment in a low-income, multiethnic sample of families with children aged 6-16. Results supported the hypothesized indirect relation between disorder and youth outcomes via parenting processes. Higher levels of neighborhood and housing disorder were associated with higher levels of parents' psychological distress, which was in turn related to more frequent use of harsh and inconsistent discipline strategies and lower parental warmth. More frequent use of harsh and inconsistent discipline was associated with higher levels of youth internalizing and externalizing behaviors 3 years later. Housing disorder contributed more strongly to parents' psychological distress than neighborhood disorder, whereas neighborhood disorder contributed more strongly to youth externalizing behaviors compared to housing disorder. Multiple-group analyses showed that the patterns of relations were similar for younger and older children, and for girls and boys.

Prethermal time crystals in a one-dimensional periodically driven Floquet system

NASA Astrophysics Data System (ADS)

Zeng, Tian-Sheng; Sheng, D. N.

2017-09-01

Motivated by experimental observations of time-symmetry breaking behavior in a periodically driven (Floquet) system, we study a one-dimensional spin model to explore the stability of such Floquet discrete time crystals (DTCs) under the interplay between interaction and the microwave driving. For intermediate interactions and high drivings, from the time evolution of both stroboscopic spin polarization and mutual information between two ends, we show that Floquet DTCs can exist in a prethermal time regime without the tuning of strong disorder. For much weak interactions the system is a symmetry-unbroken phase, while for strong interactions it gives its way to a thermal phase. Through analyzing the entanglement dynamics, we show that large driving fields protect the prethermal DTCs from many-body localization and thermalization. Our results suggest that by increasing the spin interaction, one can drive the experimental system into optimal regime for observing a robust prethermal DTC phase.

Can one trust quantum simulators?

PubMed

Hauke, Philipp; Cucchietti, Fernando M; Tagliacozzo, Luca; Deutsch, Ivan; Lewenstein, Maciej

2012-08-01

Various fundamental phenomena of strongly correlated quantum systems such as high-T(c) superconductivity, the fractional quantum-Hall effect and quark confinement are still awaiting a universally accepted explanation. The main obstacle is the computational complexity of solving even the most simplified theoretical models which are designed to capture the relevant quantum correlations of the many-body system of interest. In his seminal 1982 paper (Feynman 1982 Int. J. Theor. Phys. 21 467), Richard Feynman suggested that such models might be solved by 'simulation' with a new type of computer whose constituent parts are effectively governed by a desired quantum many-body dynamics. Measurements on this engineered machine, now known as a 'quantum simulator,' would reveal some unknown or difficult to compute properties of a model of interest. We argue that a useful quantum simulator must satisfy four conditions: relevance, controllability, reliability and efficiency. We review the current state of the art of digital and analog quantum simulators. Whereas so far the majority of the focus, both theoretically and experimentally, has been on controllability of relevant models, we emphasize here the need for a careful analysis of reliability and efficiency in the presence of imperfections. We discuss how disorder and noise can impact these conditions, and illustrate our concerns with novel numerical simulations of a paradigmatic example: a disordered quantum spin chain governed by the Ising model in a transverse magnetic field. We find that disorder can decrease the reliability of an analog quantum simulator of this model, although large errors in local observables are introduced only for strong levels of disorder. We conclude that the answer to the question 'Can we trust quantum simulators?' is … to some extent.

Can one trust quantum simulators?

NASA Astrophysics Data System (ADS)

Hauke, Philipp; Cucchietti, Fernando M.; Tagliacozzo, Luca; Deutsch, Ivan; Lewenstein, Maciej

2012-08-01

Various fundamental phenomena of strongly correlated quantum systems such as high-Tc superconductivity, the fractional quantum-Hall effect and quark confinement are still awaiting a universally accepted explanation. The main obstacle is the computational complexity of solving even the most simplified theoretical models which are designed to capture the relevant quantum correlations of the many-body system of interest. In his seminal 1982 paper (Feynman 1982 Int. J. Theor. Phys. 21 467), Richard Feynman suggested that such models might be solved by ‘simulation’ with a new type of computer whose constituent parts are effectively governed by a desired quantum many-body dynamics. Measurements on this engineered machine, now known as a ‘quantum simulator,’ would reveal some unknown or difficult to compute properties of a model of interest. We argue that a useful quantum simulator must satisfy four conditions: relevance, controllability, reliability and efficiency. We review the current state of the art of digital and analog quantum simulators. Whereas so far the majority of the focus, both theoretically and experimentally, has been on controllability of relevant models, we emphasize here the need for a careful analysis of reliability and efficiency in the presence of imperfections. We discuss how disorder and noise can impact these conditions, and illustrate our concerns with novel numerical simulations of a paradigmatic example: a disordered quantum spin chain governed by the Ising model in a transverse magnetic field. We find that disorder can decrease the reliability of an analog quantum simulator of this model, although large errors in local observables are introduced only for strong levels of disorder. We conclude that the answer to the question ‘Can we trust quantum simulators?’ is … to some extent.

Avoided ferromagnetic quantum critical point: unusual short-range ordered state in CeFePO.

PubMed

Lausberg, S; Spehling, J; Steppke, A; Jesche, A; Luetkens, H; Amato, A; Baines, C; Krellner, C; Brando, M; Geibel, C; Klauss, H-H; Steglich, F

2012-11-21

Cerium 4f electronic spin dynamics in single crystals of the heavy-fermion system CeFePO is studied by means of ac susceptibility, specific heat, and muon-spin relaxation (μSR). Short-range static magnetism occurs below the freezing temperature T(g) ≈ 0.7 K, which prevents the system from accessing a putative ferromagnetic quantum critical point. In the μSR, the sample-averaged muon asymmetry function is dominated by strongly inhomogeneous spin fluctuations below 10 K and exhibits a characteristic time-field scaling relation expected from glassy spin dynamics, strongly evidencing cooperative and critical spin fluctuations. The overall behavior can be ascribed neither to canonical spin glasses nor other disorder-driven mechanisms.

Application of the Mattis-Bardeen theory in strongly disordered superconductors

NASA Astrophysics Data System (ADS)

Seibold, G.; Benfatto, L.; Castellani, C.

2017-10-01

The low-energy optical conductivity of conventional superconductors is usually well described by Mattis-Bardeen (MB) theory, which predicts the onset of absorption above an energy corresponding to twice the superconducing (SC) gap parameter Δ . Recent experiments on strongly disordered superconductors have challenged the application of the MB formulas due to the occurrence of additional spectral weight at low energies below 2 Δ . Here we identify three crucial items that have to be included in the analysis of optical-conductivity data for these systems: (a) the correct identification of the optical threshold in the Mattis-Bardeen theory and its relation with the gap value extracted from the measured density of states, (b) the gauge-invariant evaluation of the current-current response function needed to account for the optical absorption by SC collective modes, and (c) the inclusion into the MB formula of the energy dependence of the density of states present already above Tc. By computing the optical conductivity in the disordered attractive Hubbard model, we analyze the relevance of all these items, and we provide a compelling scheme for the analysis and interpretation of the optical data in real materials.

Disordered dimer state in electron-doped Sr 3 Ir 2 O 7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogan, Tom; Dally, Rebecca; Upton, Mary

2016-09-06

Spin excitations are explored in the electron-doped spin-orbit Mott insulator (Sr 1-xLa x) 3Ir 2O 7. As this bilayer square lattice system is doped into the metallic regime, long-range antiferromagnetism vanishes, yet a spectrum of gapped spin excitation remains. Excitation lifetimes are strongly damped with increasing carrier concentration, and the energy-integrated spectral weight becomes nearly momentum independent as static spin order is suppressed. Local magnetic moments, absent in the parent system, grow in metallic samples and approach values consistent with one J=12 impurity per electron doped. Our combined data suggest that the magnetic spectra of metallic (Sr 1-xLa x) 3Irmore » 2O 7 are best described by excitations out of a disordered dimer state.« less

Quantum Order-by-Disorder in Strongly Correlated Metals

NASA Astrophysics Data System (ADS)

Green, Andrew G.; Conduit, Gareth; Krüger, Frank

2018-03-01

Entropic forces in classical many-body systems, e.g., colloidal suspensions, can lead to the formation of new phases. Quantum fluctuations can have similar effects: spin fluctuations drive the superfluidity of helium-3, and a similar mechanism operating in metals can give rise to superconductivity. It is conventional to discuss the latter in terms of the forces induced by the quantum fluctuations. However, focusing directly upon the free energy provides a useful alternative perspective in the classical case and can also be applied to study quantum fluctuations. Villain first developed this approach for insulating magnets and coined the term order-by-disorder to describe the observed effect. We discuss the application of this idea to metallic systems, recent progress made in doing so, and the broader prospects for the future.

Phase diagram of the disordered Bose-Hubbard model

NASA Astrophysics Data System (ADS)

Gurarie, V.; Pollet, L.; Prokof'Ev, N. V.; Svistunov, B. V.; Troyer, M.

2009-12-01

We establish the phase diagram of the disordered three-dimensional Bose-Hubbard model at unity filling which has been controversial for many years. The theorem of inclusions, proven by Pollet [Phys. Rev. Lett. 103, 140402 (2009)] states that the Bose-glass phase always intervenes between the Mott insulating and superfluid phases. Here, we note that assumptions on which the theorem is based exclude phase transitions between gapped (Mott insulator) and gapless phases (Bose glass). The apparent paradox is resolved through a unique mechanism: such transitions have to be of the Griffiths type when the vanishing of the gap at the critical point is due to a zero concentration of rare regions where extreme fluctuations of disorder mimic a regular gapless system. An exactly solvable random transverse field Ising model in one dimension is used to illustrate the point. A highly nontrivial overall shape of the phase diagram is revealed with the worm algorithm. The phase diagram features a long superfluid finger at strong disorder and on-site interaction. Moreover, bosonic superfluidity is extremely robust against disorder in a broad range of interaction parameters; it persists in random potentials nearly 50 (!) times larger than the particle half-bandwidth. Finally, we comment on the feasibility of obtaining this phase diagram in cold-atom experiments, which work with trapped systems at finite temperature.

Strongly disordered TiN and NbTiN s-wave superconductors probed by microwave electrodynamics.

PubMed

Driessen, E F C; Coumou, P C J J; Tromp, R R; de Visser, P J; Klapwijk, T M

2012-09-07

We probe the effects of strong disorder (2.4

Clean Floquet Time Crystals: Models and Realizations in Cold Atoms

NASA Astrophysics Data System (ADS)

Huang, Biao; Wu, Ying-Hai; Liu, W. Vincent

2018-03-01

Time crystals, a phase showing spontaneous breaking of time-translation symmetry, has been an intriguing subject for systems far away from equilibrium. Recent experiments found such a phase in both the presence and the absence of localization, while in theories localization by disorder is usually assumed a priori. In this work, we point out that time crystals can generally exist in systems without disorder. A series of clean quasi-one-dimensional models under Floquet driving are proposed to demonstrate this unexpected result in principle. Robust time crystalline orders are found in the strongly interacting regime along with the emergent integrals of motion in the dynamical system, which can be characterized by level statistics and the out-of-time-ordered correlators. We propose two cold atom experimental schemes to realize the clean Floquet time crystals, one by making use of dipolar gases and another by synthetic dimensions.

Long-range Prethermal Time Crystals

NASA Astrophysics Data System (ADS)

Machado, Francisco; Meyer, Gregory D.; Else, Dominic; Olund, Christopher; Nayak, Chetan; Yao, Norman Y.

2017-04-01

Driven quantum systems have recently enabled the realization of a discrete time crystal - an intrinsically out-of-equilibrium phase of matter. One strategy to prevent the drive-induced, runaway heating of the time crystal is the presence of strong disorder leading to many-body localization (MBL). A more elegant, disorder-less approach is simply to work in the prethermal regime where time crystalline order can persist to exponentially long times. One key difference between prethermal and MBL time crystals is that the former is prohibited from existing in one dimensional systems with short-range interactions. In this work, we demonstrate that long-range interactions can stabilize a one dimensional prethermal time crystal. By numerically studying the pre-thermal regime, we find evidence for a phase transition out of the time crystal as a function of increasing energy density. Finally, generalizations of previous analytical bounds for the heating time-scale of driven quantum systems to long-range interactions will also be discussed.

The association between autism spectrum disorders and congenital anomalies by organ systems in a Finnish national birth cohort.

PubMed

Timonen-Soivio, Laura; Sourander, Andre; Malm, Heli; Hinkka-Yli-Salomäki, Susanna; Gissler, Mika; Brown, Alan; Vanhala, Raija

2015-10-01

The aim of this study was to evaluate the association between autism spectrum disorders (ASD) with and without intellectual disability (ID) and congenital anomalies (CAs) by organ system. The sample included all children diagnosed with ASD (n = 4441) from the Finnish Hospital Discharge Register during 1987-2000 and a total of four controls per case (n = 17,695). CAs of the eye, central nervous system, and specific craniofacial anomalies were most strongly associated with ASD. Children with ASD and co-occurring ID were more likely to have CAs compared to ASD children without ID. The results suggest that some cases of ASD may originate during organogenesis, in the early first trimester of pregnancy. The results of this study may be useful for identifying prenatal etiological factors and elucidating the molecular pathogenesis of ASD.

Nontrivial interplay of strong disorder and interactions in quantum spin-Hall insulators doped with dilute magnetic impurities

NASA Astrophysics Data System (ADS)

Zheng, Jun-Hui; Cazalilla, Miguel A.

2018-06-01

We investigate nonperturbatively the effect of a magnetic dopant impurity on the edge transport of a quantum spin Hall (QSH) insulator. We show that for a strongly coupled magnetic dopant located near the edge of a system, a pair of transmission antiresonances appear. When the chemical potential is on resonance, interaction effects broaden the antiresonance width with decreasing temperature, thus suppressing transport for both repulsive and moderately attractive interactions. Consequences for the recently observed QSH insulating phase of the 1 -T' of WTe2 are briefly discussed.

IS GENERALIZED ANXIETY DISORDER AN ANXIETY OR MOOD DISORDER? CONSIDERING MULTIPLE FACTORS AS WE PONDER THE FATE OF GAD

PubMed Central

Mennin, Douglas S.; Heimberg, Richard G.; Fresco, David M.; Ritter, Michael R.

2016-01-01

Generalized anxiety disorder (GAD) and major depressive disorder (MDD) demonstrate a strong relationship to each other at both genotypic and phenotypic levels, and both demonstrate substantial loadings on a higher-order negative affectivity factor. On the basis of these findings, there have been a number of calls to reclassify GAD in the same category as MDD (the “distress disorders”). However, any consideration of the reclassification of GAD should also take into account a number of other factors not only related to GAD and MDD but also to the overlap of these disorders with other anxiety and mood disorders. First, GAD has established reliability and validity in its own right, and specific features (e.g., worry) may become obscured by attempts at reclassification. Second, examination of the nature of the overlap of GAD and MDD with each other and with other disorders suggests a more complex pattern of differences between these conditions than has been suggested (e.g., MDD has strong relationships with other anxiety disorders, and GAD may be more strongly related to fear than it may first appear). Third, although findings suggest that GAD and MDD may have overlapping heritable characteristics, other evidence suggests that the two disorders may be distinguished by both environmental factors and temporal presentations. Finally, although overlap between GAD and MDD is reflected in their relationships to negative affectivity, temporal relationships between these disorders may be demonstrated by functional changes in emotional responsivity. PMID:18412056

Shear-induced rigidity in athermal materials

NASA Astrophysics Data System (ADS)

Chakraborty, Bulbul; Sarkar, Sumantra

2014-03-01

In this talk, we present a minimal model of rigidity and plastic failure in solids whose rigidity emerges directly as a result of applied stresses. Examples include shear-jamming (SJ) in dry grains and discontinuous shear thickening (DST) of dense non-Brownian suspensions. Both SJ and DST states are examples of non-equilibrium, self-assembled structures that have evolved to support the load that created them. These are strongly-interacting systems where the interactions arise primarily from the strict constraints of force and torque balance at the local and global scales. Our model is based on a reciprocal-space picture that strictly enforces the local and global constraints, and is, therefore, best suited to capturing the strong correlations in these non-equilibrium systems. The reciprocal space is a tiling whose edges represent contact forces, and whose faces represent grains. A separation of scale between force fluctuations and displacements of grains is used to represent the positional disorder as quenched randomness on variables in the reciprocal space. Comparing theoretical results to experiments, we will argue that the packing fraction controls the strength of the quenched disorder. Sumantra Sarkar et al, Phys. Rev. Lett. 111, 068301 (2013)

Other- and Self-Directed Forms of Violence and Their Relationships to DSM-IV Substance Use and Other Psychiatric Disorders in a National Survey of Adults

PubMed Central

Harford, Thomas C.; Yi, Hsiao-ye; Grant, Bridget F.

2013-01-01

Objective To examine associations between DSM-IV psychiatric disorders and other- and self- directed violence in the general population. Methods Data were obtained from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) Waves 1 & 2 (n=34,653). Four violence categories were derived from a latent class analysis (LCA) of 5 other-directed and 4 self-directed violent behavior indicators. Multinomial logistic regression examined class associations for gender, race-ethnicity, age and DSM-IV substance use, mood, anxiety, and personality disorders. Results Approximately 16% of adults reported some form of violent behavior distributed as follows: other-directed only, 4.6%; self-directed only, 9.3%; combined self- and other-directed, 2.0%; and no violence, 84.1%. The majority of the DSM-IV disorders included in this study were significantly and independently related to each form of violence. Generally, other-directed violence was more strongly associated with any substance use disorders (81%) and any personality disorders (42%), while self-directed violence was more strongly associated with mood (41%) and anxiety disorders (57%). Compared with these two forms of violence, the smaller group with combined self- and other-directed violence was more strongly associated with any substance use disorders (88%), mood disorders (63%), and personality disorders (76%). Conclusion Findings from this study are consistent with recent conceptualizations of disorders as reflecting externalizing disorders and internalizing disorders. The identification of the small category with combined forms of violence further extends numerous clinical studies which established associations between self- and other-directed violent behaviors. The extent to which the combined violence category represents a meaningful and reliable category of violence requires further detailed studies. PMID:23587529

Clumsiness in Children: Developmental Coordination Disorder.

ERIC Educational Resources Information Center

Fox, Mervyn A.

1998-01-01

Explores the diagnostic criteria of developmental coordination disorder, a condition that is characterized by motor awkwardness and has a strong association with psychiatric disorders and learning disabilities. Delineates the nature of developmental coordination disorder and discusses its treatment through occupational therapy and cognitive…

Metallization of a Rashba wire by a superconducting layer in the strong-proximity regime

NASA Astrophysics Data System (ADS)

Reeg, Christopher; Loss, Daniel; Klinovaja, Jelena

2018-04-01

Semiconducting quantum wires defined within two-dimensional electron gases and strongly coupled to thin superconducting layers have been extensively explored in recent experiments as promising platforms to host Majorana bound states. We study numerically such a geometry, consisting of a quasi-one-dimensional wire coupled to a disordered three-dimensional superconducting layer. We find that, in the strong-coupling limit of a sizable proximity-induced superconducting gap, all transverse subbands of the wire are significantly shifted in energy relative to the chemical potential of the wire. For the lowest subband, this band shift is comparable in magnitude to the spacing between quantized levels that arises due to the finite thickness of the superconductor (which typically is ˜500 meV for a 10-nm-thick layer of aluminum); in higher subbands, the band shift is much larger. Additionally, we show that the width of the system, which is usually much larger than the thickness, and moderate disorder within the superconductor have almost no impact on the induced gap or band shift. We provide a detailed discussion of the ramifications of our results, arguing that a huge band shift and significant renormalization of semiconducting material parameters in the strong-coupling limit make it challenging to realize a topological phase in such a setup, as the strong coupling to the superconductor essentially metallizes the semiconductor. This metallization of the semiconductor can be tested experimentally through the measurement of the band shift.

Effectiveness of Interventions to Improve Social Participation, Play, Leisure, and Restricted and Repetitive Behaviors in People With Autism Spectrum Disorder: A Systematic Review.

PubMed

Tanner, Kelly; Hand, Brittany N; O'Toole, Gjyn; Lane, Alison E

2015-01-01

People with autism spectrum disorder (ASD) commonly experience difficulties with social participation, play, and leisure along with restricted and repetitive behaviors that can interfere with occupational performance. The objective of this systematic review was to evaluate current evidence for interventions within the occupational therapy scope of practice that address these difficulties. Strong evidence was found that social skills groups, the Picture Exchange Communication System, joint attention interventions, and parent-mediated strategies can improve social participation. The findings were less conclusive for interventions to improve play and leisure performance and to decrease restricted and repetitive behaviors, but several strategies showed promise with moderately strong supporting evidence. Occupational therapists should be guided by evidence when considering interventions to improve social participation, play, leisure, and restricted and repetitive behaviors in people with ASD. Additional research using more robust scientific methods is needed for many of the currently available strategies. Copyright © 2015 by the American Occupational Therapy Association, Inc.

Neural and behavioural responses to face-likeness of objects in adolescents with autism spectrum disorder.

PubMed

Akechi, Hironori; Kikuchi, Yukiko; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

2014-01-27

Numerous studies have revealed atypical face processing in autism spectrum disorders (ASD) characterized by social interaction and communication difficulties. This study investigated sensitivity to face-likeness in ASD. In Experiment 1, we found a strong positive correlation between the face-likeness ratings of non-face objects in the ASD (11-19 years old) and the typically developing (TD) group (9-21 years old). In Experiment 2 (the scalp-recorded event-related potential experiment), the participants of both groups (ASD, 12-19 years old; TD, 12-18 years old) exhibited an enhanced face-sensitive N170 amplitude to a face-like object. Whereas the TD adolescents showed an enhanced N170 during the face-likeness judgements, adolescents with ASD did not. Thus, both individuals with ASD and TD individuals have a perceptual and neural sensitivity to face-like features in objects. When required to process face-like features, a face-related brain system reacts more strongly in TD individuals but not in individuals with ASD.

Entanglement contour perspective for "strong area-law violation" in a disordered long-range hopping model

NASA Astrophysics Data System (ADS)

Roy, Nilanjan; Sharma, Auditya

2018-03-01

We numerically investigate the link between the delocalization-localization transition and entanglement in a disordered long-range hopping model of spinless fermions by studying various static and dynamical quantities. This includes the inverse participation ratio, level statistics, entanglement entropy, and number fluctuations in the subsystem along with quench and wave-packet dynamics. Finite systems show delocalized, quasilocalized, and localized phases. The delocalized phase shows strong area-law violation, whereas the (quasi)localized phase adheres to (for large subsystems) the strict area law. The idea of "entanglement contour" nicely explains the violation of area law and its relationship with "fluctuation contour" reveals a signature at the transition point. The relationship between entanglement entropy and number fluctuations in the subsystem also carries signatures for the transition in the model. Results from the Aubry-Andre-Harper model are compared in this context. The propagation of charge and entanglement are contrasted by studying quench and wave-packet dynamics at the single-particle and many-particle levels.

Correlates Associated with Unipolar Depressive Disorders in a Latino Population

PubMed Central

Correa-Fernandez, Virmarie; Carrión-Baralt, José R.; Alegría, Margarita; Albizu-García, Carmen E.

2014-01-01

Background This study reports the comparison and associations of demographic, clinical, and psychosocial correlates with three unipolar depressive disorders: dysthymia (DYS), major depression (MD), and double depression (DD), and examines to which extent these variables predict the disorders. Sampling and Method Previously collected data from 563 adults from a community in Puerto Rico were analyzed. One hundred and thirty individuals with DYS, 260 with MD, and 173 with DD were compared by demographic variables, psychiatric and physical comorbidity, familial psychopathology, psychosocial stressors, functional impairment, self-reliance, problem recognition and formal use of mental health services. Multinomial regression was used to assess the association of the predictor variables with each of the three disorders. Results Similarities outweighed the discrepancies between disorders. The main differences observed were between MD and DD, while DYS shared common characteristics with both MD and DD. After other variables were controlled, anxiety, functional impairment, and problem recognition most strongly predicted a DD diagnosis while age predicted a DYS diagnosis. Conclusion MD, DYS, and DD are not completely different disorders but they do differ in key aspects that might be relevant for nosology, research, and practice. A dimensional system that incorporates specific categories of disorders would better reflect the different manifestations of unipolar depressive disorders. PMID:23006435

Design and analysis of photonic crystal coupled cavity arrays for quantum simulation

NASA Astrophysics Data System (ADS)

Majumdar, Arka; Rundquist, Armand; Bajcsy, Michal; Dasika, Vaishno D.; Bank, Seth R.; Vučković, Jelena

2012-11-01

We performed an experimental study of coupled optical cavity arrays in a photonic crystal platform. We find that the coupling between the cavities is significantly larger than the fabrication-induced disorder in the cavity frequencies. Satisfying this condition is necessary for using such cavity arrays to generate strongly correlated photons, which has potential application in the quantum simulation of many-body systems.

Antiferromagnetism in pressure-amorphized Fe2SiO4

USGS Publications Warehouse

Kruger, M.B.; Jeanloz, R.; Pasternak, M.P.; Taylor, R.D.; Snyder, B.S.; Stacy, A.M.; Bohlen, S.R.

1992-01-01

Amorphous Fe2SiO4 synthesized at elevated pressures exhibits a Ne??el transition at a temperature identical to that observed in the crystalline form, TN = 65 (??2) kelvin at zero pressure. This behavior contrasts sharply with observations on other disordered systems, such as spin glasses, which characteristically exhibit strong "frustration" of the spins and consequent marked suppression of the Ne??el transition.

Interfacial adsorption in two-dimensional pure and random-bond Potts models.

PubMed

Fytas, Nikolaos G; Theodorakis, Panagiotis E; Malakis, Anastasios

2017-03-01

We use Monte Carlo simulations to study the finite-size scaling behavior of the interfacial adsorption of the two-dimensional square-lattice q-states Potts model. We consider the pure and random-bond versions of the Potts model for q=3,4,5,8, and 10, thus probing the interfacial properties at the originally continuous, weak, and strong first-order phase transitions. For the pure systems our results support the early scaling predictions for the size dependence of the interfacial adsorption at both first- and second-order phase transitions. For the disordered systems, the interfacial adsorption at the (disordered induced) continuous transitions is discussed, applying standard scaling arguments and invoking findings for bulk critical properties. The self-averaging properties of the interfacial adsorption are also analyzed by studying the infinite limit-size extrapolation of properly defined signal-to-noise ratios.

Human care system for heart-rate and human-movement trajectory in home and its application to detect mental disease

NASA Astrophysics Data System (ADS)

Hata, Yutaka; Kanazawa, Seigo; Endo, Maki; Tsuchiya, Naoki; Nakajima, Hiroshi

2012-06-01

This paper proposes a heart rate monitoring system for detecting autonomic nervous system by the heart rate variability using an air pressure sensor to diagnose mental disease. Moreover, we propose a human behavior monitoring system for detecting the human trajectory in home by an infrared camera. In day and night times, the human behavior monitoring system detects the human movement in home. The heart rate monitoring system detects the heart rate in bed in night time. The air pressure sensor consists of a rubber tube, cushion cover and pressure sensor, and it detects the heart rate by setting it to bed. It unconstraintly detects the RR-intervals; thereby the autonomic nervous system can be assessed. The autonomic nervous system analysis can examine the mental disease. While, the human behavior monitoring system obtains distance distribution image by an infrared camera. It classifies adult, child and the other object from distance distribution obtained by the camera, and records their trajectories. This behavior, i.e., trajectory in home, strongly corresponds to cognitive disorders. Thus, the total system can detect mental disease and cognitive disorders by uncontacted sensors to human body.

Effects of Herbal Medicine (Gan Mai Da Zao Decoction) on Several Types of Neuropsychiatric Disorders in an Animal Model: A Systematic Review: Herbal medicine for animal studies of neuropsychiatric diseases.

PubMed

Kim, Su Ran; Lee, Hye Won; Jun, Ji Hee; Ko, Byoung-Seob

2017-03-01

Gan Mai Da Zao (GMDZ) decoction is widely used for the treatment of various diseases of the internal organ and of the central nervous system. The aim of this study is to investigate the effects of GMDZ decoction on neuropsychiatric disorders in an animal model. We searched seven databases for randomized animal studies published until April 2015: Pubmed, four Korean databases (DBpia, Oriental Medicine Advanced Searching Integrated System, Korean Studies Information Service System, and Research Information Sharing Service), and one Chinese database (China National Knowledge Infrastructure). The randomized animal studies were included if the effects of GMDZ decoction were tested on neuropsychiatric disorders. All articles were read in full and extracted predefined criteria by two independent reviewers. From a total of 258 hits, six randomized controlled animal studies were included. Five studies used a Sprague Dawley rat model for acute psychological stress, post-traumatic stress disorders, and unpredictable mild stress depression whereas one study used a Kunming mouse model for prenatal depression. The results of the studies showed that GMDZ decoction improved the related outcomes. Regardless of the dose and concentration used, GMDZ decoction significantly improved neuropsychiatric disease-related outcomes in animal models. However, additional systematic and extensive studies should be conducted to establish a strong conclusion.

Non-Fermi liquids in oxide heterostructures

NASA Astrophysics Data System (ADS)

Stemmer, Susanne; Allen, S. James

2018-06-01

Understanding the anomalous transport properties of strongly correlated materials is one of the most formidable challenges in condensed matter physics. For example, one encounters metal-insulator transitions, deviations from Landau Fermi liquid behavior, longitudinal and Hall scattering rate separation, a pseudogap phase, and bad metal behavior. These properties have been studied extensively in bulk materials, such as the unconventional superconductors and heavy fermion systems. Oxide heterostructures have recently emerged as new platforms to probe, control, and understand strong correlation phenomena. This article focuses on unconventional transport phenomena in oxide thin film systems. We use specific systems as examples, namely charge carriers in SrTiO3 layers and interfaces with SrTiO3, and strained rare earth nickelate thin films. While doped SrTiO3 layers appear to be a well behaved, though complex, electron gas or Fermi liquid, the rare earth nickelates are a highly correlated electron system that may be classified as a non-Fermi liquid. We discuss insights into the underlying physics that can be gained from studying the emergence of non-Fermi liquid behavior as a function of the heterostructure parameters. We also discuss the role of lattice symmetry and disorder in phenomena such as metal-insulator transitions in strongly correlated heterostructures.

Synchronization crossover of polariton condensates in weakly disordered lattices

NASA Astrophysics Data System (ADS)

Ohadi, H.; del Valle-Inclan Redondo, Y.; Ramsay, A. J.; Hatzopoulos, Z.; Liew, T. C. H.; Eastham, P. R.; Savvidis, P. G.; Baumberg, J. J.

2018-05-01

We demonstrate that the synchronization of a lattice of solid-state condensates when intersite tunneling is switched on depends strongly on the weak local disorder. This finding is vital for implementation of condensate arrays as computation devices. The condensates here are nonlinear bosonic fluids of exciton-polaritons trapped in a weakly disordered Bose-Hubbard potential, where the nearest-neighboring tunneling rate (Josephson coupling) can be dynamically tuned. The system can thus be tuned from a localized to a delocalized fluid as the number density or the Josephson coupling between nearest neighbors increases. The localized fluid is observed as a lattice of unsynchronized condensates emitting at different energies set by the disorder potential. In the delocalized phase, the condensates synchronize and long-range order appears, evidenced by narrowing of momentum and energy distributions, new diffraction peaks in momentum space, and spatial coherence between condensates. Our paper identifies similarities and differences of this nonequilibrium crossover to the traditional Bose-glass to superfluid transition in atomic condensates.

Electronic transport in disordered MoS2 nanoribbons

NASA Astrophysics Data System (ADS)

Ridolfi, Emilia; Lima, Leandro R. F.; Mucciolo, Eduardo R.; Lewenkopf, Caio H.

2017-01-01

We study the electronic structure and transport properties of zigzag and armchair monolayer molybdenum disulfide nanoribbons using an 11-band tight-binding model that accurately reproduces the material's bulk band structure near the band gap. We study the electronic properties of pristine zigzag and armchair nanoribbons, paying particular attention to the edges states that appear within the MoS2 bulk gap. By analyzing both their orbital composition and their local density of states, we find that in zigzag-terminated nanoribbons these states can be localized at a single edge for certain energies independent of the nanoribbon width. We also study the effects of disorder in these systems using the recursive Green's function technique. We show that for the zigzag nanoribbons, the conductance due to the edge states is strongly suppressed by short-range disorder such as vacancies. In contrast, the local density of states still shows edge localization. We also show that long-range disorder has a small effect on the transport properties of nanoribbons within the bulk gap energy window.

Novel Therapeutic GPCRs for Psychiatric Disorders

PubMed Central

Komatsu, Hidetoshi

2015-01-01

G protein-coupled receptors (GPCRs) are the most common targets of the neuropharmacological drugs in the central nervous system (CNS). GPCRs are activated by manifold neurotransmitters, and their activation in turn evokes slow synaptic transmission. They are deeply involved in multiple neurological and psychiatric disorders such as Parkinson’s disease and schizophrenia. In the brain, the striatum is strongly innervated by the ventral tegmental area (VTA) and plays a central role in manifestation of psychiatric disorders. Recently, anatomical and comprehensive transcriptome analysis of the non-odorant GPCR superfamily revealed that the orphan GPCRs GPR88, GPR6, and GPR52, as well as dopamine D1 and D2 receptors and the adenosine A2a receptor, are the most highly enriched in the rodent striatum. Genetically engineered animal models and molecular biological studies have suggested that these striatally enriched GPCRs have a potential to be therapeutic psychiatric receptors. This review summarizes the current understanding of the therapeutic GPCR candidates for psychiatric disorders. PMID:26101869

Novel Therapeutic GPCRs for Psychiatric Disorders.

PubMed

Komatsu, Hidetoshi

2015-06-19

G protein-coupled receptors (GPCRs) are the most common targets of the neuropharmacological drugs in the central nervous system (CNS). GPCRs are activated by manifold neurotransmitters, and their activation in turn evokes slow synaptic transmission. They are deeply involved in multiple neurological and psychiatric disorders such as Parkinson's disease and schizophrenia. In the brain, the striatum is strongly innervated by the ventral tegmental area (VTA) and plays a central role in manifestation of psychiatric disorders. Recently, anatomical and comprehensive transcriptome analysis of the non-odorant GPCR superfamily revealed that the orphan GPCRs GPR88, GPR6, and GPR52, as well as dopamine D1 and D2 receptors and the adenosine A2a receptor, are the most highly enriched in the rodent striatum. Genetically engineered animal models and molecular biological studies have suggested that these striatally enriched GPCRs have a potential to be therapeutic psychiatric receptors. This review summarizes the current understanding of the therapeutic GPCR candidates for psychiatric disorders.

Majorana Kramers pairs in Rashba double nanowires with interactions and disorder

NASA Astrophysics Data System (ADS)

Thakurathi, Manisha; Simon, Pascal; Mandal, Ipsita; Klinovaja, Jelena; Loss, Daniel

2018-01-01

We analyze the effects of electron-electron interactions and disorder on a Rashba double-nanowire setup coupled to an s -wave superconductor, which has been recently proposed as a versatile platform to generate Kramers pairs of Majorana bound states in the absence of magnetic fields. We identify the regime of parameters for which these Kramers pairs are stable against interaction and disorder effects. We use bosonization, perturbative renormalization group, and replica techniques to derive the flow equations for various parameters of the model and evaluate the corresponding phase diagram with topological and disorder-dominated phases. We confirm aforementioned results by considering a more microscopic approach, which starts from the tunneling Hamiltonian between the three-dimensional s -wave superconductor and the nanowires. We find again that the interaction drives the system into the topological phase and, as the strength of the source term coming from the tunneling Hamiltonian increases, strong electron-electron interactions are required to reach the topological phase.

Atomistic analysis of valley-orbit hybrid states and inter-dot tunnel rates in a Si double quantum dot

NASA Astrophysics Data System (ADS)

Ferdous, Rifat; Rahman, Rajib; Klimeck, Gerhard

2014-03-01

Silicon quantum dots are promising candidates for solid-state quantum computing due to the long spin coherence times in silicon, arising from small spin-orbit interaction and a nearly spin free host lattice. However, the conduction band valley degeneracy adds an additional degree of freedom to the electronic structure, complicating the encoding and operation of qubits. Although the valley and the orbital indices can be uniquely identified in an ideal silicon quantum dot, atomic-scale disorder mixes valley and orbital states in realistic dots. Such valley-orbit hybridization, strongly influences the inter-dot tunnel rates.Using a full-band atomistic tight-binding method, we analyze the effect of atomic-scale interface disorder in a silicon double quantum dot. Fourier transform of the tight-binding wavefunctions helps to analyze the effect of disorder on valley-orbit hybridization. We also calculate and compare inter-dot inter-valley and intra-valley tunneling, in the presence of realistic disorder, such as interface tilt, surface roughness, alloy disorder, and interface charges. The method provides a useful way to compute electronic states in realistically disordered systems without any posteriori fitting parameters.

The DSM-5 Levels of Personality Functioning and Severity of Iranian Patients With Antisocial and Borderline Personality Disorders

PubMed Central

Amini, Mehdi; Pourshahbaz, Abbas; Mohammadkhani, Parvaneh; Khodaie Ardakani, Mohammad Reza; Lotfi, Mozhgan

2015-01-01

Background: Fundamental problems with Personality Disorders (PD) diagnostic system in the previous version of DSM, led to the revision of DSM. Therefore, a multidimensional system has been proposed for diagnosis of personality disorder features in DSM-5. In the dimensional approach of DSM-5, personality disorders diagnosis is based on levels of personality functioning (Criteria A) and personality trait domains (Criteria B). Objectives: The purpose of this study was firstly, to examine the DSM-5 levels of personality functioning in antisocial and borderline personality disorders, and second, to explore which levels of personality functioning in patients with antisocial and borderline personality disorders can better predicted severity than others. Patients and Methods: This study had a cross sectional design. The participants consisted of 252 individuals with antisocial (n = 122) and borderline personality disorders (n = 130). They were recruited from Tehran prisoners, and clinical psychology and psychiatry centers of Razi and Taleghani Hospitals, Tehran, Iran. The sample was selected based on judgmental sampling. The SCID-II-PQ, SCID-II and DSM-5 levels of personality functioning were used to diagnose and assess personality disorders. The data were analyzed by correlation and multiple regression analysis. All statistical analyses were performed using the SPSS 16 software. Results: Firstly, it was found that DSM-5 levels of personality functioning have a strong correlation with antisocial and borderline personality symptoms, specially intimacy and self-directedness (P < 0.001). Secondly, the findings showed that identity, intimacy and self-directedness significantly predicted antisocial personality disorder severity (P < 0.0001). The results showed that intimacy and empathy were good predictors of borderline personality disorder severity, as well (P < 0.0001). Conclusions: Overall, our findings showed that levels of personality functioning are a significant predictor of personality disorders severity. The results partially confirm existing studies. PMID:26430521

Evidence for a Multi-Dimensional Latent Structural Model of Externalizing Disorders

ERIC Educational Resources Information Center

Witkiewitz, Katie; King, Kevin; McMahon, Robert J.; Wu, Johnny; Luk, Jeremy; Bierman, Karen L.; Coie, John D.; Dodge, Kenneth A.; Greenberg, Mark T.; Lochman, John E.; Pinderhughes, Ellen E.

2013-01-01

Strong associations between conduct disorder (CD), antisocial personality disorder (ASPD) and substance use disorders (SUD) seem to reflect a general vulnerability to externalizing behaviors. Recent studies have characterized this vulnerability on a continuous scale, rather than as distinct categories, suggesting that the revision of the…

Associations Between Early-Adolescent Substance Use and Subsequent Young-Adult Substance Use Disorders and Psychiatric Disorders Among a Multiethnic Male Sample in South Florida

PubMed Central

Gil, Andres G.; Wagner, Eric F.; Tubman, Jonathan G.

2004-01-01

Objectives. We examined the associations among early-adolescent substance use, subsequent young-adult substance use disorders, and psychiatric disorders among a community sample of males. Methods. Early-adolescent data were collected in classroom surveys (1990–1993), and young-adult data were collected in face-to-face interviews (1998–2000). Results. We found strong associations between early-adolescent substance use and young-adult substance use disorders and psychiatric disorders. The magnitudes of these associations varied by racial/ethnic group and were strongest among African Americans and foreign-born Hispanics, who reported the lowest early-adolescent substance use. Conclusions. Early-adolescent substance use is most strongly associated with a later pattern of dysfunction among the racial/ethnic groups that reported the lowest levels of early use. The implications of our findings in the context of primary and secondary prevention are discussed. PMID:15333322

Associations among Substance Use, Mental Health Disorders, and Self-Harm in a Prison Population: Examining Group Risk for Suicide Attempt

PubMed Central

Gates, Madison L.; Turney, Asher; Ferguson, Elizabeth; Walker, Veronica; Staples-Horne, Michelle

2017-01-01

Substance use disorders (SUD) and mental health disorders are significant public health issues that co-occur and are associated with high risk for suicide attempts. SUD and mental health disorders are more prevalent among offenders (i.e., prisoners or inmates) than the non-imprisoned population, raising concerns about the risk of self-harm. This cross-sectional study examined the population of a state prison system (10,988 out of 13,079) to identify associations among SUD (alcohol, cannabis, intravenous drugs, narcotics, and tobacco smoking), mental health disorders (anxiety, bipolar, depression, and psychotic disorders), and suicide attempts. The primary aim was to determine which groups (SUD, mental health disorders, and co-occurrences) were strongly association with suicide attempts. Groups with a documented SUD or mental health disorders compared to peers without these issues had 2.0 and 9.2 greater odds, respectively, for attempting suicide, which was significant at p < 0.0001 for both conditions. There were also significant differences within SUD and mental health disorders groups in regard to suicide attempts. Groups with the greatest odds for suicide attempts were offenders with comorbid bipolar comorbid and anxiety, alcohol combined with depression, and cannabis co-occurring with depression. Documentation of suicide attempts during imprisonment indicates awareness, but also suggest a need to continue enhancing screening and evaluating environmental settings. PMID:28335531

European guideline for the diagnosis and treatment of insomnia.

PubMed

Riemann, Dieter; Baglioni, Chiara; Bassetti, Claudio; Bjorvatn, Bjørn; Dolenc Groselj, Leja; Ellis, Jason G; Espie, Colin A; Garcia-Borreguero, Diego; Gjerstad, Michaela; Gonçalves, Marta; Hertenstein, Elisabeth; Jansson-Fröjmark, Markus; Jennum, Poul J; Leger, Damien; Nissen, Christoph; Parrino, Liborio; Paunio, Tiina; Pevernagie, Dirk; Verbraecken, Johan; Weeß, Hans-Günter; Wichniak, Adam; Zavalko, Irina; Arnardottir, Erna S; Deleanu, Oana-Claudia; Strazisar, Barbara; Zoetmulder, Marielle; Spiegelhalder, Kai

2017-12-01

This European guideline for the diagnosis and treatment of insomnia was developed by a task force of the European Sleep Research Society, with the aim of providing clinical recommendations for the management of adult patients with insomnia. The guideline is based on a systematic review of relevant meta-analyses published till June 2016. The target audience for this guideline includes all clinicians involved in the management of insomnia, and the target patient population includes adults with chronic insomnia disorder. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to grade the evidence and guide recommendations. The diagnostic procedure for insomnia, and its co-morbidities, should include a clinical interview consisting of a sleep history (sleep habits, sleep environment, work schedules, circadian factors), the use of sleep questionnaires and sleep diaries, questions about somatic and mental health, a physical examination and additional measures if indicated (i.e. blood tests, electrocardiogram, electroencephalogram; strong recommendation, moderate- to high-quality evidence). Polysomnography can be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders), in treatment-resistant insomnia, for professional at-risk populations and when substantial sleep state misperception is suspected (strong recommendation, high-quality evidence). Cognitive behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (strong recommendation, high-quality evidence). A pharmacological intervention can be offered if cognitive behavioural therapy for insomnia is not sufficiently effective or not available. Benzodiazepines, benzodiazepine receptor agonists and some antidepressants are effective in the short-term treatment of insomnia (≤4 weeks; weak recommendation, moderate-quality evidence). Antihistamines, antipsychotics, melatonin and phytotherapeutics are not recommended for insomnia treatment (strong to weak recommendations, low- to very-low-quality evidence). Light therapy and exercise need to be further evaluated to judge their usefulness in the treatment of insomnia (weak recommendation, low-quality evidence). Complementary and alternative treatments (e.g. homeopathy, acupuncture) are not recommended for insomnia treatment (weak recommendation, very-low-quality evidence). © 2017 European Sleep Research Society.

The Use of Signal-Transduction and Metabolic Pathways to Predict Human Disease Targets from Electric and Magnetic Fields Using in vitro Data in Human Cell Lines

PubMed Central

Parham, Fred; Portier, Christopher J.; Chang, Xiaoqing; Mevissen, Meike

2016-01-01

Using in vitro data in human cell lines, several research groups have investigated changes in gene expression in cellular systems following exposure to extremely low frequency (ELF) and radiofrequency (RF) electromagnetic fields (EMF). For ELF EMF, we obtained five studies with complete microarray data and three studies with only lists of significantly altered genes. Likewise, for RF EMF, we obtained 13 complete microarray datasets and 5 limited datasets. Plausible linkages between exposure to ELF and RF EMF and human diseases were identified using a three-step process: (a) linking genes associated with classes of human diseases to molecular pathways, (b) linking pathways to ELF and RF EMF microarray data, and (c) identifying associations between human disease and EMF exposures where the pathways are significantly similar. A total of 60 pathways were associated with human diseases, mostly focused on basic cellular functions like JAK–STAT signaling or metabolic functions like xenobiotic metabolism by cytochrome P450 enzymes. ELF EMF datasets were sporadically linked to human diseases, but no clear pattern emerged. Individual datasets showed some linkage to cancer, chemical dependency, metabolic disorders, and neurological disorders. RF EMF datasets were not strongly linked to any disorders but strongly linked to changes in several pathways. Based on these analyses, the most promising area for further research would be to focus on EMF and neurological function and disorders. PMID:27656641

Numerical evidences of universal trap-like aging dynamics

NASA Astrophysics Data System (ADS)

Cammarota, Chiara; Marinari, Enzo

2018-04-01

Trap models have been initially proposed as toy models for dynamical relaxation in extremely simplified rough potential energy landscapes. Their importance has recently grown considerably thanks to the discovery that the trap-like aging mechanism directly controls the out-of-equilibrium relaxation processes of more sophisticated spin models, that are considered as the solvable counterpart of real disordered systems. Further establishing the connection between these spin models, out-of-equilibrium behavior and the trap like aging mechanism could shed new light on the properties, which are still largely mysterious, for the activated out-of-equilibrium dynamics of disordered systems. In this work we discuss numerical evidence based on the computations of the permanence times of an emergent trap-like aging behavior in a variety of very simple disordered models—developed from the trap model paradigm. Our numerical results are backed by analytic derivations and heuristic discussions. Such exploration reveals some of the tricks needed to reveal the trap behavior in spite of the occurrence of secondary processes, of the existence of dynamical correlations and of strong finite system’s size effects.

Dual-Gate Modulation of Carrier Density and Disorder in an Oxide Two-Dimensional Electron System

DOE PAGES

Chen, Zhuoyu; Yuan, Hongtao; Xie, Yanwu; ...

2016-09-08

Carrier density and disorder are two crucial parameters that control the properties of correlated two-dimensional electron systems. Furthermore, in order to disentangle their individual contributions to quantum phenomena, independent tuning of these two parameters is required. By utilizing a hybrid liquid/solid electric dual-gate geometry acting on the conducting LaAlO 3/SrTiO 3 heterointerface, we obtain an additional degree of freedom to strongly modify the electron confinement profile and thus the strength of interfacial scattering, independent from the carrier density. A dual-gate controlled nonlinear Hall effect is a direct manifestation of this profile, which can be quantitatively understood by a Poisson–Schrödinger sub-bandmore » model. In particular, the large nonlinear dielectric response of SrTiO 3 enables a very wide range of tunable density and disorder, far beyond that for conventional semiconductors. This study provides a broad framework for understanding various reported phenomena at the LaAlO 3/SrTiO 3 interface.« less

Sign phase transition in the problem of interfering directed paths

NASA Astrophysics Data System (ADS)

Baldwin, C. L.; Laumann, C. R.; Spivak, B.

2018-01-01

We investigate the statistical properties of interfering directed paths in disordered media. At long distance, the average sign of the sum over paths may tend to zero (sign disordered) or remain finite (sign ordered) depending on dimensionality and the concentration of negative scattering sites x . We show that in two dimensions the sign-ordered phase is unstable even for arbitrarily small x by identifying rare destabilizing events. In three dimensions, we present strong evidence that there is a sign phase transition at a finite xc>0 . These results have consequences for several different physical systems. In two-dimensional insulators at low temperature, the variable-range-hopping magnetoresistance is always negative, while in three dimensions, it changes sign at the point of the sign phase transition. We also show that in the sign-disordered regime a small magnetic field may enhance superconductivity in a random system of D -wave superconducting grains embedded in a metallic matrix. Finally, the existence of the sign phase transition in three dimensions implies new features in the spin-glass phase diagram at high temperature.

Metal insulator transitions in perovskite SrIrO{sub 3} thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biswas, Abhijit; Jeong, Yoon Hee, E-mail: yhj@postech.ac.kr; Kim, Ki-Seok

Understanding of metal insulator transitions in a strongly correlated system, driven by Anderson localization (disorder) and/or Mott localization (correlation), is a long standing problem in condensed matter physics. The prevailing fundamental question would be how these two mechanisms contrive to accomplish emergent anomalous behaviors. Here, we have grown high quality perovskite SrIrO{sub 3} thin films, containing a strong spin orbit coupled 5d element Ir, on various substrates such as GdScO{sub 3} (110), DyScO{sub 3} (110), SrTiO{sub 3} (001), and NdGaO{sub 3} (110) with increasing lattice mismatch, in order to carry out a systematic study on the transport properties. We foundmore » that metal insulator transitions can be induced in this system; by either reducing thickness (on best lattice matched substrate) or changing degree of lattice strain (by lattice mismatch between film and substrates) of films. Surprisingly these two pathways seek two distinct types of metal insulator transitions; the former falls into disorder driven Anderson type whereas the latter turns out to be of unconventional Mott-Anderson type with the interplay of disorder and correlation. More interestingly, in the metallic phases of SrIrO{sub 3}, unusual non-Fermi liquid characteristics emerge in resistivity as Δρ ∝ T{sup ε} with ε evolving from 4/5 to 1 to 3/2 with increasing lattice strain. We discuss theoretical implications of these phenomena to shed light on the metal insulator transitions.« less

Gender identity disorder. Is this a potentially fatal condition?

PubMed

Yousafzai, Abdul Wahab; Bhutto, Naila

2007-01-01

A person with a Gender Identity Disorder (GID) is a person who strongly identifies with the other sex. The individual may identify with the opposite sex to the point of believing that he/she is, in fact, a member of the other sex who is trapped in the wrong body. The treatment option is sex reassignment surgery. In Pakistan There is no specialized facility sex reassignment surgery. This case report deals with possible serious outcome of GID in Pakistan as a result of castration procedure which is carried out by 'gurus' in Pakistan. A systemic research in our country to this effect is required to find out the outcome of GID in Pakistan.

Long-Range Pre-Thermal Time Crystals

NASA Astrophysics Data System (ADS)

Machado, Francisco; Else, Dominic V.; Nayak, Chetan; Yao, Norman

Driven quantum systems have recently enabled the realization of a discrete time crystal - an intrinsically out-of-equilibrium phase of matter that spontaneously breaks time translation symmetry. One strategy to prevent the drive-induced, runaway heating of the time crystal phase is the presence of strong disorder leading to many-body localization. A simpler disorder-less approach is to work in the pre-thermal regime where time crystalline order can persist to long times, before ultimately being destroyed by thermalization. In this talk, we will consider the interplay between long-range interactions, dimensionality, and pre-thermal time-translation symmetry breaking. As an example, we will consider the phase diagram of a 1D long-range pre-thermal time crystal.

Statistics of Lyapunov exponents of quasi-one-dimensional disordered systems

NASA Astrophysics Data System (ADS)

Zhang, Yan-Yang; Xiong, Shi-Jie

2005-10-01

Statistical properties of Lyapunov exponents (LE) are numerically calculated in a quasi-one-dimensional (1D) Anderson model, which is in a 2D or 3D lattice with a finite cross section. The single-parameter scaling (SPS) variable τ relating the Lyapunov exponents γ and their variances σ by τ≡σ2L/⟨γ⟩ is calculated for different lateral coupling t and disorder strength W . In a wide range of t , τ is approximately independent of W , but it has different values for LEs in different channels. For small t , the distribution of the smallest LE is non-Gaussian and τ strongly depends on W , remarkably different from the 1D SPS hypothesis.

Functional anthology of intrinsic disorder. 3. Ligands, post-translational modifications, and diseases associated with intrinsically disordered proteins.

PubMed

Xie, Hongbo; Vucetic, Slobodan; Iakoucheva, Lilia M; Oldfield, Christopher J; Dunker, A Keith; Obradovic, Zoran; Uversky, Vladimir N

2007-05-01

Currently, the understanding of the relationships between function, amino acid sequence, and protein structure continues to represent one of the major challenges of the modern protein science. As many as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bionformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200 000 proteins from the Swiss-Prot database, each annotated with at least one of the 875 functional keywords, was described in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V.N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Using this tool, we have found that out of the 710 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (see above). The second paper of the series was devoted to the presentation of 87 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes, and coding sequence diversities possessing strong positive and negative correlation with long disordered regions (Vucetic, S.; Xie, H.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V. N. Functional anthology of intrinsic disorder. 2. Cellular components, domains, technical terms, developmental processes, and coding sequence diversities correlated with long disordered regions. J. Proteome Res. 2007, 5, 1899-1916). Protein structure and functionality can be modulated by various post-translational modifications or/and as a result of binding of specific ligands. Numerous human diseases are associated with protein misfolding/misassembly/misfunctioning. This work concludes the series of papers dedicated to the functional anthology of intrinsic disorder and describes approximately 80 Swiss-Prot functional keywords that are related to ligands, post-translational modifications, and diseases possessing strong positive or negative correlation with the predicted long disordered regions in proteins.

Seizures and Epilepsy and Their Relationship to Autism Spectrum Disorders

ERIC Educational Resources Information Center

Matson, Johnny L.; Neal, Daniene

2009-01-01

Autism spectrum disorders (ASD) are serious neurodevelopmental disorders which often co-occur with intellectual disabilities. A disorder which is strongly correlated with both of these disabilities are seizures and epilepsy. The purpose of this review was to provide an overview of available research on seizures and epilepsy in the ASD population…

Rapid onset of comorbidity of common mental disorders: findings from the Netherlands Mental Health Survey and Incidence Study (NEMESIS).

PubMed

de Graaf, R; Bijl, R V; ten Have, M; Beekman, A T F; Vollebergh, W A M

2004-01-01

In a cohort of subjects with no history of psychopathology, we determined a 3-year incidence and the risk factors of comorbid and pure mood, anxiety and substance use disorders. Data were obtained from the Netherlands Mental Health Survey and Incidence Study (NEMESIS), a longitudinal community study in which 4796 adults were interviewed in 1996, 1997 and 1999 with the Composite International Diagnostic Interview. Of 2869 cases at risk, 10.8% developed an incident disorder within 3 years, of which 16.1% was comorbid. Neuroticism, childhood trauma and parental psychiatric history were more strongly associated with comorbid than with pure disorders. No differences emerged in events occurring in the first year after baseline, but events in the period thereafter showed markedly stronger associations with comorbidity and pure mood disorder than with pure anxiety and substance use disorder. Functional disability was also linked more strongly to comorbidity and pure mood disorder. Clear risk factors exist for the rapid onset of comorbidity. Interventions are needed to prevent rapid comorbidity in subjects who recently developed a primary disorder.

Effect of site disorder on the ground state of a frustrated spin dimer quantum magnet

NASA Astrophysics Data System (ADS)

Hristov, Alexander; Shapiro, Maxwell; Lee, Minseong; Rodenbach, Linsey; Choi, Eun Sang; Park, Ju-Hyun; Munsie, Tim; Luke, Graeme; Fisher, Ian

Ba3Mn2O8 is a geometrically frustrated spin dimer quantum magnet. Pairs of Mn 5+ (S = 1) ions are strongly coupled via antiferromagnetic exchange to yield a singlet ground state, with excited triplet and quintuplet states. Isovalent substitution of V5+ (S = 0) for Mn breaks dimers, resulting in unpaired S = 1 spins, the ground state of which is investigated here for compositions spanning the range 0 <= x <= 1 of Ba3(Mn1-xVx)2O8. From a theoretical perspective, for dimers occupying an unfrustrated bipartite lattice, such site disorder is anticipated to yield long range magnetism for unpaired Mn spins both in the dilute limit where x is small, a phenomena known as order-by-disorder, and in the proximity of x = 1 / 2 where the system is maximally disordered and close to a percolation threshold. In this frustrated system, however, our experiments find evidence of spin freezing for six compositions 0 . 05 <= x <= 0 . 85 . In this regime, we find entropy removed at an energy scale independent of the freezing temperature. We discuss the possibility of a spin-glass to random singlet transition for critical compositions in the two dilute limits x -> 0 and x -> 1 . NSF DMR-Award 1205165.

Quasiclassical theory of disordered multi-channel Majorana quantum wires

NASA Astrophysics Data System (ADS)

Neven, Patrick; Bagrets, Dmitry; Altland, Alexander

2013-05-01

Multi-channel spin-orbit quantum wires, when subjected to a magnetic field and proximity coupled to an s-wave superconductor, may support Majorana states. We study what happens to these systems in the presence of disorder. Inspired by the widely established theoretical methods of mesoscopic superconductivity, we develop á la Eilenberger a quasiclassical approach to topological nanowires valid in the limit of strong spin-orbit coupling. We find that the ‘Majorana number’ {\\cal M} , distinguishing between the state with Majorana fermions (symmetry class B) and no Majorana fermions (class D), is given by the product of two Pfaffians of gapped quasiclassical Green's functions fixed by the right and left terminals connected to the wire. A numerical solution of the Eilenberger equations reveals that the class D disordered quantum wires are prone to the formation of the zero-energy anomaly (class D impurity spectral peak) in the local density of states that shares the key features of the Majorana peak. In this way, we confirm the robustness of our previous conclusions (Bagrets and Altland 2012 Phys. Rev. Lett. 109 227005) on a more restrictive system setup. Generally speaking, we find that the quasiclassical approach provides a highly efficient means to address disordered class D superconductors both in the presence and in the absence of topological structures.

Primary care access for mental illness in Australia: Patterns of access to general practice from 2006 to 2016.

PubMed

Farrer, Louise M; Walker, Jennie; Harrison, Christopher; Banfield, Michelle

2018-01-01

General practice has an important role within the Australian healthcare system to provide access to care and effective management of chronic health conditions. However, people with serious mental illness experience challenges associated with service access. The current paper seeks to examine drivers of access to general practice for people with common and serious mental disorders, compared with people who access care for type II diabetes, a common physical health problem managed in general practice. The Bettering the Evaluation and Care of Health (BEACH) programme provides the most comprehensive and objective measurement of general practitioner activity in Australia. Using BEACH data, this study compared general practice encounters for depression, anxiety, bipolar disorder, schizophrenia, and type II diabetes during a 10-year period between 2006 and 2016. Analysis revealed more frequent encounters for depression compared to anxiety, and a higher representation of women in encounters for bipolar disorder compared to men. The relationship between number of encounters and patient age was strongly associated with the life course and mortality characteristics associated with each disorder. The findings highlight specific challenges associated with access to primary care for people with serious mental illness, and suggest areas of focus to improve the ability of these patients to access and navigate the health system.

[Studies of time-course changes in human body balance after ingestion of long-acting hypnotics].

PubMed

Nakamura, Masahiro; Ishii, Masanori; Niwa, Yoji; Yamazaki, Momoko; Ito, Hiroshi

2004-02-01

Falling accidents are a serious nocosomial problem, with balance disorders after the ingestion of hypnotics said to be a cause. Based on the results of animal studies, it was postulated that this problem involves the muscle relaxation that is a pharmacological effect of benzodiazepines (BZP). No reports have, to our knowledge, been made of time-course changes in human body balance after ingestion of hypnotics. Accordingly, we used quazepam (Doral), a long-acting hypnotic considered to show comparatively weak muscle relaxation, to study static balance after drug ingestion in human volunteers. Briefly, informed consent was obtained from 8 healthy adults, then a gait analytic system (Gangas) was used to test static balance after drug ingestion (Mann and Romberg tests). We also measured circulating drug concentration over time. Our results showed that balance disorders occurred after quazepam ingestion with an unstable posture particularly striking. Given the function of quazepam receptors, it is difficult to surmise that balance disorders after drug ingestion were due to the drug's muscle relaxation. We surmised that inhibition from the central nervous system in connection with nerves awakening was involved. We found a strong correlation between the manifestation of balance disorders after drug ingestion and circulating drug concentration.

Stability and instability towards delocalization in many-body localization systems

NASA Astrophysics Data System (ADS)

De Roeck, Wojciech; Huveneers, François

2017-04-01

We propose a theory that describes quantitatively the (in)stability of fully many-body localization (MBL) systems due to ergodic, i.e., delocalized, grains, that can be, for example, due to disorder fluctuations. The theory is based on the ETH hypothesis and elementary notions of perturbation theory. The main idea is that we assume as much chaoticity as is consistent with conservation laws. The theory describes correctly—even without relying on the theory of local integrals of motion (LIOM)—the MBL phase in one dimension at strong disorder. It yields an explicit and quantitative picture of the spatial boundary between localized and ergodic systems. We provide numerical evidence for this picture. When the theory is taken to its extreme logical consequences, it predicts that the MBL phase is destabilised in the long time limit whenever (1) interactions decay slower than exponentially in d =1 and (2) always in d >1 . Finer numerics is required to assess these predictions.

Pathogenesis of depression: insights from human and rodent studies

PubMed Central

MÉNARD, Caroline; HODES, Georgia E.; RUSSO, Scott J.

2015-01-01

Major depressive disorder (MDD) will affect one out of every five people in their lifetime and is the leading cause of disability worldwide. Nevertheless, mechanisms associated with the pathogenesis of MDD have yet to be completely understood and current treatments remain ineffective in a large subset of patients. In this review, we summarize the most recent discoveries and insights for which parallel findings have been obtained in human depressed subjects and rodent models of mood disorders in order to examine the potential etiology of depression. These mechanisms range from synaptic plasticity mechanisms to epigenetics and the immune system where there is strong evidence to support a functional role in the development of specific depression symptomology. Ultimately we conclude by discussing how novel therapeutic strategies targeting central and peripheral processes might ultimately aid in the development of effective new treatments for MDD and related stress disorders. PMID:26037806

[Dopamine neurotransmission of peripheral blood lymphocytes is a potential biomarker of psychiatric and neurological disorders].

PubMed

Taraskina, A E; Nasyrova, R F; Grunina, M N; Zabotina, A M; Ivashchenko, D V; Ershov, E E; Sosin, D N; Kirnichnaya, K A; Ivanov, M V; Krupitsky, E M

2015-01-01

Current literature on a role of dopamine in the development of mental and neurological disorders suggests that the discovery of endogenous dopamine in peripheral blood lymphocytes gave rise to a new line of research. Dopamine receptors are not only found on cells of the innate immune response (nonspecific), but also on cells of adaptive immune response (specific): T and B lymphocytes. These facts bring a new evidence of interrelationships between the peripheral immune system, neuroinflammation and neurodegeneration and suggest new ways for investigation of the pathogenesis of different mental and neurological disorders, in particular Parkinson's disease, Alzheimer's disease and schizophrenia. There is strong evidence that ligands of dopamine receptors can change the expression of coding genes both in central neurons and in peripheral cells. Thus, peripheral blood lymphocytes may prove a cellular tool to identify dopamine transmission disturbances in neuropsychiatric diseases, as well as to monitor the effects of pharmacological treatment.

Cortical activity and children's rituals, habits and other repetitive behavior: a visual P300 study.

PubMed

Evans, David W; Maliken, Ashley

2011-10-10

This study examines the link between children's repetitive, ritualistic, behavior and cortical brain activity. Twelve typically developing children between the ages of 6 and 12 years were administered two visual P300, oddball tasks with a 32-electrode electroencephalogram (EEG) system. One of the oddball tasks was specifically designed to reflect sensitivity to asymmetry, a phenomenon common in children and in a variety of disorders involving compulsive behavior. Parents completed the Childhood Routines Inventory. Children's repetitive, compulsive-like behaviors were strongly associated with faster processing of an asymmetrical target stimulus, even when accounting for their P300 latencies on a control task. The research punctuates the continuity between observed brain-behavior links in clinical disorders such as OCD and autism spectrum disorders, and normative variants of repetitive behavior. Copyright © 2011 Elsevier B.V. All rights reserved.

Pervasive pleiotropy between psychiatric disorders and immune disorders revealed by integrative analysis of multiple GWAS

PubMed Central

Wang, Qian; Yang, Can; Gelernter, Joel; Zhao, Hongyu

2015-01-01

Although some existing epidemiological observations and molecular experiments suggested that brain disorders in the realm of psychiatry may be influenced by immune dysregulation, the degree of genetic overlap between psychiatric disorders and immune disorders has not been well established. We investigated this issue by integrative analysis of genome-wide association studies of 18 complex human traits/diseases (five psychiatric disorders, seven immune disorders, and others) and multiple genome-wide annotation resources (Central nervous system genes, immune-related expression-quantitative trait loci (eQTL) and DNase I hypertensive sites from 98 cell-lines). We detected pleiotropy in 24 of the 35 psychiatric-immune disorder pairs. The strongest pleiotropy was observed for schizophrenia-rheumatoid arthritis with MHC region included in the analysis (p = 3.9 × 10−285), and schizophrenia-Crohns disease with MHC region excluded (p = 1.1 × 10−36). Significant enrichment (>1.4 fold) of immune-related eQTL was observed in four psychiatric disorders. Genomic regions responsible for pleiotropy between psychiatric disorders and immune disorders were detected. The MHC region on chromosome 6 appears to be the most important with other regions, such as cytoband 1p13.2, also playing significant roles in pleiotropy. We also found that most alleles shared between schizophrenia and Crohns disease have the same effect direction, with similar trend found for other disorder pairs, such as bipolar-Crohn’s disease. Our results offer a novel birds-eye view of the genetic relationship and demonstrate strong evidence for pervasive pleiotropy between psychiatric disorders and immune disorders. Our findings might open new routes for prevention and treatment strategies for these disorders based on a new appreciation of the importance of immunological mechanisms in mediating risk of many psychiatric diseases. PMID:26340901

The Spleen: A Hub Connecting Nervous and Immune Systems in Cardiovascular and Metabolic Diseases

PubMed Central

Lori, Andrea; Perrotta, Marialuisa; Lembo, Giuseppe; Carnevale, Daniela

2017-01-01

Metabolic disorders have been identified as major health problems affecting a large portion of the world population. In addition, obesity and insulin resistance are principal risk factors for the development of cardiovascular diseases. Altered immune responses are common features of both hypertension and obesity and, moreover, the involvement of the nervous system in the modulation of immune system is gaining even more attention in both pathophysiological contexts. For these reasons, during the last decades, researches focused their efforts on the comprehension of the molecular mechanisms connecting immune system to cardiovascular and metabolic diseases. On the other hand, it has been reported that in these pathological conditions, central neural pathways modulate the activity of the peripheral nervous system, which is strongly involved in onset and progression of the disease. It is interesting to notice that neural reflex can also participate in the modulation of immune functions. In this scenario, the spleen becomes the crucial hub allowing the interaction of different systems differently involved in metabolic and cardiovascular diseases. Here, we summarize the major findings that dissect the role of the immune system in disorders related to metabolic and cardiovascular dysfunctions, and how this could also be influenced by neural reflexes. PMID:28590409

Functional Anthology of Intrinsic Disorder. I. Biological Processes and Functions of Proteins with Long Disordered Regions

PubMed Central

Xie, Hongbo; Vucetic, Slobodan; Iakoucheva, Lilia M.; Oldfield, Christopher J.; Dunker, A. Keith; Uversky, Vladimir N.; Obradovic, Zoran

2008-01-01

Identifying relationships between function, amino acid sequence and protein structure represents a major challenge. In this study we propose a bioinformatics approach that identifies functional keywords in the Swiss-Prot database that correlate with intrinsic disorder. A statistical evaluation is employed to rank the significance of these correlations. Protein sequence data redundancy and the relationship between protein length and protein structure were taken into consideration to ensure the quality of the statistical inferences. Over 200,000 proteins from Swiss-Prot database were analyzed using this approach. The predictions of intrinsic disorder were carried out using PONDR VL3E predictor of long disordered regions that achieves an accuracy of above 86%. Overall, out of the 710 Swiss-Prot functional keywords that were each associated with at least 20 proteins, 238 were found to be strongly positively correlated with predicted long intrinsically disordered regions, whereas 302 were strongly negatively correlated with such regions. The remaining 170 keywords were ambiguous without strong positive or negative correlation with the disorder predictions. These functions cover a large variety of biological activities and imply that disordered regions are characterized by a wide functional repertoire. Our results agree well with literature findings, as we were able to find at least one illustrative example of functional disorder or order shown experimentally for the vast majority of keywords showing the strongest positive or negative correlation with intrinsic disorder. This work opens a series of three papers, which enriches the current view of protein structure-function relationships, especially with regards to functionalities of intrinsically disordered proteins and provides researchers with a novel tool that could be used to improve the understanding of the relationships between protein structure and function. The first paper of the series describes our statistical approach, outlines the major findings and provides illustrative examples of biological processes and functions positively and negatively correlated with intrinsic disorder. PMID:17391014

Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions.

PubMed

Xie, Hongbo; Vucetic, Slobodan; Iakoucheva, Lilia M; Oldfield, Christopher J; Dunker, A Keith; Uversky, Vladimir N; Obradovic, Zoran

2007-05-01

Identifying relationships between function, amino acid sequence, and protein structure represents a major challenge. In this study, we propose a bioinformatics approach that identifies functional keywords in the Swiss-Prot database that correlate with intrinsic disorder. A statistical evaluation is employed to rank the significance of these correlations. Protein sequence data redundancy and the relationship between protein length and protein structure were taken into consideration to ensure the quality of the statistical inferences. Over 200,000 proteins from the Swiss-Prot database were analyzed using this approach. The predictions of intrinsic disorder were carried out using PONDR VL3E predictor of long disordered regions that achieves an accuracy of above 86%. Overall, out of the 710 Swiss-Prot functional keywords that were each associated with at least 20 proteins, 238 were found to be strongly positively correlated with predicted long intrinsically disordered regions, whereas 302 were strongly negatively correlated with such regions. The remaining 170 keywords were ambiguous without strong positive or negative correlation with the disorder predictions. These functions cover a large variety of biological activities and imply that disordered regions are characterized by a wide functional repertoire. Our results agree well with literature findings, as we were able to find at least one illustrative example of functional disorder or order shown experimentally for the vast majority of keywords showing the strongest positive or negative correlation with intrinsic disorder. This work opens a series of three papers, which enriches the current view of protein structure-function relationships, especially with regards to functionalities of intrinsically disordered proteins, and provides researchers with a novel tool that could be used to improve the understanding of the relationships between protein structure and function. The first paper of the series describes our statistical approach, outlines the major findings, and provides illustrative examples of biological processes and functions positively and negatively correlated with intrinsic disorder.

Localization in a quantum spin Hall system.

PubMed

Onoda, Masaru; Avishai, Yshai; Nagaosa, Naoto

2007-02-16

The localization problem of electronic states in a two-dimensional quantum spin Hall system (that is, a symplectic ensemble with topological term) is studied by the transfer matrix method. The phase diagram in the plane of energy and disorder strength is exposed, and demonstrates "levitation" and "pair annihilation" of the domains of extended states analogous to that of the integer quantum Hall system. The critical exponent nu for the divergence of the localization length is estimated as nu congruent with 1.6, which is distinct from both exponents pertaining to the conventional symplectic and the unitary quantum Hall systems. Our analysis strongly suggests a different universality class related to the topology of the pertinent system.

Dynamic Nuclear Polarization and the Paradox of Quantum Thermalization.

PubMed

De Luca, Andrea; Rosso, Alberto

2015-08-21

Dynamic nuclear polarization (DNP) is to date the most effective technique to increase the nuclear polarization opening disruptive perspectives for medical applications. In a DNP setting, the interacting spin system is quasi-isolated and brought out of equilibrium by microwave irradiation. Here we show that the resulting stationary state strongly depends on the ergodicity properties of the spin many-body eigenstates. In particular, the dipolar interactions compete with the disorder induced by local magnetic fields resulting in two distinct dynamical phases: while for weak interaction, only a small enhancement of polarization is observed, for strong interactions the spins collectively equilibrate to an extremely low effective temperature that boosts DNP efficiency. We argue that these two phases are intimately related to the problem of thermalization in closed quantum systems where a many-body localization transition can occur varying the strength of the interactions.

Entanglement Holographic Mapping of Many-Body Localized System by Spectrum Bifurcation Renormalization Group

NASA Astrophysics Data System (ADS)

You, Yi-Zhuang; Qi, Xiao-Liang; Xu, Cenke

We introduce the spectrum bifurcation renormalization group (SBRG) as a generalization of the real-space renormalization group for the many-body localized (MBL) system without truncating the Hilbert space. Starting from a disordered many-body Hamiltonian in the full MBL phase, the SBRG flows to the MBL fixed-point Hamiltonian, and generates the local conserved quantities and the matrix product state representations for all eigenstates. The method is applicable to both spin and fermion models with arbitrary interaction strength on any lattice in all dimensions, as long as the models are in the MBL phase. In particular, we focus on the 1 d interacting Majorana chain with strong disorder, and map out its phase diagram using the entanglement entropy. The SBRG flow also generates an entanglement holographic mapping, which duals the MBL state to a fragmented holographic space decorated with small blackholes.

Nontrivial Critical Fixed Point for Replica-Symmetry-Breaking Transitions.

PubMed

Charbonneau, Patrick; Yaida, Sho

2017-05-26

The transformation of the free-energy landscape from smooth to hierarchical is one of the richest features of mean-field disordered systems. A well-studied example is the de Almeida-Thouless transition for spin glasses in a magnetic field, and a similar phenomenon-the Gardner transition-has recently been predicted for structural glasses. The existence of these replica-symmetry-breaking phase transitions has, however, long been questioned below their upper critical dimension, d_{u}=6. Here, we obtain evidence for the existence of these transitions in d

White Matter Tract Integrity in Alzheimer's Disease vs. Late Onset Bipolar Disorder and Its Correlation with Systemic Inflammation and Oxidative Stress Biomarkers.

PubMed

Besga, Ariadna; Chyzhyk, Darya; Gonzalez-Ortega, Itxaso; Echeveste, Jon; Graña-Lecuona, Marina; Graña, Manuel; Gonzalez-Pinto, Ana

2017-01-01

Background: Late Onset Bipolar Disorder (LOBD) is the development of Bipolar Disorder (BD) at an age above 50 years old. It is often difficult to differentiate from other aging dementias, such as Alzheimer's Disease (AD), because they share cognitive and behavioral impairment symptoms. Objectives: We look for WM tract voxel clusters showing significant differences when comparing of AD vs. LOBD, and its correlations with systemic blood plasma biomarkers (inflammatory, neurotrophic factors, and oxidative stress). Materials: A sample of healthy controls (HC) ( n = 19), AD patients ( n = 35), and LOBD patients ( n = 24) was recruited at the Alava University Hospital. Blood plasma samples were obtained at recruitment time and analyzed to extract the inflammatory, oxidative stress, and neurotrophic factors. Several modalities of MRI were acquired for each subject, Methods: Fractional anisotropy (FA) coefficients are obtained from diffusion weighted imaging (DWI). Tract based spatial statistics (TBSS) finds FA skeleton clusters of WM tract voxels showing significant differences for all possible contrasts between HC, AD, and LOBD. An ANOVA F -test over all contrasts is carried out. Results of F -test are used to mask TBSS detected clusters for the AD > LOBD and LOBD > AD contrast to select the image clusters used for correlation analysis. Finally, Pearson's correlation coefficients between FA values at cluster sites and systemic blood plasma biomarker values are computed. Results: The TBSS contrasts with by ANOVA F -test has identified strongly significant clusters in the forceps minor, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and cingulum gyrus. The correlation analysis of these tract clusters found strong negative correlation of AD with the nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) blood biomarkers. Negative correlation of AD and positive correlation of LOBD with inflammation biomarker IL6 was also found. Conclusion: TBSS voxel clusters tract atlas localizations are consistent with greater behavioral impairment and mood disorders in LOBD than in AD. Correlation analysis confirms that neurotrophic factors (i.e., NGF, BDNF) play a great role in AD while are absent in LOBD pathophysiology. Also, correlation results of IL1 and IL6 suggest stronger inflammatory effects in LOBD than in AD.

Functional Anthology of Intrinsic Disorder. III. Ligands, Postranslational Modifications and Diseases Associated with Intrinsically Disordered Proteins

PubMed Central

Xie, Hongbo; Vucetic, Slobodan; Iakoucheva, Lilia M.; Oldfield, Christopher J.; Dunker, A. Keith; Obradovic, Zoran; Uversky, Vladimir N.

2008-01-01

Currently, the understanding of the relationships between function, amino acid sequence and protein structure continues to represent one of the major challenges of the modern protein science. As much as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bioinformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200,000 proteins from Swiss-Prot database, each annotated with at least one of the 875 functional keywords was described in the first paper of this series (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. I. Biological processes and functions of proteins with long disordered regions. J. Proteome Res.). Using this tool, we have found that out of the 711 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. I. Biological processes and functions of proteins with long disordered regions. J. Proteome Res.). The second paper of the series was devoted to the presentation of 87 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes and coding sequence diversities possessing strong positive and negative correlation with long disordered regions (Vucetic S., Xie H., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. II. Cellular components, domains, technical terms, developmental processes and coding sequence diversities correlated with long disordered regions. J. Proteome Res.). Protein structure and functionality can be modulated by various posttranslational modifications or/and as a result of binding of specific ligands. Numerous human diseases are associated with protein misfolding/misassembly/ misfunctioning. This work concludes the series of papers dedicated to the functional anthology of intrinsic disorder and describes ~80 Swiss-Prot functional keywords that are related to ligands, posttranslational modifications and diseases possessing strong positive or negative correlation with the predicted long disordered regions in proteins. PMID:17391016

Public beliefs about treatment and outcome of mental disorders: a comparison of Australia and Japan

PubMed Central

Jorm, Anthony F; Nakane, Yoshibumi; Christensen, Helen; Yoshioka, Kumiko; Griffiths, Kathleen M; Wata, Yuji

2005-01-01

Background Surveys of the public in a number of countries have shown poor recognition of mental disorders and beliefs about treatment that often diverge from those of health professionals. This lack of mental health literacy can limit the optimal use of treatment services. Australia and Japan are countries with very different mental health care systems, with Japan emphasising hospital care and Australia more oriented to community care. Japan is also more collectivist and Australia more individualist in values. These differences might influence recognition of disorders and beliefs about treatment in the two countries. Methods Surveys of the public were carried out in each country using as similar a methodology as feasible. In both countries, household interviews were carried out concerning beliefs in relation to one of four case vignettes, describing either depression, depression with suicidal thoughts, early schizophrenia or chronic schizophrenia. In Australia, the survey involved a national sample of 3998 adults aged 18 years or over. In Japan, the survey involved 2000 adults aged between 20 and 69 from 25 regional sites spread across the country. Results The Japanese public were found to be more reluctant to use psychiatric labels, particularly for the depression cases. The Japanese were also more reluctant to discuss mental disorders with others outside the family. They had a strong belief in counsellors, but not in GPs. They generally believe in the benefits of treatment, but are not optimistic about full recovery. By contrast, Australians used psychiatric labels more often, particularly "depression". They were also more positive about the benefits of seeking professional help, but had a strong preference for lifestyle interventions and tended to be negative about some psychiatric medications. Australians were positive about both counsellors and GPs. Psychiatric hospitalization and ECT were seen negatively in both countries. Conclusion There are some major differences between Australia and Japan in recognition of disorders and beliefs about treatment. Some of these may relate to the different health care systems, but the increasing openness about mental health in Australia is also likely to be an explanatory factor. PMID:16004615

Comorbidities in the diseasome are more apparent than real: What Bayesian filtering reveals about the comorbidities of depression

PubMed Central

Bolgar, Bence; Deakin, Bill

2017-01-01

Comorbidity patterns have become a major source of information to explore shared mechanisms of pathogenesis between disorders. In hypothesis-free exploration of comorbid conditions, disease-disease networks are usually identified by pairwise methods. However, interpretation of the results is hindered by several confounders. In particular a very large number of pairwise associations can arise indirectly through other comorbidity associations and they increase exponentially with the increasing breadth of the investigated diseases. To investigate and filter this effect, we computed and compared pairwise approaches with a systems-based method, which constructs a sparse Bayesian direct multimorbidity map (BDMM) by systematically eliminating disease-mediated comorbidity relations. Additionally, focusing on depression-related parts of the BDMM, we evaluated correspondence with results from logistic regression, text-mining and molecular-level measures for comorbidities such as genetic overlap and the interactome-based association score. We used a subset of the UK Biobank Resource, a cross-sectional dataset including 247 diseases and 117,392 participants who filled out a detailed questionnaire about mental health. The sparse comorbidity map confirmed that depressed patients frequently suffer from both psychiatric and somatic comorbid disorders. Notably, anxiety and obesity show strong and direct relationships with depression. The BDMM identified further directly co-morbid somatic disorders, e.g. irritable bowel syndrome, fibromyalgia, or migraine. Using the subnetwork of depression and metabolic disorders for functional analysis, the interactome-based system-level score showed the best agreement with the sparse disease network. This indicates that these epidemiologically strong disease-disease relations have improved correspondence with expected molecular-level mechanisms. The substantially fewer number of comorbidity relations in the BDMM compared to pairwise methods implies that biologically meaningful comorbid relations may be less frequent than earlier pairwise methods suggested. The computed interactive comprehensive multimorbidity views over the diseasome are available on the web at Co=MorNet: bioinformatics.mit.bme.hu/UKBNetworks. PMID:28644851

Posttraumatic stress disorder and suicide in 5.9 million individuals receiving care in the veterans health administration health system.

PubMed

Conner, Kenneth R; Bossarte, Robert M; He, Hua; Arora, Jyoti; Lu, Naiji; Tu, Xin M; Katz, Ira R

2014-09-01

Post-traumatic stress disorder (PTSD) confers risk for suicidal ideation and suicide attempts but a link with suicide is not yet established. Prior analyses of users of the Veterans health administration (VHA) Health System suggest that other mental disorders strongly influence the association between PTSD and suicide in this population. We examined the association between PTSD and suicide in VHA users, with a focus on the influence of other mental disorders. Data were based on linkage of VA National Patient Care Database records and the Centers for Disease Control and Prevention׳s National Death Index, with data from fiscal year 2007-2008. Analyses were based on multivariate logistic regression and structural equation models. Among users of VHA services studied (N=5,913,648), 0.6% (N=3620) died by suicide, including 423 who had had been diagnosed with PTSD. In unadjusted analysis, PTSD was associated with increased risk for suicide, with odds ratio, OR (95% confidence interval, 95% CI)=1.34 (1.21, 1.48). Similar results were obtained after adjustment for demographic variables and veteran characteristics. After adjustment for multiple other mental disorder diagnoses, PTSD was associated with decreased risk for suicide, OR (95% CI)=0.77 (0.69, 0.86). Major depressive disorder (MDD) had the largest influence on the association between PTSD and suicide. The analyses were cross-sectional. VHA users were studied, with unclear relevance to other populations. The findings suggest the importance of identifying and treating comorbid MDD and other mental disorders in VHA users diagnosed with PTSD in suicide prevention efforts. Published by Elsevier B.V.

A meta-analysis of perceptions of defeat and entrapment in depression, anxiety problems, posttraumatic stress disorder, and suicidality.

PubMed

Siddaway, Andy P; Taylor, Peter J; Wood, Alex M; Schulz, Joerg

2015-09-15

There is a burgeoning literature examining perceptions of being defeated or trapped in different psychiatric disorders. The disorders most frequently examined to date are depression, anxiety problems, posttraumatic stress disorder (PTSD), and suicidality. To quantify the size and consistency of perceptions of defeat and entrapment in depression, anxiety problems, PTSD and suicidality, test for differences across psychiatric disorders, and examine potential moderators and publication bias. Random-effects meta-analyses based on Pearson's correlation coefficient r. Forty studies were included in the meta-analysis (n = 10,072). Perceptions of defeat and entrapment were strong (around r = 0.60) and similar in size across all four psychiatric disorders. Perceptions of defeat were particularly strong in depression (r = 0.73). There was no between-study heterogeneity; therefore moderator analyses were conducted in an exploratory fashion. There was no evidence of publication bias. Analyses were cross-sectional, which precludes establishing temporal precedence or causality. Some of the meta-analyses were based on relatively small numbers of effect sizes, which may limit their generalisability. Perceptions of defeat and entrapment are clinically important in depression, anxiety problems, PTSD, and suicidality. Similar-sized, strong relationships across four different psychiatric disorders could suggest that perceptions of defeat and entrapment are transdiagnostic constructs. The results suggest that clinicians and researchers need to become more aware of perceptions of defeat and entrapment. Copyright © 2015 Elsevier B.V. All rights reserved.

Measuring order in disordered systems and disorder in ordered systems: Random matrix theory for isotropic and nematic liquid crystals and its perspective on pseudo-nematic domains

NASA Astrophysics Data System (ADS)

Zhao, Yan; Stratt, Richard M.

2018-05-01

Surprisingly long-ranged intermolecular correlations begin to appear in isotropic (orientationally disordered) phases of liquid crystal forming molecules when the temperature or density starts to close in on the boundary with the nematic (ordered) phase. Indeed, the presence of slowly relaxing, strongly orientationally correlated, sets of molecules under putatively disordered conditions ("pseudo-nematic domains") has been apparent for some time from light-scattering and optical-Kerr experiments. Still, a fully microscopic characterization of these domains has been lacking. We illustrate in this paper how pseudo-nematic domains can be studied in even relatively small computer simulations by looking for order-parameter tensor fluctuations much larger than one would expect from random matrix theory. To develop this idea, we show that random matrix theory offers an exact description of how the probability distribution for liquid-crystal order parameter tensors converges to its macroscopic-system limit. We then illustrate how domain properties can be inferred from finite-size-induced deviations from these random matrix predictions. A straightforward generalization of time-independent random matrix theory also allows us to prove that the analogous random matrix predictions for the time dependence of the order-parameter tensor are similarly exact in the macroscopic limit, and that relaxation behavior of the domains can be seen in the breakdown of the finite-size scaling required by that random-matrix theory.

Risk of central nervous system defects in offspring of women with and without mental illness.

PubMed

Ayoub, Aimina; Fraser, William D; Low, Nancy; Arbour, Laura; Healy-Profitós, Jessica; Auger, Nathalie

2018-02-22

We sought to determine the relationship between maternal mental illness and the risk of having an infant with a central nervous system defect. We analyzed a cohort of 654,882 women aged less than 20 years between 1989 and 2013 who later delivered a live born infant in any hospital in Quebec, Canada. The primary exposure was mental illness during pregnancy or hospitalization for mental illness before pregnancy. The outcomes were neural and non-neural tube defects of the central nervous system in any offspring. We computed risk ratios (RR) and 95% confidence intervals (CI) for the association between mental disorders and risk of central nervous system defects in log-binomial regression models adjusted for age at delivery, total parity, comorbidity, socioeconomic deprivation, place of residence, and time period. Maternal mental illness was associated with an increased risk of nervous system defects in offspring (RR 1.76, 95% CI 1.64-1.89). Hospitalization for any mental disorder was more strongly associated with non-neural tube (RR 1.84, 95% CI 1.71-1.99) than neural tube defects (RR 1.31, 95% CI 1.08-1.59). Women at greater risk of nervous system defects in offspring tended to be diagnosed with multiple mental disorders, have more than one hospitalization for mental disease, or be 17 or older at first hospitalization. A history of mental illness is associated with central nervous system defects in offspring. Women hospitalized for mental illness may merit counseling at first symptoms to prevent central nervous system defects at pregnancy.

Eating Disorders, Autoimmune, and Autoinflammatory Disease.

PubMed

Zerwas, Stephanie; Larsen, Janne Tidselbak; Petersen, Liselotte; Thornton, Laura M; Quaranta, Michela; Koch, Susanne Vinkel; Pisetsky, David; Mortensen, Preben Bo; Bulik, Cynthia M

2017-12-01

Identifying factors associated with risk for eating disorders is important for clarifying etiology and for enhancing early detection of eating disorders in primary care. We hypothesized that autoimmune and autoinflammatory diseases would be associated with eating disorders in children and adolescents and that family history of these illnesses would be associated with eating disorders in probands. In this large, nationwide, population-based cohort study of all children and adolescents born in Denmark between 1989 and 2006 and managed until 2012, Danish medical registers captured all inpatient and outpatient diagnoses of eating disorders and autoimmune and autoinflammatory diseases. The study population included 930 977 individuals (48.7% girls). Cox proportional hazards regression models and logistic regression were applied to evaluate associations. We found significantly higher hazards of eating disorders for children and adolescents with autoimmune or autoinflammatory diseases: 36% higher hazard for anorexia nervosa, 73% for bulimia nervosa, and 72% for an eating disorder not otherwise specified. The association was particularly strong in boys. Parental autoimmune or autoinflammatory disease history was associated with significantly increased odds for anorexia nervosa (odds ratio [OR] = 1.13, confidence interval [CI] = 1.01-1.25), bulimia nervosa (OR = 1.29; CI = 1.08-1.55) and for an eating disorder not otherwise specified (OR = 1.27; CI = 1.13-1.44). Autoimmune and autoinflammatory diseases are associated with increased risk for eating disorders. Ultimately, understanding the role of immune system disturbance for the etiology and pathogenesis of eating disorders could point toward novel treatment targets. Copyright © 2017 by the American Academy of Pediatrics.

Coulomb spin liquid in anion-disordered pyrochlore Tb 2Hf 2O 7

DOE PAGES

Sibille, Romain; Lhotel, Elsa; Hatnean, Monica Ciomaga; ...

2017-10-12

Here, the charge ordered structure of ions and vacancies characterizing rare-earth pyrochlore oxides serves as a model for the study of geometrically frustrated magnetism. The organization of magnetic ions into networks of corner-sharing tetrahedra gives rise to highly correlated magnetic phases with strong fluctuations, including spin liquids and spin ices. It is an open question how these ground states governed by local rules are affected by disorder. Here we demonstrate in the pyrochlore Tb 2Hf 2O 7, that the vicinity of the disordering transition towards a defective fluorite structure translates into a tunable density of anion Frenkel disorder while cationsmore » remain ordered. Quenched random crystal fields and disordered exchange interactions can therefore be introduced into otherwise perfect pyrochlore lattices of magnetic ions. We show that disorder can play a crucial role in preventing long-range magnetic order at low temperatures, and instead induces a strongly fluctuating Coulomb spin liquid with defect-induced frozen magnetic degrees of freedom.« less

Do the surface Fermi arcs in Weyl semimetals survive disorder?

NASA Astrophysics Data System (ADS)

Wilson, Justin H.; Pixley, J. H.; Huse, David A.; Refael, Gil; Das Sarma, S.

2018-06-01

We theoretically study the topological robustness of the surface physics induced by Weyl Fermi-arc surface states in the presence of short-ranged quenched disorder and surface-bulk hybridization. This is investigated with numerically exact calculations on a lattice model exhibiting Weyl Fermi arcs. We find that the Fermi-arc surface states, in addition to having a finite lifetime from disorder broadening, hybridize with nonperturbative bulk rare states making them no longer bound to the surface (i.e., they lose their purely surface spectral character). Thus, we provide strong numerical evidence that the Weyl Fermi arcs are not topologically protected from disorder. Nonetheless, the surface chiral velocity is robust and survives in the presence of strong disorder, persisting all the way to the Anderson-localized phase by forming localized current loops that live within the localization length of the surface. Thus, the Weyl semimetal is not topologically robust to the presence of disorder, but the surface chiral velocity is.

Transverse Anderson Localization in Disordered Glass Optical Fibers: A Review.

PubMed

Mafi, Arash; Karbasi, Salman; Koch, Karl W; Hawkins, Thomas; Ballato, John

2014-07-28

Disordered optical fibers show novel waveguiding properties that can be used for various device applications, such as beam-multiplexed optical communications and endoscopic image transport. The strong transverse scattering from the transversely disordered optical fibers results in transversely confined beams that can freely propagate in the longitudinal direction, similar to conventional optical fibers, with the advantage that any point in the cross section of the fiber can be used for beam transport. For beam multiplexing and imaging applications, it is highly desirable to make the localized beam radius as small as possible. This requires large refractive index differences between the materials that define the random features in the disordered fiber. Here, disordered glass-air fibers are briefly reviewed, where randomly placed airholes in a glass matrix provide the sufficiently large refractive index difference of 0.5 for strong random transverse scattering. The main future challenge for the fabrication of an optimally disordered glass-air fibers is to increase the fill-fraction of airholes to nearly 50% for maximum beam confinement.

Transverse Anderson Localization in Disordered Glass Optical Fibers: A Review

PubMed Central

Mafi, Arash; Karbasi, Salman; Koch, Karl W.; Hawkins, Thomas; Ballato, John

2014-01-01

Disordered optical fibers show novel waveguiding properties that can be used for various device applications, such as beam-multiplexed optical communications and endoscopic image transport. The strong transverse scattering from the transversely disordered optical fibers results in transversely confined beams that can freely propagate in the longitudinal direction, similar to conventional optical fibers, with the advantage that any point in the cross section of the fiber can be used for beam transport. For beam multiplexing and imaging applications, it is highly desirable to make the localized beam radius as small as possible. This requires large refractive index differences between the materials that define the random features in the disordered fiber. Here, disordered glass-air fibers are briefly reviewed, where randomly placed airholes in a glass matrix provide the sufficiently large refractive index difference of 0.5 for strong random transverse scattering. The main future challenge for the fabrication of an optimally disordered glass-air fibers is to increase the fill-fraction of airholes to nearly 50% for maximum beam confinement. PMID:28788142

Temperament and suicide: A national study.

PubMed

Karam, Elie G; Itani, Lynn; Fayyad, John; Hantouche, Elie; Karam, Aimee; Mneimneh, Zeina; Akiskal, Hagop; Rihmer, Zoltán

2015-09-15

Several studies have shown temperament variants in suicidality. Yet, to our knowledge, the association between temperaments and suicide attempts has not been studied on a nationally representative level nor systematically in subjects with no mental disorders. Also, although hyperthymic temperament is recognized as protective of most mental disorders, its role in the protection from self-harm remains inconclusive. The study is based on nationally representative data of all Lebanese adults. Mental disorders were assessed using the Composite International Diagnostic Interview, whereas the five affective temperaments were assessed using the TEMPS-A. Anxious temperament is a solid and strong risk factor for suicide attempts in subjects with (OR: 10.1) and without (OR: 9.0) mental disorders. Depressive (OR: 4.3) and irritable (OR: 5.1) temperaments are risk factors for suicide attempt among subjects with mental disorders. Hyperthymic temperament plays a dual role in females with mental disorders: while the hyperthymic trait "having self-confidence" is strongly protective of suicide attempts, "liking to be the boss", "getting into heated arguments", and "the right and privilege to do as I please" are hyperthymic risk traits for suicide attempts reflecting the "dark side" of the hyperthymic temperament. Interestingly, these three hyperthymic risk traits--in the absence of "having self-confidence"--are a universal risk for suicide attempt in females with mental disorder. Social desirability could have led to the under-reporting of suicide attempts and mental disorders. The anxious temperament plays a strong role in predicting suicide attempts in the community, in the presence and absence of diagnosable mental disorders. The irritable and the depressive temperaments are additional risks in subjects with mental disorders. The dual role of the hyperthymic temperament is quite interesting: while it is protective of suicidal behavior, it also has a dark side in subjects with mental disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Fun Seeking and Reward Responsiveness Moderate the Effect of the Behavioural Inhibition System on Coping-Motivated Problem Gambling.

PubMed

Keough, Matthew T; Wardell, Jeffrey D; Hendershot, Christian S; Bagby, R Michael; Quilty, Lena C

2017-09-01

Gray's Reinforcement Sensitivity Theory (RST) predicts that the Behavioral Inhibition System (BIS) may relate to coping-motivated problem gambling, given its central role in anxiety. Studies examining the BIS-problem gambling association, however, are mixed. The revised RST posits that the Behavioral Approach System (BAS) may moderate the effect of the BIS on coping-motivated problem gambling. A concurrently strong BAS may highlight the negatively reinforcing effects of gambling, which may strengthen coping motives and increase gambling-related harms. We examined these interactive effects to clarify the moderators and mediators of the negative reinforcement pathway to problem gambling. Data came from a larger investigation of problem gambling among individuals with mood disorders. All participants (N = 275) met criteria for a lifetime depressive or bipolar disorder. During a two-day assessment, participants completed a diagnostic assessment and self-reports. Mediated moderation path analysis showed positive indirect effects from the BIS to problem gambling via coping motives at high, but not at low, levels of BAS-Reward Responsiveness and BAS-Fun Seeking. Enhancement motives were also found to mediate the associations of BAS-Fun Seeking and BAS-Drive with problem gambling. Reward Responsiveness and Fun Seeking facets of the BAS may strengthen coping gambling motives within the mood disorders.

A personality classification system for eating disorders: a longitudinal study.

PubMed

Thompson-Brenner, Heather; Eddy, Kamryn T; Franko, Debra L; Dorer, David J; Vashchenko, Maryna; Kass, Andrea E; Herzog, David B

2008-01-01

Studies of eating disorders (EDs) suggest that empirically derived personality subtypes may explain heterogeneity in ED samples that is not captured by the current diagnostic system. Longitudinal outcomes for personality subtypes have not been examined. In this study, personality pathology was assessed by clinical interview in 213 individuals with anorexia nervosa and bulimia nervosa at baseline. Interview data on EDs, comorbid diagnoses, global functioning, and treatment utilization were collected at baseline and at 6-month follow-up intervals over a median of 9 years. Q-factor analysis of the participants based on personality items produced a 5-prototype system, including high-functioning, behaviorally dysregulated, emotionally dysregulated, avoidant-insecure, and obsessional-sensitive types. Dimensional prototype scores were associated with baseline functioning and longitudinal outcome. Avoidant-Insecure scores showed consistent associations with poor functioning and outcome, including failure to show ED improvement, poor global functioning after 5 years, and high treatment utilization after 5 years. Behavioral dysregulation was associated with poor baseline functioning but did not show strong associations with ED or global outcome when histories of major depression and substance use disorder were covaried. Emotional dysregulation and obsessional-sensitivity were not associated with negative outcomes. High-functioning prototype scores were consistently associated with positive outcomes. Longitudinal results support the importance of personality subtypes to ED classification.

Sleep complaints and psychiatric symptoms in children evaluated at a pediatric mental health clinic.

PubMed

Ivanenko, Anna; Crabtree, Valerie McLaughlin; Obrien, Louise Margaret; Gozal, David

2006-01-15

To examine the association of sleep problems with psychiatric symptoms in children evaluated at a university-based outpatient child psychiatry clinic. Parents of 174 children attending psychiatric services completed a 47-item Childhood Sleep Questionnaire and the Behavioral Assessment System for Children. Psychiatric diagnosis was obtained through retrospective chart review. Sleep characteristics were compared among 4 diagnostic subcategories: attention-deficit/hyperactivity disorder (ADHD) alone (n=29), ADHD with comorbid mood and anxiety disorders (ADHD+; n=50), mood and anxiety disorders alone (n=67), and other psychiatric disorders (n= 28). Data from sleep habits survey of 174 community children without reported psychiatric history served as controls. Children with psychiatric disorders had a significantly higher prevalence of sleep complaints compared with nonpsychiatric controls. Children with ADHD had frequent nocturnal awakenings, bad dreams, and bedtime struggles. In addition, the presence of leg jerks during sleep was particularly frequent in patients with ADHD compared with any other psychiatric disorder. More frequent nighttime awakenings were present in children with mood and anxiety disorders. Sleep duration and sleep latency strongly correlated with aggression, hyperactivity, and depression. Restless sleep scores highly correlated with all psychiatric symptoms. Sleep problems are highly prevalent among children with psychiatric disorders. Children with ADHD and comorbid anxiety or mood disorders are more likely to report sleep disturbances. Restless sleep, long sleep latency, short sleep duration, and frequent nocturnal awakenings correlate with the severity of psychiatric symptoms.

Neural and behavioural responses to face-likeness of objects in adolescents with autism spectrum disorder

PubMed Central

Akechi, Hironori; Kikuchi, Yukiko; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

2014-01-01

Numerous studies have revealed atypical face processing in autism spectrum disorders (ASD) characterized by social interaction and communication difficulties. This study investigated sensitivity to face-likeness in ASD. In Experiment 1, we found a strong positive correlation between the face-likeness ratings of non-face objects in the ASD (11–19 years old) and the typically developing (TD) group (9–21 years old). In Experiment 2 (the scalp-recorded event-related potential experiment), the participants of both groups (ASD, 12–19 years old; TD, 12–18 years old) exhibited an enhanced face-sensitive N170 amplitude to a face-like object. Whereas the TD adolescents showed an enhanced N170 during the face-likeness judgements, adolescents with ASD did not. Thus, both individuals with ASD and TD individuals have a perceptual and neural sensitivity to face-like features in objects. When required to process face-like features, a face-related brain system reacts more strongly in TD individuals but not in individuals with ASD. PMID:24464152

Remanent Magnetization: Signature of Many-Body Localization in Quantum Antiferromagnets

NASA Astrophysics Data System (ADS)

Ros, V.; Müller, M.

2017-06-01

We study the remanent magnetization in antiferromagnetic, many-body localized quantum spin chains, initialized in a fully magnetized state. Its long time limit is an order parameter for the localization transition, which is readily accessible by standard experimental probes in magnets. We analytically calculate its value in the strong-disorder regime exploiting the explicit construction of quasilocal conserved quantities of the localized phase. We discuss analogies in cold atomic systems.

Quantum entanglement in inhomogeneous 1D systems

NASA Astrophysics Data System (ADS)

Ramírez, Giovanni

2018-04-01

The entanglement entropy of the ground state of a quantum lattice model with local interactions usually satisfies an area law. However, in 1D systems some violations may appear in inhomogeneous systems or in random systems. In our inhomogeneous system, the inhomogeneity parameter, h, allows us to tune different regimes where a volumetric violation of the area law appears. We apply the strong disorder renormalization group to describe the maximally entangled state of the system in a strong inhomogeneity regime. Moreover, in a weak inhomogeneity regime, we use a continuum approximation to describe the state as a thermo-field double in a conformal field theory with an effective temperature which is proportional to the inhomogeneity parameter of the system. The latter description also shows that the universal scaling features of this model are captured by a massless Dirac fermion in a curved space-time with constant negative curvature R = h2, providing another example of the relation between quantum entanglement and space-time geometry. The results we discuss here were already published before, but here we present a more didactic exposure of basic concepts of the rainbow system for the students attending the Latin American School of Physics "Marcos Moshinsky" 2017.

Materials considerations for forming the topological insulator phase in InAs/GaSb heterostructures

NASA Astrophysics Data System (ADS)

Shojaei, B.; McFadden, A. P.; Pendharkar, M.; Lee, J. S.; Flatté, M. E.; Palmstrøm, C. J.

2018-06-01

In an ideal InAs/GaSb bilayer of appropriate dimension, in-plane electron and hole bands overlap and hybridize, and a topologically nontrivial, or quantum spin Hall (QSH) insulator, phase is predicted to exist. The in-plane dispersion's potential landscape, however, is subject to microscopic perturbations originating from material imperfections. In this work, the effect of disorder on the electronic structure of InAs/GaSb (001) bilayers was studied by observing the temperature and magnetic-field dependence of the resistance of a dual-gated heterostructure gate-tuned through the inverted to normal gap regimes. Conduction with the electronic structure tuned to the inverted (predicted topological) regime and the Fermi level in the hybridization gap was qualitatively similar to behavior in a disordered two-dimensional system. The impact of charged impurities and interface roughness on the formation of topologically protected edge states and an insulating bulk was estimated. The experimental evidence and estimates of disorder in the potential landscape indicated that the potential fluctuations in state-of-the-art films are sufficiently strong such that conduction with the electronic structure tuned to the predicted topological insulator (TI) regime and the Fermi level in the hybridization gap was dominated by a symplectic metal phase rather than a TI phase. The implications are that future efforts must address disorder in this system, and focus must be placed on the reduction of defects and disorder in these heterostructures if a TI regime is to be achieved.

Electron-phonon mediated heat flow in disordered graphene

NASA Astrophysics Data System (ADS)

Chen, Wei; Clerk, Aashish A.

2012-09-01

We calculate the heat flux and electron-phonon thermal conductance in a disordered graphene sheet, going beyond a Fermi’s golden rule approach to fully account for the modification of the electron-phonon interaction by disorder. Using the Keldysh technique combined with standard impurity averaging methods in the regime kFl≫1 (where kF is the Fermi wave vector and l is the mean free path), we consider both scalar potential (i.e., deformation potential) and vector-potential couplings between electrons and phonons. We also consider the effects of electronic screening at the Thomas-Fermi level. We find that the temperature dependence of the heat flux and thermal conductance is sensitive to the presence of disorder and screening, and reflects the underlying chiral nature of electrons in graphene and the corresponding modification of their diffusive behavior. In the case of weak screening, disorder enhances the low-temperature heat flux over the clean system (changing the associated power law from T4 to T3), and the deformation potential dominates. For strong screening, both the deformation potential and vector-potential couplings make comparable contributions, and the low-temperature heat flux obeys a T5 power law.

Clinical Uses of Melatonin in Neurological Diseases and Mental and Behavioural Disorders.

PubMed

Sanchez-Barcelo, Emilio J; Rueda, Noemi; Mediavilla, María D; Martinez-Cue, Carmen; Reiter, Russel J

2017-11-20

Melatonin is a molecule with numerous properties applicable to the treatment of neurological diseases. Among these properties are the following: potent scavenger of oxygen and nitrogen reactive species, anti-inflammatory features, immuno-enhancing nature, and modulation of circadian rhythmicity. Furthermore, low concentrations of melatonin are usually found in patients with neurological diseases and mental disorders. The positive results obtained in experimental models of diverse pathologies, including diseases of the nervous system (e.g., Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, epilepsy, headaches, etc.) as well as mental and behavioural disordes (e.g., autism spectrum disorders, attention-deficit hyperactivity disorders, etc.), have served as a basis for the design of clinical trials to study melatonin's possible usefulness in human pathology, although the satisfactory results obtained from the laboratory "bench" are not always applicable to the patient's "bedside". In this article, we review those papers describing the results of the administration of melatonin to humans for various therapeutic purposes in the field of neuropathology. Clinical trials with strong methodologies and appropriate doses of melatonin are necessary to support or reject the usefulness of melatonin in neurological diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Optimal dephasing for ballistic energy transfer in disordered linear chains

NASA Astrophysics Data System (ADS)

Zhang, Yang; Celardo, G. Luca; Borgonovi, Fausto; Kaplan, Lev

2017-11-01

We study the interplay between dephasing, disorder, and coupling to a sink on transport efficiency in a one-dimensional chain of finite length N , and in particular the beneficial or detrimental effect of dephasing on transport. The excitation moves along the chain by coherent nearest-neighbor hopping Ω , under the action of static disorder W and dephasing γ . The last site is coupled to an external acceptor system (sink), where the excitation can be trapped with a rate Γtrap. While it is known that dephasing can help transport in the localized regime, here we show that dephasing can enhance energy transfer even in the ballistic regime. Specifically, in the localized regime we recover previous results, where the optimal dephasing is independent of the chain length and proportional to W or W2/Ω . In the ballistic regime, the optimal dephasing decreases as 1 /N or 1 /√{N } , respectively, for weak and moderate static disorder. When focusing on the excitation starting at the beginning of the chain, dephasing can help excitation transfer only above a critical value of disorder Wcr, which strongly depends on the sink coupling strength Γtrap. Analytic solutions are obtained for short chains.

Dissatisfaction with work as a risk factor of musculoskeletal complaints among foresters in Poland.

PubMed

Lachowski, Stanisław; Choina, Piotr; Florek-Łuszczki, Magdalena; Goździewska, Małgorzata; Jezior, Jagoda

2017-12-23

Researchers indicate an important relationship between the level of job satisfaction and the state of health of the employees. Some elements of work related with its character, organization, and interpersonal relationships may evoke strong stress, manifested by, among others, an increased musculoskeletal tension which, in turn, may lead to permanent dysfunction of this system. The objective of the study was analysis of the relationship between the level of job satisfaction and occurrence of musculoskeletal disorders among employees of the State Forests. The research material was collected using two instruments: the modified Nordic Questionnaire for assessment of musculoskeletal disorders, and a questionnaire concerning job satisfaction. The study was conducted in a group of 396 employees of the State Forests from 8 regions of Poland. The results of analysis confirmed a significant relationship between job satisfaction and the occurrence of musculoskeletal disorders. The lower the level of job satisfaction, the more frequent the experiencing of musculoskeletal disorders. Low level of job satisfaction is a risk factor for the occurrence of musculoskeletal disorders. Shaping of work conditions, which are the source of job satisfaction, should be considered as one of the main elements of prevention of musculoskeletal complaints.

Sex, Glia, and Development: interactions in health and disease

PubMed Central

Schwarz, Jaclyn M.; Bilbo, Staci D.

2012-01-01

Microglia and astrocytes are the primary immune cells within the central nervous system. Microglia influence processes including neural development, synaptic plasticity and cognition; while their activation and production of immune molecules can induce stereotyped sickness behaviors or pathologies including cognitive dysfunction. Given their role in health and disease, we propose that glia may be also be a critical link in understanding the etiology of many neuropsychiatric disorders that present with a strong sex-bias in their symptoms or prevalence. Specifically, males are more likely to be diagnosed with disorders that have distinct developmental origins such as autism or schizophrenia. In contrast, females are more likely to be diagnosed with disorders that present later in life, after the onset of adolescence, such as depression and anxiety disorders. In this review we will summarize the evidence suggesting that sex differences in the colonization and function of glia within the normal developing brain may contribute to distinct windows of vulnerability between males and females. We will also highlight the current gaps in our knowledge as well as the future directions and considerations of research aimed at understanding the link between neuroimmune function and sex differences in mental health disorders. PMID:22387107

Incidence and risk patterns of anxiety and depressive disorders and categorization of generalized anxiety disorder.

PubMed

Beesdo, Katja; Pine, Daniel S; Lieb, Roselind; Wittchen, Hans-Ulrich

2010-01-01

Controversy surrounds the diagnostic categorization of generalized anxiety disorder (GAD). To examine the incidence, comorbidity, and risk patterns for anxiety and depressive disorders and to test whether developmental features of GAD more strongly support a view of this condition as a depressive as opposed to an anxiety disorder. Face-to-face, 10-year prospective longitudinal and family study with as many as 4 assessment waves. The DSM-IV Munich Composite International Diagnostic Interview was administered by clinically trained interviewers. Munich, Germany. A community sample of 3021 individuals aged 14 to 24 years at baseline and 21 to 34 years at last follow-up. Cumulative incidence of GAD, other anxiety disorders (specific phobias, social phobia, agoraphobia, and panic disorder), and depressive disorders (major depressive disorder, and dysthymia). Longitudinal associations between GAD and depressive disorders are not stronger than those between GAD and anxiety disorders or between other anxiety and depressive disorders. Survival analyses reveal that the factors associated with GAD overlap more strongly with those specific to anxiety disorders than those specific to depressive disorders. In addition, GAD differs from anxiety and depressive disorders with regard to family climate and personality profiles. Anxiety and depressive disorders appear to differ with regard to risk constellations and temporal longitudinal patterns, and GAD is a heterogeneous disorder that is, overall, more closely related to other anxiety disorders than to depressive disorders. More work is needed to elucidate the potentially unique aspects of pathways and mechanisms involved in the etiopathogenesis of GAD. Grouping GAD with depressive disorders, as suggested by cross-sectional features and diagnostic comorbidity patterns, minimizes the importance of longitudinal data on risk factors and symptom trajectories.

Theory of current-driven skyrmions in disordered magnets.

PubMed

Koshibae, Wataru; Nagaosa, Naoto

2018-04-20

An emergent topological particle in magnets, skyrmion, has several unique features distinct from the other magnetic textures such as domain wall, helical structure, and vortex. It is characterized by a topological integer called skyrmion number N sk , which counts how many times the directions of the magnetic moments wrap the unit sphere. This N sk gives the chiral nature of the skyrmion dynamics, and leads to the extremely small critical current density j c for the current-driven motion in terms of spin transfer torque effect. The finite j c indicates the pinning effect due to the disorder such as impurities and defects, and the behaviors of skyrmions under disorder have not been explored well theoretically although it is always relevant in real systems. Here we reveal by a numerical simulation of Landau-Lifshitz-Gilbert equation that there are four different skyrmion phases with the strong disorder, i.e., (A) pinned state, (B) depinned state, (C) skyrmion multiplication/annihilation, and (D) segregation of skyrmions, as the current density increases, while only two phases (A) and (B) appear in the weak disorder case. The microscopic mechanisms of the new phases (C) and (D) are analyzed theoretically. These results offer a coherent understanding of the skyrmion dynamics under current with disorder.

What Virtual Reality Research in Addictions Can Tell Us about the Future of Obesity Assessment and Treatment

PubMed Central

Bordnick, Patrick S; Carter, Brian L; Traylor, Amy C

2011-01-01

Virtual reality (VR), a system of human–computer interaction that allows researchers and clinicians to immerse people in virtual worlds, is gaining considerable traction as a research, education, and treatment tool. Virtual reality has been used successfully to treat anxiety disorders such as fear of flying and post-traumatic stress disorder, as an aid in stroke rehabilitation, and as a behavior modification aid in the treatment of attention deficit disorder. Virtual reality has also been employed in research on addictive disorders. Given the strong evidence that drug-dependent people are highly prone to use and relapse in the presence of environmental stimuli associated with drug use, VR is an ideal platform from which to study this relationship. Research using VR has shown that drug-dependent people react with strong craving to specific cues (e.g., cigarette packs, liquor bottles) as well as environments or settings (e.g., bar, party) associated with drug use. Virtual reality has also been used to enhance learning and generalization of relapse prevention skills in smokers by reinforcing these skills in lifelike environments. Obesity researchers and treatment professionals, building on the lessons learned from VR research in substance abuse, have the opportunity to adapt these methods for investigating their own research and treatment questions. Virtual reality is ideally suited to investigate the link between food cues and environmental settings with eating behaviors and self-report of hunger. In addition, VR can be used as a treatment tool for enhancing behavior modification goals to support healthy eating habits by reinforcing these goals in life–like situations. PMID:21527092

Low Dimensionality Effects in Complex Magnetic Oxides

NASA Astrophysics Data System (ADS)

Kelley, Paula J. Lampen

Complex magnetic oxides represent a unique intersection of immense technological importance and fascinating physical phenomena originating from interwoven structural, electronic and magnetic degrees of freedom. The resulting energetically close competing orders can be controllably selected through external fields. Competing interactions and disorder represent an additional opportunity to systematically manipulate the properties of pure magnetic systems, leading to frustration, glassiness, and other novel phenomena while finite sample dimension plays a similar role in systems with long-range cooperative effects or large correlation lengths. A rigorous understanding of these effects in strongly correlated oxides is key to manipulating their functionality and device performance, but remains a challenging task. In this dissertation, we examine a number of problems related to intrinsic and extrinsic low dimensionality, disorder, and competing interactions in magnetic oxides by applying a unique combination of standard magnetometry techniques and unconventional magnetocaloric effect and transverse susceptibility measurements. The influence of dimensionality and disorder on the nature and critical properties of phase transitions in manganites is illustrated in La0.7 Ca0.3MnO3, in which both size reduction to the nanoscale and chemically-controlled quenched disorder are observed to induce a progressive weakening of the first-order nature of the transition, despite acting through the distinct mechanisms of surface effects and site dilution. In the second-order material La0.8Ca0.2MnO3, a strong magnetic field is found to drive the system toward its tricritical point as competition between exchange interactions in the inhomogeneous ground state is suppressed. In the presence of large phase separation stabilized by chemical disorder and long-range strain, dimensionality has a profound effect. With the systematic reduction of particle size in microscale-phase-separated (La, Pr, Ca)MnO3 we observe a disruption of the long-range glassy strains associated with the charge-ordered phase in the bulk, lowering the field and pressure threshold for charge-order melting and increasing the ferromagnetic volume fraction as particle size is decreased. The long-range charge-ordered phase becomes completely suppressed when the particle size falls below 100 nm. In contrast, low dimensionality in the geometrically frustrated pseudo-1D spin chain compound Ca3Co2O6 is intrinsic, arising from the crystal lattice. We establish a comprehensive phase diagram for this exotic system consistent with recent reports of an incommensurate ground state and identify new sub-features of the ferrimagnetic phase. When defects in the form of grain boundaries are incorporated into the system the low-temperature slow-dynamic state is weakened, and new crossover phenomena emerge in the spin relaxation behavior along with an increased distribution of relaxation times. The presence of both disorder and randomness leads to a spin-glass-like state, as observed in gammaFe2O3 hollow nanoparticles, where freezing of surface spins at low temperature generates an irreversible magnetization component and an associated exchange-biasing effect. Our results point to distinct dynamic behaviors on the inner and outer surfaces of the hollow structures. Overall, these studies yield new physical insights into the role of dimensionality and disorder in these complex oxide systems and highlight the sensitivity of their manifested magnetic ground states to extrinsic factors, leading in many cases to crossover behaviors where the balance between competing phases is altered, or to the emergence of entirely new magnetic phenomena.

Increasing Comorbidities Suggest that Atopic Dermatitis Is a Systemic Disorder.

PubMed

Brunner, Patrick M; Silverberg, Jonathan I; Guttman-Yassky, Emma; Paller, Amy S; Kabashima, Kenji; Amagai, Masayuki; Luger, Thomas A; Deleuran, Mette; Werfel, Thomas; Eyerich, Kilian; Stingl, Georg

2017-01-01

Atopic dermatitis comorbidities extend well beyond the march to allergic conditions (food allergy, asthma, allergic rhinitis, allergic conjunctivitis, and eosinophilic esophagitis), suggesting both cutaneous and systemic immune activation. In reviewing atopic dermatitis comorbidities, Councilors of the International Eczema Council found a strong pattern of immune activation in peripheral blood and the propensity to both skin and systemic infections. Associations with cardiovascular, neuropsychiatric, and malignant diseases were increasingly reported, but confirmation of their link with atopic dermatitis requires longitudinal studies. Given the possibility of atopic dermatitis-related systemic immune activation, future investigations of new interventions should concurrently examine the impact on these comorbidities. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Strengthening mental health systems in low- and middle-income countries: the Emerald programme.

PubMed

Semrau, Maya; Evans-Lacko, Sara; Alem, Atalay; Ayuso-Mateos, Jose Luis; Chisholm, Dan; Gureje, Oye; Hanlon, Charlotte; Jordans, Mark; Kigozi, Fred; Lempp, Heidi; Lund, Crick; Petersen, Inge; Shidhaye, Rahul; Thornicroft, Graham

2015-04-10

There is a large treatment gap for mental health care in low- and middle-income countries (LMICs), with the majority of people with mental, neurological, and substance use (MNS) disorders receiving no or inadequate care. Health system factors are known to play a crucial role in determining the coverage and effectiveness of health service interventions, but the study of mental health systems in LMICs has been neglected. The 'Emerging mental health systems in LMICs' (Emerald) programme aims to improve outcomes of people with MNS disorders in six LMICs (Ethiopia, India, Nepal, Nigeria, South Africa, and Uganda) by generating evidence and capacity to enhance health system performance in delivering mental health care. A mixed-methods approach is being applied to generate evidence on: adequate, fair, and sustainable resourcing for mental health (health system inputs); integrated provision of mental health services (health system processes); and improved coverage and goal attainment in mental health (health system outputs). Emerald has a strong focus on capacity-building of researchers, policymakers, and planners, and on increasing service user and caregiver involvement to support mental health systems strengthening. Emerald also addresses stigma and discrimination as one of the key barriers for access to and successful delivery of mental health services.

Cyclotron resonance of interacting quantum Hall droplets

NASA Astrophysics Data System (ADS)

Widmann, M.; Merkt, U.; Cortés, M.; Häusler, W.; Eberl, K.

1998-06-01

The line shape and position of cyclotron resonance in gated GaAs/GaAlAs heterojunctions with δ-doped layers of negatively charged beryllium acceptors, that provide strong potential fluctuations in the channels of the quasi-two-dimensional electron systems, are examined. Specifically, the magnetic quantum limit is considered when the electrons are localized in separate quantum Hall droplets in the valleys of the disorder potential. A model treating disorder and electron-electron interaction on an equal footing accounts for all of the principal experimental findings: blue shifts from the unperturbed cyclotron frequency that decrease when the electron density is reduced, surprisingly narrow lines in the magnetic quantum limit, and asymmetric lines due to additional oscillator strength on their high-frequency sides.

Metals and Neurodegeneration

PubMed Central

Chen, Pan; Miah, Mahfuzur Rahman; Aschner, Michael

2016-01-01

Metals play important roles in the human body, maintaining cell structure and regulating gene expression, neurotransmission, and antioxidant response, to name a few. However, excessive metal accumulation in the nervous system may be toxic, inducing oxidative stress, disrupting mitochondrial function, and impairing the activity of numerous enzymes. Damage caused by metal accumulation may result in permanent injuries, including severe neurological disorders. Epidemiological and clinical studies have shown a strong correlation between aberrant metal exposure and a number of neurological diseases, including Alzheimer’s disease, amyotrophic lateral sclerosis, autism spectrum disorders, Guillain–Barré disease, Gulf War syndrome, Huntington’s disease, multiple sclerosis, Parkinson’s disease, and Wilson’s disease. Here, we briefly survey the literature relating to the role of metals in neurodegeneration. PMID:27006759

Scalability of transport parameters with pore sizes in isodense disordered media

NASA Astrophysics Data System (ADS)

Reginald, S. William; Schmitt, V.; Vallée, R. A. L.

2014-09-01

We study light multiple scattering in complex disordered porous materials. High internal phase emulsion-based isodense polystyrene foams are designed. Two types of samples, exhibiting different pore size distributions, are investigated for different slab thicknesses varying from L = 1 \\text{mm} to 10 \\text{mm} . Optical measurements combining steady-state and time-resolved detection are used to characterize the photon transport parameters. Very interestingly, a clear scalability of the transport mean free path \\ellt with the average size of the pores S is observed, featuring a constant velocity of the transport energy in these isodense structures. This study strongly motivates further investigations into the limits of validity of this scalability as the scattering strength of the system increases.

A Pilot Study of the DBT Coach: An Interactive Mobile Phone Application for Individuals with Borderline Personality Disorder and Substance Use Disorder

ERIC Educational Resources Information Center

Rizvi, Shireen L.; Dimeff, Linda A.; Skutch, Julie; Carroll, David; Linehan, Marsha M.

2011-01-01

Dialectical behavior therapy (DBT) has received strong empirical support and is practiced widely as a treatment for borderline personality disorder (BPD) and BPD with comorbid substance use disorders (BPD-SUD). Therapeutic success in DBT requires that individuals generalize newly acquired skills to their natural environment. However, there have…

Gamma-glutamyltransferase and disability pension: a cohort study of construction workers in Germany.

PubMed

Claessen, Heiner; Brenner, Hermann; Drath, Christoph; Arndt, Volker

2010-02-01

Given the accumulating evidence that gamma-glutamyltransferase (gamma-GT) is not merely a sensitive marker for liver and bile disorders but also a risk marker for a multiplicity of other chronic diseases, gamma-GT may represent a promising risk indicator for occupational disability, which has emerged as an important public health problem. The association between gamma-GT and disability pension was examined in a cohort of 16,520 male construction workers in Württemberg, Germany, who participated in routine occupational health examinations from 1986 to 1992 and who were followed until 2005. Using the Cox proportional hazards model, hazard ratios were calculated with gamma-GT concentrations in the lowest quartile (1 to 24 U/L) as reference category after adjustment for age and further adjustment for potential confounding factors such as nationality, type of occupation, smoking, alcohol consumption, cholesterol, and body mass index (BMI). Overall, a monotonically increasing association of gamma-GT with all-cause disability pension (total number: n = 2,998 cases) was observed, with the steepest increase at lower levels of gamma-GT. Particularly strong associations were observed for participants in the highest quartile (>67 U/L) and disability pension due to musculoskeletal disorders, diseases of the digestive system, and cardiovascular as well as mental diseases (age-adjusted hazard ratios with 95% confidence intervals: 1.53, 1.27-1.85; 9.68, 3.10-30.21; 1.76, 1.28-2.42; and 1.83, 1.23-2.72, respectively). gamma-GT is a strong risk indicator of all-cause occupational disability even at levels of gamma-GT in the "normal range" and is in particular associated with disability pension due to diseases of the digestive system, musculoskeletal disorders, cardiovascular, and mental diseases.

Dynamics of molecular motors with finite processivity on heterogeneous tracks.

PubMed

Kafri, Yariv; Lubensky, David K; Nelson, David R

2005-04-01

The dynamics of molecular motors which occasionally detach from a heterogeneous track like DNA or RNA is considered. Motivated by recent single-molecule experiments, we study a simple model for a motor moving along a disordered track using chemical energy while an external force opposes its motion. The motors also have finite processivity, i.e., they can leave the track with a position-dependent rate. We show that the response of the system to disorder in the hopping-off rate depends on the value of the external force. For most values of the external force, strong disorder causes the motors which survive for long times on the track to be localized at preferred positions. However, near the stall force, localization occurs for any amount of disorder. To obtain these results, we study the complex eigenvalue spectrum of the time evolution operator. Existence of localized states near the top of the band implies a stretched exponential contribution to the decay of the survival probability. A similar spectral analysis also provides a very efficient method for studying the dynamics of motors with infinite processivity.

Functional Anthology of Intrinsic Disorder. II. Cellular Components, Domains, Technical Terms, Developmental Processes and Coding Sequence Diversities Correlated with Long Disordered Regions

PubMed Central

Vucetic, Slobodan; Xie, Hongbo; Iakoucheva, Lilia M.; Oldfield, Christopher J.; Dunker, A. Keith; Obradovic, Zoran; Uversky, Vladimir N.

2008-01-01

Biologically active proteins without stable ordered structure (i.e., intrinsically disordered proteins) are attracting increased attention. Functional repertoires of ordered and disordered proteins are very different, and the ability to differentiate whether a given function is associated with intrinsic disorder or with a well-folded protein is crucial for modern protein science. However, there is a large gap between the number of proteins experimentally confirmed to be disordered and their actual number in nature. As a result, studies of functional properties of confirmed disordered proteins, while helpful in revealing the functional diversity of protein disorder, provide only a limited view. To overcome this problem, a bioinformatics approach for comprehensive study of functional roles of protein disorder was proposed in the first paper of this series (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. I. Biological processes and functions of proteins with long disordered regions. J. Proteome Res.). Applying this novel approach to Swiss-Prot sequences and functional keywords, we found over 238 and 302 keywords to be strongly positively or negatively correlated, respectively, with long intrinsically disordered regions. This paper describes ~90 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes and coding sequence diversities possessing strong positive and negative correlation with long disordered regions. PMID:17391015

Functional anthology of intrinsic disorder. 2. Cellular components, domains, technical terms, developmental processes, and coding sequence diversities correlated with long disordered regions.

PubMed

Vucetic, Slobodan; Xie, Hongbo; Iakoucheva, Lilia M; Oldfield, Christopher J; Dunker, A Keith; Obradovic, Zoran; Uversky, Vladimir N

2007-05-01

Biologically active proteins without stable ordered structure (i.e., intrinsically disordered proteins) are attracting increased attention. Functional repertoires of ordered and disordered proteins are very different, and the ability to differentiate whether a given function is associated with intrinsic disorder or with a well-folded protein is crucial for modern protein science. However, there is a large gap between the number of proteins experimentally confirmed to be disordered and their actual number in nature. As a result, studies of functional properties of confirmed disordered proteins, while helpful in revealing the functional diversity of protein disorder, provide only a limited view. To overcome this problem, a bioinformatics approach for comprehensive study of functional roles of protein disorder was proposed in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V. N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Applying this novel approach to Swiss-Prot sequences and functional keywords, we found over 238 and 302 keywords to be strongly positively or negatively correlated, respectively, with long intrinsically disordered regions. This paper describes approximately 90 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes, and coding sequence diversities possessing strong positive and negative correlation with long disordered regions.

Child development and personality disorder.

PubMed

Cohen, Patricia

2008-09-01

The evidence is surprisingly strong that even early adolescent personality disorders or elevated personality disorder symptoms have a broad range of negative effects well into adulthood, for the most part comparable to or even larger than those of Axis I disorders. Current evidence suggests that the most severe long-term prognosis is associated with borderline and schizotypal PDs and elevated symptoms. And of course, childhood conduct disorder is in a peculiar status, disappearing in adulthood to be manifest as a very severe disorder-antisocial PD-in a minority of those with the adolescent disorder.

Relationship between attention deficit hyperactive disorder symptoms and perceived parenting practices of school-age children.

PubMed

Kim, Dong Hee; Yoo, Il Young

2013-04-01

To examine the relationship between the perception on parenting practices and attention deficit hyperactivity disorder (ADHD) symptoms in school-age children. Psychosocial attention deficit hyperactivity disorder intervention approaches emphasise environmental risk factors at the individual, family and community level. Parenting variables are strongly related to attention deficit hyperactivity disorder symptom severity. A cross-sectional questionnaire survey. The participants were 747 children and their parents in two elementary schools. The instruments used were Korean Conners Abbreviated Parent Questionnaire and Korean version Maternal Behavior Research Instrument (measuring four dimensions of parenting practices: affection, autonomy, rejection, control). Descriptive and logistic regression analyses were performed. The rejective parenting practice was statistically significant in logistic regression controlling gender and age of children, family structure, maternal education level and socio-economic status. The rejection parenting is associated with attention deficit hyperactivity disorder symptoms in children (OR=1.356). These results suggest the importance of specific parenting educational programmes for parents to prevent and decrease attention deficit hyperactivity disorder symptoms. It would be more effective rather than focusing only on the child's attention deficit hyperactivity disorder symptoms, developing educational programmes for parents to prevent rejection parenting practice and improve parenting skills in the family system. When developing a treatment programme for children with attention deficit hyperactivity disorder, healthcare providers should consider not only the child's attention deficit hyperactivity disorder symptoms, but also the parenting practices. Comprehensive interventions designed to prevent rejection and improve parenting skills may be helpful in mitigating attention deficit hyperactivity disorder symptoms. © 2012 Blackwell Publishing Ltd.

Ultracold neutral plasmas

NASA Astrophysics Data System (ADS)

Lyon, M.; Rolston, S. L.

2017-01-01

By photoionizing samples of laser-cooled atoms with laser light tuned just above the ionization limit, plasmas can be created with electron and ion temperatures below 10 K. These ultracold neutral plasmas have extended the temperature bounds of plasma physics by two orders of magnitude. Table-top experiments, using many of the tools from atomic physics, allow for the study of plasma phenomena in this new regime with independent control over the density and temperature of the plasma through the excitation process. Characteristic of these systems is an inhomogeneous density profile, inherited from the density distribution of the laser-cooled neutral atom sample. Most work has dealt with unconfined plasmas in vacuum, which expand outward at velocities of order 100 m/s, governed by electron pressure, and with lifetimes of order 100 μs, limited by stray electric fields. Using detection of charged particles and optical detection techniques, a wide variety of properties and phenomena have been observed, including expansion dynamics, collective excitations in both the electrons and ions, and collisional properties. Through three-body recombination collisions, the plasmas rapidly form Rydberg atoms, and clouds of cold Rydberg atoms have been observed to spontaneously avalanche ionize to form plasmas. Of particular interest is the possibility of the formation of strongly coupled plasmas, where Coulomb forces dominate thermal motion and correlations become important. The strongest impediment to strong coupling is disorder-induced heating, a process in which Coulomb energy from an initially disordered sample is converted into thermal energy. This restricts electrons to a weakly coupled regime and leaves the ions barely within the strongly coupled regime. This review will give an overview of the field of ultracold neutral plasmas, from its inception in 1999 to current work, including efforts to increase strong coupling and effects on plasma properties due to strong coupling.

Genetic Causes of Syndromic and Non-Syndromic Autism

ERIC Educational Resources Information Center

Caglayan, Ahmet O.

2010-01-01

Aims: Over the past decade, genetic tests have become available for numerous heritable disorders, especially those whose inheritance follows the Mendelian model. Autism spectrum disorders (ASDs) represent a group of developmental disorders with a strong genetic basis. During the past few years, genetic research in ASDs has been successful in…

Conceptual Relations between Anxiety Disorder and Fearful Temperament

ERIC Educational Resources Information Center

Rapee, Ronald M.; Coplan, Robert J.

2010-01-01

Fearful temperaments have been identified as a major risk factor for anxiety disorders. However, descriptions of fearful temperament and several forms of anxiety disorder show strong similarities. This raises the question whether these terms may simply refer to different aspects of the same underlying construct. The current review examines…

Personality Disorder among Male Prisoner in Erbil/ Iraq

ERIC Educational Resources Information Center

Aziz, Saman SH.; Ali, Sirwan K.

2015-01-01

Background and objectives: Personality disorders are enduring, persistent and pervasive disorders of inner experience and behavior that cause distress or significant impairment in social functioning. They have strong relationship to offending and violence; our aim in the study was to determine the prevalence rate of each specific types of…

Cognitive Therapy of Anxiety Disorders.

ERIC Educational Resources Information Center

Chambless, Dianne L.; Gillis, Martha M.

1993-01-01

Reviews studies of cognitive-behavioral therapy (CBT) for generalized anxiety disorder, panic disorder with and without agoraphobia, and social phobia. Sees CBT as consistently more effective than waiting-list and placebo control groups. Notes that cognitive change may be strong predictor of treatment outcome but that such change may be produced…

Differential associations of specific depressive and anxiety disorders with somatic symptoms.

PubMed

Bekhuis, Ella; Boschloo, Lynn; Rosmalen, Judith G M; Schoevers, Robert A

2015-02-01

Previous studies have shown that depressive and anxiety disorders are strongly related to somatic symptoms, but much is unclear about the specificity of this association. This study examines the associations of specific depressive and anxiety disorders with somatic symptoms, and whether these associations are independent of comorbid depressive and anxiety disorders. Cross-sectional data were derived from The Netherlands Study of Depression and Anxiety (NESDA). A total of 2008 persons (mean age: 41.6 years, 64.9% women) were included, consisting of 1367 patients with a past-month DSM-diagnosis (established with the Composite International Diagnostic Interview [CIDI]) of depressive disorder (major depressive disorder, dysthymic disorder) and/or anxiety disorder (generalized anxiety disorder, social phobia, panic disorder, agoraphobia), and 641 controls. Somatic symptoms were assessed with the somatization scale of the Four-Dimensional Symptom Questionnaire (4DSQ), and included cardiopulmonary, musculoskeletal, gastrointestinal, and general symptoms. Analyses were adjusted for covariates such as chronic somatic diseases, sociodemographics, and lifestyle factors. All clusters of somatic symptoms were more prevalent in patients with depressive and/or anxiety disorders than in controls (all p<.001). Multivariable logistic regression analyses showed that all types of depressive and anxiety disorders were independently related to somatic symptoms, except for dysthymic disorder. Major depressive disorder showed the strongest associations. Associations remained similar after adjustment for covariates. This study demonstrated that depressive and anxiety disorders show strong and partly differential associations with somatic symptoms. Future research should investigate whether an adequate consideration and treatment of somatic symptoms in depressed and/or anxious patients improve treatment outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

Differential associations of affective temperaments and diagnosis of major affective disorders with suicidal behavior.

PubMed

Baldessarini, Ross J; Innamorati, Marco; Erbuto, Denise; Serafini, Gianluca; Fiorillo, Andrea; Amore, Mario; Girardi, Paolo; Pompili, Maurizio

2017-03-01

Affective temperaments are associated with suicidal risk, but their predictive value relative to diagnosis of major affective disorder is uncertain. We compared diagnoses, affective-temperament ratings (TEMPS-A), and other potential risk factors in 956 psychiatric inpatients, using bivariate analyses and multivariable logistic regression modeling for associations with suicidal status. Lifetime suicide-attempt rates were high (43.9% overall), ranking by diagnosis: bipolar-II (58.4%), major depressive (50.0%), bipolar-I (44.6%), other (38.0%), and psychotic (33.9%) disorders. TEMPS-A scores for depressive (dep), cyclothymic (cyc), irritable (irr), and anxious (anx) temperaments and their sum were strongly associated with suicidal risk; hyperthymic (hyp) temperament scores were inversely associated; and a composite measure (dep+cyc+irr+anx - hyp), even more strongly associated. The composite score was highly, independently associated with suicidal behavior (p<0.0001), as was female sex (p=0.0002), but older age and diagnosis of major affective disorder, much less (both p=0.02). Measures of affective temperament-types were independently and more strongly associated with lifetime suicide attempt than was diagnosis of a major affective disorder. However, in this hospitalized cohort, suicide rates were high across diagnoses, possibly limiting the predictive value of diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Disorder effects in the evolution from BCS to BEC superfluidity

NASA Astrophysics Data System (ADS)

Han, Li; de Melo, Carlos A. R. Sa

2009-03-01

We discuss the effects of disorder on the critical temperature of superfluids during the evolution from BCS to BEC. For s-wave superfluids we find that the critical temperature is weakly affected by disorder in the BCS regime as described in Anderson’s theorem, even less affected by disorder at zero chemical potential (near unitarity), but strongly affected by disorder in the BEC regime, where Anderson's theorem does not apply. This suggests that the superfluid is more robust to the effects of disorder at the interaction parameter where the chemical potential vanishes (close to unitarity). We construct a three dimensional phase diagram of critical temperature, disorder and interaction parameter [1], and show that there are regions of localized superfluidity, as well as insulating regions due to Anderson localization of fermions (BCS regime) and molecular bosons (BEC regime). The phase diagram for higher angular momentum (e.g. p-wave and d-wave) is also analyzed, where the effects of disorder are much more dramatic in the BCS regime in comparison to the s-wave case because pair breaking is strong, while the disorder effects in BEC regime are similar to what occurs in the s-wave case. [1] Li Han, C. A. R. Sa de Melo, arXiv:0812.xxxx

Force-induced bone growth and adaptation: A system theoretical approach to understanding bone mechanotransduction

NASA Astrophysics Data System (ADS)

Maldonado, Solvey; Findeisen, Rolf

2010-06-01

The modeling, analysis, and design of treatment therapies for bone disorders based on the paradigm of force-induced bone growth and adaptation is a challenging task. Mathematical models provide, in comparison to clinical, medical and biological approaches an structured alternative framework to understand the concurrent effects of the multiple factors involved in bone remodeling. By now, there are few mathematical models describing the appearing complex interactions. However, the resulting models are complex and difficult to analyze, due to the strong nonlinearities appearing in the equations, the wide range of variability of the states, and the uncertainties in parameters. In this work, we focus on analyzing the effects of changes in model structure and parameters/inputs variations on the overall steady state behavior using systems theoretical methods. Based on an briefly reviewed existing model that describes force-induced bone adaptation, the main objective of this work is to analyze the stationary behavior and to identify plausible treatment targets for remodeling related bone disorders. Identifying plausible targets can help in the development of optimal treatments combining both physical activity and drug-medication. Such treatments help to improve/maintain/restore bone strength, which deteriorates under bone disorder conditions, such as estrogen deficiency.

Effects of sudden density changes in disordered superconductors and semiconductors

NASA Astrophysics Data System (ADS)

Assi, Hiba; Chaturvedi, Harshwardhan; Pleimling, Michel; Täuber, Uwe

Vortices in type-II superconductors in the presence of extended, linear defects display the strongly pinned Bose glass phase at low temperatures. This disorder-dominated thermodynamic state is characterized by suppressed lateral flux line fluctuations and very slow structural relaxation kinetics: The vortices migrate between different columnar pinning centers to minimize the mutual repulsive interactions and eventually optimize the system's pinning configuration. To monitor the flux lines' late-time structural relaxations, we employ a mapping between an effectively two-dimensional Bose glass system and a modified Coulomb glass model, originally developed to describe disordered semiconductors at low temperatures. By means of Monte Carlo simulations, we investigate the effects of the introduction of random bare site energies and sudden changes in the vortex or charge carrier density on the soft Coulomb gap that appears in the density of states due to the emerging spatial anticorrelations. The non-equilibrium relaxation properties of the Bose and Coulomb glass states and the ensuing aging kinetics are studied through the two-time density autocorrelation function and its various scaling forms. Research supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award DE-FG02-09ER46613.

Particle-hole symmetry, many-body localization, and topological edge modes

NASA Astrophysics Data System (ADS)

Vasseur, Romain; Friedman, Aaron J.; Parameswaran, S. A.; Potter, Andrew C.

We study the excited states of interacting fermions in one dimension with particle-hole symmetric disorder (equivalently, random-bond XXZ chains) using a combination of renormalization group methods and exact diagonalization. Absent interactions, the entire many-body spectrum exhibits infinite-randomness quantum critical behavior with highly degenerate excited states. We show that though interactions are an irrelevant perturbation in the ground state, they drastically affect the structure of excited states: even arbitrarily weak interactions split the degeneracies in favor of thermalization (weak disorder) or spontaneously broken particle-hole symmetry, driving the system into a many-body localized spin glass phase (strong disorder). In both cases, the quantum critical properties of the non-interacting model are destroyed, either by thermal decoherence or spontaneous symmetry breaking. This system then has the interesting and counterintuitive property that edges of the many-body spectrum are less localized than the center of the spectrum. We argue that our results rule out the existence of certain excited state symmetry-protected topological orders. Supported by the Gordon and Betty Moore Foundation's EPiQS Initiative (Grant GBMF4307 (ACP), the Quantum Materials Program at LBNL (RV), NSF Grant DMR-1455366 and UCOP Research Catalyst Award No. CA-15-327861 (SAP).

Examination of the interrelations between the factors of PTSD, major depression, and generalized anxiety disorder in a heterogeneous trauma-exposed sample using DSM 5 criteria.

PubMed

Price, Matthew; van Stolk-Cooke, Katherine

2015-11-01

Exposure to traumatic events places individuals at high risk for multiple psychiatric disorders, including posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and generalized anxiety disorder (GAD). The high rates of comorbidity among these conditions merit evaluation in order to improve diagnosis and treatment approaches. The current study evaluated the association between PTSD, MDD, and GAD factors as presented in the DSM 5. 602 trauma-exposed individuals who experienced an event that met Criterion A for the DSM 5 PTSD diagnosis were recruited through Amazon.com, Inc.'s Mechanical Turk (MTurk) to complete an assessment of the impact of stressful events on their lives. High interrelations were detected among the 4 PTSD factors, 2 MDD factors that corresponded to somatic and affective symptoms, and the single GAD factor. The affective factor of MDD was most strongly related to the emotional numbing factor of PTSD, whereas the somatic factor of MDD was most strongly related to the hyperarousal factor of PTSD. The GAD factor was most strongly related to the hyperarousal factor of PTSD, relative to the other PTSD factors. The strength of the interrelations between factors of the three disorders is largely a function of the overlap in symptoms and calls into question the uniqueness of negative affective symptoms of PTSD, MDD and GAD. Results suggest that improved understanding of the trauma reaction requires a focus on the unique presentation of each individual and assessment of multiple disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

The relationship between religion and mental disorders in a Korean population.

PubMed

Park, Jong-Ik; Hong, Jin Pyo; Park, Subin; Cho, Maeng-Je

2012-03-01

The question of whether religion has beneficial or detrimental effects on the mental well-being of the adult individual is debatable. Because most Korean citizens are free to select their own religion, there is a higher proportion of non-believers than believers among the Korean population. The aim of this research was to investigate the association between spiritual values and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition mental disorders in Korea across all types of belief systems, including Koreans not affiliated with a particular religion. The Korean version of the Composite International Diagnostic Interview 2.1 was used to interview 6,275 people across South Korea in 2001. While controlling for age and sex, we used logistic regression to analyze the relationship between mental disorders (both current and past) and the types of religion and spiritual values. Strong spiritual values were positively associated with increased rates of current depressive disorder and decreased rates of current alcohol use disorder. Using "atheist" as the reference category, Catholics had higher lifetime odds of single episodes of depression whilst Protestants had higher lifetime odds of anxiety disorder and lower lifetime odds of alcohol use disorders. The results of this study suggest that depressive episodes often lead to a search for spirituality and that religion may be helpful in overcoming depression or becoming less vulnerable to relapsing. The associations between religion, spiritual values, and mental health have not been fully elucidated and warrant further exploration.

The Relationship between Religion and Mental Disorders in a Korean Population

PubMed Central

Park, Jong-Ik; Hong, Jin Pyo; Park, Subin

2012-01-01

Objective The question of whether religion has beneficial or detrimental effects on the mental well-being of the adult individual is debatable. Because most Korean citizens are free to select their own religion, there is a higher proportion of non-believers than believers among the Korean population. The aim of this research was to investigate the association between spiritual values and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition mental disorders in Korea across all types of belief systems, including Koreans not affiliated with a particular religion. Methods The Korean version of the Composite International Diagnostic Interview 2.1 was used to interview 6,275 people across South Korea in 2001. While controlling for age and sex, we used logistic regression to analyze the relationship between mental disorders (both current and past) and the types of religion and spiritual values. Results Strong spiritual values were positively associated with increased rates of current depressive disorder and decreased rates of current alcohol use disorder. Using "atheist" as the reference category, Catholics had higher lifetime odds of single episodes of depression whilst Protestants had higher lifetime odds of anxiety disorder and lower lifetime odds of alcohol use disorders. Conclusion The results of this study suggest that depressive episodes often lead to a search for spirituality and that religion may be helpful in overcoming depression or becoming less vulnerable to relapsing. The associations between religion, spiritual values, and mental health have not been fully elucidated and warrant further exploration. PMID:22396682

Panic disorder with agoraphobia from a behavioral neuroscience perspective: Applying the research principles formulated by the Research Domain Criteria (RDoC) initiative.

PubMed

Hamm, Alfons O; Richter, Jan; Pané-Farré, Christiane; Westphal, Dorte; Wittchen, Hans-Ulrich; Vossbeck-Elsebusch, Anna N; Gerlach, Alexander L; Gloster, Andrew T; Ströhle, Andreas; Lang, Thomas; Kircher, Tilo; Gerdes, Antje B M; Alpers, Georg W; Reif, Andreas; Deckert, Jürgen

2016-03-01

In the current review, we reconceptualize a categorical diagnosis-panic disorder and agoraphobia-in terms of two constructs within the domain "negative valence systems" suggested by the Research Domain Criteria initiative. Panic attacks are considered as abrupt and intense fear responses to acute threat arising from inside the body, while anxious apprehension refers to anxiety responses to potential harm and more distant or uncertain threat. Taking a dimensional view, panic disorder with agoraphobia is defined with the threat-imminence model stating that defensive responses are dynamically organized along the dimension of the proximity of the threat. We tested this model within a large group of patients with panic disorder and agoraphobia (N = 369 and N = 124 in a replication sample) and found evidence that panic attacks are indeed instances of circa strike defense. This component of the defensive reactivity was related to genetic modulators within the serotonergic system. In contrast, anxious apprehension-characterized by attentive freezing during postencounter defense-was related to general distress and depressive mood, as well as to genetic modulations within the hypothalamic-pituitary-adrenal (HPA) axis. Patients with a strong behavioral tendency for active and passive avoidance responded better to exposure treatment if the therapist guides the patient through the exposure exercises. © 2016 Society for Psychophysiological Research.

Concurrent validity of persian version of wechsler intelligence scale for children - fourth edition and cognitive assessment system in patients with learning disorder.

PubMed

Rostami, Reza; Sadeghi, Vahid; Zarei, Jamileh; Haddadi, Parvaneh; Mohazzab-Torabi, Saman; Salamati, Payman

2013-04-01

The aim of this study was to compare the Persian version of the wechsler intelligence scale for children - fourth edition (WISC-IV) and cognitive assessment system (CAS) tests, to determine the correlation between their scales and to evaluate the probable concurrent validity of these tests in patients with learning disorders. One-hundered-sixty-two children with learning disorder who were presented at Atieh Comprehensive Psychiatry Center were selected in a consecutive non-randomized order. All of the patients were assessed based on WISC-IV and CAS scores questionnaires. Pearson correlation coefficient was used to analyze the correlation between the data and to assess the concurrent validity of the two tests. Linear regression was used for statistical modeling. The type one error was considered 5% in maximum. There was a strong correlation between total score of WISC-IV test and total score of CAS test in the patients (r=0.75, P<0.001). The correlations among the other scales were mostly high and all of them were statistically significant (P<0.001). A linear regression model was obtained (α = 0.51, β = 0.81 and P<0.001). There is an acceptable correlation between the WISC-IV scales and CAS test in children with learning disorders. A concurrent validity is established between the two tests and their scales.

Novel investigational therapeutics for panic disorder.

PubMed

Perna, Giampaolo; Schruers, Koen; Alciati, Alessandra; Caldirola, Daniela

2015-04-01

Panic disorder (PD) is a common disabling anxiety disorder associated with relevant social costs. Effective anti-panic medications exist but have several drawbacks. From a clinical perspective, there is still a strong unmet need for more effective, faster acting and more tolerable therapeutic treatments. The authors review the available results on novel mechanism-based anti-panic drugs that are under investigation in animal studies up to Phase II studies. The preclinical studies investigated include: the modulators of the glutamate/orexin/cannabinoid systems, corticotrophin-releasing factor 1 (CRF1)/arginine vasopressine V₁B/angiotensin II receptor antagonists and neuropeptide S. The Phase I/II studies investigated include: the modulators of the glutamate system, isoxazoline derivative, translocator protein (18 kDa) ligands and CRF1/neurokinin receptor antagonists. There has been little progress in recent times. However, glutamate- and orexin-related molecular targets may represent very promising opportunities for treating panic attacks. Very preliminary findings suggest that the antagonists of CRF1 and A-II receptors may have anti-panic properties. However, new medications for PD are far from being implemented in clinical use. The reasons are multiple, including: the heterogeneity of the disorder, the translational validity of animal models and the insufficient use of biomarkers in preclinical/clinical studies. Nevertheless, biomarker-based strategies, pharmacogenomics, 'personalized psychiatry' and the NIH's Research Domain Criteria approach could help to remove those obstacles limiting drug development.

Concurrent Validity of Persian Version of Wechsler Intelligence Scale for Children - Fourth Edition and Cognitive Assessment System in Patients with Learning Disorder

PubMed Central

Rostami, Reza; Sadeghi, Vahid; Zarei, Jamileh; Haddadi, Parvaneh; Mohazzab-Torabi, Saman; Salamati, Payman

2013-01-01

Objective The aim of this study was to compare the Persian version of the wechsler intelligence scale for children - fourth edition (WISC-IV) and cognitive assessment system (CAS) tests, to determine the correlation between their scales and to evaluate the probable concurrent validity of these tests in patients with learning disorders. Methods One-hundered-sixty-two children with learning disorder who were presented at Atieh Comprehensive Psychiatry Center were selected in a consecutive non-randomized order. All of the patients were assessed based on WISC-IV and CAS scores questionnaires. Pearson correlation coefficient was used to analyze the correlation between the data and to assess the concurrent validity of the two tests. Linear regression was used for statistical modeling. The type one error was considered 5% in maximum. Findings There was a strong correlation between total score of WISC-IV test and total score of CAS test in the patients (r=0.75, P<0.001). The correlations among the other scales were mostly high and all of them were statistically significant (P<0.001). A linear regression model was obtained (α = 0.51, β = 0.81 and P<0.001). Conclusion There is an acceptable correlation between the WISC-IV scales and CAS test in children with learning disorders. A concurrent validity is established between the two tests and their scales. PMID:23724180

Spin-glass-like freezing of inner and outer surface layers in hollow γ-Fe 2O 3 nanoparticles

DOE PAGES

Khurshid, Hafsa; Lampen-Kelley, Paula; Iglesias, Òscar; ...

2015-10-27

Disorder among surface spins largely dominates the magnetic response of ultrafine magnetic particle systems. In this work, we examine time-dependent magnetization in high-quality, monodisperse hollow maghemite nanoparticles (NPs) with a 14.8±0.5 nm outer diameter and enhanced surface-to-volume ratio. The nanoparticle ensemble exhibits spin-glass-like signatures in dc magnetic aging and memory protocols and ac magnetic susceptibility. The dynamics of the system slow near 50 K, and becomes frozen on experimental time scales below 20 K. Remanence curves indicate the development of magnetic irreversibility concurrent with the freezing of the spin dynamics. A strong exchange-bias effect and its training behavior point tomore » highly frustrated surface spins that rearrange much more slowly than interior spins with bulk coordination. Monte Carlo simulations of a hollow particle reproducing the experimental morphology corroborate strongly disordered surface layers with complex energy landscapes that underlie both glass-like dynamics and magnetic irreversibility. Calculated hysteresis loops reveal that magnetic behavior is not identical at the inner and outer surfaces, with spins at the outer surface layer of the 15 nm hollow particles exhibiting a higher degree of frustration. Lastly, our combined experimental and simulated results shed light on the origin of spin-glass-like phenomena and the important role played by the surface spins in magnetic hollow nanostructures.« less

Spin-glass-like freezing of inner and outer surface layers in hollow γ-Fe2O3 nanoparticles

PubMed Central

Khurshid, Hafsa; Lampen-Kelley, Paula; Iglesias, Òscar; Alonso, Javier; Phan, Manh-Huong; Sun, Cheng-Jun; Saboungi, Marie-Louise; Srikanth, Hariharan

2015-01-01

Disorder among surface spins is a dominant factor in the magnetic response of magnetic nanoparticle systems. In this work, we examine time-dependent magnetization in high-quality, monodisperse hollow maghemite nanoparticles (NPs) with a 14.8 ± 0.5 nm outer diameter and enhanced surface-to-volume ratio. The nanoparticle ensemble exhibits spin-glass-like signatures in dc magnetic aging and memory protocols and ac magnetic susceptibility. The dynamics of the system slow near 50 K, and become frozen on experimental time scales below 20 K. Remanence curves indicate the development of magnetic irreversibility concurrent with the freezing of the spin dynamics. A strong exchange-bias effect and its training behavior point to highly frustrated surface spins that rearrange much more slowly than interior spins. Monte Carlo simulations of a hollow particle corroborate strongly disordered surface layers with complex energy landscapes that underlie both glass-like dynamics and magnetic irreversibility. Calculated hysteresis loops reveal that magnetic behavior is not identical at the inner and outer surfaces, with spins at the outer surface layer of the 15 nm hollow particles exhibiting a higher degree of frustration. Our combined experimental and simulated results shed light on the origin of spin-glass-like phenomena and the important role played by the surface spins in magnetic hollow nanostructures. PMID:26503506

Endocannabinoid system and mood disorders: priming a target for new therapies.

PubMed

Micale, Vincenzo; Di Marzo, Vincenzo; Sulcova, Alexandra; Wotjak, Carsten T; Drago, Filippo

2013-04-01

The endocannabinoid system (ECS), comprising two G protein-coupled receptors (the cannabinoid receptors 1 and 2 [CB1 and CB2] for marijuana's psychoactive principle ∆(9)-tetrahydrocannabinol [∆(9)-THC]), their endogenous small lipid ligands (namely anandamide [AEA] and 2-arachidonoylglycerol [2-AG], also known as endocannabinoids), and the proteins for endocannabinoid biosynthesis and degradation, has been suggested as a pro-homeostatic and pleiotropic signaling system activated in a time- and tissue-specific way during physiopathological conditions. In the brain activation of this system modulates the release of excitatory and inhibitory neurotransmitters and of cytokines from glial cells. As such, the ECS is strongly involved in neuropsychiatric disorders, particularly in affective disturbances such as anxiety and depression. It has been proposed that synthetic molecules that inhibit endocannabinoid degradation can exploit the selectivity of endocannabinoid action, thus activating cannabinoid receptors only in those tissues where there is perturbed endocannabinoid turnover due to the disorder, and avoiding the potential side effects of direct CB1 and CB2 activation. However, the realization that endocannabinoids, and AEA in particular, also act at other molecular targets, and that these mediators can be deactivated by redundant pathways, has recently led to question the efficacy of such approach, thus opening the way to new multi-target therapeutic strategies, and to the use of non-psychotropic cannabinoids, such as cannabidiol (CBD), which act via several parallel mechanisms, including indirect interactions with the ECS. The state of the art of the possible therapeutic use of endocannabinoid deactivation inhibitors and phytocannabinoids in mood disorders is discussed in this review article. Copyright © 2012 Elsevier Inc. All rights reserved.

Relationships between Behavioural Addictions and Psychiatric Disorders: What Is Known and What Is Yet to Be Learned?

PubMed Central

Starcevic, Vladan; Khazaal, Yasser

2017-01-01

This article provides a narrative review of the relationships between several behavioural addictions [pathological gambling, problematic Internet use (PIU), problematic online gaming, compulsive sexual behaviour disorder, compulsive buying, and exercise addiction] and psychiatric disorders. Associations between most behavioural addictions and depressive and anxiety disorders are strong and seem relatively non-specific. Strong links with substance use disorders may support the notion that some people are more prone to addictive behaviours, regardless of whether these involve substances or problematic activities. Other associations seem relatively specific, for example, those between PIU/online gaming and attention-deficit/hyperactivity disorder, between compulsive buying on the one hand and eating disorders and hoarding on the other hand and between exercise addiction and eating disorders. The quality of the research varies, but most studies suffer from methodological limitations, including a cross-sectional or correlational design, non-representative study populations, small sample sizes, reliance on self-report assessment instruments, diverse diagnostic criteria, and conceptual heterogeneity of most behavioural addictions. Due to these limitations, generalisability of the findings is questionable and the direction of causality, if any, is unknown in the relationships between behavioural addictions and psychiatric disorders. Regardless of the aetiological uncertainty, these relationships often call for a modified treatment approach. Prospective studies are needed to clarify the longitudinal relationships between behavioural addictions and psychiatric disorders. PMID:28439243

Relationships between Behavioural Addictions and Psychiatric Disorders: What Is Known and What Is Yet to Be Learned?

PubMed

Starcevic, Vladan; Khazaal, Yasser

2017-01-01

This article provides a narrative review of the relationships between several behavioural addictions [pathological gambling, problematic Internet use (PIU), problematic online gaming, compulsive sexual behaviour disorder, compulsive buying, and exercise addiction] and psychiatric disorders. Associations between most behavioural addictions and depressive and anxiety disorders are strong and seem relatively non-specific. Strong links with substance use disorders may support the notion that some people are more prone to addictive behaviours, regardless of whether these involve substances or problematic activities. Other associations seem relatively specific, for example, those between PIU/online gaming and attention-deficit/hyperactivity disorder, between compulsive buying on the one hand and eating disorders and hoarding on the other hand and between exercise addiction and eating disorders. The quality of the research varies, but most studies suffer from methodological limitations, including a cross-sectional or correlational design, non-representative study populations, small sample sizes, reliance on self-report assessment instruments, diverse diagnostic criteria, and conceptual heterogeneity of most behavioural addictions. Due to these limitations, generalisability of the findings is questionable and the direction of causality, if any, is unknown in the relationships between behavioural addictions and psychiatric disorders. Regardless of the aetiological uncertainty, these relationships often call for a modified treatment approach. Prospective studies are needed to clarify the longitudinal relationships between behavioural addictions and psychiatric disorders.

Topology, localization, and quantum information in atomic, molecular and optical systems

NASA Astrophysics Data System (ADS)

Yao, Norman Ying

The scientific interface between atomic, molecular and optical (AMO) physics, condensed matter, and quantum information science has recently led to the development of new insights and tools that bridge the gap between macroscopic quantum behavior and detailed microscopic intuition. While the dialogue between these fields has sharpened our understanding of quantum theory, it has also raised a bevy of new questions regarding the out-of-equilibrium dynamics and control of many-body systems. This thesis is motivated by experimental advances that make it possible to produce and probe isolated, strongly interacting ensembles of disordered particles, as found in systems ranging from trapped ions and Rydberg atoms to ultracold polar molecules and spin defects in the solid state. The presence of strong interactions in these systems underlies their potential for exploring correlated many-body physics and this thesis presents recent results on realizing fractionalization and localization. From a complementary perspective, the controlled manipulation of individual quanta can also enable the bottom-up construction of quantum devices. To this end, this thesis also describes blueprints for a room-temperature quantum computer, quantum credit cards and nanoscale quantum thermometry.

Personality and Psychiatric Disorders in Women Affected by Polycystic Ovary Syndrome

PubMed Central

Scaruffi, Elisabetta; Gambineri, Alessandra; Cattaneo, Stefania; Turra, Jenni; Vettor, Roberto; Mioni, Roberto

2014-01-01

Background: Polycystic ovary syndrome (PCOS) is the most prevalent endocrine disorder among fertile women. Studies show reduced quality of life, anxiety, depression, body dissatisfaction, eating disorder, and sexual dysfunction, but the etiology of these disturbs remains still debated. The aim of our study is to verify whether this hyperandrogenic syndrome characterizes a strong psycho(patho)logical personality. Method: Sixty PCOS subjects (mean age 25.8 ± 4.7 years) were evaluated by anthropometric, metabolic, hormonal, clinical, and psychological parameters. After the certainty of the diagnosis of PCOS, the Rorschach test, according to Exner’s comprehensive system (CS) and the Millon Clinical Multiaxial Inventory-III (MCMI-III) were administered to each patient. The control group, on which the comparison was carried out, was composed by 40 healthy and aged compared women who were exclusively administered the Rorschach test according to CS. Results: MCMI-III evidenced axis II DSM-IV personality disorders [4.1% schizoid, depressive, sadistic, negativistic (passive–aggressive), and masochistic, 6.1% avoiding, 12.2% dependent, 20.4% histrionic, 16.3% narcissistic, 2.0% obsessive–compulsive], and axis I DSM-IV psychiatric disorders: 10.2% anxiety, 2.0% somatoform disorder and bipolar disorder, 16.3% major depressive disorder. Finally, we found 44.9% delusional disorder and 4.1% thought disorder. Rorschach test’s results show 53.1% reduced coping abilities and social skills, 55.1% depression, 30.6% perceptual distortion and cognitive slippage, 24.5% constantly alert and worry, 8.1% at risk for suicide, and finally about 50% of our patients had chronic stress. Conclusion: PCOS women have relevant personality and psychiatric disorders, when compared with normal subjects. PMID:25429283

FAMILY ANALYSIS OF IMMUNOGLOBULIN CLASSES AND SUBCLASSES IN CHILDREN WITH AUTISTIC DISORDER

PubMed Central

Spiroski, Mirko; Trajkovski, Vladimir; Trajkov, Dejan; Petlichkovski, Aleksandar; Efinska-Mladenovska, Olivija; Hristomanova, Slavica; Djulejic, Eli; Paneva, Meri; Bozhikov, Jadranka

2009-01-01

Autistic disorder is a severe neurodevelopment disorder characterized by a triad of impairments in reciprocal social interaction, verbal and nonverbal communication, and a pattern of repetitive stereotyped activities, behaviours and interests. There are strong lines of evidence to suggest that the immune system plays an important role in the pathogenesis of autistic disorder. The aim of this study was to analyze quantitative plasma concentration of immunoglobulin classes, and subclasses in autistic patients and their families. The investigation was performed retrospectively in 50 persons with autistic disorder in the Republic of Macedonia. Infantile autistic disorder was diagnosed by DSM-IV and ICD-10 criteria. Plasma immunoglobulin classes (IgM, IgA, and IgG) and subclasses (IgG1, IgG2, IgG3, and IgG4) were determined using Nephelometer Analyzer BN-100. Multiple comparisons for the IgA variable have shown statistically significant differences between three pairs: male autistic from the fathers (p = 0,001), female autistic from the mothers (p = 0,008), as well as healthy sisters from the fathers (p = 0,011). Statistically significant differences found between three groups regarding autistic disorder (person with autistic disorder, father/mother of a person with autistic disorder, and brother/sister) independent of sex belongs to IgA, IgG2, and IgG3 variables. Multiple comparisons for the IgA variable have shown statistically significant differences between children with autistic disorder from the fathers and mothers (p < 0,001), and healthy brothers and sisters from the fathers and mothers (p < 0,001). Comparison between healthy children and children with autistic disorder from the same family should be tested for immunoglobulin classes and subclasses in order to avoid differences between generations. PMID:20001993

Family analysis of immunoglobulin classes and subclasses in children with autistic disorder.

PubMed

Spiroski, Mirko; Trajkovski, Vladimir; Trajkov, Dejan; Petlichkovski, Aleksandar; Efinska-Mladenovska, Olivija; Hristomanova, Slavica; Djulejic, Eli; Paneva, Meri; Bozhikov, Jadranka

2009-11-01

Autistic disorder is a severe neurodevelopment disorder characterized by a triad of impairments in reciprocal social interaction, verbal and nonverbal communication, and a pattern of repetitive stereotyped activities, behaviours and interests. There are strong lines of evidence to suggest that the immune system plays an important role in the pathogenesis of autistic disorder. The aim of this study was to analyze quantitative plasma concentration of immunoglobulin classes, and subclasses in autistic patients and their families. The investigation was performed retrospectively in 50 persons with autistic disorder in the Republic of Macedonia. Infantile autistic disorder was diagnosed by DSM-IV and ICD-10 criteria. Plasma immunoglobulin classes (IgM, IgA, and IgG) and subclasses (IgG1, IgG2, IgG3, and IgG4) were determined using Nephelometer Analyzer BN-100. Multiple comparisons for the IgA variable have shown statistically significant differences between three pairs: male autistic from the fathers (p = 0,001), female autistic from the mothers (p = 0,008), as well as healthy sisters from the fathers (p = 0,011). Statistically significant differences found between three groups regarding autistic disorder (person with autistic disorder, father/mother of a person with autistic disorder, and brother/sister) independent of sex belongs to IgA, IgG2, and IgG3 variables. Multiple comparisons for the IgA variable have shown statistically significant differences between children with autistic disorder from the fathers and mothers (p < 0,001), and healthy brothers and sisters from the fathers and mothers (p < 0,001). Comparison between healthy children and children with autistic disorder from the same family should be tested for immunoglobulin classes and subclasses in order to avoid differences between generations.

Exploration of 19 serotoninergic candidate genes in adults and children with attention-deficit/hyperactivity disorder identifies association for 5HT2A, DDC and MAOB.

PubMed

Ribasés, M; Ramos-Quiroga, J A; Hervás, A; Bosch, R; Bielsa, A; Gastaminza, X; Artigas, J; Rodriguez-Ben, S; Estivill, X; Casas, M; Cormand, B; Bayés, M

2009-01-01

Attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric disorder in which different genetic and environmental susceptibility factors are involved. Several lines of evidence support the view that at least 30% of ADHD patients diagnosed in childhood continue to suffer the disorder during adulthood and that genetic risk factors may play an essential role in the persistence of the disorder throughout lifespan. Genetic, biochemical and pharmacological studies support the idea that the serotonin system participates in the etiology of ADHD. Based on these data, we aimed to analyze single nucleotide polymorphisms across 19 genes involved in the serotoninergic neurotransmission in a clinical sample of 451 ADHD patients (188 adults and 263 children) and 400 controls using a population-based association study. Several significant associations were found after correcting for multiple testing: (1) the DDC gene was strongly associated with both adulthood (P=0.00053; odds ratio (OR)=2.17) and childhood ADHD (P=0.0017; OR=1.90); (2) the MAOB gene was found specifically associated in the adult ADHD sample (P=0.0029; OR=1.90) and (3) the 5HT2A gene showed evidence of association only with the combined ADHD subtype both in adults (P=0.0036; OR=1.63) and children (P=0.0084; OR=1.49). Our data support the contribution of the serotoninergic system in the genetic predisposition to ADHD, identifying common childhood and adulthood ADHD susceptibility factors, associations that are specific to ADHD subtypes and one variant potentially involved in the continuity of the disorder throughout lifespan.

The Contribution of Epigenetics to Understanding Genetic Factors in Autism

ERIC Educational Resources Information Center

Hall, Layla; Kelley, Elizabeth

2014-01-01

Autism spectrum disorder is a grouping of neurodevelopmental disorders characterized by deficits in social communication and language, as well as by repetitive and stereotyped behaviors. While the environment is believed to play a role in the development of autism spectrum disorder, there is now strong evidence for a genetic link to autism.…

Psychosocial Outcomes at 15 Years of Children with a Preschool History of Speech-Language Impairment

ERIC Educational Resources Information Center

Snowling, Margaret J.; Bishop, D. V. M.; Stothard, Susan E.; Chipchase, Barry; Kaplan, Carole

2006-01-01

Background: Evidence suggests there is a heightened risk of psychiatric disorder in children with speech-language impairments. However, not all forms of language impairment are strongly associated with psychosocial difficulty, and some psychiatric disorders (e.g., attention deficit/hyperactivity disorder (ADHD)) are more prevalent than others in…

Application of Fuzzy Logic in Oral Cancer Risk Assessment

PubMed Central

SCROBOTĂ, Ioana; BĂCIUȚ, Grigore; FILIP, Adriana Gabriela; TODOR, Bianca; BLAGA, Florin; BĂCIUȚ, Mihaela Felicia

2017-01-01

Background: The mapping of the malignization mechanism is still incomplete, but oxidative stress is strongly correlated to carcinogenesis. In our research, using fuzzy logic, we aimed to estimate the oxidative stress related-cancerization risk of the oral potentially malignant disorders. Methods: Serum from 16 patients diagnosed (clinical and histopathological) with oral potentially malignant disorders (Dept. of Cranio-Maxillofacial Surgery and Radiology, ”Iuliu Hațieganu” University of Medicine and Pharmacy, Cluj Napoca, Romania) was processed fluorometric for malondialdehyde and proton donors assays (Dept. of Physiology,”Iuliu Hațieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania). The values were used as inputs, they were associated linguistic terms using MIN-MAX method and 25 IF-THEN inference rules were generated to estimate the output value, the cancerization risk appreciated on a scale from 1 to 10 - IF malondialdehyde is very high and donors protons are very low THEN the cancer risk is reaching the maximum value (Dept. of Industrial Engineering, Faculty of Managerial and Technological Engineering, University of Oradea, Oradea, Romania) (2012–2014). Results: We estimated the cancerization risk of the oral potentially malignant disorders by implementing the multi-criteria decision support system based on serum malondialdehyde and proton donors’ values. The risk was estimated as a concrete numerical value on a scale from 1 to 10 depending on the input numerical/linguistic value. Conclusion: The multi-criteria decision support system proposed by us, integrated into a more complex computerized decision support system, could be used as an important aid in oral cancer screening and establish future medical decision in oral potentially malignant disorders. PMID:28560191

Application of Fuzzy Logic in Oral Cancer Risk Assessment.

PubMed

Scrobotă, Ioana; Băciuț, Grigore; Filip, Adriana Gabriela; Todor, Bianca; Blaga, Florin; Băciuț, Mihaela Felicia

2017-05-01

The mapping of the malignization mechanism is still incomplete, but oxidative stress is strongly correlated to carcinogenesis. In our research, using fuzzy logic, we aimed to estimate the oxidative stress related-cancerization risk of the oral potentially malignant disorders. Serum from 16 patients diagnosed (clinical and histopathological) with oral potentially malignant disorders (Dept. of Cranio-Maxillofacial Surgery and Radiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, Cluj Napoca, Romania) was processed fluorometric for malondialdehyde and proton donors assays (Dept. of Physiology,"Iuliu Hațieganu" University of Medicine and Pharmacy, Cluj-Napoca, Romania). The values were used as inputs, they were associated linguistic terms using MIN-MAX method and 25 IF-THEN inference rules were generated to estimate the output value, the cancerization risk appreciated on a scale from 1 to 10 - IF malondialdehyde is very high and donors protons are very low THEN the cancer risk is reaching the maximum value (Dept. of Industrial Engineering, Faculty of Managerial and Technological Engineering, University of Oradea, Oradea, Romania) (2012-2014). We estimated the cancerization risk of the oral potentially malignant disorders by implementing the multi-criteria decision support system based on serum malondialdehyde and proton donors' values. The risk was estimated as a concrete numerical value on a scale from 1 to 10 depending on the input numerical/linguistic value. The multi-criteria decision support system proposed by us, integrated into a more complex computerized decision support system, could be used as an important aid in oral cancer screening and establish future medical decision in oral potentially malignant disorders.

Dyscalculia and the Calculating Brain.

PubMed

Rapin, Isabelle

2016-08-01

Dyscalculia, like dyslexia, affects some 5% of school-age children but has received much less investigative attention. In two thirds of affected children, dyscalculia is associated with another developmental disorder like dyslexia, attention-deficit disorder, anxiety disorder, visual and spatial disorder, or cultural deprivation. Infants, primates, some birds, and other animals are born with the innate ability, called subitizing, to tell at a glance whether small sets of scattered dots or other items differ by one or more item. This nonverbal approximate number system extends mostly to single digit sets as visual discrimination drops logarithmically to "many" with increasing numerosity (size effect) and crowding (distance effect). Preschoolers need several years and specific teaching to learn verbal names and visual symbols for numbers and school agers to understand their cardinality and ordinality and the invariance of their sequence (arithmetic number line) that enables calculation. This arithmetic linear line differs drastically from the nonlinear approximate number system mental number line that parallels the individual number-tuned neurons in the intraparietal sulcus in monkeys and overlying scalp distribution of discrete functional magnetic resonance imaging activations by number tasks in man. Calculation is a complex skill that activates both visual and spatial and visual and verbal networks. It is less strongly left lateralized than language, with approximate number system activation somewhat more right sided and exact number and arithmetic activation more left sided. Maturation and increasing number skill decrease associated widespread non-numerical brain activations that persist in some individuals with dyscalculia, which has no single, universal neurological cause or underlying mechanism in all affected individuals. Copyright © 2016 Elsevier Inc. All rights reserved.

Random hopping fermions on bipartite lattices: density of states, inverse participation ratios, and their correlations in a strong disorder regime

NASA Astrophysics Data System (ADS)

Yamada, Hiroki; Fukui, Takahiro

2004-02-01

We study Anderson localization of non-interacting random hopping fermions on bipartite lattices in two dimensions, focusing our attention to strong disorder features of the model. We concentrate ourselves on specific models with a linear dispersion in the vicinity of the band center, which can be described by a Dirac fermion in the continuum limit. Based on the recent renormalization group method developed by Carpentier and Le Doussal for the XY gauge glass model, we calculate the density of states, inverse participation ratios, and their spatial correlations. It turns out that their behavior is quite different from those expected within naive weak disorder approaches.

Phonons in random alloys: The itinerant coherent-potential approximation

NASA Astrophysics Data System (ADS)

Ghosh, Subhradip; Leath, P. L.; Cohen, Morrel H.

2002-12-01

We present the itinerant coherent-potential approximation (ICPA), an analytic, translationally invariant, and tractable form of augmented-space-based multiple-scattering theory18 in a single-site approximation for harmonic phonons in realistic random binary alloys with mass and force-constant disorder. We provide expressions for quantities needed for comparison with experimental structure factors such as partial and average spectral functions and derive the sum rules associated with them. Numerical results are presented for Ni55Pd45 and Ni50Pt50 alloys which serve as test cases, the former for weak force-constant disorder and the latter for strong. We present results on dispersion curves and disorder-induced widths. Direct comparisons with the single-site coherent potential approximation (CPA) and experiment are made which provide insight into the physics of force-constant changes in random alloys. The CPA accounts well for the weak force-constant disorder case but fails for strong force-constant disorder where the ICPA succeeds.

Prevalence and correlates of eating disorders among Asian Americans: results from the National Latino and Asian American Study.

PubMed

Nicdao, Ethel G; Hong, Seunghye; Takeuchi, David T

2007-11-01

Our study examines lifetime and 12-month prevalence estimates of eating disorders in Asian American men and women. We also report on the association between social factors and eating disorders, BMI categories, treatment, and impairment. We use data from the National Latino and Asian American Study, a nationally representative survey of the U.S. household population of Latino and Asian Americans. Our present study is based on data from the sample of Asian Americans (N = 2,095). Overall, Asian Americans present with low prevalence for eating disorders. Only lifetime prevalence for binge eating disorder (BED) is significantly higher for Asian women compared to Asian men. Our results show that age is strongly associated with BED and any binge eating. High current BMI of 30-39.9 and >or=40 is strongly associated with BED and any binge eating. Treatment utilization is low, and respondents reported some role impairment. Our findings show that despite low prevalence estimates, eating disorders are present among Asian American men and women. Our data suggest that researchers consider more flexibility in defining and classifying eating disorders, to better detect and measure the prevalence of eating disorders among Asian Americans. (c) 2007 by Wiley Periodicals, Inc.

Entanglement between random and clean quantum spin chains

NASA Astrophysics Data System (ADS)

Juhász, Róbert; Kovács, István A.; Roósz, Gergő; Iglói, Ferenc

2017-08-01

The entanglement entropy in clean, as well as in random quantum spin chains has a logarithmic size-dependence at the critical point. Here, we study the entanglement of composite systems that consist of a clean subsystem and a random subsystem, both being critical. In the composite, antiferromagnetic XX-chain with a sharp interface, the entropy is found to grow in a double-logarithmic fashion {{ S}}∼ \\ln\\ln(L) , where L is the length of the chain. We have also considered an extended defect at the interface, where the disorder penetrates into the homogeneous region in such a way that the strength of disorder decays with the distance l from the contact point as  ∼l-κ . For κ<1/2 , the entropy scales as {{ S}}(κ) ≃ \\frac{\\ln 2 (1-2κ)}{6}{\\ln L} , while for κ ≥slant 1/2 , when the extended interface defect is an irrelevant perturbation, we recover the double-logarithmic scaling. These results are explained through strong-disorder RG arguments.

'Look at me when I am talking to you': evidence and assessment of social pragmatics interventions for children with autism and social communication disorders.

PubMed

Tierney, Cheryl D; Kurtz, Marie; Panchik, Ann; Pitterle, Kathleen

2014-04-01

This article provides an analysis of the effectiveness of commonly used interventions for social pragmatic interventions for children with autism spectrum disorder (ASD) and social communication disorders. Several evidence-based social skills interventions are emerging, including peer mentoring, social skills groups, and video modeling. Social stories are effective as supports for improved interactions but generalization is limited. Research supports the need for multimodality and individualized treatment programs. Research validates that video and visual learning is highly effective with children with ASD when utilized with specific, appropriate targets. Multiple studies have shown that picture-based communication systems are effective at improving functional communication with moderate effects on social communication. Despite limitations in research, there is strong evidence in the existing literature for the role of alternative augmentative communication in improving both functional and social communication. Social pragmatic interventions when individualized are effective for improving language, adaptive behavior and social skills.

Omics analysis of mouse brain models of human diseases.

PubMed

Paban, Véronique; Loriod, Béatrice; Villard, Claude; Buee, Luc; Blum, David; Pietropaolo, Susanna; Cho, Yoon H; Gory-Faure, Sylvie; Mansour, Elodie; Gharbi, Ali; Alescio-Lautier, Béatrice

2017-02-05

The identification of common gene/protein profiles related to brain alterations, if they exist, may indicate the convergence of the pathogenic mechanisms driving brain disorders. Six genetically engineered mouse lines modelling neurodegenerative diseases and neuropsychiatric disorders were considered. Omics approaches, including transcriptomic and proteomic methods, were used. The gene/protein lists were used for inter-disease comparisons and further functional and network investigations. When the inter-disease comparison was performed using the gene symbol identifiers, the number of genes/proteins involved in multiple diseases decreased rapidly. Thus, no genes/proteins were shared by all 6 mouse models. Only one gene/protein (Gfap) was shared among 4 disorders, providing strong evidence that a common molecular signature does not exist among brain diseases. The inter-disease comparison of functional processes showed the involvement of a few major biological processes indicating that brain diseases of diverse aetiologies might utilize common biological pathways in the nervous system, without necessarily involving similar molecules. Copyright © 2016 Elsevier B.V. All rights reserved.

Nonmonotonic Aging and Memory in a Frictional Interface

NASA Astrophysics Data System (ADS)

Dillavou, Sam; Rubinstein, Shmuel M.

2018-06-01

We measure the static frictional resistance and the real area of contact between two solid blocks subjected to a normal load. We show that following a two-step change in the normal load the system exhibits nonmonotonic aging and memory effects, two hallmarks of glassy dynamics. These dynamics are strongly influenced by the discrete geometry of the frictional interface, characterized by the attachment and detachment of unique microcontacts. The results are in good agreement with a theoretical model we propose that incorporates this geometry into the framework recently used to describe Kovacs-like relaxation in glasses as well as thermal disordered systems. These results indicate that a frictional interface is a glassy system and strengthen the notion that nonmonotonic relaxation behavior is generic in such systems.

What virtual reality research in addictions can tell us about the future of obesity assessment and treatment.

PubMed

Bordnick, Patrick S; Carter, Brian L; Traylor, Amy C

2011-03-01

Virtual reality (VR), a system of human-computer interaction that allows researchers and clinicians to immerse people in virtual worlds, is gaining considerable traction as a research, education, and treatment tool. Virtual reality has been used successfully to treat anxiety disorders such as fear of flying and post-traumatic stress disorder, as an aid in stroke rehabilitation, and as a behavior modification aid in the treatment of attention deficit disorder. Virtual reality has also been employed in research on addictive disorders. Given the strong evidence that drug-dependent people are highly prone to use and relapse in the presence of environmental stimuli associated with drug use, VR is an ideal platform from which to study this relationship. Research using VR has shown that drug-dependent people react with strong craving to specific cues (e.g., cigarette packs, liquor bottles) as well as environments or settings (e.g., bar, party) associated with drug use. Virtual reality has also been used to enhance learning and generalization of relapse prevention skills in smokers by reinforcing these skills in lifelike environments. Obesity researchers and treatment professionals, building on the lessons learned from VR research in substance abuse, have the opportunity to adapt these methods for investigating their own research and treatment questions. Virtual reality is ideally suited to investigate the link between food cues and environmental settings with eating behaviors and self-report of hunger. In addition, VR can be used as a treatment tool for enhancing behavior modification goals to support healthy eating habits by reinforcing these goals in life-like situations. © 2011 Diabetes Technology Society.

FRACTAL DIMENSION OF SPIN-GLASSES INTERFACES IN DIMENSION d = 2 AND d = 3 VIA STRONG DISORDER RENORMALIZATION AT ZERO TEMPERATURE

NASA Astrophysics Data System (ADS)

Monthus, Cécile

2015-09-01

For Gaussian Spin-Glasses in low dimensions, we introduce a simple Strong Disorder renormalization at zero temperature in order to construct ground states for Periodic and Anti-Periodic boundary conditions. The numerical study in dimensions d = 2 (up to sizes 20482) and d = 3 (up to sizes 1283) yields that Domain Walls are fractal of dimensions ds(d = 2) ≃ 1.27 and ds(d = 3) ≃ 2.55, respectively.

Cross-cultural comparison of the sleep-disordered breathing prevalence among Americans and Japanese

PubMed Central

Yamagishi, Kazumasa; Ohira, Tetsuya; Nakano, Hiroshi; Bielinski, Suzette J.; Sakurai, Susumu; Imano, Hironori; Kiyama, Masahiko; Kitamura, Akihiko; Sato, Shinichi; Konishi, Masamitsu; Shahar, Eyal; Folsom, Aaron R.; Iso, Hiroyasu; Tanigawa, Takeshi

2010-01-01

To compare the sleep-disordered breathing prevalence among Hispanic and white Americans and Japanese, we performed a one-night sleep study with a single channel airflow monitor on 211 Hispanics and 246 whites from the Minnesota Field Center of the Multi-Ethnic Study of Atherosclerosis (MESA), and 978 Japanese from three community-based cohorts of the Circulatory Risk in Communities Study (CIRCS) in Japan. The respiratory disturbance index and sleep-disordered breathing, defined as respiratory disturbance index ≥ 15 disturbances/hr, were estimated. The sleep-disordered breathing prevalence was higher in men (34.2%) than women (14.8%), and higher among Hispanics (36.5%) and whites (33.3%) than among Japanese (18.4%), corresponding to differences in body mass index. Within body mass index strata, the race difference in sleep-disordered breathing was attenuated. This was also true when we adjusted for body mass index instead of stratification. The strong association between body mass index and sleep-disordered breathing was similar in Japanese and Americans. The sleep-disordered breathing prevalence was lower among Japanese than the Americans. However, the association of body mass index with sleep-disordered breathing was strong, and similar among the race/ethnic groups studied. The majority of the race/ethnic difference in sleep-disordered breathing prevalence was explained by a difference in body mass index distribution. PMID:20110399

Mental capacity, diagnosis and insight in psychiatric in-patients: a cross-sectional study.

PubMed

Owen, G S; David, A S; Richardson, G; Szmukler, G; Hayward, P; Hotopf, M

2009-08-01

Mental capacity is now a core part of UK mental health law and clinicians will increasingly be expected to assess it. Because it is a legal concept there is a need to clarify associations with variables that clinicians are more familiar with, especially insight. In this cross-sectional study we recruited consecutive psychiatric admissions to the Maudsley Hospital, London. We carried out structured assessments of decision making using the MacArthur Competence Assessment Tool for Treatment (MacCAT-T), resulting in a clinical judgement about capacity status. We analysed associations with a range of sociodemographic and clinical variables, including insight score on the Expanded Schedule for the Assessment of Insight (SAI-E). The same variables were compared in an analysis stratified according to diagnostic group: psychotic disorders/bipolar affective disorder (BPAD)/non-psychotic disorders. Psychotic disorders and manic episodes of BPAD are most strongly associated with incapacity. In such patients, insight is the best discriminator of capacity status. In patients with non-psychotic disorders, insight is less strongly associated with capacity; in this group depressed mood discriminates capacity status whereas it does not in psychotic disorders. Cognitive performance does not discriminate capacity status in patients with psychotic disorders. Mental capacity has complex relationships with psychopathological variables, and these relationships are different according to diagnostic group. Insight is the best discriminator of capacity status in psychotic disorders and BPAD but not in non-psychotic disorders.

A Parallel Process Growth Model of Avoidant Personality Disorder Symptoms and Personality Traits

PubMed Central

Wright, Aidan G. C.; Pincus, Aaron L.; Lenzenweger, Mark F.

2012-01-01

Background Avoidant personality disorder (AVPD), like other personality disorders, has historically been construed as a highly stable disorder. However, results from a number of longitudinal studies have found that the symptoms of AVPD demonstrate marked change over time. Little is known about which other psychological systems are related to this change. Although cross-sectional research suggests a strong relationship between AVPD and personality traits, no work has examined the relationship of their change trajectories. The current study sought to establish the longitudinal relationship between AVPD and basic personality traits using parallel process growth curve modeling. Methods Parallel process growth curve modeling was applied to the trajectories of AVPD and basic personality traits from the Longitudinal Study of Personality Disorders (Lenzenweger, 2006), a naturalistic, prospective, multiwave, longitudinal study of personality disorder, temperament, and normal personality. The focus of these analyses is on the relationship between the rates of change in both AVPD symptoms and basic personality traits. Results AVPD symptom trajectories demonstrated significant negative relationships with the trajectories of interpersonal dominance and affiliation, and a significant positive relationship to rates of change in neuroticism. Conclusions These results provide some of the first compelling evidence that trajectories of change in PD symptoms and personality traits are linked. These results have important implications for the ways in which temporal stability is conceptualized in AVPD specifically, and PD in general. PMID:22506627

Immune system gene dysregulation in autism and schizophrenia.

PubMed

Michel, Maximilian; Schmidt, Martin J; Mirnics, Karoly

2012-10-01

Gene*environment interactions play critical roles in the emergence of autism and schizophrenia pathophysiology. In both disorders, recent genetic association studies have provided evidence for disease-linked variation in immune system genes and postmortem gene expression studies have shown extensive chronic immune abnormalities in brains of diseased subjects. Furthermore, peripheral biomarker studies revealed that both innate and adaptive immune systems are dysregulated. In both disorders symptoms of the disease correlate with the immune system dysfunction; yet, in autism this process appears to be chronic and sustained, while in schizophrenia it is exacerbated during acute episodes. Furthermore, since immune abnormalities endure into adulthood and anti-inflammatory agents appear to be beneficial, it is likely that these immune changes actively contribute to disease symptoms. Modeling these changes in animals provided further evidence that prenatal maternal immune activation alters neurodevelopment and leads to behavioral changes that are relevant for autism and schizophrenia. The converging evidence strongly argues that neurodevelopmental immune insults and genetic background critically interact and result in increased risk for either autism or schizophrenia. Further research in these areas may improve prenatal health screening in genetically at-risk families and may also lead to new preventive and/or therapeutic strategies. Copyright © 2012 Wiley Periodicals, Inc.

Probiotics and Prebiotics: Present Status and Future Perspectives on Metabolic Disorders.

PubMed

Yoo, Ji Youn; Kim, Sung Soo

2016-03-18

Metabolic disorders, including type 2 diabetes (T2DM) and cardiovascular disease (CVD), present an increasing public health concern and can significantly undermine an individual's quality of life. The relative risk of CVD, the primary cause of death in T2DM patients, is two to four times higher in people with T2DM compared with those who are non-diabetic. The prevalence of metabolic disorders has been associated with dynamic changes in dietary macronutrient intake and lifestyle changes over recent decades. Recently, the scientific community has considered alteration in gut microbiota composition to constitute one of the most probable factors in the development of metabolic disorders. The altered gut microbiota composition is strongly conducive to increased adiposity, β-cell dysfunction, metabolic endotoxemia, systemic inflammation, and oxidative stress. Probiotics and prebiotics can ameliorate T2DM and CVD through improvement of gut microbiota, which in turn leads to insulin-signaling stimulation and cholesterol-lowering effects. We analyze the currently available data to ascertain further potential benefits and limitations of probiotics and prebiotics in the treatment of metabolic disorders, including T2DM, CVD, and other disease (obesity). The current paper explores the relevant contemporary scientific literature to assist in the derivation of a general perspective of this broad area.

Probiotics and Prebiotics: Present Status and Future Perspectives on Metabolic Disorders

PubMed Central

Yoo, Ji Youn; Kim, Sung Soo

2016-01-01

Metabolic disorders, including type 2 diabetes (T2DM) and cardiovascular disease (CVD), present an increasing public health concern and can significantly undermine an individual’s quality of life. The relative risk of CVD, the primary cause of death in T2DM patients, is two to four times higher in people with T2DM compared with those who are non-diabetic. The prevalence of metabolic disorders has been associated with dynamic changes in dietary macronutrient intake and lifestyle changes over recent decades. Recently, the scientific community has considered alteration in gut microbiota composition to constitute one of the most probable factors in the development of metabolic disorders. The altered gut microbiota composition is strongly conducive to increased adiposity, β-cell dysfunction, metabolic endotoxemia, systemic inflammation, and oxidative stress. Probiotics and prebiotics can ameliorate T2DM and CVD through improvement of gut microbiota, which in turn leads to insulin-signaling stimulation and cholesterol-lowering effects. We analyze the currently available data to ascertain further potential benefits and limitations of probiotics and prebiotics in the treatment of metabolic disorders, including T2DM, CVD, and other disease (obesity). The current paper explores the relevant contemporary scientific literature to assist in the derivation of a general perspective of this broad area. PMID:26999199

Infinite-disorder critical points of models with stretched exponential interactions

NASA Astrophysics Data System (ADS)

Juhász, Róbert

2014-09-01

We show that an interaction decaying as a stretched exponential function of distance, J(l)˜ e-cl^a , is able to alter the universality class of short-range systems having an infinite-disorder critical point. To do so, we study the low-energy properties of the random transverse-field Ising chain with the above form of interaction by a strong-disorder renormalization group (SDRG) approach. We find that the critical behavior of the model is controlled by infinite-disorder fixed points different from those of the short-range model if 0 < a < 1/2. In this range, the critical exponents calculated analytically by a simplified SDRG scheme are found to vary with a, while, for a > 1/2, the model belongs to the same universality class as its short-range variant. The entanglement entropy of a block of size L increases logarithmically with L at the critical point but, unlike the short-range model, the prefactor is dependent on disorder in the range 0 < a < 1/2. Numerical results obtained by an improved SDRG scheme are found to be in agreement with the analytical predictions. The same fixed points are expected to describe the critical behavior of, among others, the random contact process with stretched exponentially decaying activation rates.

Augmentative and alternative communication supports for adults with autism spectrum disorders.

PubMed

Trembath, David; Iacono, Teresa; Lyon, Katie; West, Denise; Johnson, Hilary

2014-11-01

Many adults with autism spectrum disorders have complex communication needs and may benefit from the use of augmentative and alternative communication. However, there is a lack of research examining the specific communication needs of these adults, let alone the outcomes of interventions aimed at addressing them. The aim of this study was to explore the views and experiences of support workers and family members regarding the outcomes of providing low-technology communication aids to adults with autism spectrum disorders. The participants were six support workers and two family members of six men and women with autism spectrum disorders, who had received low-technology communication aids. Using semi-structured, in-depth interviews and following thematic analysis, the results revealed strong support for, and the potential benefits of, augmentative and alternative communication for both adults with autism spectrum disorders and their communication partners. The results also revealed inconsistencies in the actions taken to support the use of the prescribed augmentative and alternative communication systems, pointing to the clinical need to address common barriers to the provision of augmentative and alternative communication support. These barriers include organisational practices and limitations in the knowledge and skills of key stakeholders, as well as problematic attitudes. © The Author(s) 2013.

Moebius Sequence and Autism Spectrum Disorders--Less Frequently Associated than Formerly Thought

ERIC Educational Resources Information Center

Briegel, Wolfgang; Schimek, Martina; Kamp-Becker, Inge

2010-01-01

Moebius sequence is a rare congenital disorder usually defined as a combination of facial weakness with impairment of ocular abduction. It is questionable, whether there is a strong association of the sequence with autism spectrum disorders (ASDs) as suggested in some earlier case reports and studies. Twenty-two participants with Moebius sequence…

Applications of the Dot Probe Task in Attentional Bias Research in Eating Disorders: A Review

ERIC Educational Resources Information Center

Starzomska, Malgorzata

2017-01-01

Recent years have seen an increasing interest in the cognitive approach to eating disorders, which postulates that patients selectively attend to information associated with eating, body shape, and body weight. The unreliability of self-report measures in eating disorders due to strong denial of illness gave rise to experimental studies inspired…

Desire for Thinness among High School Cheerleaders: Relationship to Disordered Eating and Weight Control Behaviors.

ERIC Educational Resources Information Center

Lundholm, Jean K.; Littrell, John M.

1986-01-01

Examined cheerleaders' desire for thinness in relationship to disordered eating and weight control behaviors. A Desire for Thinness Scale and selected scales from three eating disorder instruments were administered to 751 high school cheerleaders. Cheerleaders who expressed a strong desire for thinness had significantly higher scores on seven of…

The Effect of Autism Spectrum Disorders on Adaptive Independent Living Skills in Adults with Severe Intellectual Disability

ERIC Educational Resources Information Center

Matson, Johnny L.; Dempsey, Timothy; Fodstad, Jill C.

2009-01-01

Autism Spectrum Disorders are a class of conditions categorized by communication problems, ritualistic behaviors, and deficits in social behaviors. While evidence supporting a genetic component of Autism Spectrum Disorders (ASDs) is strong, no specific genetic marker has been identified. Thus, professionals have had to utilize intelligence tests…

Observation of migrating transverse Anderson localizations of light in nonlocal media.

PubMed

Leonetti, Marco; Karbasi, Salman; Mafi, Arash; Conti, Claudio

2014-05-16

We report the experimental observation of the interaction and attraction of many localized modes in a two-dimensional system realized by a disordered optical fiber supporting transverse Anderson localization. We show that a nonlocal optically nonlinear response of thermal origin alters the localization length by an amount determined by the optical power and also induces an action at a distance between the localized modes and their spatial migration. Evidence of a collective and strongly interacting regime is given.

Microscopic model of superconductivity in carbon nanotubes.

PubMed

González, J

2002-02-18

We propose the model of a manifold of one-dimensional interacting electron systems to account for the superconductivity observed in ropes of nanotubes. We rely on the strong suppression of single-particle hopping between neighboring nanotubes in a disordered rope and conclude that the tunneling takes place in pairs of electrons, which are formed within each nanotube due to the existence of large superconducting correlations. Our estimate of the transition temperature is consistent with the values that have been measured experimentally in ropes with about 100 metallic nanotubes.

Extremely High Resolution Spectroscopy of Oxide Electronic Systems

DTIC Science & Technology

2013-01-29

about 0.3-0.4 Bohr Magnetons per unit sell – extremely strong, and it may be indicative of an unusual order parameter in the superconductor . Each of...Publication [1]), and the fact that the enhancement exists in a highly disordered sample. While the origin of the effect may lie in the same exchange...order  parameter  in  the   superconductor .   Each of these results has lead to interesting questions (detailed below) that we would like to

Sedative effect of galphimine B, a nor-seco-triterpenoid from Galphimia glauca.

PubMed

Tortoriello, J; Ortega, A

1993-10-01

Galphimia glauca Cav. (Malpighiaceae) is used in Mexican traditional medicine as a sedative in the treatment of mental disorders. Sedative properties of a methanolic extract of the aerial parts of this plant have been established in animal trials and an active compound, named galphimine B, has already been isolated. This compound was submitted to neuropharmacological testing, where it was shown that galphimine B had no significant effect as an anticonvulsant, while it exhibited a strong depressant activity on the nervous system.

Wealth redistribution in our small world

NASA Astrophysics Data System (ADS)

Iglesias, J. R.; Gonçalves, S.; Pianegonda, S.; Vega, J. L.; Abramson, G.

2003-09-01

We present a simplified model for the exploitation of resources by interacting agents, in an economy with small-world properties. It is shown that Gaussian distributions of wealth, with some cutoff at a poverty line are present for all values of the parameters, while the frequency of maxima and minima strongly depends on the connectivity and the disorder of the lattice. Finally, we compare a system where the commercial links are frozen with an economy where agents can choose their commercial partners at each time step.

Neural Biomarkers for Dyslexia, ADHD, and ADD in the Auditory Cortex of Children.

PubMed

Serrallach, Bettina; Groß, Christine; Bernhofs, Valdis; Engelmann, Dorte; Benner, Jan; Gündert, Nadine; Blatow, Maria; Wengenroth, Martina; Seitz, Angelika; Brunner, Monika; Seither, Stefan; Parncutt, Richard; Schneider, Peter; Seither-Preisler, Annemarie

2016-01-01

Dyslexia, attention deficit hyperactivity disorder (ADHD), and attention deficit disorder (ADD) show distinct clinical profiles that may include auditory and language-related impairments. Currently, an objective brain-based diagnosis of these developmental disorders is still unavailable. We investigated the neuro-auditory systems of dyslexic, ADHD, ADD, and age-matched control children (N = 147) using neuroimaging, magnetencephalography and psychoacoustics. All disorder subgroups exhibited an oversized left planum temporale and an abnormal interhemispheric asynchrony (10-40 ms) of the primary auditory evoked P1-response. Considering right auditory cortex morphology, bilateral P1 source waveform shapes, and auditory performance, the three disorder subgroups could be reliably differentiated with outstanding accuracies of 89-98%. We therefore for the first time provide differential biomarkers for a brain-based diagnosis of dyslexia, ADHD, and ADD. The method allowed not only allowed for clear discrimination between two subtypes of attentional disorders (ADHD and ADD), a topic controversially discussed for decades in the scientific community, but also revealed the potential for objectively identifying comorbid cases. Noteworthy, in children playing a musical instrument, after three and a half years of training the observed interhemispheric asynchronies were reduced by about 2/3, thus suggesting a strong beneficial influence of music experience on brain development. These findings might have far-reaching implications for both research and practice and enable a profound understanding of the brain-related etiology, diagnosis, and musically based therapy of common auditory-related developmental disorders and learning disabilities.

Neural Biomarkers for Dyslexia, ADHD, and ADD in the Auditory Cortex of Children

PubMed Central

Serrallach, Bettina; Groß, Christine; Bernhofs, Valdis; Engelmann, Dorte; Benner, Jan; Gündert, Nadine; Blatow, Maria; Wengenroth, Martina; Seitz, Angelika; Brunner, Monika; Seither, Stefan; Parncutt, Richard; Schneider, Peter; Seither-Preisler, Annemarie

2016-01-01

Dyslexia, attention deficit hyperactivity disorder (ADHD), and attention deficit disorder (ADD) show distinct clinical profiles that may include auditory and language-related impairments. Currently, an objective brain-based diagnosis of these developmental disorders is still unavailable. We investigated the neuro-auditory systems of dyslexic, ADHD, ADD, and age-matched control children (N = 147) using neuroimaging, magnetencephalography and psychoacoustics. All disorder subgroups exhibited an oversized left planum temporale and an abnormal interhemispheric asynchrony (10–40 ms) of the primary auditory evoked P1-response. Considering right auditory cortex morphology, bilateral P1 source waveform shapes, and auditory performance, the three disorder subgroups could be reliably differentiated with outstanding accuracies of 89–98%. We therefore for the first time provide differential biomarkers for a brain-based diagnosis of dyslexia, ADHD, and ADD. The method allowed not only allowed for clear discrimination between two subtypes of attentional disorders (ADHD and ADD), a topic controversially discussed for decades in the scientific community, but also revealed the potential for objectively identifying comorbid cases. Noteworthy, in children playing a musical instrument, after three and a half years of training the observed interhemispheric asynchronies were reduced by about 2/3, thus suggesting a strong beneficial influence of music experience on brain development. These findings might have far-reaching implications for both research and practice and enable a profound understanding of the brain-related etiology, diagnosis, and musically based therapy of common auditory-related developmental disorders and learning disabilities. PMID:27471442

Psychopathology and weapon choice: a study of 103 perpetrators of homicide or attempted homicide.

PubMed

Catanesi, Roberto; Carabellese, Felice; Troccoli, Giuseppe; Candelli, Chiara; Grattagliano, Ignazio; Solarino, Biagio; Fortunato, Francesca

2011-06-15

The aim of this study was to ascertain if a relationship between weapon choice and psychopathology existed. The perpetrators (103) were evaluated at the Department of Criminology and Forensic Psychiatry of the University of Bari in southern Italy. Psychiatric examination and psycho-diagnostic tests were administered for each of the perpetrators and a database was subsequently formulated. The results showed a significant correlation between some types of mental disorder and weapon choice. A strong correlation was found between delusional disorders and the use of sharp weapons, whereas depressive disorders were more strongly associated with asphyxia. Organic disorders were found to be highly correlated with the use of blunt instruments. In cases where the homicide was the result of an impulsive reaction, the use of sharp weapons was most often observed. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Soft Coulomb gap and asymmetric scaling towards metal-insulator quantum criticality in multilayer MoS2.

PubMed

Moon, Byoung Hee; Bae, Jung Jun; Joo, Min-Kyu; Choi, Homin; Han, Gang Hee; Lim, Hanjo; Lee, Young Hee

2018-05-24

Quantum localization-delocalization of carriers are well described by either carrier-carrier interaction or disorder. When both effects come into play, however, a comprehensive understanding is not well established mainly due to complexity and sparse experimental data. Recently developed two-dimensional layered materials are ideal in describing such mesoscopic critical phenomena as they have both strong interactions and disorder. The transport in the insulating phase is well described by the soft Coulomb gap picture, which demonstrates the contribution of both interactions and disorder. Using this picture, we demonstrate the critical power law behavior of the localization length, supporting quantum criticality. We observe asymmetric critical exponents around the metal-insulator transition through temperature scaling analysis, which originates from poor screening in insulating regime and conversely strong screening in metallic regime due to free carriers. The effect of asymmetric scaling behavior is weakened in monolayer MoS 2 due to a dominating disorder.

The oxytocin system in drug discovery for autism: Animal models and novel therapeutic strategies

PubMed Central

Modi, Meera E.; Young, Larry J.

2012-01-01

Animal models and behavioral paradigms are critical for elucidating the neural mechanism involved in complex behaviors, including social cognition. Both genotype and phenotype based models have implicated the neuropeptide oxytocin (OT) in the regulation of social behavior. Based on the findings in animal models, alteration of the OT system has been hypothesized to play a role in the social deficits associated with autism and other neuropsychiatric disorders. While the evidence linking the peptide to the etiology of the disorder is not yet conclusive, evidence from multiple animal models suggest modulation of the OT system may be a viable strategy for the pharmacological treatment of social deficits. In this review, we will discuss how animal models have been utilized to understand the role of OT in social cognition and how those findings can be applied to the conceptualization and treatment of the social impairments in ASD. Animal models with genetic alterations of the OT system, like the OT, OT receptor and CD38 knock-out mice, and those with phenotypic variation in social behavior, like BTBR inbred mice and prairie voles, coupled with behavioral paradigms with face and construct validity may prove to have predictive validity for identifying the most efficacious methods of stimulating the OT system to enhance social cognition in humans. The widespread use of strong animal models of social cognition has the potential yield pharmacological, interventions for the treatment social impairments psychiatric disorders. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior. PMID:22206823

Disorder-induced inhomogeneities of the superconducting state close to the superconductor-insulator transition.

PubMed

Sacépé, B; Chapelier, C; Baturina, T I; Vinokur, V M; Baklanov, M R; Sanquer, M

2008-10-10

Scanning tunneling spectroscopy at very low temperatures on homogeneously disordered superconducting titanium nitride thin films reveals strong spatial inhomogeneities of the superconducting gap Delta in the density of states. Upon increasing disorder, we observe suppression of the superconducting critical temperature Tc towards zero, enhancement of spatial fluctuations in Delta, and growth of the Delta/Tc ratio. These findings suggest that local superconductivity survives across the disorder-driven superconductor-insulator transition.

Anxiety and depression as bidirectional risk factors for one another: A meta-analysis of longitudinal studies.

PubMed

Jacobson, Nicholas C; Newman, Michelle G

2017-11-01

Not only do anxiety and depression diagnoses tend to co-occur, but their symptoms are highly correlated. Although a plethora of research has examined longitudinal associations between anxiety and depression, these data have not yet been effectively synthesized. To address this need, the current study undertook a systematic review and meta-analysis of 66 studies involving 88,336 persons examining the prospective relationship between anxiety and depression at both symptom and disorder levels. Using mixed-effect models, results suggested that all types of anxiety symptoms predicted later depressive symptoms (r = .34), and all types of depressive symptoms predicted later anxiety symptoms (r = .31). Although anxiety symptoms more strongly predicted depressive symptoms than vice versa, the difference in effect size for this analysis was very small and likely not clinically meaningful. Additionally, all types of diagnosed anxiety disorders predicted all types of later depressive disorders (OR = 2.77), and all depressive disorders predicted later anxiety disorders (OR = 2.73). Most anxiety and depressive disorders predicted each other with similar degrees of strength, but depressive disorders more strongly predicted social anxiety disorder (OR = 6.05) and specific phobia (OR = 2.93) than vice versa. Contrary to conclusions of prior reviews, our findings suggest that depressive disorders may be prodromes for social and specific phobia, whereas other anxiety and depressive disorders are bidirectional risk factors for one another. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A moving target: responding to magnetic and structural disorder in lanthanide- and actinide-based superconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauer, Eric D; Mitchell, Jeremy N; Booth, C H

2009-01-01

The effects of various chemical substitutions and induced lattice disorder in the Ce- and Pu-based 115 superconductors are reviewed, with particular emphasis on results from x-ray absorption fine structure (XAFS) measurements. The competition between spin, charge, and lattice interactions is at the heart of many of the strongly-correlated ground states in materials of current interest, such as in colossal magnetoresistors and high-temperature superconductors. This relationship is particularly strong in the CeTIn{sub 5} and PuTGa{sub 5} series (T = Co, Rh, Ir) of heavy-fermion superconductors. In these systems (figure 1), competition between bulk magnetic and non-magnetic ground states, as well asmore » between superconducting and normal states, are directly related to local properties around the lanthanide or actinide ion, such as the nearest-neighbor bond lengths and the local density of states at the Fermi level. Tiny changes in the latter values can easily tip the balance from one ground state to another. This paper reviews recent work by the authors exploring the relationship between local crystal and electronic structure and ground state magnetic and conducting properties in the Ce- and Pu-based 115 materials.« less

Rates and Predictors of Conversion to Schizophrenia or Bipolar Disorder Following Substance-Induced Psychosis.

PubMed

Starzer, Marie Stefanie Kejser; Nordentoft, Merete; Hjorthøj, Carsten

2018-04-01

The authors investigated the rates of conversion to schizophrenia and bipolar disorder after a substance-induced psychosis, as well as risk factors for conversion. All patient information was extracted from the Danish Civil Registration System and the Psychiatric Central Research Register. The study population included all persons who received a diagnosis of substance-induced psychosis between 1994 and 2014 (N=6,788); patients were followed until first occurrence of schizophrenia or bipolar disorder or until death, emigration, or August 2014. The Kaplan-Meier method was used to obtain cumulative probabilities for the conversion from a substance-induced psychosis to schizophrenia or bipolar disorder. Cox proportional hazards regression models were used to calculate hazard ratios for all covariates. Overall, 32.2% (95% CI=29.7-34.9) of patients with a substance-induced psychosis converted to either bipolar or schizophrenia-spectrum disorders. The highest conversion rate was found for cannabis-induced psychosis, with 47.4% (95% CI=42.7-52.3) converting to either schizophrenia or bipolar disorder. Young age was associated with a higher risk of converting to schizophrenia. Self-harm after a substance-induced psychosis was significantly linked to a higher risk of converting to both schizophrenia and bipolar disorder. Half the cases of conversion to schizophrenia occurred within 3.1 years after a substance-induced psychosis, and half the cases of conversion to bipolar disorder occurred within 4.4 years. Substance-induced psychosis is strongly associated with the development of severe mental illness, and a long follow-up period is needed to identify the majority of cases.

The Diagnostic Validity and Reliability of an Internet-Based Clinical Assessment Program for Mental Disorders

PubMed Central

Klein, Britt; Meyer, Denny; Austin, David William; Abbott, Jo-Anne M

2015-01-01

Background Internet-based assessment has the potential to assist with the diagnosis of mental health disorders and overcome the barriers associated with traditional services (eg, cost, stigma, distance). Further to existing online screening programs available, there is an opportunity to deliver more comprehensive and accurate diagnostic tools to supplement the assessment and treatment of mental health disorders. Objective The aim was to evaluate the diagnostic criterion validity and test-retest reliability of the electronic Psychological Assessment System (e-PASS), an online, self-report, multidisorder, clinical assessment and referral system. Methods Participants were 616 adults residing in Australia, recruited online, and representing prospective e-PASS users. Following e-PASS completion, 158 participants underwent a telephone-administered structured clinical interview and 39 participants repeated the e-PASS within 25 days of initial completion. Results With structured clinical interview results serving as the gold standard, diagnostic agreement with the e-PASS varied considerably from fair (eg, generalized anxiety disorder: κ=.37) to strong (eg, panic disorder: κ=.62). Although the e-PASS’ sensitivity also varied (0.43-0.86) the specificity was generally high (0.68-1.00). The e-PASS sensitivity generally improved when reducing the e-PASS threshold to a subclinical result. Test-retest reliability ranged from moderate (eg, specific phobia: κ=.54) to substantial (eg, bulimia nervosa: κ=.87). Conclusions The e-PASS produces reliable diagnostic results and performs generally well in excluding mental disorders, although at the expense of sensitivity. For screening purposes, the e-PASS subclinical result generally appears better than a clinical result as a diagnostic indicator. Further development and evaluation is needed to support the use of online diagnostic assessment programs for mental disorders. Trial Registration Australian and New Zealand Clinical Trials Registry ACTRN121611000704998; http://www.anzctr.org.au/trial_view.aspx?ID=336143 (Archived by WebCite at http://www.webcitation.org/618r3wvOG). PMID:26392066

Application of native prick test in diagnosis of bed bug allergy.

PubMed

Ukleja-Sokołowska, Natalia; Sokołowski, Lukasz; Gawrońska-Ukleja, Ewa; Bartuzi, Zbigniew

2013-02-01

The aim of the study was case report of the patient with systemic reaction after a bed bug (Cimex lectularius) bite. A 23-year-old female, previously healthy, reports systemic reaction, including rash on her corpus and limbs, itching, nausea, conciseness disorder, forcing her to call the ambulance. The interview revealed that the bed bug occurs in the patient's apartment. A prick-by-prick test with bed bug excretion was made. The skin test with native allergen was strongly positive (histamine 5 mm/5 mm, prick-by-prick 12 mm/8 mm). The prick-by-prick test was useful in objective confirmation of the source of symptoms.

Magnetoplasmon spectrum for realistic off-plane structure of dissipative 2D system

NASA Astrophysics Data System (ADS)

Cheremisin, M. V.

2017-12-01

The rigorous analysis of the textbook result (Chiu and Quinn, 1974) gives unexpectedly the dramatic change of the magnetoplasmon spectrum taking into account both the arbitrary dissipation and asymmetric off-plane structure of 2D system. For given wave vector the dissipation enhancement leads to decrease(increase) of magnetoplasmon frequency at low(high) magnetic field. At certain range of disorder the purely relaxational mode appears in magnetoplasmon spectrum. In strong magnetic fields the magnetoplasmon frequency falls to cyclotron resonance line even in presence of finite dissipation. The observation of nonlinearity and, moreover, the mysterious zig-zag behavior 2D magnetoplasmon spectrum is consistent with our findings.

Disorder-induced exciton localization and violation of optical selection rules in supramolecular nanotubes

NASA Astrophysics Data System (ADS)

Vlaming, S. M.; Bloemsma, E. A.; Nietiadi, M. Linggarsari; Knoester, J.

2011-03-01

Using numerical simulations, we study the effect of disorder on the optical properties of cylindrical aggregates of molecules with strong excitation transfer interactions. The exciton states and the energy transport properties of such molecular nanotubes attract considerable interest for application in artificial light-harvesting systems and energy transport wires. In the absence of disorder, such nanotubes exhibit two optical absorption peaks, resulting from three super-radiant exciton states, one polarized along the axis of the cylinder, the other two (degenerate) polarized perpendicular to this axis. These selection rules, imposed by the cylindrical symmetry, break down in the presence of disorder in the molecular transition energies, due to the fact that the exciton states localize and no longer wrap completely around the tube. We show that the important parameter is the ratio of the exciton localization length and the tube's circumference. When this ratio decreases, the distribution of polarization angles of the exciton states changes from a two-peak structure (at zero and ninety degrees) to a single peak determined by the orientation of individual molecules within the tube. This is also reflected in a qualitative change of the absorption spectrum. The latter agrees with recent experimental findings.

Chemotaxis and flow disorder shape microbial dispersion in porous media

NASA Astrophysics Data System (ADS)

De Anna, Pietro; Yawata, Yutaka; Stocker, Roman; Juanes, Ruben

2017-04-01

Bacteria drive a plethora of natural processes in the subsurface, consuming organic matter and catalysing chemical reactions that are key to global elemental cycles. These macro-scale consequences result from the collective action of individual bacteria at the micro-scale, which are modulated by the highly heterogeneous subsurface environment, dominated by flow disorder and strong chemical gradients. Yet, despite the generally recognized importance of these microscale processes, microbe-host medium interaction at the pore scale remain poorly characterized and understood. Here, we introduce a microfluidic model system to directly image and quantify the role of cell motility on bacterial dispersion and residence time in confined, porous, media. Using the soil-dwelling bacterium Bacillus subtilis and the common amino acid serine as a resource, we observe that chemotaxis in highly disordered and confined physico-chemical environment affords bacteria an increase in their ability to persistently occupy the host medium. Our findings illustrate that the interplay between bacterial behaviour and pore-scale disorder in fluid velocity and nutrient concentration directly impacts the residence time, transport and bio-geo-chemical transformation rates of biota in the subsurface, and thus likely the processes they mediate.

Association between family history of mood disorders and clinical characteristics of bipolar disorder: results from the Brazilian bipolar research network.

PubMed

Berutti, Mariangeles; Nery, Fabiano G; Sato, Rodrigo; Scippa, Angela; Kapczinski, Flavio; Lafer, Beny

2014-06-01

To compare clinical characteristics of bipolar disorder (BD) in patients with and without a family history of mood disorders (FHMD) in a large sample from the Brazilian Research Network of Bipolar Disorders. Four-hundred eighty-eight DSM-IV BD patients participating in the Brazilian Research Network of Bipolar Disorders were included. Participants were divided between those with FHMD (n=230) and without FHMD (n=258). We compared these two groups on demographic and clinical variables and performed a logistic regression to identify which variables were most strongly associated with positive family history of mood disorders. BD patients with FHMD presented with significantly higher lifetime prevalence of any anxiety disorder, obsessive-compulsive disorder, social phobia, substance abuse, and were more likely to present history of suicide attempts, family history of suicide attempts and suicide, and more psychiatric hospitalizations than BD patients without FHMD. Logistic regression showed that the variables most strongly associated with a positive FHMD were any comorbid anxiety disorder, comorbid substance abuse, and family history of suicide. Cross-sectional study and verification of FHMD by indirect information. BD patients with FHMD differ from BD patients without FHMD in rates of comorbid anxiety disorder and substance abuse, number of hospitalizations and suicide attempts. As FHMD is routinely assessed in clinical practice, these findings may help to identify patients at risk for particular manifestations of BD and may point to a common, genetically determined neurobiological substrate that increases the risk of conditions such as comorbidities and suicidality in BD patients. Copyright © 2014 Elsevier B.V. All rights reserved.

A population-based longitudinal study of risk factors for suicide attempts in major depressive disorder.

PubMed

Bolton, James M; Pagura, Jina; Enns, Murray W; Grant, Bridget; Sareen, Jitender

2010-10-01

No longitudinal study has examined risk factors for future suicide attempts in major depressive disorder in a nationally representative sample. The objective of this study was to investigate baseline sociodemographic characteristics, comorbid mental disorders, specific depressive symptoms, and previous suicidal behavior as potential risk factors for suicide attempts at 3 years follow-up. Data came from the national epidemiologic survey on alcohol and related conditions (NESARC), a large nationally representative longitudinal survey of mental illness in adults [Wave 1 (2001-2002); Wave 2 (2004-2005) n=34,653]. Logistic regression examined associations between risk factors present at Wave 1 and suicide attempts at Wave 2 (n=169) among individuals with major depressive disorder at baseline assessment (n=6004). Risk factors for incident suicide attempts at Wave 2 (n=63) were identified among those with major depressive disorder at Wave 1 and no lifetime history of suicide attempts (n=5170). Results revealed specific comorbid anxiety, personality, and substance use disorders to be associated with incident suicide attempts at Wave 2. Comorbid borderline personality disorder was strongly associated with suicide attempts in all models. Several comorbid disorders were strongly associated with suicide attempts at Wave 2 even after adjusting for previous suicidal behavior, notably posttraumatic stress disorder (adjusted odds ratio (AOR)=2.20; 95% confidence interval (95% CI) 1.27-3.83) and dependent personality disorder (AOR=4.43; 95% CI 1.93-10.18). These findings suggest that mental illness comorbidity confers an increased risk of future suicide attempts in major depressive disorder that is not solely accounted for by past suicidal behavior.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuchinskii, E. Z., E-mail: kuchinsk@iep.uran.ru; Kuleeva, N. A.; Sadovskii, M. V., E-mail: sadovski@iep.uran.ru

We derive a Ginzburg–Landau (GL) expansion in the disordered attractive Hubbard model within the combined Nozieres–Schmitt-Rink and DMFT+Σ approximation. Restricting ourselves to the homogeneous expansion, we analyze the disorder dependence of GL expansion coefficients for a wide range of attractive potentials U, from the weak BCS coupling region to the strong-coupling limit, where superconductivity is described by Bose–Einstein condensation (BEC) of preformed Cooper pairs. We show that for the a semielliptic “bare” density of states of the conduction band, the disorder influence on the GL coefficients A and B before quadratic and quartic terms of the order parameter, as wellmore » as on the specific heat discontinuity at the superconducting transition, is of a universal nature at any strength of the attractive interaction and is related only to the general widening of the conduction band by disorder. In general, disorder growth increases the values of the coefficients A and B, leading either to a suppression of the specific heat discontinuity (in the weak-coupling limit), or to its significant growth (in the strong-coupling region). However, this behavior actually confirms the validity of the generalized Anderson theorem, because the disorder dependence of the superconducting transition temperature T{sub c}, is also controlled only by disorder widening of the conduction band (density of states).« less

[Efficacy of Topical Agents for Symptomatic Treatment of Rotigotine Patch-Induced Skin Disorders].

PubMed

Yasutaka, Yuki; Fujioka, Shinsuke; Shibaguchi, Hirotomo; Kiyomi, Fumiaki; Hara, Koyomi; Ogata, Kentaro; Tsuboi, Yoshio; Kamimura, Hidetoshi

2017-09-01

Since the effect of a percutaneous absorption-type dopamine agonist (DA) preparation, rotigotine patch, stably persists by once-a-day application, this dosage form is appropriate for Parkinson's disease patients showing levodopa induced wearing off phenomenon. On the other hand, skin disorders, mainly application site reaction, are characteristic problems associated with use of the patch. In this study, to clarify the influence of a topical agent used to prevent or treat rotigotine patch-induced skin disorder on continuation of the patch application, patients who started rotigotine patch application at our hospital were retrospectively surveyed. The one-year continuation rate of rotigotine patch application was 37.3% (53 of 142 cases). It was insufficient to prevent skin disorders, only by the pre-treatment of a moisturizing agent alone. Regarding the effective rate of topical agents used to treat skin disorders, that of very strong-class steroids was 89.5%, being significantly higher than those of weak steroids, moisturizing agents, and antihistamines. It was suggested that for countermeasures against rotigotine patch-induced skin disorders, treatment with very strong-class steroids for external use early after development of skin disorders is more effective than preventive treatment with topical agents regardless of the type. (Received March 30, 2017; Accepted May 16, 2017; Published September 1, 2017).

Measuring Social Anxiety in College Students: A Comprehensive Evaluation of the Psychometric Properties of the SPAI-23

ERIC Educational Resources Information Center

Schry, Amie R.; Roberson-Nay, Roxann; White, Susan W.

2012-01-01

Social anxiety disorder (SAD) is 1 of the most prevalent psychological disorders, and among college students in particular, social anxiety has been associated with other problems such as substance use problems and increased vulnerability to other psychiatric disorders. The Social Phobia and Anxiety Inventory-23 (SPAI-23; Roberson-Nay, Strong, Nay,…

Childhood ADHD Is Strongly Associated with a Broad Range of Psychiatric Disorders during Adolescence: A Population-Based Birth Cohort Study

ERIC Educational Resources Information Center

Yoshimasu, Kouichi; Barbaresi, William J.; Colligan, Robert C.; Voigt, Robert G.; Killian, Jill M.; Weaver, Amy L.; Katusic, Slavica K.

2012-01-01

Background: To evaluate associations between attention-deficit/hyperactivity disorder (ADHD) and comorbid psychiatric disorders using research-identified incident cases of ADHD and population-based controls. Methods: Subjects included a birth cohort of all children born 1976-1982 remaining in Rochester, MN after age five (n = 5,718). Among them we…

Recent Life Events Preceding Suicide Attempts in a Personality Disorder Sample: Findings from the Collaborative Longitudinal Personality Disorders Study

ERIC Educational Resources Information Center

Yen, Shirley; Pagano, Maria E.; Shea, Tracie M.; Grilo, Carlos M.; Gunderson, John G.; Skodol, Andrew E.; McGlashan, Thomas H.; Sanislow, Charles A.; Bender, Donna S.

2005-01-01

Few studies have examined the relationship between life events, suicide attempts, and personality disorders (PDs), in spite of the strong associations between PDs and suicidal behavior, and the poor coping strategies often exhibited by these individuals. The authors examined whether participants with PDs who attempted suicide during the first 3…

Influence of disorder on the superconducting critical temperature in indium-opal nanocomposites

NASA Astrophysics Data System (ADS)

Zakharchuk, I.; Januzaj, A.; Mikhailin, N. Yu.; Traito, K. B.; Chernyaev, A. V.; Romanov, S. G.; Safonchik, M.; Shamshur, D. V.; Lähderanta, E.

2018-06-01

Transport properties of bulk indium-opal and indium-porous glass superconducting nanocomposites possessing moderate and strong disorder are investigated. A strongly nonmonotonous dependence of the global critical temperature Tc versus normal state conductivity of samples is found. The maximum, which is observed at moderate disorder, has Tc higher than that of clean bulk indium. The increasing part can be explained by the Eliashberg equations with disorder and an additional mechanism of interaction between superconducting and dielectric granules. The descending part of the maximum at higher disorder can be explained by the increasing of long-range Coulomb repulsion due to diffusion of charges. Negative slope in magnetic field dependence of resistivity and a peak in the temperature dependence of resistivity, observed in the sample near the proximity to the disorder-induced superconductor-insulator transition (SIT). A large difference between the onset temperature of superconducting fluctuations, Tcon , and global critical temperature Tc is found and considered in the framework of the weak multifractal theory. Slow time-logarithmic relaxation of the resistivity between Tc and Tcon is observed, which assumes existence of the precursor state near the SIT. This unusual state is discussed in the scope of the many-body localization theory.

Comorbid mental disorders among the patients with alcohol abuse and dependence in Korea.

PubMed Central

Cho, Maeng Je; Hahm, Bong-Jin; Suh, Tongwoo; Suh, Guk-Hee; Cho, Seong-Jin; Lee, Chung Kyoon

2002-01-01

This study investigated the patterns of alcohol disorder comorbidity with other psychiatric disorders, using Korean nationwide epidemiological data. By two-stage cluster sampling, 5,176 adult household residents of Korea were interviewed using the Korean version of the Diagnostic Interview Schedule. Psychiatric disorders strongly associated with alcohol disorders were, other drug abuse or dependence, major depression, simple phobia, antisocial personality disorder, tobacco dependence, and pathological gambling. Male alcoholics had a tendency to begin with tobacco dependence, and some male pathological gamblers first had alcohol disorders. The presence of comorbid psychiatric disorders was associated with a more severe form and the later onset of alcohol disorders, and associated with help-seeking for alcohol abuse/dependence. PMID:11961310

Contribution of the Mission in Afghanistan to the Burden of Past-Year Mental Disorders in Canadian Armed Forces Personnel, 2013

PubMed Central

Zamorski, Mark A.

2016-01-01

Objective: The purpose of this study was to estimate the contribution of the mission in Afghanistan to the burden of mental health problems in the Canadian Armed Forces (CAF). Methods: Data were obtained from the 2013 Canadian Forces Mental Health Survey, which assessed mental disorders using the World Health Organization’s Composite International Diagnostic Interview. The sample consisted of 6696 Regular Force (RegF) personnel, 3384 of whom had deployed in support of the mission. We estimated the association of past-year mental health problems with Afghanistan deployment status, adjusting for covariates using logistic regression; population attributable fractions (PAFs) were also calculated. Results: Indication of a past-year mental disorder was identified in 18.4% (95% confidence interval [CI], 17.0% to 19.7%) of Afghanistan deployers compared with 14.6% (95% CI, 13.3% to 15.8%) in others. Afghanistan-related deployments contributed to the burden of a past-year disorder (PAF = 8.7%; 95% CI, 3.0% to 14.2%), with the highest PAFs being seen for panic disorder (34.7%) and posttraumatic stress disorder (32.1%). The PAFs for individual alcohol use disorders and suicide ideation were not different from zero. Child abuse, however, had a much greater PAF for any past-year disorder (28.7%; 95% CI, 23.4% to 33.7%) than did the Afghanistan mission. Conclusions: The mission in Afghanistan contributed significantly to the burden of mental disorders in the CAF RegF in 2013. However, the much stronger contribution of child abuse highlights the need for strong military mental health systems, even in peacetime, and the need to target the full range of determinants of mental health in prevention and control efforts. PMID:27270744

High surface conductivity of Fermi-arc electrons in Weyl semimetals

NASA Astrophysics Data System (ADS)

Resta, Giacomo; Pi, Shu-Ting; Wan, Xiangang; Savrasov, Sergey Y.

2018-02-01

Weyl semimetals (WSMs), a new type of topological condensed matter, are currently attracting great interest due to their unusual electronic states and intriguing transport properties such as chiral anomaly induced negative magnetoresistance, a semiquantized anomalous Hall effect, and the debated chiral magnetic effect. These systems are close cousins of topological insulators (TIs) which are known for their disorder-tolerant surface states. Similarly, WSMs exhibit unique topologically protected Fermi-arc surface states. Here, we analyze electron-phonon scattering, a primary source of resistivity in metals at finite temperatures, as a function of the shape of the Fermi arc where we find that the impact on surface transport is significantly dependent on the arc curvature and disappears in the limit of a straight arc. Next, we discuss the effect of strong surface disorder on the resistivity by numerically simulating a tight-binding model with the presence of quenched surface vacancies using the coherent potential approximation and Kubo-Greenwood formalism. We find that the limit of a straight arc geometry is remarkably disorder tolerant, producing surface conductivity that is one to two orders of magnitude larger than a comparable setup with surface states of TI. This is primarily attributed to a significantly different hybridization strength of the surface states with the remaining electrons in two systems. Finally, a simulation of the effects of surface vacancies on TaAs is presented, illustrating the disorder tolerance of the topological surface states in a recently discovered WSM material.

Psychophysiological Associations with Gastrointestinal Symptomatology in Autism Spectrum Disorder

PubMed Central

Ferguson, Bradley J.; Marler, Sarah; Altstein, Lily L.; Lee, Evon Batey; Akers, Jill; Sohl, Kristin; McLaughlin, Aaron; Hartnett, Kaitlyn; Kille, Briana; Mazurek, Micah; Macklin, Eric A.; McDonnell, Erin; Barstow, Mariah; Bauman, Margaret L.; Margolis, Kara Gross; Veenstra-VanderWeele, Jeremy; Beversdorf, David Q.

2017-01-01

Autism spectrum disorder (ASD) is often accompanied by gastrointestinal disturbances, which also may impact behavior. Alterations in autonomic nervous system functioning are also frequently observed in ASD. The relationship between these findings in ASD is not known. We examined the relationship between gastrointestinal symptomatology, examining upper and lower gastrointestinal tract symptomatology separately, and autonomic nervous system functioning, as assessed by heart rate variability and skin conductance level, in a sample of 120 individuals with ASD. Relationships with co-occurring medical and psychiatric symptoms were also examined. While the number of participants with significant upper gastrointestinal tract problems was small in this sample, 42.5% of participants met criteria for functional constipation, a disorder of the lower gastrointestinal tract. Heart rate variability, a measure of parasympathetic modulation of cardiac activity, was found to be positively associated with lower gastrointestinal tract symptomatology at baseline. This relationship was particularly strong for participants with co-occurring diagnoses of anxiety disorder and for those with a history of regressive ASD or loss of previously acquired skills. These findings suggest that autonomic function and gastrointestinal problems are intertwined in children with ASD; although it is not possible to assess causality in this data set. Future work should examine the impact of treatment of gastrointestinal problems on autonomic function and anxiety, as well as the impact of anxiety treatment on gastrointestinal problems. Clinicians should be aware that gastrointestinal problems, anxiety, and autonomic dysfunction may cluster in children with ASD and should be addressed in a multidisciplinary treatment plan. PMID:27321113

Translational science and the hidden research system in universities and academic hospitals: a case study.

PubMed

Lander, Bryn; Atkinson-Grosjean, Janet

2011-02-01

Innovation systems (IS) and science policy scholarship predominantly focus on linkages between universities and industry, and the commercial translation of academic discoveries. Overlooked in such analyses are important connections between universities and academic hospitals, and the non-commercial aspects of translational science. The two types of institutions tend to be collapsed into a single entity-'the university'-and relational flows are lost. Yet the distinctions and flows between the two are crucial elements of translational science and the biomedical innovation system. This paper explores what has been called the 'hidden research system' that connects hospitals, universities, and their resources, with the clinical and scientific actors who make the linkages possible. Then, using a novel conceptual model of translational science, we examine the individual interactions and dynamics involved in a particular example of the biomedical innovation system at work: the diagnosis of IRAK-4 deficiency, a rare immunological disorder, and the translational flows that result. Contra to conventional IS analyses, we are able to point to the strong role of public-sector institutions, and the weak role of the private-sector, in the translational processes described here. Our research was conducted within a Canadian network of scientists and clinician-scientists studying the pathogenomics of immunological disorders and innate immunity. Copyright © 2010 Elsevier Ltd. All rights reserved.

How Stuttering Develops: The Multifactorial Dynamic Pathways Theory

PubMed Central

Weber, Christine

2017-01-01

Purpose We advanced a multifactorial, dynamic account of the complex, nonlinear interactions of motor, linguistic, and emotional factors contributing to the development of stuttering. Our purpose here is to update our account as the multifactorial dynamic pathways theory. Method We review evidence related to how stuttering develops, including genetic/epigenetic factors; motor, linguistic, and emotional features; and advances in neuroimaging studies. We update evidence for our earlier claim: Although stuttering ultimately reflects impairment in speech sensorimotor processes, its course over the life span is strongly conditioned by linguistic and emotional factors. Results Our current account places primary emphasis on the dynamic developmental context in which stuttering emerges and follows its course during the preschool years. Rapid changes in many neurobehavioral systems are ongoing, and critical interactions among these systems likely play a major role in determining persistence of or recovery from stuttering. Conclusion Stuttering, or childhood onset fluency disorder (Diagnostic and Statistical Manual of Mental Disorders, 5th edition; American Psychiatric Association [APA], 2013), is a neurodevelopmental disorder that begins when neural networks supporting speech, language, and emotional functions are rapidly developing. The multifactorial dynamic pathways theory motivates experimental and clinical work to determine the specific factors that contribute to each child's pathway to the diagnosis of stuttering and those most likely to promote recovery. PMID:28837728

Intrinsic disorder in pathogen effectors: protein flexibility as an evolutionary hallmark in a molecular arms race.

PubMed

Marín, Macarena; Uversky, Vladimir N; Ott, Thomas

2013-09-01

Effector proteins represent a refined mechanism of bacterial pathogens to overcome plants' innate immune systems. These modular proteins often manipulate host physiology by directly interfering with immune signaling of plant cells. Even if host cells have developed efficient strategies to perceive the presence of pathogenic microbes and to recognize intracellular effector activity, it remains an open question why only few effectors are recognized directly by plant resistance proteins. Based on in-silico genome-wide surveys and a reevaluation of published structural data, we estimated that bacterial effectors of phytopathogens are highly enriched in long-disordered regions (>50 residues). These structurally flexible segments have no secondary structure under physiological conditions but can fold in a stimulus-dependent manner (e.g., during protein-protein interactions). The high abundance of intrinsic disorder in effectors strongly suggests positive evolutionary selection of this structural feature and highlights the dynamic nature of these proteins. We postulate that such structural flexibility may be essential for (1) effector translocation, (2) evasion of the innate immune system, and (3) host function mimicry. The study of these dynamical regions will greatly complement current structural approaches to understand the molecular mechanisms of these proteins and may help in the prediction of new effectors.

How Stuttering Develops: The Multifactorial Dynamic Pathways Theory.

PubMed

Smith, Anne; Weber, Christine

2017-09-18

We advanced a multifactorial, dynamic account of the complex, nonlinear interactions of motor, linguistic, and emotional factors contributing to the development of stuttering. Our purpose here is to update our account as the multifactorial dynamic pathways theory. We review evidence related to how stuttering develops, including genetic/epigenetic factors; motor, linguistic, and emotional features; and advances in neuroimaging studies. We update evidence for our earlier claim: Although stuttering ultimately reflects impairment in speech sensorimotor processes, its course over the life span is strongly conditioned by linguistic and emotional factors. Our current account places primary emphasis on the dynamic developmental context in which stuttering emerges and follows its course during the preschool years. Rapid changes in many neurobehavioral systems are ongoing, and critical interactions among these systems likely play a major role in determining persistence of or recovery from stuttering. Stuttering, or childhood onset fluency disorder (Diagnostic and Statistical Manual of Mental Disorders, 5th edition; American Psychiatric Association [APA], 2013), is a neurodevelopmental disorder that begins when neural networks supporting speech, language, and emotional functions are rapidly developing. The multifactorial dynamic pathways theory motivates experimental and clinical work to determine the specific factors that contribute to each child's pathway to the diagnosis of stuttering and those most likely to promote recovery.

Survival and weak chaos.

PubMed

Nee, Sean

2018-05-01

Survival analysis in biology and reliability theory in engineering concern the dynamical functioning of bio/electro/mechanical units. Here we incorporate effects of chaotic dynamics into the classical theory. Dynamical systems theory now distinguishes strong and weak chaos. Strong chaos generates Type II survivorship curves entirely as a result of the internal operation of the system, without any age-independent, external, random forces of mortality. Weak chaos exhibits (a) intermittency and (b) Type III survivorship, defined as a decreasing per capita mortality rate: engineering explicitly defines this pattern of decreasing hazard as 'infant mortality'. Weak chaos generates two phenomena from the normal functioning of the same system. First, infant mortality- sensu engineering-without any external explanatory factors, such as manufacturing defects, which is followed by increased average longevity of survivors. Second, sudden failure of units during their normal period of operation, before the onset of age-dependent mortality arising from senescence. The relevance of these phenomena encompasses, for example: no-fault-found failure of electronic devices; high rates of human early spontaneous miscarriage/abortion; runaway pacemakers; sudden cardiac death in young adults; bipolar disorder; and epilepsy.

Survival and weak chaos

PubMed Central

2018-01-01

Survival analysis in biology and reliability theory in engineering concern the dynamical functioning of bio/electro/mechanical units. Here we incorporate effects of chaotic dynamics into the classical theory. Dynamical systems theory now distinguishes strong and weak chaos. Strong chaos generates Type II survivorship curves entirely as a result of the internal operation of the system, without any age-independent, external, random forces of mortality. Weak chaos exhibits (a) intermittency and (b) Type III survivorship, defined as a decreasing per capita mortality rate: engineering explicitly defines this pattern of decreasing hazard as ‘infant mortality’. Weak chaos generates two phenomena from the normal functioning of the same system. First, infant mortality—sensu engineering—without any external explanatory factors, such as manufacturing defects, which is followed by increased average longevity of survivors. Second, sudden failure of units during their normal period of operation, before the onset of age-dependent mortality arising from senescence. The relevance of these phenomena encompasses, for example: no-fault-found failure of electronic devices; high rates of human early spontaneous miscarriage/abortion; runaway pacemakers; sudden cardiac death in young adults; bipolar disorder; and epilepsy. PMID:29892407

Stable biexcitons in two-dimensional metal-halide perovskites with strong dynamic lattice disorder

NASA Astrophysics Data System (ADS)

Thouin, Félix; Neutzner, Stefanie; Cortecchia, Daniele; Dragomir, Vlad Alexandru; Soci, Cesare; Salim, Teddy; Lam, Yeng Ming; Leonelli, Richard; Petrozza, Annamaria; Kandada, Ajay Ram Srimath; Silva, Carlos

2018-03-01

With strongly bound and stable excitons at room temperature, single-layer, two-dimensional organic-inorganic hybrid perovskites are viable semiconductors for light-emitting quantum optoelectronics applications. In such a technological context, it is imperative to comprehensively explore all the factors—chemical, electronic, and structural—that govern strong multiexciton correlations. Here, by means of two-dimensional coherent spectroscopy, we examine excitonic many-body effects in pure, single-layer (PEA) 2PbI4 (PEA = phenylethylammonium). We determine the binding energy of biexcitons—correlated two-electron, two-hole quasiparticles—to be 44 ±5 meV at room temperature. The extraordinarily high values are similar to those reported in other strongly excitonic two-dimensional materials such as transition-metal dichalcogenides. Importantly, we show that this binding energy increases by ˜25 % upon cooling to 5 K. Our work highlights the importance of multiexciton correlations in this class of technologically promising, solution-processable materials, in spite of the strong effects of lattice fluctuations and dynamic disorder.

Attention-deficit/hyperactivity disorder and eating disorders across the lifespan: A systematic review of the literature.

PubMed

Levin, Rivka L; Rawana, Jennine S

2016-12-01

Attention-deficit/hyperactivity disorder (ADHD) and eating disorders are common and concerning mental health disorders. There is both empirical and theoretical support for an association between ADHD and eating disorders or disordered eating. This systematic review aims to summarize the extant literature on the comorbidity of ADHD and eating disorders across the lifespan, including the influences of sex, age, eating disorder diagnosis, and potential mediators. A total of 37 peer-reviewed studies on diagnosed ADHD and eating disturbances were identified through key research databases. Twenty-six studies supported a strong empirical association between ADHD and eating disorders or disordered eating. The systematic review findings suggest that children with ADHD are at risk for disordered eating, while adolescents, emerging adults, and adults are at risk for both eating disorders and disordered eating. Methodological considerations, future research, and clinical implications are discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Did goethe describe attention deficit hyperactivity disorder?

PubMed

Bonazza, Sara; Scaglione, Cesa; Poppi, Massimo; Rizzo, Giovanni

2011-01-01

As early as 1846, the typical symptoms of attention deficit hyperactivity disorder (ADHD) were described by Heinrich Hoffmann (1809-1894). However, in Goethe's masterpiece Faust (1832), the character of Euphorion strongly suggests ADHD diagnosis. Copyright © 2011 S. Karger AG, Basel.

Evolution of microstructural disorder in annealed bismuth telluride nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erickson, Kristopher J.; Limmer, Steven J.; Yelton, W. Graham

Controlling the distribution of structural defects in nanostructures is important since such defects can strongly affect critical properties, including thermal and electronic transport. However, characterizing the defect arrangements in individual nanostructures is difficult because of the small length scales involved. Here, we investigate the evolution of microstructural disorder with annealing in electrochemically deposited Bi2Te3 nanowires, which are of interest for thermoelectrics. We combine Convergent Beam Electron Diffraction (CBED) and Scanning Transmission Electron Microscopy (STEM) to provide the necessary spatial and orientational resolution. We find that despite their large initial grain sizes and strong Formula crystallographic texturing, the as-deposited nanowires stillmore » exhibit significant intragranular orientational disorder. Annealing drives both grain growth and a significant reduction in the intragranular disorder. The results are discussed in the context of the existing understanding of the initial microstructure of electrodeposited materials and the understanding of annealing microstructures in both electrochemically deposited and bulk-deformed materials. Finally, this analysis highlights the importance of assessing both the grain size and intragranular disorder in understanding the microstructural evolution of individual nanostructures.« less

Evolution of microstructural disorder in annealed bismuth telluride nanowires

DOE PAGES

Erickson, Kristopher J.; Limmer, Steven J.; Yelton, W. Graham; ...

2017-03-01

Controlling the distribution of structural defects in nanostructures is important since such defects can strongly affect critical properties, including thermal and electronic transport. However, characterizing the defect arrangements in individual nanostructures is difficult because of the small length scales involved. Here, we investigate the evolution of microstructural disorder with annealing in electrochemically deposited Bi2Te3 nanowires, which are of interest for thermoelectrics. We combine Convergent Beam Electron Diffraction (CBED) and Scanning Transmission Electron Microscopy (STEM) to provide the necessary spatial and orientational resolution. We find that despite their large initial grain sizes and strong Formula crystallographic texturing, the as-deposited nanowires stillmore » exhibit significant intragranular orientational disorder. Annealing drives both grain growth and a significant reduction in the intragranular disorder. The results are discussed in the context of the existing understanding of the initial microstructure of electrodeposited materials and the understanding of annealing microstructures in both electrochemically deposited and bulk-deformed materials. Finally, this analysis highlights the importance of assessing both the grain size and intragranular disorder in understanding the microstructural evolution of individual nanostructures.« less

Prevalence, correlates, comorbidity and treatment of electronic nicotine delivery system use in the United States.

PubMed

Chou, S Patricia; Saha, Tulshi D; Zhang, Haitao; Ruan, W June; Huang, Boji; Grant, Bridget F; Blanco, Carlos; Compton, Wilson

2017-09-01

This study presents nationally representative data on the prevalence, correlates, psychiatric comorbidity and treatment (including pharmacological and nonpharmacological) among electronic nicotine delivery system (ENDS) users. Face-to-face interviews in the National Epidemiologic Survey on Alcohol and Related Conditions-III. Prevalences of 12-month and lifetime ENDS use were 3.8% (SE=0.14) and 5.4% (SE=0.17). Odds of ENDS use were greater among men than women, regardless of timeframe. Rates were lower among Blacks, Hispanics and Asians/Pacific Islanders relative to Whites. Odds of 12-month and lifetime ENDS use was also higher among younger (<65years) than older (≥65years) individuals and higher among individuals with high school education relative to these with some college education. Odds of 12-month and lifetime ENDS use was also higher among individuals with incomes <$70,000.00 compared with those with incomes≥$70,000.00 and higher among the previously married relative to those who were currently married. Associations between 12-month ENDS use and severe nicotine use disorder were strong, whereas associations with other substance use disorders and borderline and antisocial personality disorders were modest (AORs=1.3-2.6). Rates of treatment seeking to cut down or quit tobacco or nicotine use (12-month, 25.0% (SE=1.6); lifetime, 24.4% (SE=1.4)) were low. ENDS use is substantially comorbid, especially with nicotine use disorder. Virtually all ENDS users smoked cigarettes. Research is needed to understand their role in smoking cessation, adverse effects on bodily systems and their potential for addiction and comorbidity. Copyright © 2017. Published by Elsevier B.V.

Liquid structure of the urea-water system studied by dielectric spectroscopy.

PubMed

Hayashi, Yoshihito; Katsumoto, Yoichi; Omori, Shinji; Kishii, Noriyuki; Yasuda, Akio

2007-02-08

Dielectric spectroscopy measurements for aqueous urea solutions were performed at 298 K through a concentration range from 0.5 to 9.0 M with frequencies between 200 MHz and 40 GHz. Observed dielectric spectra were well represented by the superposition of two Debye type relaxation processes attributable to the bulk-water clusters and the urea-water coclusters. Our quantitative analysis of the spectra shows that the number of hydration water molecules is approximately two per urea molecule for the lower concentration region below 5.0 M, while the previous molecular dynamics studies predicted approximately six water molecules. It was also indicated by those studies, however, that there are two types of hydration water molecule in urea solution, which are strongly and weakly associated to the urea molecule, respectively. Only the strongly associated water was distinguishable in our analysis, while the weakly associated water exhibited the same dynamic feature as bulk water. This implies that urea retains the weakly associated water in the tetrahedral structure and, thus, is not a strong structure breaker of water. We also verified the model of liquid water where water consists of two states: the icelike-ordered and dense-disordered phases. Our dielectric data did not agree with the theoretical prediction based on the two-phase model. The present work supports the argument that urea molecules can easily replace near-neighbor water in the hydrogen-bonding network and do not require the presence of the disordered phase of water to dissolve into water.

Many-body-localization: strong disorder perturbative approach for the local integrals of motion

NASA Astrophysics Data System (ADS)

Monthus, Cécile

2018-05-01

For random quantum spin models, the strong disorder perturbative expansion of the local integrals of motion around the real-spin operators is revisited. The emphasis is on the links with other properties of the many-body-localized phase, in particular the memory in the dynamics of the local magnetizations and the statistics of matrix elements of local operators in the eigenstate basis. Finally, this approach is applied to analyze the many-body-localization transition in a toy model studied previously from the point of view of the entanglement entropy.

Phase relationships and cation disorder in RE{sub 1+x}Ba{sub 2-x}Cu{sub 3}O{sub 7+{delta}}, RE = Pr, Nd, Sm, Gd

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kramer, M.J.; Wu, H.; Dennis, K.W.

1995-12-31

Unlike Y123 which forms only a stoichiometric compound, the light arare earth elements (LRE) form a solid solution LRE{sub 1+x}Ba{sub 2-x}Cu{sub 3}O{sub 7+{delta}} (LRE123ss), with increasing substitution of the LRE{sup 3+} for the Ba{sup 2+} as the ionic radii of the LRE increases. The sub-solidus phase relationships around the LRE123ss change for La, Pr and Nd, but are similar for Sm and Gd. However, the solubility limit decreases with decreasing ionic radii. In addition, the solubility limits for Sm and Gd are strongly influenced by PO{sub 2} during high temperature annealing. The range of solubility is, for any given LREmore » system, strongly dependent on the oxygen partial pressure (PO{sub 2}) providing a new means by which to control the microstructure in the RE123 system.« less

Influence of Criminal Justice Involvement and Psychiatric Diagnoses on Treatment Costs Among Adults With Serious Mental Illness

PubMed Central

Robertson, Allison G.; Swanson, Jeffrey W.; Lin, Hsiuju; Easter, Michele M.; Frisman, Linda K.; Swartz, Marvin S.

2015-01-01

The impact of criminal justice involvement and clinical characteristics on the cost of public treatment services for adults with serious mental illnesses is unknown. The authors examined differential effects of justice involvement on behavioral health treatment costs by primary psychiatric diagnosis (schizophrenia or bipolar disorder) and also by substance use diagnosis among 25,133 adult clients of Connecticut’s public behavioral health system in fiscal years 2006 and 2007. Justice-involved adults with schizophrenia had the highest costs, strongly driven by forensic hospitalizations. Addressing the cross-system burdens of forensic hospitalizations may be a sensible starting point in the effort to reduce costs in both the public behavioral health and justice systems. PMID:25975893

Exuberant juvenile hyaline fibromatosis in two patients.

PubMed

Muniz, Mariela Leão; Lobo, Alice Zoghbi Coelho; Machado, Maria Cecília da Matta Rivitti; Valente, Neusa Yuriko Sakai; Kim, Chong Ae; Lourenço, Sílvia Vanessa; Nico, Marcello Menta Simonsen

2006-01-01

Juvenile hyaline fibromatosis and infantile systemic hyalinosis are rare autosomal recessive disorders of infancy and early childhood that are histologically characterized by deposition of hyaline material. The main clinical features are papulo-nodular skin lesions, gingival hypertrophy, joint contractures, and bone abnormalities. However, infantile systemic hyalinosis has a more severe clinical presentation, including visceral involvement and premature death. Very recently, genetic studies identified mutations in the same gene in patients with both conditions, strongly suggesting that they belong to the same disease spectrum. We report two new nonrelated patients who met the criteria for the diagnosis of juvenile hyaline fibromatosis/infantile systemic hyalinosis. Clinical, histopathologic, immunohistochemical, and ultrastructural findings are presented, as well as an extensive review of the literature. Recent information regarding pathogenesis and treatment is discussed.

Can Robotic Interaction Improve Joint Attention Skills?

PubMed Central

Zheng, Zhi; Swanson, Amy R.; Bekele, Esubalew; Zhang, Lian; Crittendon, Julie A.; Weitlauf, Amy F.; Sarkar, Nilanjan

2013-01-01

Although it has often been argued that clinical applications of advanced technology may hold promise for addressing impairments associated with autism spectrum disorder (ASD), relatively few investigations have indexed the impact of intervention and feedback approaches. This pilot study investigated the application of a novel robotic interaction system capable of administering and adjusting joint attention prompts to a small group (n = 6) of children with ASD. Across a series of four sessions, children improved in their ability to orient to prompts administered by the robotic system and continued to display strong attention toward the humanoid robot over time. The results highlight both potential benefits of robotic systems for directed intervention approaches as well as potent limitations of existing humanoid robotic platforms. PMID:24014194

Can Robotic Interaction Improve Joint Attention Skills?

PubMed

Warren, Zachary E; Zheng, Zhi; Swanson, Amy R; Bekele, Esubalew; Zhang, Lian; Crittendon, Julie A; Weitlauf, Amy F; Sarkar, Nilanjan

2015-11-01

Although it has often been argued that clinical applications of advanced technology may hold promise for addressing impairments associated with autism spectrum disorder (ASD), relatively few investigations have indexed the impact of intervention and feedback approaches. This pilot study investigated the application of a novel robotic interaction system capable of administering and adjusting joint attention prompts to a small group (n = 6) of children with ASD. Across a series of four sessions, children improved in their ability to orient to prompts administered by the robotic system and continued to display strong attention toward the humanoid robot over time. The results highlight both potential benefits of robotic systems for directed intervention approaches as well as potent limitations of existing humanoid robotic platforms.

Topological Edge Modes in Active Mikado Networks

NASA Astrophysics Data System (ADS)

Zhou, Di; Zhang, Leyou; Mao, Xiaoming

Mechanical properties of disordered fiber networks are not only important in understanding a broad range of natural (such as the cytoskeleton and the extracellular matrix) and manmade materials (such as aerogels and porous media) but also exhibit interesting and rich physics. In this talk, we discuss how topological floppy edge modes can emerge from these fiber networks as a result of active driving. It is known that straight fibers in a network carries a state of self-stress and bears a bulk floppy mode. We find that, interestingly, by driving the network with a tiny perturbation, the bulk modes evolve into edge modes. We introduce a new transfer matrix formulation that can be applied to this strongly disordered system, to characterize the topological edge modes. We also discuss possible implications of these edge modes in biological processes. NSF-DMR-1609051.

PTSD as a mediator between lifetime sexual abuse and substance use among jail diversion participants.

PubMed

Cusack, Karen J; Herring, Amy H; Steadman, Henry J

2013-08-01

Many of the individuals with serious mental illness involved in the criminal justice system have experienced interpersonal victimization, such as sexual abuse, and have high rates of alcohol and drug use disorders. Little attention has been paid to the prevalence of posttraumatic stress disorder (PTSD) and its potential role in the substance misuse of offenders with mental illness. The study used a path analytic framework to test the hypothesis that PTSD mediates the relationship between sexual abuse and level of alcohol and drug use among individuals (N=386) with mental illness enrolled in a multisite (N=7) jail diversion project. Sexual abuse was strongly associated with PTSD, which was in turn associated with both heavy drug use and heavy drinking. These findings suggest that PTSD may be an important target for jail diversion programs.

Measurements of the magnetic-field-tuned conductivity of disordered two-dimensional Mo43Ge57 and InOx superconducting films: evidence for a universal minimum superfluid response.

PubMed

Misra, S; Urban, L; Kim, M; Sambandamurthy, G; Yazdani, A

2013-01-18

Our measurements of the low frequency ac conductivity in strongly disordered two-dimensional films near the magnetic-field-tuned superconductor-to-insulator transition show a sudden drop in the phase stiffness of superconducting order with either increased temperature or magnetic field. Surprisingly, for two different material systems, the abrupt drop in the superfluid density in a magnetic field has the same universal value as that expected for a Berezinskii-Kosterlitz-Thouless transition in a zero magnetic field. The characteristic temperature at which phase stiffness is suddenly lost can be tuned to zero at a critical magnetic field, following a power-law behavior with a critical exponent consistent with that obtained in previous dc transport studies on the dissipative side of the transition.

Attitudes of cystic fibrosis patients and their parents towards direct-to-consumer genetic testing for carrier status.

PubMed

Janssens, Sandra; Kalokairinou, Louiza; Chokoshvilli, Davit; Binst, Carmen; Mahieu, Inge; Henneman, Lidewij; De Paepe, Anne; Borry, Pascal

2015-03-01

An increasing number of direct-to-consumer (DTC) genetic testing companies have started offering tests for carrier status of autosomal recessive disorders. A written questionnaire was administered to 47 patients and 65 parents of children with Cystic Fibrosis (CF), a common severe autosomal recessive disorder, to assess their views about the offer of DTC carrier tests. All participants were recruited from a CF patient registry in Belgium. We found that very few patients and parents were aware of the offer of DTC genetic testing for carrier status, and were generally skeptical. A strong preference for the healthcare system over commercial companies as the provider of the test was observed. However, many participants believe people should have a right to access DTC genetic tests provided by commercial companies.

[Performance and personality of patients with hypersomnia].

PubMed

Mayer, G; Leonhardt, E

1996-01-01

5 groups of patients with hypersomnia (narcolepsy, posttraumatic, psychophysiologic, idiopathic hypersomnia and circadian sleep-wake disorders) were tested with a battery of psychometric tests (FPI, MMPI, BVND, BIV, Benton, d2, WIP), visual vigilance test, polysomnography and MSLT in order to investigate the context between personality and performance. MSLT showed a range from clear pathologic to borderline sleep latencies among all groups, only patients with posttraumatic hypersomnia and narcolepsy displayed sleep onset REM. Correct results of vigilance tests correlated negatively with performance-motivation and orientation in patients with narcolepsy and posttraumatic hypersomnia, whereas there was positive correlation for patients with idiopathic hypersomnia. In patients with psychophysiologic hypersomnia performance orientation and false reactions correlate negatively. Patients with posttraumatic hypersomnia have better results on d2. Benton and vigilance tests than all other groups. Results of personality diagnosis are similar to those of healthy subjects, while patients with psychophysiologic hypersomnia are more sensible than all other groups with high social fears and the highest disposition among all groups toward somatic complaints. Patients with idiopathic hypersomnia show strong introversion and inhibition. Patients with circadian sleep-wake disorders display the most striking personality disorders, which are most probably sequelae of their strong disease-dependent impairment. The degree of personality disorder seems to be strongly dependent on the duration of the hypersomnias. The assessment of the whole set of tests can only be recommended for patients with psychophysiologic hypersomnia and circadian sleep-wake disorders, a few tests suffice to describe the other groups.

Association between mandibular retrognathia and TMJ disorders in adult females.

PubMed

Miller, James R; Burgess, Jeffrey A; Critchlow, Cathy W

2004-01-01

This study assesses the association between temporomandibular joint (TMJ) disorders and mandibular retrognathia. We conducted a case-control study among women, aged 18-70 years, recruited from Kaiser Permanente Northwest Division (KPNW, Portland, OR) and Group Health Cooperative of Puget Sound (GHC, Seattle, WA). Cases (N= 160) were women seeking treatment for TMJ disorders at KPNW and GHC clinics. Controls (N=151) were women without TMJ disorders, selected from among adult female dental hygiene patients at KPNW or GHC enrollees. Case status was determined by questionnaire; mandibular sagittal position (orthognathic, mildly retrognathic, severely retrognathic, or prognathic) was measured using digitized facial photographs. Odds ratios (OR) and associated 95 percent confidence intervals (CI) estimated the magnitude of the association between TMJ disorders and mandibular sagittal position. Women with TMJ disorders were 4.0 times (95% CI=1.5, 10.8) more likely than controls to have severe retrognathia; no association with mild retrognathia or prognathia was seen. Results were similar when cases were restricted to those with recent onset of TMJ pain (OR=6.3; 95% CI=1.8, 21.8). We found a strong association between TMJ disorders and severe mandibular retrognathia in adult females. In some women this likely resulted from TMJ disorders influencing mandibular development over time. However, among a subset of women, our data support the reverse hypothesis--that severe mandibular retrognathia may influence the development of TMJ disorders. Despite this strong association, abnormal mandibular position contributed only a small portion to the overall rate at which women sought treatment for TMJ disorders.

Network analysis of pediatric eating disorder symptoms in a treatment-seeking, transdiagnostic sample.

PubMed

Goldschmidt, Andrea B; Crosby, Ross D; Cao, Li; Moessner, Markus; Forbush, Kelsie T; Accurso, Erin C; Le Grange, Daniel

2018-02-01

Classifying eating disorders in youth is challenging in light of developmental considerations and high rates of diagnostic migration. Understanding the transactional relationships among eating disorder symptoms, both across the transdiagnostic spectrum and within specific diagnostic categories, may clarify which core eating disorder symptoms contribute to, and maintain, eating-related psychopathology in youth. We utilized network analysis to investigate interrelationships among eating disorder symptoms in 636 treatment-seeking children and adolescents (90.3% female) ages 6-18 years (M age = 15.4 ± 2.2). An undirected, weighted network of eating disorder symptoms was created using behavioral and attitudinal items from the Eating Disorder Examination. Across diagnostic groups, symptoms reflecting appearance-related concerns (e.g., dissatisfaction with shape and weight) and dietary restraint (e.g., a desire to have an empty stomach) were most strongly associated with other eating disorder symptoms in the network. Binge eating and compensatory behaviors (e.g., self-induced vomiting) were strongly connected to one another but not to other symptoms in the network. Network connectivity was similar across anorexia nervosa, bulimia nervosa, and otherwise specified feeding or eating disorder subgroups. Among treatment-seeking children and adolescents, dietary restraint and shape- and weight-related concerns appear to play key roles in the psychopathology of eating disorders, supporting cognitive-behavioral theories of onset and maintenance. Similarities across diagnostic categories provide support for a transdiagnostic classification scheme. Clinical interventions should seek to disrupt these symptoms early in treatment to achieve maximal outcomes. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Multidimensional dynamic piezoresponse measurements. Unraveling local relaxation behavior in relaxor-ferroelectrics via big data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vasudevan, Rama K.; Zhang, Shujun; Okatan, Mahmut Baris

Compositional and charge disorder in ferroelectric relaxors lies at the heart of the unusual properties of these systems, such as aging and non-ergodicity, polarization rotations, and a host of temperature and field-driven phase transitions. However, much information about the field-dynamics of the polarization in the prototypical ferroelectric relaxor (1-x)Pb(Mg 1/3Nb 2/3)O 3-xPbTiO 3 (PMN-xPT) remains unprobed at the mesoscopic level. We use a piezoresponse force microscopy-based dynamic multimodal relaxation spectroscopy technique, enabling the study of ferroelectric switching and polarization relaxation at mesoscopic length scales, and carry out measurements on a PMN-0.28PT sample with minimal polishing. Results indicate that beyond amore » threshold DC bias the average relaxation increases as the system attempts to relax to the previous state. Phenomenological fitting reveals the presence of mesoscale heterogeneity in relaxation amplitudes and clearly suggests the presence of two distinct amplitudes. Independent component analysis reveals the presence of a disorder component of the relaxation, which is found to be strongly anti-correlated with the maximum piezoresponse at that location, suggesting smaller disorder effects where the polarization reversal is large and vice versa. The disorder in the relaxation amplitudes is postulated to arise from rhombohedral and field-induced tetragonal phase in the crystal, with each phase associated with its own relaxation amplitude. As a result, these studies highlight the crucial importance of the mixture of ferroelectric phases in the compositions in proximity of the morphotropic phase boundary in governing the local response and further highlight the ability of PFM voltage and time spectroscopies, in conjunction with big-data multivariate analyses, to locally map disorder and correlate it with parameters governing the dynamic behavior.« less

Multidimensional dynamic piezoresponse measurements. Unraveling local relaxation behavior in relaxor-ferroelectrics via big data

DOE PAGES

Vasudevan, Rama K.; Zhang, Shujun; Okatan, Mahmut Baris; ...

2015-08-19

Compositional and charge disorder in ferroelectric relaxors lies at the heart of the unusual properties of these systems, such as aging and non-ergodicity, polarization rotations, and a host of temperature and field-driven phase transitions. However, much information about the field-dynamics of the polarization in the prototypical ferroelectric relaxor (1-x)Pb(Mg 1/3Nb 2/3)O 3-xPbTiO 3 (PMN-xPT) remains unprobed at the mesoscopic level. We use a piezoresponse force microscopy-based dynamic multimodal relaxation spectroscopy technique, enabling the study of ferroelectric switching and polarization relaxation at mesoscopic length scales, and carry out measurements on a PMN-0.28PT sample with minimal polishing. Results indicate that beyond amore » threshold DC bias the average relaxation increases as the system attempts to relax to the previous state. Phenomenological fitting reveals the presence of mesoscale heterogeneity in relaxation amplitudes and clearly suggests the presence of two distinct amplitudes. Independent component analysis reveals the presence of a disorder component of the relaxation, which is found to be strongly anti-correlated with the maximum piezoresponse at that location, suggesting smaller disorder effects where the polarization reversal is large and vice versa. The disorder in the relaxation amplitudes is postulated to arise from rhombohedral and field-induced tetragonal phase in the crystal, with each phase associated with its own relaxation amplitude. As a result, these studies highlight the crucial importance of the mixture of ferroelectric phases in the compositions in proximity of the morphotropic phase boundary in governing the local response and further highlight the ability of PFM voltage and time spectroscopies, in conjunction with big-data multivariate analyses, to locally map disorder and correlate it with parameters governing the dynamic behavior.« less

Correlated Fluctuations in Strongly Coupled Binary Networks Beyond Equilibrium

NASA Astrophysics Data System (ADS)

Dahmen, David; Bos, Hannah; Helias, Moritz

2016-07-01

Randomly coupled Ising spins constitute the classical model of collective phenomena in disordered systems, with applications covering glassy magnetism and frustration, combinatorial optimization, protein folding, stock market dynamics, and social dynamics. The phase diagram of these systems is obtained in the thermodynamic limit by averaging over the quenched randomness of the couplings. However, many applications require the statistics of activity for a single realization of the possibly asymmetric couplings in finite-sized networks. Examples include reconstruction of couplings from the observed dynamics, representation of probability distributions for sampling-based inference, and learning in the central nervous system based on the dynamic and correlation-dependent modification of synaptic connections. The systematic cumulant expansion for kinetic binary (Ising) threshold units with strong, random, and asymmetric couplings presented here goes beyond mean-field theory and is applicable outside thermodynamic equilibrium; a system of approximate nonlinear equations predicts average activities and pairwise covariances in quantitative agreement with full simulations down to hundreds of units. The linearized theory yields an expansion of the correlation and response functions in collective eigenmodes, leads to an efficient algorithm solving the inverse problem, and shows that correlations are invariant under scaling of the interaction strengths.

Parental bonding in men with alcohol disorders: a relationship with conduct disorder.

PubMed

Joyce, P R; Sellman, D; Wells, E; Frampton, C M; Bushnell, J A; Oakley-Browne, M; Hornblow, A R

1994-09-01

Men from a clinical treatment setting suffering from alcohol dependence, and randomly selected men from the community diagnosed as having alcohol abuse and/or dependence, completed the Parental Bonding Instrument. The men from the alcohol treatment setting perceived both parents as having been uncaring and overprotective. In the general population sample, an uncaring and overprotective parental style was strongly associated with childhood conduct disorder, but not with alcohol disorder symptoms. This discrepancy in perceived parenting highlights the difficulties in extrapolating findings about aetiological factors for alcohol disorders from clinical samples. It also suggests that childhood conduct disorder and adult antisocial behaviour could influence which men with alcohol disorders receive inpatient treatment.

77 FR 5734 - New Medical Criteria for Evaluating Language and Speech Disorders

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

... Medical Criteria for Evaluating Language and Speech Disorders AGENCY: Social Security Administration... Security numbers or medical information. 1. Internet: We strongly recommend that you submit your comments... INFORMATION CONTACT: Cheryl A. Williams, Office of Medical Listings Improvement, Social Security...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Mukhtiyar; Saini, Hardev S.; Thakur, Jyoti

Heusler alloys based thin-films often exhibit a degree of atomic disorder which leads to the lowering of spin polarization in spintronic devices. We present ab-initio calculations of atomic disorder effects on spin polarization and half-metallicity of Mn{sub 2}CoSi inverse Heusler alloy. The five types of disorder in Mn{sub 2}CoSi have been proposed and investigated in detail. The A2{sub a}-type and B2-type disorders destroy the half-metallicity whereas it sustains for all disorders concentrations in DO{sub 3a}- and A2{sub b}-type disorder and for smallest disorder concentration studied in DO{sub 3b}-type disorder. Lower formation energy/atom for A2{sub b}-type disorder than other four disordersmore » in Mn{sub 2}CoSi advocates the stability of this disorder. The total magnetic moment shows a strong dependence on the disorder and the change in chemical environment. The 100% spin polarization even in the presence of disorders explicitly supports that these disorders shall not hinder the use of Mn{sub 2}CoSi inverse Heusler alloy in device applications. - Graphical abstract: Minority-spin gap (E{sub g↓}) and HM gap (E{sub sf}) as a function of concentrations of various possible disorder in Mn{sub 2}CoSi inverse Heusler alloy. The squares with solid line (black color)/dotted line (blue color)/dashed line (red color) reperesents E{sub g↓} for DO{sub 3a}-/DO{sub 3b}-/A2{sub b}-type disorder in Mn{sub 2}CoSi and the spheres with solid line (black color)/dottedline (blue color)/dashed line (red color) represents E{sub sf} for DO{sub 3a}-/DO{sub 3b}-/A2{sub b}-type disorder in Mn{sub 2}CoSi. - Highlights: • The DO{sub 3}- and A2-type disorders do not affect the half-metallicity in Mn{sub 2}CoSi. • The B2-type disorder solely destroys half-metallicity in Mn{sub 2}CoSi. • The A2-type disorder most probable to occur out of all three types. • The total spin magnetic moment strongly depends on the disorder concentrations.« less

Computational and Theoretical Investigations of Strongly Correlated Fermions in Optical Lattices

DTIC Science & Technology

2013-08-29

and two-particle spectral functions across the disorder - driven superconductor - insulator transition". 22. Invited speaker, \\Fermions in Optical...energy gaps across the disorder - driven superconductor - insulator transition", October 7, 2010, Harvard. 27. Seminar on \\Probing Quantum Phases of...Perimeter Institute, November 14, 2011. 37. Seminar on \\Single and two-particle energy gaps across the disorder - driven superconductor - insulator transition

Obsessive-compulsive disorder as a disturbance of security motivation: constraints on comorbidity.

PubMed

Szechtman, H; Woody, E Z

2006-10-01

Patients with OCD often meet criteria for additional psychiatric disorders, with the incidence of comorbidity being as high as 75% in some studies. Here we examine the theoretical plausibility that in OCD much of the domain of co-morbid presentations encompasses related perturbations of the security motivation system. According to a recent proposal, the security motivation system represents a biologically primitive special motivation that is activated by potential (as opposed to imminent) danger to self or intimate others and engages a set of specialized species-typical behaviors (such as checking and washing) to handle potential danger. Because the task of security motivation is open ended, in the sense that no consummatory stimuli can exist in the real world to indicate the absence of potential danger, the shutdown of security motivation is produced by a self-generated feeling of knowing, a satiety signal termed yedasentience. In this schema, OCD results from a failure to generate or respond to the yedasentience signal: without this negative feedback the patient persists abnormally long in a strong motivational state having to do with primal, basic threats to existence, a condition that leads to prolonged engagement in security-related behaviors, such as the checking and washing, characteristic of OCD compulsions and obsessions. Considering the proposed neuronatomy of security motivation system and OCD, we discuss the likelihood that the phenomenon of "spread of allied reflexes" can produce other security-related psychiatric conditions, as well as the possibility that disturbances along different pathways of the security motivation system can lead to apparently different disorders.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jana, R. N.; Meikap, A. K.

The results of a comprehensive study of weak electron localization (WEL) and electron-electron interaction (EEI) effects in disordered V{sub 75}X{sub 25} (X = Pd, Al) alloys has been reported. The resistivity in absence of magnetic field shows a minimum at temperature T = T{sub m} and follows T{sup 1/2} law within the temperature range 5 K ≤ T ≤ T{sub m}, which suggests predominant EEI effect. Magnetoresistivity is positive due to strong spin-orbit interaction. The dephasing scattering time is dominated by the electron-phonon scattering. The electron-phonon scattering rate shows quadratic temperature dependence behavior, which is explained by the theory ofmore » incomplete dragging at the random scattering potential by phonons. The zero temperature scattering time strongly depends on the disorder and its magnitude decreases with increasing disorder.« less

Relations among symptoms of social phobia subtypes, avoidant personality disorder, panic, and depression.

PubMed

Carter, Shawn A; Wu, Kevin D

2010-03-01

This study's primary goal was to examine relations between symptoms of specific social phobia (SSP), generalized social phobia (GSP), avoidant personality disorder (APD), and panic and depression. Past research has suggested a single social phobia continuum in which SSP displays less symptom severity than GSP or APD. We found SSP symptoms correlated less strongly with depression but more strongly with panic relative to both GSP and APD symptoms. These findings challenge a unidimensional model of social phobia, suggesting a multidimensional model may be more appropriate. These findings also inform current research aimed at classifying mood and anxiety disorders more broadly by identifying that the different factors of fear versus distress appear to underlie different subtypes of social phobia. 2008. Published by Elsevier Ltd.

Probing individual tunneling fluctuators with coherently controlled tunneling systems

NASA Astrophysics Data System (ADS)

Meißner, Saskia M.; Seiler, Arnold; Lisenfeld, Jürgen; Ustinov, Alexey V.; Weiss, Georg

2018-05-01

Josephson junctions made from aluminum and its oxide are the most commonly used functional elements for superconducting circuits and qubits. It is generally known that the disordered thin film AlOx contains atomic tunneling systems. Coherent tunneling systems may couple strongly to a qubit via their electric dipole moment, giving rise to spectral level repulsion. In addition, slowly fluctuating tunneling systems are observable when they are located close to coherent ones and distort their potentials. This interaction causes telegraphic switching of the coherent tunneling systems' energy splitting. Here, we measure such switching induced by individual fluctuators on timescales from hours to minutes using a superconducting qubit as a detector. Moreover, we extend the range of measurable switching times to millisecond scales by employing a highly sensitive single-photon qubit swap spectroscopy and statistical analysis of the measured qubit states.

Correlation between spermatogenesis disorders and rat testes CYP2E1 mRNA contents under experimental alcoholism or type I diabetes.

PubMed

Shayakhmetova, Ganna M; Bondarenko, Larysa B; Matvienko, Anatoliy V; Kovalenko, Valentina M

2014-09-01

The aim of the study was to investigate the correlation between spermatogenesis disorders and CYP2E1 mRNA contents in testes of rats with experimental alcoholism or type I diabetes. Two pathological states characterized by CYP2E1 induction were simulated on Wistar male rats: experimental alcoholism and type I diabetes. As controls for each state, equal number of animals (of the same age and weight) were used. Morphological evaluation of rat testes was carried out. The spermatogenic epithelium state was estimated by four points system. CYP2E1 mRNA expression was rated by method of reverse transcriptase polymerase chain reaction. Pearson correlation coefficients were used for describing relationships between variables. The presence of alcoholism and diabetes-mediated quantitative and qualitative changes in male rat spermatogenic epithelium in comparison with norm has been demonstrated. The increased levels of testes CYP2E1 have been fixed simultaneously. CYP2E1 mRNA content negatively strongly correlated with spermatogenic index value (r=-0.99; P<0.001) and positively strongly correlated with epithelium desquamation occurrence (r=0.99; P<0.001) in testes of rats with chronic alcoholism. The strong correlation between CYP2E1 mRNA content and number of spermatogonia (r=0.99; P<0.001) and "windows" occurrence (r=0.96; P<0.001) has been fixed in diabetic rats testes. Present investigation has demonstrated that the testicular failure following chronic ethanol consumption and diabetes type I in male rats accompanied CYP2E1 mRNA over-expression in testes. The correlation between the levels of CYP2E1 mRNA in testes and spermatogenesis disorders allow supposing the involvement of CYP2E1 into the non-specific pathogenetic mechanisms of male infertility under above-mentioned pathologies. Copyright © 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Transport processes in directional solidification and their effects on microstructure development

NASA Astrophysics Data System (ADS)

Mazumder, Prantik

The processing of materials with unique electronic, mechanical, optical and thermal properties plays a crucial role in modern technology. The quality of these materials depend strongly on the microstructures and the solute/dopant fields in the solid product, that are strongly influenced by the intricate coupling of heat and mass transfer and melt flow in the growth systems. An integrated research program is developed that include precisely characterized experiments and detailed physical and numerical modeling of the complex transport and dynamical processes. Direct numerical simulation of the solidification process is carried out that takes into account the unsteady thermo-solutal convection in the vertical Bridgman crystal growth system, and accurately models the thermal interaction between the furnace and the ampoule by appropriately using experimentally measured thermal profiles. The flow instabilities and transitions and the nonlinear evolution following the transitions are investigated by time series and flow pattern analysis. A range of complex dynamical behavior is predicted with increasing thermal Rayleigh number. The route to chaos appears as: steady convection --> transient mono-periodic --> transient bi-periodic --> transient quasiperiodic --> transient intermittent oscillation- relaxation --> stable intermittent oscillation-relaxation attractor. The spatio-temporal dynamics of the melt flow is found to be directly related to the spatial patterns observed experimentally in the solidified crystals. The application of the model to two phase Sn-Cd peritectic alloys showed that a new class of tree-like oscillating microstructure develops in the solid phase due to unsteady thermo-solutal convection in the liquid melt. These oscillating layered structures can give the illusion of band structures on a plane of polish. The model is applied to single phase solidification in the Al-Cu and Pb-Sn systems to characterize the effect of convection on the macroscopic shape and disorder in the primary arm spacing of the cellular/dendritic freezing front. The apparently puzzling experimental observation of higher disorder in the weakly convective Al-Cu system than that in the highly convective Pb-Sn system is explained by the numerical calculations.

Canadian Guidelines on Pharmacotherapy for Disruptive and Aggressive Behaviour in Children and Adolescents With Attention-Deficit Hyperactivity Disorder, Oppositional Defiant Disorder, or Conduct Disorder

PubMed Central

Gorman, Daniel A; Gardner, David M; Murphy, Andrea L; Feldman, Mark; Bélanger, Stacey A; Steele, Margaret M; Boylan, Khrista; Cochrane-Brink, Kate; Goldade, Roxanne; Soper, Paul R; Ustina, Judy; Pringsheim, Tamara

2015-01-01

Objective: To develop evidence-based guidelines on pharmacotherapy for severe disruptive and aggressive behaviour in children and adolescents with attention-deficit hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), or conduct disorder (CD). The guidelines assume that psychosocial interventions have been pursued but did not achieve sufficient improvement. Method: A multidisciplinary consensus group used the Grading of Recommendations Assessment, Development and Evaluation approach for rating evidence quality and for grading recommendations. We conducted a systematic review of medications studied in placebo-controlled trials for treating disruptive and aggressive behaviour in children and adolescents with ADHD, ODD, or CD. We followed consensus procedures to make 1 of 4 recommendations for each medication: strong, in favour (↑↑); conditional, in favour (↑?); conditional, against (↓?); and strong, against (↓↓). Results: For children and adolescents with disruptive or aggressive behaviour associated with ADHD, psychostimulants received a strong recommendation in favour of use, while atomoxetine and alpha-2 agonists received a conditional recommendation in favour of use. If these patients do poorly with ADHD medications, the medication with the most evidence is risperidone. Risperidone also has the most evidence for treating disruptive or aggressive behaviour in the absence of ADHD. However, given risperidone’s major adverse effects, it received only a conditional recommendation in favour of use. We recommended against using quetiapine, haloperidol, lithium, or carbamazepine because of the poor quality of evidence and their major adverse effects. Conclusion: When severe disruptive or aggressive behaviour occurs with ADHD, medications for ADHD should be used first. Other medications have major adverse effects and, with the exception of risperidone, very limited evidence to support their use. PMID:25886657

Long-term work disability and absenteeism in anxiety and depressive disorders.

PubMed

Hendriks, Sanne M; Spijker, Jan; Licht, Carmilla M M; Hardeveld, Florian; de Graaf, Ron; Batelaan, Neeltje M; Penninx, Brenda W J H; Beekman, Aartjan T F

2015-06-01

This longitudinal study aims to compare long-term work disability and absenteeism between anxiety and depressive disorders focusing on the effects of different course trajectories (remission, recurrence and chronic course) and specific symptom dimensions (anxiety arousal, avoidance behaviour and depressive mood). We included healthy controls, subjects with a history of - and current anxiety and/or depressive disorders with a paid job (n=1632). The Composite International Diagnostic Interview was used to diagnose anxiety and depressive disorders and to assess course trajectories at baseline, over 2 and 4 years. The World Health Organization Disability Assessment Schedule II and the Health and Labour Questionnaire Short Form were used to measure work disability and absenteeism. Symptom dimensions were measured using the Beck Anxiety Inventory, the Fear Questionnaire and the Inventory for Depressive Symptomatology. A history of - and current anxiety and/or depressive disorders were associated with increasing work disability and absenteeism over 4 years, compared to healthy controls. Long-term work disability and absenteeism were most prominent in comorbid anxiety-depressive disorder, followed by depressive disorders, and lowest in anxiety disorders. A chronic course, anxiety arousal and depressive mood were strong predictors for long-term work disability while baseline psychiatric status, a chronic course and depressive mood were strong predictors for long-term work absenteeism. Results cannot be generalized to other anxiety disorders, such as obsessive compulsive disorder, posttraumatic stress disorder and specific phobias. Self-reported measures of work disability and absenteeism were used. Our results demonstrate that depressive syndromes and symptoms have more impact on future work disability and absenteeism than anxiety, implying that prevention of depression is of major importance. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of Structural and Electronic Disorder in Topological Insulator Sb2Te3 Thin Films

NASA Astrophysics Data System (ADS)

Korzhovska, Inna

Topological quantum matter is a unique and potentially transformative protectorate against disorder-induced backscattering. The ultimate disorder limits to the topological state, however, are still not known - understanding these limits is critical to potential applications in the fields of spintronics and information processing. In topological insulators spin-orbit interaction and time-reversal-symmetry invariance guarantees - at least up to a certain disorder strength - that charge transport through 2D gapless Dirac surface states is robust against backscattering by non-magnetic disorder. Strong disorder may destroy topological protection and gap out Dirac surface states, although recent theories predict that under severe electronic disorder a quantized topological conductance might yet reemerge. Very strong electronic disorder, however, is not trivial to install and quantify, and topological matter under such conditions thus far has not been experimentally tested. This thesis addresses the behavior of three-dimensional (3D) topological insulator (TI) films in a wide range of structural and electronic disorder. We establish strong positional disorder in thin (20-50 nm) Sb2Te 3 films, free of extrinsic magnetic dopants. Sb 2Te3 is a known 2nd generation topological insulator in the low-disorder crystalline state. It is also a known phase-change material that undergoes insulator-to-metal transition with the concurrent orders of magnitude resistive drop, where a huge range of disorder could be controllably explored. In this work we show that even in the absence of magnetic dopants, disorder may induce spin correlations detrimental to the topological state. Chapter 1 contains a brief introduction to the topological matter and describes the role played by disorder. This is followed by theory considerations and a survey of prior experimental work. Next we describe the motivation for our experiments and explain the choice of the material. Chapter 2 describes deposition techniques used for material growth, including the parameters significance and effects on the material properties. Chapter 3 describes structural and electrical characterization techniques employed in the work. In Chapter 4-5 we discuss the experimental results. Sb2Te 3 films at extreme disorder, where spin correlations dominate the transport of charge, are discussed in Chapter 4. We employ transport measurements as our main tool to explore disorder-induced changes in the Sb2Te 3. In addition we directly detect disorder-induced spin response in thin Sb2Te3 films free of extrinsic magnetic dopants; it onsets at a surprisingly high temperature ( 200 K) and vanishes when disorder is reduced. Localized spins control the hopping (tunneling) transport through spin memory induced by the non-equilibrium charge currents. The observed spin-memory phenomenon emerges as negative magnetoresistance distinct from orbital quantum interference effects. The hopping mechanism and spin correlations dominate transport over an extensive disorder range. Spin correlations are eventually suppressed by the restoration of positional order in the (bulk) crystalline state, implying a disorder threshold to the topological state. As disorder is reduced the material undergoes structural and electronic transitions, which are discussed in Chapter 5. We obtain a number of characteristic attributes that change sharply at the structural and electronic transitions: localization length, dimensionality, and the nature of conductance. Structural transition is clearly seen in the changes in lattice vibrations tracked by Raman spectroscopy, which we use here as a metric of disorder. The significance of the disorder-induced localization transition is discussed. Next we investigate the effects of structural and electronic disorder on the bulk and surfaces in the crystalline state of Sb2Te3. The nontrivial topology of this strongly spin-orbit coupled material comes from the band inversion in the bulk. One of the key transport signatures of topological surfaces is weak antilocalization (WAL) correction to conductivity; it is associated with the topological pi Berry phase and should display a two-dimensional (2D) character. In our work, we establish the disorder level at which 2D WAL appears. The conduction at this threshold is one conduction quantum G0; it corresponds to the topological quantum channel. Finally, we summarize our key findings and discuss open questions and next steps toward the understanding of disorder-induced correlations in the spin and charge channels that can alter the emergent behaviors of the topological states.

Lightning may pose a danger to patients receiving deep brain stimulation: case report.

PubMed

Prezelj, Neža; Trošt, Maja; Georgiev, Dejan; Flisar, Dušan

2018-05-01

Deep brain stimulation (DBS) is an established treatment option for advanced stages of Parkinson's disease and other movement disorders. It is known that DBS is susceptible to strong electromagnetic fields (EMFs) that can be generated by various electrical devices at work, home, and in medical environments. EMFs can interfere with the proper functioning of implantable pulse generators (IPGs). Very strong EMFs can generate induction currents in implanted electrodes and even damage the brain. Manufacturers of DBS devices have issued a list of warnings on how to avoid this danger. Strong EMFs can result from natural forces as well. The authors present the case of a 66-year-old woman who was being treated with a rechargeable DBS system for neck dystonia when her apartment was struck by lightning. Domestic electronic devices that were operating during the event were burned and destroyed. The woman's IPG switched off but remained undamaged, and she suffered no neurological consequences.

Structure of water in mesoporous organosilica by calorimetry and inelastic neutron scattering

NASA Astrophysics Data System (ADS)

Levy, Esthy; Kolesnikov, Alexander I.; Li, Jichen; Mastai, Yitzhak

2009-01-01

In this paper, we describe the preparation of mesoporous organosilica samples with hydrophilic or hydrophobic organic functionality inside the silica channel. We synthesized mesoporous organosilica of identical pore sizes based on two different organic surface functionality namely hydrophobic (based on octyltriethoxysilane OTES) and hydrophilic (3-aminopropyltriethoxysilane ATES) and MCM-41 was used as a reference system. The structure of water/ice in those porous silica samples have been investigated over a range temperatures by differential scanning calorimetry (DSC) and inelastic neutron scattering (INS). INS study revealed that water confined in hydrophobic mesoporous organosilica shows vibrational behavior strongly different than bulk water. It consists of two states: water with strong and weak hydrogen bonds (with ratio 1:2.65, respectively), compared to ice-Ih. The corresponding O-O distances in these water states are 2.67 and 2.87 Ǻ, which strongly differ compared to ice-Ih (2.76 Ǻ). INS spectra for water in hydrophilic mesoporous organosilica ATES show behavior similar to bulk water, but with greater degree of disorder.

Fe-vacancy and superconductivity in FeSe-based superconductors

NASA Astrophysics Data System (ADS)

Wang, C. H.; Chen, T. K.; Chang, C. C.; Lee, Y. C.; Wang, M. J.; Huang, K. C.; Wu, P. M.; Wu, M. K.

2018-06-01

This review summarizes recent advancements in FeSe and related systems. The FeSe and related superconductors are currently receiving considerable attention for the high Tcs observed and for many similar features to the high Tc cuprate superconductors. These similarities suggest that understanding the FeSe based compounds could potentially help our understanding of the cuprates. We shall first review the common features observed in the FeSe-based system. It was found that with a careful control of material synthesizing processes, numerous rich phases have been observed in the FeSe-based system. Detailed studies show that the Fe-vacancy ordered phases found in the FeSe based compounds, which are non-superconducting Mott insulators, are the parent compounds of the superconductors. Superconductivity emerges from the parent phases by disordering the Fe vacancy order, often by a simple annealing treatment. Recent high temperature X-ray diffraction experiments show that the degree of structural distortion associated with the disorder of Fe-vacancy is closely related to volume fraction of the superconductivity observed. These results suggest the strong lattice to spin coupling are important for the occurrence of superconductivity in FeSe based superconductors.

Intra- and Inter-database Study for Arabic, English, and German Databases: Do Conventional Speech Features Detect Voice Pathology?

PubMed

Ali, Zulfiqar; Alsulaiman, Mansour; Muhammad, Ghulam; Elamvazuthi, Irraivan; Al-Nasheri, Ahmed; Mesallam, Tamer A; Farahat, Mohamed; Malki, Khalid H

2017-05-01

A large population around the world has voice complications. Various approaches for subjective and objective evaluations have been suggested in the literature. The subjective approach strongly depends on the experience and area of expertise of a clinician, and human error cannot be neglected. On the other hand, the objective or automatic approach is noninvasive. Automatic developed systems can provide complementary information that may be helpful for a clinician in the early screening of a voice disorder. At the same time, automatic systems can be deployed in remote areas where a general practitioner can use them and may refer the patient to a specialist to avoid complications that may be life threatening. Many automatic systems for disorder detection have been developed by applying different types of conventional speech features such as the linear prediction coefficients, linear prediction cepstral coefficients, and Mel-frequency cepstral coefficients (MFCCs). This study aims to ascertain whether conventional speech features detect voice pathology reliably, and whether they can be correlated with voice quality. To investigate this, an automatic detection system based on MFCC was developed, and three different voice disorder databases were used in this study. The experimental results suggest that the accuracy of the MFCC-based system varies from database to database. The detection rate for the intra-database ranges from 72% to 95%, and that for the inter-database is from 47% to 82%. The results conclude that conventional speech features are not correlated with voice, and hence are not reliable in pathology detection. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Borderline Personality Disorder Symptom Severity and Sexually Transmitted Infection and HIV Risk in African American Incarcerated Men.

PubMed

Scheidell, Joy D; Lejuez, Carl W; Golin, Carol E; Hobbs, Marcia M; Wohl, David A; Adimora, Adaora A; Khan, Maria R

2016-05-01

Sexually transmitted infections (STI)/HIV rates are disproportionately high among men involved in the criminal justice system. Mental health disorders, including personality disorders, are also elevated among inmates. Borderline personality disorder (BPD) may be an important risk factor for STI/HIV, yet remains relatively understudied, particularly among inmates. We used baseline data from Project DISRUPT, a cohort study of African American men being released from prison in North Carolina who were in heterosexual relationships at prison entry (n=189), to assess their STI/HIV risk in the 6 months before incarceration and BPD symptoms focused on emotional lability and relationship dysfunction. We created a continuous BPD symptom severity score and a dichotomous BPD indicator split at the top quartile of the score (BPD-TQ) to examine associations between BPD and STI/HIV outcomes using logistic regression. We also examined associations between individual symptoms and outcomes. After adjustment for sociodemographics and antisocial personality disorder, BPD-TQ was associated with sexual risk behaviors including multiple partnerships (adjusted odds ratio, 2.58; 95% confidence interval, 1.24-5.36) and sex with nonmonogamous partners (adjusted odds ratio, 2.54; 95% confidence interval, 1.17-5.51). Prevalence of previous STI (47.5% vs. 29.6%) and prevalent chlamydial infection (6.9% vs. 3.1%) seemed higher in those in BPD-TQ, although the associations were not statistically significant. Associations were similar to those with the continuous score. Borderline personality disorder symptoms most associated with STI/HIV risk were abandonment worry, mood swings, and shifts in opinions. Borderline personality disorder is strongly associated with STI/HIV risk in this sample. Researchers should further evaluate the relationship between STI/HIV and BPD, in addition to mood disorders.

Substance use disorders: Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) and International Classification of Diseases, tenth edition (ICD-10).

PubMed

Hasin, Deborah; Hatzenbuehler, Mark L; Keyes, Katherine; Ogburn, Elizabeth

2006-09-01

Two major nomenclatures, Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) and International Classification of Diseases, tenth edition (ICD-10), currently define substance use disorders for broad audiences of users with different training, experience and interests. A comparison of these definitions and their implications for DSM-V and ICD-11 has not been available. The background for the dependence concept and abuse, harmful use, withdrawal, substance-induced disorders and remission and other substance-related conditions is reviewed. Reliability evidence is presented, as is validity evidence from approaches including psychometric, genetic and animal studies. The relevance of the DSM-IV and ICD-10 compared to alternative systems (e.g. the Addiction Severity Index) is considered. Reliability and psychometric validity evidence for substance dependence is consistently strong, but more mixed for abuse and harmful use. Findings on the genetics of alcohol disorders support the validity of the dependence concept, while animal studies underscore the centrality of continued use despite negative consequences to the concept of dependence. While few studies on substance-induced disorders have been conducted, those published show good reliability and validity when elements of DSM-IV and ICD-10 are combined. Dependence in DSM-V and ICD-11 should be retained, standardizing both criteria sets and adding a severity measure. The consequences of heavy use should be measured independently of dependence; add cannabis withdrawal if further research supports existing evidence; conduct further studies of the substance-induced psychiatric categories; standardize their criteria across DSM-V and ICD-11; develop a theoretical basis for better remission criteria; consider changing substance 'abuse' to substance 'dysfunction disorder'; and conduct clinician education on the value of the diagnostic criteria.

Worry is associated with robust reductions in heart rate variability: a transdiagnostic study of anxiety psychopathology.

PubMed

Chalmers, John A; Heathers, James A J; Abbott, Maree J; Kemp, Andrew H; Quintana, Daniel S

2016-06-03

Individuals with anxiety disorders display reduced resting-state heart rate variability (HRV), although findings have been contradictory and the role of specific symptoms has been less clear. It is possible that HRV reductions may transcend diagnostic categories, consistent with dimensional-trait models of psychopathology. Here we investigated whether anxiety disorders or symptoms of anxiety, stress, worry and depression are more strongly associated with resting-state HRV. Resting-state HRV was calculated in participants with clinical anxiety (n = 25) and healthy controls (n = 58). Symptom severity measures of worry, anxiety, stress, and depression were also collected from participants, regardless of diagnosis. Participants who fulfilled DSM-IV criteria for an anxiety disorder displayed diminished HRV, a difference at trend level significance (p = .1, Hedges' g = -.37, BF10 = .84). High worriers (Total n = 41; n = 22 diagnosed with an anxiety disorder and n = 19 not meeting criteria for any psychopathology) displayed a robust reduction in resting state HRV relative to low worriers (p = .001, Hedges' g = -.75, BF10 = 28.16). The specific symptom of worry - not the diagnosis of an anxiety disorder - was associated with the most robust reductions in HRV, indicating that HRV may provide a transdiagnostic biomarker of worry. These results enhance understanding of the relationship between the cardiac autonomic nervous system and anxiety psychopathology, providing support for dimensional-trait models consistent with the Research Domain Criteria framework.

Understanding Interpersonal Function in Psychiatric Illness Through Multiplayer Economic Games

PubMed Central

2014-01-01

Interpersonal factors play significant roles in the onset, maintenance, and remission of psychiatric conditions. In the current major diagnostic classification systems for psychiatric disorders, some conditions are defined by the presence of impairments in social interaction or maintaining interpersonal relationships; these include autism, social phobia, and the personality disorders. Other psychopathologies confer significant difficulties in the social domain, including major depression, posttraumatic stress disorder, and psychotic disorders. Still other mental health conditions, including substance abuse and eating disorders, seem to be exacerbated or triggered in part by the influence of social peers. For each of these and other psychiatric conditions, the extent and quality of social support is a strong determinant of outcome such that high social support predicts symptom improvement and remission. Despite the central role of interpersonal factors in psychiatric illness, the neurobiology of social impairments remains largely unexplored, in part due to difficulties eliciting and quantifying interpersonal processes in a parametric manner. Recent advances in functional neuroimaging, combined with multiplayer exchange games drawn from behavioral economics, and computational/quantitative approaches more generally, provide a fitting paradigm within which to study interpersonal function and dysfunction in psychiatric conditions. In this review, we outline the importance of interpersonal factors in psychiatric illness and discuss ways in which neuroeconomics provides a tractable framework within which to examine the neurobiology of social dysfunction. PMID:22579510

Measuring social anxiety in college students: a comprehensive evaluation of the psychometric properties of the SPAI-23.

PubMed

Schry, Amie R; Roberson-Nay, Roxann; White, Susan W

2012-12-01

Social anxiety disorder (SAD) is 1 of the most prevalent psychological disorders, and among college students in particular, social anxiety has been associated with other problems such as substance use problems and increased vulnerability to other psychiatric disorders. The Social Phobia and Anxiety Inventory-23 (SPAI-23; Roberson-Nay, Strong, Nay, Beidel, & Turner, 2007) may be a useful, brief measure of problematic social anxiety in college students. Results from 4 studies (total n = 2,436) using the SPAI-23 with college student samples are presented. Scores on the SPAI-23 demonstrated strong convergent validity with other measures of social anxiety and discriminant validity as evidenced by lower correlations with measures of dissimilar constructs. Difference scores on the SPAI-23 also demonstrated adequate test-retest reliability over 5 ½ weeks (r = .72). Exploratory factor analysis suggested a two-factor structure: social anxiety and agoraphobia. Finally, differential item function analyses suggested that the items function similarly in men and women. In conclusion, the SPAI-23 demonstrated strong psychometric properties for use with college students.

An Australian Brain Bank: a critical investment with a high return!

PubMed Central

Garrick, T.; Dedova, I.; Hunt, C.; Miller, R.; Sundqvist, N.; Harper, C.

2012-01-01

Research into neuropsychiatric disorders, including alcohol-related problems, is limited in part by the lack of appropriate animal models. However, the development of new technologies in pathology and molecular biology means that many more questions can be addressed using appropriately stored human brain tissues. The New South Wales Tissue Resource Centre (TRC) in the University of Sydney (Australia) is a human brain bank that can provide tissues to the neuroscience research community studying alcohol-related brain disorders, schizophrenia, depression and bipolar disorders. Carefully standardised operational protocols and integrated information systems means that the TRC can provide high quality, accurately characterised, tissues for research. A recent initiative, the pre-mortem donor program called “Using our Brains”, encourages individuals without neuropsychiatric illness to register as control donors, a critical group for all research. Community support for this program is strong with over 2,000 people registering their interest. Discussed herein are the protocols pertaining to this multifaceted facility and the benefits of investment, both scientific and financial, to neuroscience researchers and the community at large. PMID:18543078

An Australian Brain Bank: a critical investment with a high return!

PubMed

Sheedy, D; Garrick, T; Dedova, I; Hunt, C; Miller, R; Sundqvist, N; Harper, C

2008-09-01

Research into neuropsychiatric disorders, including alcohol-related problems, is limited in part by the lack of appropriate animal models. However, the development of new technologies in pathology and molecular biology means that many more questions can be addressed using appropriately stored human brain tissues. The New South Wales Tissue Resource Centre (TRC) in the University of Sydney (Australia) is a human brain bank that can provide tissues to the neuroscience research community studying alcohol-related brain disorders, schizophrenia, depression and bipolar disorders. Carefully standardised operational protocols and integrated information systems means that the TRC can provide high quality, accurately characterised, tissues for research. A recent initiative, the pre-mortem donor program called "Using our Brains", encourages individuals without neuropsychiatric illness to register as control donors, a critical group for all research. Community support for this program is strong with over 2,000 people registering their interest. Discussed herein are the protocols pertaining to this multifaceted facility and the benefits of investment, both scientific and financial, to neuroscience researchers and the community at large.

Call for a change in research funding priorities: the example of mental health in Costa Rica.

PubMed

Contreras, Javier; Raventós, Henriette; Rodríguez, Gloriana; Leandro, Mauricio

2014-10-01

The World Health Organization (WHO) Mental Health Action Plan 2013-2020 urges its Member States to strengthen leadership in mental health, ensure mental and social health interventions in community-based settings, promote mental health and strengthen information systems, and increase evidence and research for mental health. Although Costa Rica has strongly invested in public health and successfully reduced the burden of nutritional and infectious diseases, its transitional epidemiological pattern, population growth, and immigration from unstable neighboring countries has shifted the burden to chronic disorders. Although policies for chronic disorders have been in place for several decades, mental disorders have not been included. Recently, as the Ministry of Health of Costa Rica developed a Mental Health Policy for 2013-2020, it became evident that the country needs epidemiological data to prioritize evidence-based intervention areas. This article stresses the importance of conducting local epidemiological studies on mental health, and calls for changes in research funding priorities by public and private national and international funding agencies in order to follow the WHO Mental Health Action Plan.

Psychiatry and Chinese Culture

PubMed Central

Lin, Tsung-Yi

1983-01-01

When we examine the cultural characteristics that influence mental disorders and related behavior among the Chinese, no major differences are found between Chinese and other groups in the range of disorders or in overall prevalence. Several cultural factors influence the recognition and treatment of mental illness, among which are attitudes toward emotional display, somatic as opposed to psychogenic disorders and features of the traditional medical belief system in Chinese culture. The Chinese have a relatively favorable prognosis of schizophrenia, low rates of depressive illness, a strong tendency towards somatization and the presence of several unique culture-bound syndromes. From studying Chinese in Vancouver, it was found that they have a characteristic way of dealing with mental illness in the family, in that there is first a protracted period of intrafamilial coping with serious psychiatric illness, followed by recourse to friends, elders and neighbors in the community; third, consultation with traditional specialists, religious healers or general physicians; fourth, outpatient or inpatient treatment from specialists, and, finally, a process of rejection and scapegoating of the patient. The efficacy of Western psychiatric treatment of Chinese patients has yet to be objectively assessed. PMID:6364576

Abnormal Barrier Function in Gastrointestinal Disorders.

PubMed

Farré, Ricard; Vicario, María

2017-01-01

There is increasing concern in identifying the mechanisms underlying the intimate control of the intestinal barrier, as deregulation of its function is strongly associated with digestive (organic and functional) and a number of non-digestive (schizophrenia, diabetes, sepsis, among others) disorders. The intestinal barrier is a complex and effective defensive functional system that operates to limit luminal antigen access to the internal milieu while maintaining nutrient and electrolyte absorption. Intestinal permeability to substances is mainly determined by the physicochemical properties of the barrier, with the epithelium, mucosal immunity, and neural activity playing a major role. In functional gastrointestinal disorders (FGIDs), the absence of structural or biochemical abnormalities that explain chronic symptoms is probably close to its end, as recent research is providing evidence of structural gut alterations, at least in certain subsets, mainly in functional dyspepsia (FD) and irritable bowel syndrome (IBS). These alterations are associated with increased permeability, which seems to reflect mucosal inflammation and neural activation. The participation of each anatomical and functional component of barrier function in homeostasis and intestinal dysfunction is described, with a special focus on FGIDs.

Hydrodynamic description of transport in strongly correlated electron systems.

PubMed

Andreev, A V; Kivelson, Steven A; Spivak, B

2011-06-24

We develop a hydrodynamic description of the resistivity and magnetoresistance of an electron liquid in a smooth disorder potential. This approach is valid when the electron-electron scattering length is sufficiently short. In a broad range of temperatures, the dissipation is dominated by heat fluxes in the electron fluid, and the resistivity is inversely proportional to the thermal conductivity, κ. This is in striking contrast to the Stokes flow, in which the resistance is independent of κ and proportional to the fluid viscosity. We also identify a new hydrodynamic mechanism of spin magnetoresistance.

Nonequilibrium critical behavior of model statistical systems and methods for the description of its features

NASA Astrophysics Data System (ADS)

Prudnikov, V. V.; Prudnikov, P. V.; Mamonova, M. V.

2017-11-01

This paper reviews features in critical behavior of far-from-equilibrium macroscopic systems and presents current methods of describing them by referring to some model statistical systems such as the three-dimensional Ising model and the two-dimensional XY model. The paper examines the critical relaxation of homogeneous and structurally disordered systems subjected to abnormally strong fluctuation effects involved in ordering processes in solids at second-order phase transitions. Interest in such systems is due to the aging properties and fluctuation-dissipation theorem violations predicted for and observed in systems slowly evolving from a nonequilibrium initial state. It is shown that these features of nonequilibrium behavior show up in the magnetic properties of magnetic superstructures consisting of alternating nanoscale-thick magnetic and nonmagnetic layers and can be observed not only near the film’s critical ferromagnetic ordering temperature Tc, but also over the wide temperature range T ⩽ Tc.

Looking for the interactions between omeprazole and amoxicillin in a disordered phase. An experimental and theoretical study.

PubMed

Russo, Marcos G; Sancho, Matias I; Silva, Lorena M A; Baldoni, Hector A; Venancio, Tiago; Ellena, Javier; Narda, Griselda E

2016-03-05

In this paper, co-grinding mixtures of omeprazole-amoxicillin trihydrate (CGM samples) and omeprazole-anhydrous amoxicillin (CGMa samples) at 3:7, 1:1 and 7:3 molar ratios, respectively, were studied with the aim of obtaining a co-amorphous system and determining the potential intermolecular interactions. These systems were fully characterized by differential scanning calorimetry (DSC), FT-infrared spectroscopy (FTIR), X-ray powder diffraction (PXRD), scanning electron microscopy (SEM) and solid state Nuclear Magnetic Resonance (ssNMR). The co-grinding process was not useful to get a co-amorphous system but it led to obtaining the 1:1 CGMa disordered phase. Moreover, in this system both FTIR and ssNMR analysis strongly suggest intermolecular interactions between the sulfoxide group of omeprazole and the primary amine of amoxicillin anhydrous. The solubility measurements were performed in simulated gastric fluid (SGF) to prove the effect of the co-grinding process. Complementarily, we carried out density functional theory calculations (DFT) followed by quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analyses in order to shed some light on the principles that guide the possible formation of heterodimers at the molecular level, which are supported by spectroscopic experimental findings. Copyright © 2015 Elsevier B.V. All rights reserved.

Lobular patterns of cerebellar resting-state connectivity in adults with Autism Spectrum Disorder.

PubMed

Olivito, Giusy; Lupo, Michela; Laghi, Fiorenzo; Clausi, Silvia; Baiocco, Roberto; Cercignani, Mara; Bozzali, Marco; Leggio, Maria

2018-03-01

Autism spectrum disorder is a neurodevelopmental disorder characterized by core deficits in social functioning. Core autistics traits refer to poor social and imagination skills, poor attention-switching/strong focus of attention, exceptional attention to detail, as expressed by the autism-spectrum quotient. Over the years, the importance of the cerebellum in the aetiology of autism spectrum disorder has been acknowledged. Neuroimaging studies have provided a strong support to this view, showing both structural and functional connectivity alterations to affect the cerebellum in autism spectrum disorder. According to the underconnectivity theory, disrupted connectivity within cerebello-cerebral networks has been specifically implicated in the aetiology of autism spectrum disorder. However, inconsistent results have been generated across studies. In this study, an integrated approach has been used in a selected population of adults with autism spectrum disorder to analyse both cerebellar morphometry and functional connectivity. In individuals with autism spectrum disorder, a decreased cerebellar grey matter volume affected the right Crus II, a region showing extensive connections with cerebral areas related to social functions. This grey matter reduction correlates with the degree of autistic traits as measured by autism-spectrum quotient. Interestingly, altered functional connectivity was found between the reduced cerebellar Crus II and contralateral cerebral regions, such as frontal and temporal areas. Overall, the present data suggest that adults with autism spectrum disorder present with specific cerebellar structural alterations that may affect functional connectivity within cerebello-cerebral modules relevant to social processing and account for core autistics traits. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Me, Myself, and Money II: Relative Deprivation Predicts Disordered Gambling Severity via Delay Discounting, Especially Among Gamblers Who Have a Financially Focused Self-Concept.

PubMed

Tabri, Nassim; Will Shead, N; Wohl, Michael J A

2017-12-01

In the current research, we examined whether the known link between relative deprivation and disordered gambling (via delay discounting; i.e., preferences for immediate smaller rewards relative to delayed larger rewards) is moderated by the extent to which gamblers have a financially focused self-concept. Specifically, we hypothesized that delay discounting would be a strong predictor of disordered gambling among those who base their self-worth on their financial success. To test this moderated-mediation model, a community sample of gamblers (N = 239) completed measures that assessed relative deprivation, delay discounting, financially focused self-concept, and disordered gambling severity. As predicted, people who felt more relative deprivation reported more severe symptoms of disordered gambling and this association was mediated by delay discounting. Importantly, this mediated relationship was moderated by the extent to which participants' self-concept was focused on financial success. Among participants whose self-concept was high in financial focus, greater delay discounting (stemming from relative deprivation) was a strong predictor of disordered gambling. Among people whose self-concept was low in financial focus, delay discounting (stemming from relative deprivation) was a weak predictor of disordered gambling. Thus, the magnitude of the indirect effect of relative deprivation on disordered gambling severity was larger among people with a more financially focused self-concept-an effect mediated by delay discounting. These findings suggest that targeting gamblers' financial focus in prevention and treatment interventions may be instrumental in curtailing the development and maintenance of disordered gambling.

The Role of Dopamine and Its Dysfunction as a Consequence of Oxidative Stress

PubMed Central

Juárez Olguín, Hugo; Calderón Guzmán, David; Hernández García, Ernestina; Barragán Mejía, Gerardo

2016-01-01

Dopamine is a neurotransmitter that is produced in the substantia nigra, ventral tegmental area, and hypothalamus of the brain. Dysfunction of the dopamine system has been implicated in different nervous system diseases. The level of dopamine transmission increases in response to any type of reward and by a large number of strongly additive drugs. The role of dopamine dysfunction as a consequence of oxidative stress is involved in health and disease. Introduce new potential targets for the development of therapeutic interventions based on antioxidant compounds. The present review focuses on the therapeutic potential of antioxidant compounds as a coadjuvant treatment to conventional neurological disorders is discussed. PMID:26770661

A recurrence network approach to analyzing forced synchronization in hydrodynamic systems

NASA Astrophysics Data System (ADS)

Murugesan, Meenatchidevi; Zhu, Yuanhang; Li, Larry K. B.

2016-11-01

Hydrodynamically self-excited systems can lock into external forcing, but their lock-in boundaries and the specific bifurcations through which they lock in can be difficult to detect. We propose using recurrence networks to analyze forced synchronization in a hydrodynamic system: a low-density jet. We find that as the jet bifurcates from periodicity (unforced) to quasiperiodicity (weak forcing) and then to lock-in (strong forcing), its recurrence network changes from a regular distribution of links between nodes (unforced) to a disordered topology (weak forcing) and then to a regular distribution again at lock-in (strong forcing). The emergence of order at lock-in can be either smooth or abrupt depending on the specific lock-in route taken. Furthermore, we find that before lock-in, the probability distribution of links in the network is a function of the characteristic scales of the system, which can be quantified with network measures and used to estimate the proximity to the lock-in boundaries. This study shows that recurrence networks can be used (i) to detect lock-in, (ii) to distinguish between different routes to lock-in, and (iii) as an early warning indicator of the proximity of a system to its lock-in boundaries. This work was supported by the Research Grants Council of Hong Kong (Project No. 16235716 and 26202815).

Auditory Processing Disorders: Acquisition and Treatment

ERIC Educational Resources Information Center

Moore, David R.

2007-01-01

Auditory processing disorder (APD) describes a mixed and poorly understood listening problem characterised by poor speech perception, especially in challenging environments. APD may include an inherited component, and this may be major, but studies reviewed here of children with long-term otitis media with effusion (OME) provide strong evidence…

Creative Cognition and Psychosis Vulnerability: What's the Difference?

ERIC Educational Resources Information Center

Crabtree, Julie; Green, Melissa J.

2016-01-01

Evidence from experimental psychology provides unequivocal support for enhanced creativity among individuals who are prone to psychotic and mood disorders. At the same time, there is strong epidemiological evidence for greater incidence of creative achievement among those diagnosed with bipolar disorder (but not schizophrenia). This review…

Developing Handheld Video Intervention for Students with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Hughes, Elizabeth M.; Yakubova, Gulnoza

2016-01-01

Video-based intervention (VBI) has strong evidence supporting efficiency in teaching social, communication, functional, behavior, play, and self-help skills and emerging evidence for teaching academic skills to students with autism spectrum disorder (ASD). VBI allows opportunities to electronically provide personalized, consistent, and prerecorded…

Effect of Marriage on Risk for Onset of Alcohol Use Disorder: A Longitudinal and Co-Relative Analysis in a Swedish National Sample.

PubMed

Kendler, Kenneth S; Lönn, Sara Larsson; Salvatore, Jessica; Sundquist, Jan; Sundquist, Kristina

2016-09-01

The authors sought to clarify the relationship between marriage and risk for alcohol use disorder. The association between marital status and risk for first registration for alcohol use disorder in medical, criminal, and pharmacy registries was assessed in a population-based Swedish cohort (N=3,220,628) using longitudinal time-dependent survival and co-relative designs. First marriage was associated with a substantial decline in risk for onset of alcohol use disorder in men (hazard ratio=0.41, 95% CI=0.40-0.42) and women (hazard ratio=0.27, 95% CI=0.26-0.28). This association was slightly stronger when the spouse had no lifetime alcohol use disorder, while marriage to a spouse with lifetime alcohol use disorder increased risk for subsequent alcohol use disorder registration in both men (hazard ratio=1.29, 95% CI=1.16-1.43) and women (hazard ratio=1.18, 95% CI=1.06-1.30). In both sexes, the protective effect of marriage was significantly stronger in those with than those without a family history of alcohol use disorder. In both men and women, the associations between marriage and risk for alcohol use disorder in cousins, half siblings, full siblings, and monozygotic twins discordant for marital status were as strong as that seen in the general population. First marriage to a spouse with no lifetime alcohol use disorder is associated with a large reduction in risk for alcohol use disorder. This association cannot be explained by standard covariates or, as indicated by co-relative analyses, familial genetic or shared environmental confounders. These results are consistent with the hypothesis that the psychological and social aspects of marriage, and in particular health-monitoring spousal interactions, strongly protect against the development of alcohol use disorder. The protective effects of marriage on risk for alcohol use disorder are increased in those at high familial risk for alcoholism.

High-density Two-Dimensional Small Polaron Gas in a Delta-Doped Mott Insulator

PubMed Central

Ouellette, Daniel G.; Moetakef, Pouya; Cain, Tyler A.; Zhang, Jack Y.; Stemmer, Susanne; Emin, David; Allen, S. James

2013-01-01

Heterointerfaces in complex oxide systems open new arenas in which to test models of strongly correlated material, explore the role of dimensionality in metal-insulator-transitions (MITs) and small polaron formation. Close to the quantum critical point Mott MITs depend on band filling controlled by random disordered substitutional doping. Delta-doped Mott insulators are potentially free of random disorder and introduce a new arena in which to explore the effect of electron correlations and dimensionality. Epitaxial films of the prototypical Mott insulator GdTiO3 are delta-doped by substituting a single (GdO)+1 plane with a monolayer of charge neutral SrO to produce a two-dimensional system with high planar doping density. Unlike metallic SrTiO3 quantum wells in GdTiO3 the single SrO delta-doped layer exhibits thermally activated DC and optical conductivity that agree in a quantitative manner with predictions of small polaron transport but with an extremely high two-dimensional density of polarons, ~7 × 1014 cm−2. PMID:24257578

Psychological interventions in the management of common skin conditions

PubMed Central

Shenefelt, Philip D

2010-01-01

The nervous system and the skin develop next to each other in the embryo and remain intimately interconnected and interactive throughout life. The nervous system can influence skin conditions through psychoneuroimmunoendocrine mechanisms and through behaviors. Understanding the pathophysiology aids in selection of treatment plans for correcting the negative effects of the psyche on specific skin conditions. Medication options include standard psychotropic medications and alternative herbs and supplements. Other options include biofeedback, cognitive-behavioral methods, hypnosis, meditation, progressive relaxation, the placebo effect, and suggestion. When simple measures fail, combining medications with other therapeutic options may produce better results. Skin conditions that have strong psychophysiologic aspects may respond well to techniques such as biofeedback, cognitive-behavioral methods, hypnosis, meditation, or progressive relaxation that help to counteract stress. Treatment of primary psychiatric disorders that negatively influence skin conditions often results in improvement of those skin conditions. Abnormal conditions of the skin, hair, and nails can also influence the psyche negatively. Treatment of secondary psychiatric disorders such as anxiety or depression that are triggered or exacerbated by the appearance of these skin conditions or the associated discomfort may also be required. PMID:22110329

Atypical activation of the mirror neuron system during perception of hand motion in autism.

PubMed

Martineau, Joëlle; Andersson, Frédéric; Barthélémy, Catherine; Cottier, Jean-Philippe; Destrieux, Christophe

2010-03-12

Disorders in the autism spectrum are characterized by deficits in social and communication skills such as imitation, pragmatic language, theory of mind, and empathy. The discovery of the "mirror neuron system" (MNS) in macaque monkeys may provide a basis from which to explain some of the behavioral dysfunctions seen in individuals with autism spectrum disorders (ASD).We studied seven right-handed high-functioning male autistic and eight normal subjects (TD group) using functional magnetic resonance imaging during observation and execution of hand movements compared to a control condition (rest). The between group comparison of the contrast [observation versus rest] provided evidence of a bilateral greater activation of inferior frontal gyrus during observation of human motion than during rest for the ASD group than for the TD group. This hyperactivation of the pars opercularis (belonging to the MNS) during observation of human motion in autistic subjects provides strong support for the hypothesis of atypical activity of the MNS that may be at the core of the social deficits in autism. Copyright 2010 Elsevier B.V. All rights reserved.

Stress, glucocorticoid hormones, and hippocampal neural progenitor cells: implications to mood disorders.

PubMed

Kino, Tomoshige

2015-01-01

The hypothalamic-pituitary-adrenal (HPA) axis and its end-effectors glucocorticoid hormones play central roles in the adaptive response to numerous stressors that can be either internal or external. Thus, this system has a strong impact on the brain hippocampus and its major functions, such as cognition, memory as well as behavior, and mood. The hippocampal area of the adult brain contains neural stem cells or more committed neural progenitor cells, which retain throughout the human life the ability of self-renewal and to differentiate into multiple neural cell lineages, such as neurons, astrocytes, and oligodendrocytes. Importantly, these characteristic cells contribute significantly to the above-indicated functions of the hippocampus, while various stressors and glucocorticoids influence proliferation, differentiation, and fate of these cells. This review offers an overview of the current understanding on the interactions between the HPA axis/glucocorticoid stress-responsive system and hippocampal neural progenitor cells by focusing on the actions of glucocorticoids. Also addressed is a further discussion on the implications of such interactions to the pathophysiology of mood disorders.

2D coherent charge transport in highly ordered conducting polymers doped by solid state diffusion

NASA Astrophysics Data System (ADS)

Kang, Keehoon; Watanabe, Shun; Broch, Katharina; Sepe, Alessandro; Brown, Adam; Nasrallah, Iyad; Nikolka, Mark; Fei, Zhuping; Heeney, Martin; Matsumoto, Daisuke; Marumoto, Kazuhiro; Tanaka, Hisaaki; Kuroda, Shin-Ichi; Sirringhaus, Henning

2016-08-01

Doping is one of the most important methods to control charge carrier concentration in semiconductors. Ideally, the introduction of dopants should not perturb the ordered microstructure of the semiconducting host. In some systems, such as modulation-doped inorganic semiconductors or molecular charge transfer crystals, this can be achieved by spatially separating the dopants from the charge transport pathways. However, in conducting polymers, dopants tend to be randomly distributed within the conjugated polymer, and as a result the transport properties are strongly affected by the resulting structural and electronic disorder. Here, we show that in the highly ordered lamellar microstructure of a regioregular thiophene-based conjugated polymer, a small-molecule p-type dopant can be incorporated by solid state diffusion into the layers of solubilizing side chains without disrupting the conjugated layers. In contrast to more disordered systems, this allows us to observe coherent, free-electron-like charge transport properties, including a nearly ideal Hall effect in a wide temperature range, a positive magnetoconductance due to weak localization and the Pauli paramagnetic spin susceptibility.

The impact of early symptom change and therapeutic alliance on treatment outcome in cognitive-behavioural therapy for eating disorders.

PubMed

Turner, Hannah; Bryant-Waugh, Rachel; Marshall, Emily

2015-10-01

The present study explored the impact of early symptom change (cognitive and behavioural) and the early therapeutic alliance on treatment outcome in cognitive-behavioural therapy (CBT) for the eating disorders. Participants were 94 adults with diagnosed eating disorders who completed a course of CBT in an out-patient community eating disorders service in the UK. Patients completed a measure of eating disorder psychopathology at the start of treatment, following the 6th session and at the end of treatment. They also completed a measure of therapeutic alliance following the 6th session. Greater early reduction in dietary restraint and eating concerns, and smaller levels of change in shape concern, significantly predicted later reduction in global eating pathology. The early therapeutic alliance was strong across the three domains of tasks, goals and bond. Early symptom reduction was a stronger predictor of later reduction in eating pathology than early therapeutic alliance. The early therapeutic alliance did not mediate the relationship between early symptom reduction and later reduction in global eating pathology. Instead, greater early symptom reduction predicted a strong early therapeutic alliance. Early clinical change was the strongest predictor of treatment outcome and this also facilitated the development of a strong early alliance. Clinicians should be encouraged to deliver all aspects of evidence-based CBT, including behavioural change. The findings suggest that this will have a positive impact on both the early therapeutic alliance and later change in eating pathology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hot spot of structural ambivalence in prion protein revealed by secondary structure principal component analysis.

PubMed

Yamamoto, Norifumi

2014-08-21

The conformational conversion of proteins into an aggregation-prone form is a common feature of various neurodegenerative disorders including Alzheimer's, Huntington's, Parkinson's, and prion diseases. In the early stage of prion diseases, secondary structure conversion in prion protein (PrP) causing β-sheet expansion facilitates the formation of a pathogenic isoform with a high content of β-sheets and strong aggregation tendency to form amyloid fibrils. Herein, we propose a straightforward method to extract essential information regarding the secondary structure conversion of proteins from molecular simulations, named secondary structure principal component analysis (SSPCA). The definite existence of a PrP isoform with an increased β-sheet structure was confirmed in a free-energy landscape constructed by mapping protein structural data into a reduced space according to the principal components determined by the SSPCA. We suggest a "spot" of structural ambivalence in PrP-the C-terminal part of helix 2-that lacks a strong intrinsic secondary structure, thus promoting a partial α-helix-to-β-sheet conversion. This result is important to understand how the pathogenic conformational conversion of PrP is initiated in prion diseases. The SSPCA has great potential to solve various challenges in studying highly flexible molecular systems, such as intrinsically disordered proteins, structurally ambivalent peptides, and chameleon sequences.

Time-dependent real space RG on the spin-1/2 XXZ chain

NASA Astrophysics Data System (ADS)

Mason, Peter; Zagoskin, Alexandre; Betouras, Joseph

In order to measure the spread of information in a system of interacting fermions with nearest-neighbour couplings and strong bond disorder, one could utilise a dynamical real space renormalisation group (RG) approach on the spin-1/2 XXZ chain. Under such a procedure, a many-body localised state is established as an infinite randomness fixed point and the entropy scales with time as log(log(t)). One interesting further question that results from such a study is the case when the Hamiltonian explicitly depends on time. Here we answer this question by considering a dynamical renormalisation group treatment on the strongly disordered random spin-1/2 XXZ chain where the couplings are time-dependent and chosen to reflect a (slow) evolution of the governing Hamiltonian. Under the condition that the renormalisation process occurs at fixed time, a set of coupled second order, nonlinear PDE's can be written down in terms of the random distributions of the bonds and fields. Solution of these flow equations at the relevant critical fixed points leads us to establish the dynamics of the flow as we sweep through the quantum critical point of the Hamiltonian. We will present these critical flows as well as discussing the issues of duality, entropy and many-body localisation.

Berry phase mechanism of the anomalous Hall effect in a disordered two-dimensional magnetic semiconductor structure.

DOE PAGES

Oveshnikov, L. N.; Kulbachinskii, V. A.; Davydov, A. B.; ...

2015-11-24

In this study, the anomalous Hall effect (AHE) arises from the interplay of spin-orbit interactions and ferromagnetic order and is a potentially useful probe of electron spin polarization, especially in nanoscale systems where direct measurement is not feasible. While AHE is rather well-understood in metallic ferromagnets, much less is known about the relevance of different physical mechanisms governing AHE in insulators. As ferromagnetic insulators, but not metals, lend themselves to gatecontrol of electron spin polarization, understanding AHE in the insulating state is valuable from the point of view of spintronic applications. Among the mechanisms proposed in the literature for AHEmore » in insulators, the one related to a geometric (Berry) phase effect has been elusive in past studies. The recent discovery of quantized AHE in magnetically doped topological insulators - essentially a Berry phase effect - provides strong additional motivation to undertake more careful search for geometric phase effects in AHE in the magnetic semiconductors. Here we report our experiments on the temperature and magnetic field dependences of AHE in insulating, strongly-disordered two-dimensional Mn delta-doped semiconductor heterostructures in the hopping regime. In particular, it is shown that at sufficiently low temperatures, the mechanism of AHE related to the Berry phase is favoured.« less

Signatures of evanescent transport in ballistic suspended graphene-superconductor junctions

PubMed Central

Kumaravadivel, Piranavan; Du, Xu

2016-01-01

In Dirac materials, the low energy excitations behave like ultra-relativistic massless particles with linear energy dispersion. A particularly intriguing phenomenon arises with the intrinsic charge transport behavior at the Dirac point where the charge density approaches zero. In graphene, a 2-D Dirac fermion gas system, it was predicted that charge transport near the Dirac point is carried by evanescent modes, resulting in unconventional “pseudo-diffusive” charge transport even in the absence of disorder. In the past decade, experimental observation of this phenomenon remained challenging due to the presence of strong disorder in graphene devices which limits the accessibility of the low carrier density regime close enough to the Dirac point. Here we report transport measurements on ballistic suspended graphene-Niobium Josephson weak links that demonstrate a transition from ballistic to pseudo-diffusive like evanescent transport below a carrier density of ~1010 cm−2. Approaching the Dirac point, the sub-harmonic gap structures due to multiple Andreev reflections display a strong Fermi energy-dependence and become increasingly pronounced, while the normalized excess current through the superconductor-graphene interface decreases sharply. Our observations are in qualitative agreement with the long standing theoretical prediction for the emergence of evanescent transport mediated pseudo-diffusive transport in graphene. PMID:27080733

Impaired movement timing in neurological disorders: rehabilitation and treatment strategies.

PubMed

Hove, Michael J; Keller, Peter E

2015-03-01

Timing abnormalities have been reported in many neurological disorders, including Parkinson's disease (PD). In PD, motor-timing impairments are especially debilitating in gait. Despite impaired audiomotor synchronization, PD patients' gait improves when they walk with an auditory metronome or with music. Building on that research, we make recommendations for optimizing sensory cues to improve the efficacy of rhythmic cuing in gait rehabilitation. Adaptive rhythmic metronomes (that synchronize with the patient's walking) might be especially effective. In a recent study we showed that adaptive metronomes synchronized consistently with PD patients' footsteps without requiring attention; this improved stability and reinstated healthy gait dynamics. Other strategies could help optimize sensory cues for gait rehabilitation. Groove music strongly engages the motor system and induces movement; bass-frequency tones are associated with movement and provide strong timing cues. Thus, groove and bass-frequency pulses could deliver potent rhythmic cues. These strategies capitalize on the close neural connections between auditory and motor networks; and auditory cues are typically preferred. However, moving visual cues greatly improve visuomotor synchronization and could warrant examination in gait rehabilitation. Together, a treatment approach that employs groove, auditory, bass-frequency, and adaptive (GABA) cues could help optimize rhythmic sensory cues for treating motor and timing deficits. © 2014 New York Academy of Sciences.

Berry phase mechanism of the anomalous Hall effect in a disordered two-dimensional magnetic semiconductor structure

PubMed Central

Oveshnikov, L. N.; Kulbachinskii, V. A.; Davydov, A. B.; Aronzon, B. A.; Rozhansky, I. V.; Averkiev, N. S.; Kugel, K. I.; Tripathi, V.

2015-01-01

The anomalous Hall effect (AHE) arises from the interplay of spin-orbit interactions and ferromagnetic order and is a potentially useful probe of electron spin polarization, especially in nanoscale systems where direct measurement is not feasible. While AHE is rather well-understood in metallic ferromagnets, much less is known about the relevance of different physical mechanisms governing AHE in insulators. As ferromagnetic insulators, but not metals, lend themselves to gate-control of electron spin polarization, understanding AHE in the insulating state is valuable from the point of view of spintronic applications. Among the mechanisms proposed in the literature for AHE in insulators, the one related to a geometric (Berry) phase effect has been elusive in past studies. The recent discovery of quantized AHE in magnetically doped topological insulators - essentially a Berry phase effect - provides strong additional motivation to undertake more careful search for geometric phase effects in AHE in the magnetic semiconductors. Here we report our experiments on the temperature and magnetic field dependences of AHE in insulating, strongly-disordered two-dimensional Mn delta-doped semiconductor heterostructures in the hopping regime. In particular, it is shown that at sufficiently low temperatures, the mechanism of AHE related to the Berry phase is favoured. PMID:26596472

Deciphering chemical order/disorder and material properties at the single-atom level.

PubMed

Yang, Yongsoo; Chen, Chien-Chun; Scott, M C; Ophus, Colin; Xu, Rui; Pryor, Alan; Wu, Li; Sun, Fan; Theis, Wolfgang; Zhou, Jihan; Eisenbach, Markus; Kent, Paul R C; Sabirianov, Renat F; Zeng, Hao; Ercius, Peter; Miao, Jianwei

2017-02-01

Perfect crystals are rare in nature. Real materials often contain crystal defects and chemical order/disorder such as grain boundaries, dislocations, interfaces, surface reconstructions and point defects. Such disruption in periodicity strongly affects material properties and functionality. Despite rapid development of quantitative material characterization methods, correlating three-dimensional (3D) atomic arrangements of chemical order/disorder and crystal defects with material properties remains a challenge. On a parallel front, quantum mechanics calculations such as density functional theory (DFT) have progressed from the modelling of ideal bulk systems to modelling 'real' materials with dopants, dislocations, grain boundaries and interfaces; but these calculations rely heavily on average atomic models extracted from crystallography. To improve the predictive power of first-principles calculations, there is a pressing need to use atomic coordinates of real systems beyond average crystallographic measurements. Here we determine the 3D coordinates of 6,569 iron and 16,627 platinum atoms in an iron-platinum nanoparticle, and correlate chemical order/disorder and crystal defects with material properties at the single-atom level. We identify rich structural variety with unprecedented 3D detail including atomic composition, grain boundaries, anti-phase boundaries, anti-site point defects and swap defects. We show that the experimentally measured coordinates and chemical species with 22 picometre precision can be used as direct input for DFT calculations of material properties such as atomic spin and orbital magnetic moments and local magnetocrystalline anisotropy. This work combines 3D atomic structure determination of crystal defects with DFT calculations, which is expected to advance our understanding of structure-property relationships at the fundamental level.

Intestinal worms eating neuropsychiatric disorders? Apparently so.

PubMed

Kou, Henry H; Parker, William

2018-02-02

A number of factors in Western society, including inflammatory diets, sedentary lifestyles, vitamin D deficiency and chronic psychological stress, are known to induce inflammation and to be associated with neuropsychiatric disorders. One factor that is emerging as a potential inflammation inducing factor is biota depletion, or loss of biodiversity from the ecosystem of the human body as a result of industrialization. Originally known as the "hygiene hypothesis", biota alteration theory describes the effects of biota alteration on the human immune system. Work on this topic has pinpointed depletion of helminths as a key loss to the body's ecosystem in Western society, and suggests that some exposure to helminths, ubiquitous prior to the modern era, may be necessary for normal immune system development. Socio-medical studies of humans "self-treating" with helminths as well as limited studies in animal models strongly suggest that helminth therapy may be a productive approach toward treating a range of neuropsychiatric disorders, including chronic fatigue, migraine headaches, depression and anxiety disorders. However, helminth therapy faces some daunting hurdles, including the lack of a financial incentive for development, despite a tremendous potential market for the organisms. It is argued that benevolent donation for early trials as well as changes in regulatory policy to accommodate helminth therapy may be important for the field to develop. It is hoped that future success with some high-profile trials can propel the field, now dominated more by self-treatment than by clinical trials, forward into the main stream of medicine. Copyright © 2018 Elsevier B.V. All rights reserved.

Neuroanatomical phenotypes in mental illness: identifying convergent and divergent cortical phenotypes across autism, ADHD and schizophrenia.

PubMed

Park, Min Tae M; Raznahan, Armin; Shaw, Philip; Gogtay, Nitin; Lerch, Jason P; Chakravarty, M Mallar

2018-05-01

There is evidence suggesting neuropsychiatric disorders share genomic, cognitive and clinical features. Here, we ask if autism-spectrum disorders (ASD), attention-deficit/hyperactivity disorder (ADHD) and schizophrenia share neuroanatomical variations. First, we used measures of cortical anatomy to estimate spatial overlap of neuroanatomical variation using univariate methods. Next, we developed a novel methodology to determine whether cortical deficits specifically target or are "enriched" within functional resting-state networks. We found cortical anomalies were preferentially enriched across functional networks rather than clustering spatially. Specifically, cortical thickness showed significant enrichment between patients with ASD and those with ADHD in the default mode network, between patients with ASD and those with schizophrenia in the frontoparietal and limbic networks, and between patients with ADHD and those with schizophrenia in the ventral attention network. Networks enriched in cortical thickness anomalies were also strongly represented in functional MRI results (Neurosynth; r = 0.64, p = 0.032). We did not account for variable symptom dimensions and severity in patient populations, and our cross-sectional design prevented longitudinal analyses of developmental trajectories. These findings suggest that common deficits across neuropsychiatric disorders cannot simply be characterized as arising out of local changes in cortical grey matter, but rather as entities of both local and systemic alterations targeting brain networks.

Development of the Brief Bipolar Disorder Symptom Scale for patients with bipolar disorder.

PubMed

Dennehy, Ellen B; Suppes, Trisha; Crismon, M Lynn; Toprac, Marcia; Carmody, Thomas J; Rush, A John

2004-06-30

The Brief Bipolar Disorder Symptom Scale (BDSS) is a 10-item measure of symptom severity that was derived from the 24-item Brief Psychiatric Rating Scale (BPRS24). It was developed for clinical use in settings where systematic evaluation is desired within the constraints of a brief visit. The psychometric properties of the BDSS were evaluated in 409 adult outpatients recruited from 19 clinics within the public mental health system of Texas, as part of the Texas Medication Algorithm Project (TMAP). The selection process for individual items is discussed in detail, and was based on multiple analyses, including principal components analysis with varimax rotation. Selection of the final items considered the statistical strength and factor loading of items within each of those factors as well as the need for comprehensive coverage of critical symptoms of bipolar disorder. The BDSS demonstrated good psychometric properties in this preliminary investigation. It demonstrated a strong association with the BPRS24 and performed similarly to the BPRS24 in its relationship to other symptom measures. The BDSS demonstrated superior sensitivity to symptom change, and an excellent level of agreement for classification of patients as either responders or non-responders with the BPRS24. Copyright 2004 Elsevier Ireland Ltd.

Neuroanatomical phenotypes in mental illness: identifying convergent and divergent cortical phenotypes across autism, ADHD and schizophrenia.

PubMed

Park, Min Tae M; Raznahan, Armin; Shaw, Philip; Gogtay, Nitin; Lerch, Jason P; Chakravarty, M Mallar

2018-02-05

There is evidence suggesting neuropsychiatric disorders share genomic, cognitive and clinical features. Here, we ask if autism-spectrum disorders (ASD), attention-deficit/hyperactivity disorder (ADHD) and schizophrenia share neuroanatomical variations. First, we used measures of cortical anatomy to estimate spatial overlap of neuroanatomical variation using univariate methods. Next, we developed a novel methodology to determine whether cortical deficits specifically target or are "enriched" within functional resting-state networks. We found cortical anomalies were preferentially enriched across functional networks rather than clustering spatially. Specifically, cortical thickness showed significant enrichment between patients with ASD and those with ADHD in the default mode network, between patients with ASD and those with schizophrenia in the frontoparietal and limbic networks, and between patients with ADHD and those with schizophrenia in the ventral attention network. Networks enriched in cortical thickness anomalies were also strongly represented in functional MRI results (Neurosynth; r = 0.64, p = 0.032). We did not account for variable symptom dimensions and severity in patient populations, and our cross-sectional design prevented longitudinal analyses of developmental trajectories. These findings suggest that common deficits across neuropsychiatric disorders cannot simply be characterized as arising out of local changes in cortical grey matter, but rather as entities of both local and systemic alterations targeting brain networks.

Large-scale atomistic simulations demonstrate dominant alloy disorder effects in GaBixAs1 -x/GaAs multiple quantum wells

NASA Astrophysics Data System (ADS)

Usman, Muhammad

2018-04-01

Bismide semiconductor materials and heterostructures are considered a promising candidate for the design and implementation of photonic, thermoelectric, photovoltaic, and spintronic devices. This work presents a detailed theoretical study of the electronic and optical properties of strongly coupled GaBixAs1 -x /GaAs multiple quantum well (MQW) structures. Based on a systematic set of large-scale atomistic tight-binding calculations, our results reveal that the impact of atomic-scale fluctuations in alloy composition is stronger than the interwell coupling effect, and plays an important role in the electronic and optical properties of the investigated MQW structures. Independent of QW geometry parameters, alloy disorder leads to a strong confinement of charge carriers, a large broadening of the hole energies, and a red-shift in the ground-state transition wavelength. Polarization-resolved optical transition strengths exhibit a striking effect of disorder, where the inhomogeneous broadening could exceed an order of magnitude for MQWs, in comparison to a factor of about 3 for single QWs. The strong influence of alloy disorder effects persists when small variations in the size and composition of MQWs typically expected in a realistic experimental environment are considered. The presented results highlight the limited scope of continuum methods and emphasize on the need for large-scale atomistic approaches to design devices with tailored functionalities based on the novel properties of bismide materials.

Adapting the multifamily group model for treating veterans with posttraumatic stress disorder.

PubMed

Sherman, Michelle D; Perlick, Deborah A; Straits-Tröster, Kristy

2012-11-01

The Department of Veterans Affairs (VA) health care system's leadership has endorsed family involvement in veterans' mental health care as an important component of treatment. Both veterans and families describe family participation as highly desirable, and research has documented that having healthy social support is a strong protective factor for posttraumatic stress disorder (PTSD). Family psychoeducation has been shown to be effective in preventing relapse among severely mentally ill, and preliminary evidence suggests that family interventions for PTSD may improve veteran and family outcomes. The multifamily group (MFG) treatment model incorporates psychoeducation, communication training, and problem-solving skill building, and it increases social support through its group format. This article describes the rationale for further adaptation of the MFG model for PTSD, and it reviews issues related to its implementation as a promising adjunctive treatment as part of the continuum of PTSD services available in VA.

Ballistic superconductivity in semiconductor nanowires.

PubMed

Zhang, Hao; Gül, Önder; Conesa-Boj, Sonia; Nowak, Michał P; Wimmer, Michael; Zuo, Kun; Mourik, Vincent; de Vries, Folkert K; van Veen, Jasper; de Moor, Michiel W A; Bommer, Jouri D S; van Woerkom, David J; Car, Diana; Plissard, Sébastien R; Bakkers, Erik P A M; Quintero-Pérez, Marina; Cassidy, Maja C; Koelling, Sebastian; Goswami, Srijit; Watanabe, Kenji; Taniguchi, Takashi; Kouwenhoven, Leo P

2017-07-06

Semiconductor nanowires have opened new research avenues in quantum transport owing to their confined geometry and electrostatic tunability. They have offered an exceptional testbed for superconductivity, leading to the realization of hybrid systems combining the macroscopic quantum properties of superconductors with the possibility to control charges down to a single electron. These advances brought semiconductor nanowires to the forefront of efforts to realize topological superconductivity and Majorana modes. A prime challenge to benefit from the topological properties of Majoranas is to reduce the disorder in hybrid nanowire devices. Here we show ballistic superconductivity in InSb semiconductor nanowires. Our structural and chemical analyses demonstrate a high-quality interface between the nanowire and a NbTiN superconductor that enables ballistic transport. This is manifested by a quantized conductance for normal carriers, a strongly enhanced conductance for Andreev-reflecting carriers, and an induced hard gap with a significantly reduced density of states. These results pave the way for disorder-free Majorana devices.

Onset of meso-scale turbulence in active nematics

NASA Astrophysics Data System (ADS)

Doostmohammadi, Amin; Shendruk, Tyler N.; Thijssen, Kristian; Yeomans, Julia M.

2017-05-01

Meso-scale turbulence is an innate phenomenon, distinct from inertial turbulence, that spontaneously occurs at low Reynolds number in fluidized biological systems. This spatiotemporal disordered flow radically changes nutrient and molecular transport in living fluids and can strongly affect the collective behaviour in prominent biological processes, including biofilm formation, morphogenesis and cancer invasion. Despite its crucial role in such physiological processes, understanding meso-scale turbulence and any relation to classical inertial turbulence remains obscure. Here we show how the motion of active matter along a micro-channel transitions to meso-scale turbulence through the evolution of locally disordered patches (active puffs) from an ordered vortex-lattice flow state. We demonstrate that the stationary critical exponents of this transition to meso-scale turbulence in a channel coincide with the directed percolation universality class. This finding bridges our understanding of the onset of low-Reynolds-number meso-scale turbulence and traditional scale-invariant turbulence in confinement.

Object Recognition in Williams Syndrome: Uneven Ventral Stream Activation

ERIC Educational Resources Information Center

O'Hearn, Kirsten; Roth, Jennifer K.; Courtney, Susan M.; Luna, Beatriz; Street, Whitney; Terwillinger, Robert; Landau, Barbara

2011-01-01

Williams syndrome (WS) is a genetic disorder associated with severe visuospatial deficits, relatively strong language skills, heightened social interest, and increased attention to faces. On the basis of the visuospatial deficits, this disorder has been characterized primarily as a deficit of the dorsal stream, the occipitoparietal brain regions…

Role of Communication in the Context of Educating Children with Attention-Deficit/Hyperactivity Disorder: Parents' and Teachers' Perspectives

ERIC Educational Resources Information Center

Koro-Ljungberg, Mirka; Bussing, Regina; Wilder, JeffriAnne; Gary, Faye

2011-01-01

Recent school policies increasingly support "parent-integrated" school environments, which benefit from effective parent-school collaborations and strong communication skills to ensure optimal educational outcomes. However, invisible disabilities, such as attention-deficit/hyperactivity disorder, provide unique sociopolitical contexts that shape…

Video Game Use and Problem Behaviors in Boys with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Mazurek, Micah O.; Engelhardt, Christopher R.

2013-01-01

Children with autism spectrum disorders (ASD) have strong preferences for screen-based media, particularly video games. Although problematic video game use has been associated with behavior problems among typically developing children, the relationship between these variables has not been previously examined among children with ASD. The current…

Habit Reversal Training for Tic Disorders in Children and Adolescents

ERIC Educational Resources Information Center

Piacentini, John; Chang, Susanna

2005-01-01

Chronic tic disorders, including Tourette's syndrome (TS), affect approximately .5% of children and adolescents. Although strong evidence exists supporting a neurobiological etiology, operant factors may play a role in the maintenance of tic behaviors. Pharmacological approaches remain the most commonly used intervention for chronic tic disorder…

Neuroepileptic Correlates of Autistic Symptomatology in Tuberous Sclerosis

ERIC Educational Resources Information Center

Bolton, Patrick F.

2004-01-01

Tuberous sclerosis is a genetic condition that is strongly associated with the development of an autism spectrum disorder. However, there is marked variability in expression, and only a subset of children with tuberous sclerosis develop autism spectrum disorder. Clarification of the mechanisms that underlie the association and variability in…

Psychosocial Functioning in the Context of Diagnosis: Assessment and Theoretical Issues

ERIC Educational Resources Information Center

Ro, Eunyoe; Clark, Lee Anna

2009-01-01

Psychosocial functioning is an important focus of attention in the revision of the "Diagnostic and Statistical Manual of Mental Disorders". Researchers and clinicians are converging upon the opinion that psychometrically strong, comprehensive assessment of individuals' functioning is needed to characterize disorder fully. Also shared is the…

Improving the Transportability of CBT for Internalizing Disorders in Children

ERIC Educational Resources Information Center

Elkins, R. Meredith; McHugh, R. Kathryn; Santucci, Lauren C.; Barlow, David H.

2011-01-01

Research provides strong support for the efficacy and effectiveness of cognitive behavioral therapy (CBT) for the treatment of childhood internalizing disorders. Given evidence for limited dissemination and implementation of CBT outside of academic settings, efforts are underway to improve its transportability so that more children with mental…

Parental Depression and Child Behavior Problems: A Pilot Study Examining Pathways of Influence

ERIC Educational Resources Information Center

Xu, Yangmu; Neece, Cameron L.; Parker, Kathleen H.

2014-01-01

Parents of children with autism spectrum disorders (ASD) have higher rates of depressive symptoms than parents of typically developing children and parents of children with other developmental disorders. Parental depressive symptoms are strongly associated with problem behaviors in children; however, the mechanisms through which parental…

Electronic transport on the Shastry-Sutherland lattice in Ising-type rare-earth tetraborides

NASA Astrophysics Data System (ADS)

Ye, Linda; Suzuki, Takehito; Checkelsky, Joseph G.

2017-05-01

In the presence of a magnetic field frustrated spin systems may exhibit plateaus at fractional values of saturation magnetization. Such plateau states are stabilized by classical and quantum mechanisms including order by disorder, triplon crystallization, and various competing order effects. In the case of electrically conducting systems, free electrons represent an incisive probe for the plateau states. Here we study the electrical transport of Ising-type rare-earth tetraborides R B4 (R =Er , Tm), a metallic Shastry-Sutherland lattice showing magnetization plateaus. We find that the longitudinal and transverse resistivities reflect scattering with both the static and the dynamic plateau structure. We model these results consistently with the expected strong uniaxial anisotropy on a quantitative level, providing a framework for the study of plateau states in metallic frustrated systems.

Perpendicular susceptibility and geometrical frustration in two-dimensional Ising antiferromagnets: Exact solutions

NASA Astrophysics Data System (ADS)

Muttalib, K. A.; Khatun, M.; Barry, J. H.

2017-11-01

Discovery of new materials and improved experimental as well as numerical techniques have led to a renewed interest in geometrically frustrated spin systems. However, there are very few exact results available that can provide a benchmark for comparison. In this work, we calculate exactly the perpendicular susceptibility χ⊥ for an Ising antiferromagnet with (i) nearest-neighbor pair interaction on a kagome lattice where strong frustration prevents long-range ordering and (ii) elementary triplet interactions on a kagome lattice which has no frustration but the system remains disordered down to zero temperature. By comparing with other known exact results with and without frustration, we propose that an appropriately temperature-scaled χ⊥ can be used as a quantitative measure of the degree of frustration in Ising spin systems.

Treating patients with bipolar disorder and substance dependence: lessons learned.

PubMed

Weiss, Roger D

2004-12-01

Although bipolar disorder is the Axis I psychiatric disorder associated with the highest rate of co-occurring substance use disorders, little research has focused on treatments specifically designed for these patients. The author and his colleagues have developed and studied Integrated Group Therapy (IGT) for this population. This paper describes common themes that have emerged in carrying out IGT for patients with bipolar disorder and substance dependence. These include the strong emphasis on depression, as opposed to mania; the predominance of hopelessness; specific patterns of medication noncompliance; and the implications of patients' labeling their substance use as self-medication. Therapeutic aspects involved in addressing these themes are discussed.

Stability and dynamical properties of material flow systems on random networks

NASA Astrophysics Data System (ADS)

Anand, K.; Galla, T.

2009-04-01

The theory of complex networks and of disordered systems is used to study the stability and dynamical properties of a simple model of material flow networks defined on random graphs. In particular we address instabilities that are characteristic of flow networks in economic, ecological and biological systems. Based on results from random matrix theory, we work out the phase diagram of such systems defined on extensively connected random graphs, and study in detail how the choice of control policies and the network structure affects stability. We also present results for more complex topologies of the underlying graph, focussing on finitely connected Erdös-Réyni graphs, Small-World Networks and Barabási-Albert scale-free networks. Results indicate that variability of input-output matrix elements, and random structures of the underlying graph tend to make the system less stable, while fast price dynamics or strong responsiveness to stock accumulation promote stability.

Prethermal Phases of Matter Protected by Time-Translation Symmetry

NASA Astrophysics Data System (ADS)

Else, Dominic V.; Bauer, Bela; Nayak, Chetan

2017-01-01

In a periodically driven (Floquet) system, there is the possibility for new phases of matter, not present in stationary systems, protected by discrete time-translation symmetry. This includes topological phases protected in part by time-translation symmetry, as well as phases distinguished by the spontaneous breaking of this symmetry, dubbed "Floquet time crystals." We show that such phases of matter can exist in the prethermal regime of periodically driven systems, which exists generically for sufficiently large drive frequency, thereby eliminating the need for integrability or strong quenched disorder, which limited previous constructions. We prove a theorem that states that such a prethermal regime persists until times that are nearly exponentially long in the ratio of certain couplings to the drive frequency. By similar techniques, we can also construct stationary systems that spontaneously break continuous time-translation symmetry. Furthermore, we argue that for driven systems coupled to a cold bath, the prethermal regime could potentially persist to infinite time.

Patient-oncologist alliance as protection against suicidal ideation in young adults with advanced cancer.

PubMed

Trevino, Kelly M; Abbott, Caroline H; Fisch, Michael J; Friedlander, Robert J; Duberstein, Paul R; Prigerson, Holly G

2014-08-01

Young adults with cancer are at an increased risk of suicidal ideation. To the authors' knowledge, the impact of the patient-oncologist alliance on suicidal ideation has not been examined to date. The current study examined the relationship between the patient-oncologist therapeutic alliance and suicidal ideation in young adults with advanced cancer. A total of 93 young adult patients (aged 20 years-40 years) with incurable, recurrent, or metastatic cancer were evaluated by trained interviewers. Suicidal ideation was assessed with the Yale Evaluation of Suicidality scale, dichotomized into a positive and negative score. Predictors included diagnoses of major depressive disorder and posttraumatic stress disorder, physical quality of life, social support, and use of mental health and supportive care services. The Human Connection Scale, dichotomized into a strong (upper third) and weak (lower two-thirds) therapeutic alliance, assessed the strength of the patients' perceived oncologist alliance. Approximately 22.6% of patients screened positive for suicidal ideation. Patients with a strong therapeutic alliance were found to be at reduced risk of suicidal ideation after controlling for confounding influences of cancer diagnosis, Karnofsky performance status, number of physical symptoms, physical quality of life, major depressive disorder, posttraumatic stress disorder, and social support. A strong therapeutic alliance was also associated with a reduced risk of suicidal ideation after controlling for mental health discussions with health care providers and use of mental health interventions. The patient-oncologist alliance was found to be a robust predictor of suicidal ideation and provided better protection against suicidal ideation than mental health interventions, including psychotropic medications. Oncologists may significantly influence patients' mental health and may benefit from training and guidance in building strong alliances with their young adult patients. © 2014 American Cancer Society.

Structure and properties of a complex of α-synuclein and a single-domain camelid antibody.

PubMed

De Genst, Erwin J; Guilliams, Tim; Wellens, Joke; O'Day, Elizabeth M; Waudby, Christopher A; Meehan, Sarah; Dumoulin, Mireille; Hsu, Shang-Te Danny; Cremades, Nunilo; Verschueren, Koen H G; Pardon, Els; Wyns, Lode; Steyaert, Jan; Christodoulou, John; Dobson, Christopher M

2010-09-17

The aggregation of the intrinsically disordered protein α-synuclein to form fibrillar amyloid structures is intimately associated with a variety of neurological disorders, most notably Parkinson's disease. The molecular mechanism of α-synuclein aggregation and toxicity is not yet understood in any detail, not least because of the paucity of structural probes through which to study the behavior of such a disordered system. Here, we describe an investigation involving a single-domain camelid antibody, NbSyn2, selected by phage display techniques to bind to α-synuclein, including the exploration of its effects on the in vitro aggregation of the protein under a variety of conditions. We show using isothermal calorimetric methods that NbSyn2 binds specifically to monomeric α-synuclein with nanomolar affinity and by means of NMR spectroscopy that it interacts with the four C-terminal residues of the protein. This latter finding is confirmed by the determination of a crystal structure of NbSyn2 bound to a peptide encompassing the nine C-terminal residues of α-synuclein. The NbSyn2:α-synuclein interaction is mediated mainly by side-chain interactions while water molecules cross-link the main-chain atoms of α-synuclein to atoms of NbSyn2, a feature we believe could be important in intrinsically disordered protein interactions more generally. The aggregation behavior of α-synuclein at physiological pH, including the morphology of the resulting fibrillar structures, is remarkably unaffected by the presence of NbSyn2 and indeed we show that NbSyn2 binds strongly to the aggregated as well as to the soluble forms of α-synuclein. These results give strong support to the conjecture that the C-terminal region of the protein is not directly involved in the mechanism of aggregation and suggest that binding of NbSyn2 could be a useful probe for the identification of α-synuclein aggregation in vitro and possibly in vivo. Copyright © 2010. Published by Elsevier Ltd.

Remarkable effects of disorder on superconductivity of single atomic layers of lead on silicon

NASA Astrophysics Data System (ADS)

Brun, Christophe

2015-03-01

It is well known that conventional superconductivity is very robust against non-magnetic disorder. Nevertheless for thin and ultrathin films the structural properties play a major role in determining the superconducting properties, through a subtle interplay between disorder and Coulomb interactions. Unexpectedly, in 2010 superconductivity was discovered in single atomic layers of lead and indium grown on silicon substrate using scanning tunneling spectroscopy and confirmed later on by macroscopic transport measurements. Such well-controlled and tunable crystalline monolayers are ideal systems for studying the influence of various kinds of structural defects on the superconducting properties at the atomic and mesoscopic scale. In particular, Pb monolayers offer the opportunity of probing new effects of disorder because not only superconductivity is 2D but also the electronic wave functions are 2D. Our study of two Pb monolayers of different crystal structures by very-low temperature STM (300 mK) under magnetic field reveals unexpected results involving new spatial spectroscopic variations. Our results show that although the sheet resistance of the Pb monolayers is much below the resistance quantum, strong non-BCS corrections appear leading to peak heights fluctuations in the dI/dV tunneling spectra at a spatial scale much smaller than the superconducting coherence length. Furthermore, strong local evidence of the signature of Rashba effect on the superconductivity of the Pb/Si(111) monolayer is revealed through filling of in gap states and local spatial variations of this filling. Finally the nature of vortices in a monolayer is found to be very sensitive to the properties of step edges areas. This work was supported by University Pierre et Marie Curie UPMC `Emergence' project, French ANR Project `ElectroVortex,' ANR-QuDec and Templeton Foundation (40381), ARO (W911NF-13-1-0431) and CNRS PICS funds. Partial funding by US-DOE Grant DE-AC02-07CH1.

Global gene expression and Ingenuity biological functions analysis on PCBs 153 and 138 induced human PBMC in vitro reveals differential mode(s) of action in developing toxicities.

PubMed

Ghosh, Somiranjan; Zang, Shizhu; Mitra, Partha S; Ghimbovschi, Svetlana; Hoffman, Eric P; Dutta, Sisir K

2011-07-01

Several reports have indicated that low level of polychlorinated biphenyl (PCB) exposure can adversely affect a multitude of physiological disorders and diseases in in vitro, in vivo, and as reported in epidemiological studies. This investigation is focused on the possible contribution of two most prevalent PCB congeners in vitro in developing toxicities. We used PCBs 138 and 153 at the human equivalence level as model agents to test their specificity in developing toxicities. We chose a global approach using oligonucleotide microarray technology to investigate modulated gene expression for biological effects, upon exposure of PCBs, followed by Ingenuity Pathway Analysis (IPA), to understand the underlying consequence in developing disease and disorders. We performed in vitro studies with human peripheral blood mononuclear cells (PBMC), where PBMC cells were exposed to respective PCBs for 48 h. Overall, our observation on gene expression indicated that PCB produces a unique signature affecting different pathways, specific for each congener. While analyzing these data through IPA, the prominent and interesting disease and disorders were neurological disease, cancer, cardiovascular disease, respiratory disease, as well as endocrine system disorders, genetic disorders, and reproductive system disease. They showed strong resemblances with in vitro, in vivo, and in the epidemiological studies. A distinct difference was observed in renal and urological diseases, organisimal injury and abnormalities, dental disease, ophthalmic disease, and psychological disorders, which are only revealed by PCB 138 exposure, but not in PCB 153. The present study emphasizes the challenges of global gene expression in vitro and was correlated with the results of exposed human population. The microarray results give a molecular mechanistic insight and functional effects, following PCB exposure. The extent of changes in genes related to several possible mode(s) of action highlights the changes in cellular functions and signaling pathways that play major roles. In addition to understanding the pathways related to mode of action for chemicals, these data could lead to the identification of genomic signatures that could be used for screening of chemicals for their potential to cause disease and developmental disorders. Copyright © 2011 Elsevier Ltd. All rights reserved.

Lives in isolation: stories and struggles of low-income African American women with panic disorder.

PubMed

Johnson, Michael; Mills, Terry L; Deleon, Jessica M; Hartzema, Abraham G; Haddad, Judella

2009-01-01

Research evidence points to the existence of racial-ethnic disparities in both access to and quality of mental health services for African Americans with panic disorder. Current panic disorder evaluation and treatment paradigms are not responsive to the needs of many African Americans. The primary individual, social, and health-care system factors that limit African Americans' access to care and response to treatment are not well understood. Low-income African American women with panic disorder participated in a series of focus-group sessions designed to elicit (1) their perspectives regarding access and treatment barriers and (2) their recommendations for designing a culturally consistent panic treatment program. Fear of confiding to others about panic symptoms, fear of social stigma, and lack of information about panic disorder were major individual barriers. Within their social networks, stigmatizing attitudes toward mental illness and the mentally ill, discouragement about the use of psychiatric medication, and perceptions that symptoms were the result of personal or spiritual weakness had all interfered with the participants' treatment seeking efforts and contributed to a common experience of severe social isolation. None of the focus-group members had developed fully effective therapeutic relationships with either medical or mental health providers. They described an unmet need for more interactive and culturally authentic relationships with treatment providers. Although the focus-group sessions were not intended to be therapeutic, the women reported that participation in the meetings had been an emotionally powerful and beneficial experience. They expressed a strong preference for the utilization of female-only, panic disorder peer-support groups as an initial step in the treatment/recovery process. Peer-support groups for low-income African American women with panic disorder could address many of the identified access and treatment barriers.

Neuromodulatory Systems and Their Interactions: A Review of Models, Theories, and Experiments

PubMed Central

Avery, Michael C.; Krichmar, Jeffrey L.

2017-01-01

Neuromodulatory systems, including the noradrenergic, serotonergic, dopaminergic, and cholinergic systems, track environmental signals, such as risks, rewards, novelty, effort, and social cooperation. These systems provide a foundation for cognitive function in higher organisms; attention, emotion, goal-directed behavior, and decision-making derive from the interaction between the neuromodulatory systems and brain areas, such as the amygdala, frontal cortex, hippocampus, and sensory cortices. Given their strong influence on behavior and cognition, these systems also play a key role in disease states and are the primary target of many current treatment strategies. The fact that these systems interact with each other either directly or indirectly, however, makes it difficult to understand how a failure in one or more systems can lead to a particular symptom or pathology. In this review, we explore experimental evidence, as well as focus on computational and theoretical models of neuromodulation. Better understanding of neuromodulatory systems may lead to the development of novel treatment strategies for a number of brain disorders. PMID:29311844

Neuromodulatory Systems and Their Interactions: A Review of Models, Theories, and Experiments.

PubMed

Avery, Michael C; Krichmar, Jeffrey L

2017-01-01

Neuromodulatory systems, including the noradrenergic, serotonergic, dopaminergic, and cholinergic systems, track environmental signals, such as risks, rewards, novelty, effort, and social cooperation. These systems provide a foundation for cognitive function in higher organisms; attention, emotion, goal-directed behavior, and decision-making derive from the interaction between the neuromodulatory systems and brain areas, such as the amygdala, frontal cortex, hippocampus, and sensory cortices. Given their strong influence on behavior and cognition, these systems also play a key role in disease states and are the primary target of many current treatment strategies. The fact that these systems interact with each other either directly or indirectly, however, makes it difficult to understand how a failure in one or more systems can lead to a particular symptom or pathology. In this review, we explore experimental evidence, as well as focus on computational and theoretical models of neuromodulation. Better understanding of neuromodulatory systems may lead to the development of novel treatment strategies for a number of brain disorders.

A high-efficiency spin polarizer based on edge and surface disordered silicene nanoribbons

NASA Astrophysics Data System (ADS)

Xu, Ning; Zhang, Haiyang; Wu, Xiuqiang; Chen, Qiao; Ding, Jianwen

2018-07-01

Using the tight-binding formalism, we explore the effect of weak disorder upon the conductance of zigzag edge silicene nanoribbons (SiNRs), in the limit of phase-coherent transport. We find that the fashion of the conductance varies with disorder, and depends strongly on the type of disorder. Conductance dips are observed at the Van Hove singularities, owing to quasilocalized states existing in surface disordered SiNRs. A conductance gap is observed around the Fermi energy for both edge and surface disordered SiNRs, because edge states are localized. The average conductance of the disordered SiNRs decreases exponentially with the increase of disorder, and finally tends to disappear. The near-perfect spin polarization can be realized in SiNRs with a weak edge or surface disorder, and also can be attained by both the local electric field and the exchange field.

Ergonomic stressors and upper extremity disorders in vehicle manufacturing: cross sectional exposure-response trends

PubMed Central

Punnett, L.

1998-01-01

OBJECTIVE: To evaluate the association between upper extremity soft tissue disorders and exposure to preventable ergonomic stressors in vehicle manufacturing operations. METHODS: A cross sectional study was conducted in one vehicle stamping plant and one engine assembly plant. A standardised physical examination of the upper extremities was performed on all subjects. An interviewer administered questionnaire obtained data on demographics, work history, musculoskeletal symptoms, non-occupational covariates, and psycho-physical (relative intensity) ratings of ergonomic stressors. The primary exposure score was computed by summing the responses to the psychophysical exposure items. Multivariate regression analysis was used to model the prevalence of disorders of the shoulders or upper arms, wrists or hands, and all upper extremity regions (each defined both by symptoms and by physical examination plus symptoms) as a function of exposure quartile. RESULTS: A total of 1315 workers (85% of the target population) was examined. The prevalence of symptom disorders was 22% for the wrists or hands and 15% for the shoulders or upper arms; cases defined on the basis of a physical examination were about 80% as frequent. Disorders of the upper extremities, shoulders, and wrists or hands all increased markedly with exposure score, after adjustment for plant, acute injury, sex, body mass index, systemic disease, and seniority. CONCLUSIONS: Musculoskeletal disorders of the upper extremities were strongly associated with exposure to combined ergonomic stressors. The exposure- response trend was very similar for symptom cases and for physical examination cases. It is important to evaluate all dimensions of ergonomic exposure in epidemiological studies, as exposures often occur in combination in actual workplaces.   PMID:9764102

Relationships between self-reported childhood traumatic experiences, attachment style, neuroticism and features of borderline personality disorders in patients with mood disorders.

PubMed

Baryshnikov, Ilya; Joffe, Grigori; Koivisto, Maaria; Melartin, Tarja; Aaltonen, Kari; Suominen, Kirsi; Rosenström, Tom; Näätänen, Petri; Karpov, Boris; Heikkinen, Martti; Isometsä, Erkki

2017-03-01

Co-occurring borderline personality disorder (BPD) features have a marked impact on treatment of patients with mood disorders. Overall, high neuroticism, childhood traumatic experiences (TEs) and insecure attachment are plausible aetiological factors for BPD. However, their relationship with BPD features specifically among patients with mood disorders remains unclear. We investigated these relationships among unipolar and bipolar mood disorder patients. As part of the Helsinki University Psychiatric Consortium study, the McLean Screening Instrument (MSI), the Experiences in Close Relationships-Revised (ECR-R), the Short Five (S5) and the Trauma and Distress Scale (TADS) were filled in by patients with mood disorders (n=282) in psychiatric care. Correlation coefficients between total scores of scales and their dimensions were estimated, and multivariate regression (MRA) and mediation analyses were conducted. Spearman's correlations were strong (rho=0.58; p<0.001) between total scores of MSI and S5 Neuroticism and moderate (rho=0.42; p<0.001) between MSI and TADS as well as between MSI and ECR-R Attachment Anxiety. In MRA, young age, S5 Neuroticism and TADS predicted scores of MSI (p<0.001). ECR-R Attachment Anxiety mediated 33% (CI=17-53%) of the relationships between TADS and MSI. Cross-sectional questionnaire study. We found moderately strong correlations between self-reported BPD features and concurrent high neuroticism, reported childhood traumatic experiences and Attachment Anxiety also among patients with mood disorders. Independent predictors for BPD features include young age, frequency of childhood traumatic experiences and high neuroticism. Insecure attachment may partially mediate the relationship between childhood traumatic experiences and borderline features among mood disorder patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact of vacancy ordering on thermal transport in crystalline phase-change materials.

PubMed

Siegert, K S; Lange, F R L; Sittner, E R; Volker, H; Schlockermann, C; Siegrist, T; Wuttig, M

2015-01-01

Controlling thermal transport in solids is of paramount importance for many applications. Often thermal management is crucial for a device's performance, as it affects both reliability and power consumption. A number of intricate concepts have been developed to address this challenge, such as diamond-like coatings to enhance the thermal conductivity or low symmetry complex super-structures to reduce it. Here, a different approach is pursued, where we explore the potential of solids with a high yet controllable degree of disorder. Recently, it has been demonstrated that an unconventionally high degree of structural disorder characterizes a number of crystalline phase-change materials (PCMs). This disorder strongly impacts electronic transport and even leads to disorder induced localization (Anderson localization). This raises the question how thermal transport is affected by such conditions. Here thermal transport in highly disordered crystalline Ge-Sb-Te (GST) based PCMs is investigated. Glass-like thermal properties are observed for several crystalline PCMs, which are attributed to strong scattering by disordered point defects. A systematic study of different compounds along the pseudo-binary line between GeTe and Sb2Te3 reveals that disordered vacancies act as point defects responsible for pronounced phonon scattering. Annealing causes a gradual ordering of the vacancies and leads to a more 'crystal-like' thermal conductivity. While both vibrational and electronic degrees of freedom are affected by disorder, the consequences differ for different stoichiometries. This opens up a pathway to tune electrical and thermal transport by controlling the degree of disorder. Materials with tailored transport properties may not only help to improve power efficiency and scaling in upcoming phase-change memories but are also of fundamental interest in the field of thermoelectric materials.

Impact of vacancy ordering on thermal transport in crystalline phase-change materials

NASA Astrophysics Data System (ADS)

Siegert, K. S.; Lange, F. R. L.; Sittner, E. R.; Volker, H.; Schlockermann, C.; Siegrist, T.; Wuttig, M.

2015-01-01

Controlling thermal transport in solids is of paramount importance for many applications. Often thermal management is crucial for a device's performance, as it affects both reliability and power consumption. A number of intricate concepts have been developed to address this challenge, such as diamond-like coatings to enhance the thermal conductivity or low symmetry complex super-structures to reduce it. Here, a different approach is pursued, where we explore the potential of solids with a high yet controllable degree of disorder. Recently, it has been demonstrated that an unconventionally high degree of structural disorder characterizes a number of crystalline phase-change materials (PCMs). This disorder strongly impacts electronic transport and even leads to disorder induced localization (Anderson localization). This raises the question how thermal transport is affected by such conditions. Here thermal transport in highly disordered crystalline Ge-Sb-Te (GST) based PCMs is investigated. Glass-like thermal properties are observed for several crystalline PCMs, which are attributed to strong scattering by disordered point defects. A systematic study of different compounds along the pseudo-binary line between GeTe and Sb2Te3 reveals that disordered vacancies act as point defects responsible for pronounced phonon scattering. Annealing causes a gradual ordering of the vacancies and leads to a more ‘crystal-like’ thermal conductivity. While both vibrational and electronic degrees of freedom are affected by disorder, the consequences differ for different stoichiometries. This opens up a pathway to tune electrical and thermal transport by controlling the degree of disorder. Materials with tailored transport properties may not only help to improve power efficiency and scaling in upcoming phase-change memories but are also of fundamental interest in the field of thermoelectric materials.

Genetic utility of broadly defined bipolar schizoaffective disorder as a diagnostic concept

PubMed Central

Hamshere, M. L.; Green, E. K.; Jones, I. R.; Jones, L.; Moskvina, V.; Kirov, G.; Grozeva, D.; Nikolov, I.; Vukcevic, D.; Caesar, S.; Gordon-Smith, K.; Fraser, C.; Russell, E.; Breen, G.; St Clair, D.; Collier, D. A.; Young, A. H.; Ferrier, I. N.; Farmer, A.; McGuffin, P.; Holmans, P. A.; Owen, M. J.; O’Donovan, M. C.; Craddock, N.

2009-01-01

Background Psychiatric phenotypes are currently defined according to sets of descriptive criteria. Although many of these phenotypes are heritable, it would be useful to know whether any of the various diagnostic categories in current use identify cases that are particularly helpful for biological–genetic research. Aims To use genome-wide genetic association data to explore the relative genetic utility of seven different descriptive operational diagnostic categories relevant to bipolar illness within a large UK case–control bipolar disorder sample. Method We analysed our previously published Wellcome Trust Case Control Consortium (WTCCC) bipolar disorder genome-wide association data-set, comprising 1868 individuals with bipolar disorder and 2938 controls genotyped for 276 122 single nucleotide polymorphisms (SNPs) that met stringent criteria for genotype quality. For each SNP we performed a test of association (bipolar disorder group v. control group) and used the number of associated independent SNPs statistically significant at P<0.00001 as a metric for the overall genetic signal in the sample. We next compared this metric with that obtained using each of seven diagnostic subsets of the group with bipolar disorder: Research Diagnostic Criteria (RDC): bipolar I disorder; manic disorder; bipolar II disorder; schizoaffective disorder, bipolar type; DSM–IV: bipolar I disorder; bipolar II disorder; schizoaffective disorder, bipolar type. Results The RDC schizoaffective disorder, bipolar type (v. controls) stood out from the other diagnostic subsets as having a significant excess of independent association signals (P<0.003) compared with that expected in samples of the same size selected randomly from the total bipolar disorder group data-set. The strongest association in this subset of participants with bipolar disorder was at rs4818065 (P = 2.42×10–7). Biological systems implicated included gamma amniobutyric acid (GABA)A receptors. Genes having at least one associated polymorphism at P<10–4 included B3GALTS, A2BP1, GABRB1, AUTS2, BSN, PTPRG, GIRK2 and CDH12. Conclusions Our findings show that individuals with broadly defined bipolar schizoaffective features have either a particularly strong genetic contribution or that, as a group, are genetically more homogeneous than the other phenotypes tested. The results point to the importance of using diagnostic approaches that recognise this group of individuals. Our approach can be applied to similar data-sets for other psychiatric and non-psychiatric phenotypes. PMID:19567891

Glassy phase in quenched disordered crystalline membranes

NASA Astrophysics Data System (ADS)

Coquand, O.; Essafi, K.; Kownacki, J.-P.; Mouhanna, D.

2018-03-01

We investigate the flat phase of D -dimensional crystalline membranes embedded in a d -dimensional space and submitted to both metric and curvature quenched disorders using a nonperturbative renormalization group approach. We identify a second-order phase transition controlled by a finite-temperature, finite-disorder fixed point unreachable within the leading order of ɛ =4 -D and 1 /d expansions. This critical point divides the flow diagram into two basins of attraction: that associated with the finite-temperature fixed point controlling the long-distance behavior of disorder-free membranes and that associated with the zero-temperature, finite-disorder fixed point. Our work thus strongly suggests the existence of a whole low-temperature glassy phase for quenched disordered crystalline membranes and, possibly, for graphene and graphene-like compounds.

Spin transfer torque in antiferromagnetic spin valves: From clean to disordered regimes

NASA Astrophysics Data System (ADS)

Saidaoui, Hamed Ben Mohamed; Manchon, Aurelien; Waintal, Xavier

2014-05-01

Current-driven spin torques in metallic spin valves composed of antiferromagnets are theoretically studied using the nonequilibrium Green's function method implemented on a tight-binding model. We focus our attention on G-type and L-type antiferromagnets in both clean and disordered regimes. In such structures, spin torques can either rotate the magnetic order parameter coherently (coherent torque) or compete with the internal antiferromagnetic exchange (exchange torque). We show that, depending on the symmetry of the spin valve, the coherent and exchange torques can either be in the plane, ∝n×(q×n) or out of the plane ∝n×q, where q and n are the directions of the order parameter of the polarizer and the free antiferromagnetic layers, respectively. Although disorder conserves the symmetry of the torques, it strongly reduces the torque magnitude, pointing out the need for momentum conservation to ensure strong spin torque in antiferromagnetic spin valves.

Amplitude fluctuations driven by the density of electron pairs within nanosize granular structures inside strongly disordered superconductors: evidence for a shell-like effect.

PubMed

Ghosh, Sanjib; Mandal, Sudhansu S

2013-11-15

Motivated by the recent observation of the shell effect in a nanoscale pure superconductor by Bose et al. [Nat. Mater. 9, 550 (2010)], we explore the possible shell-like effect in a strongly disordered superconductor as it is known to produce nanosize superconducting puddles (SPs). We find a remarkable change in the texture of the pairing amplitudes that is responsible for forming the SP, upon monotonic tuning of the average electron density, , and keeping the disorder landscape unaltered. Both the spatially averaged pairing amplitude and the quasiparticle excitation gap oscillate with . This oscillation is due to a rapid change in the low-lying quasiparticle energy spectra and thereby a change in the shapes and positions of the SPs. We establish a correlation between the formation of SPs and the shell-like effect. The experimental consequences of our theory are also discussed.

Influence of lattice vibrations on the field driven electronic transport in chains with correlated disorder

NASA Astrophysics Data System (ADS)

da Silva, L. D.; Sales, M. O.; Ranciaro Neto, A.; Lyra, M. L.; de Moura, F. A. B. F.

2016-12-01

We investigate electronic transport in a one-dimensional model with four different types of atoms and long-ranged correlated disorder. The latter was attained by choosing an adequate distribution of on-site energies. The wave-packet dynamics is followed by taking into account effects due to a static electric field and electron-phonon coupling. In the absence of electron-phonon coupling, the competition between correlated disorder and the static electric field promotes the occurrence of wave-packet oscillations in the regime of strong correlations. When the electron-lattice coupling is switched on, phonon scattering degrades the Bloch oscillations. For weak electron-phonon couplings, a coherent oscillatory-like dynamics of the wave-packet centroid persists for short periods of time. For strong couplings the wave-packet acquires a diffusive-like displacement and spreading. A slower sub-diffusive spreading takes place in the regime of weak correlations.

Collaborative mental health services in primary care systems in Latin America: contextualized evaluation needs and opportunities.

PubMed

Sapag, Jaime C; Rush, Brian; Ferris, Lorraine E

2016-02-01

This study examined Latin American evaluation needs regarding the development of a collaborative mental health care (CMHC) evaluation framework as seen by local key health-care leaders and professionals. Potential implementation challenges and opportunities were also identified. This multisite research study used an embedded mixed methods approach in three public health networks in Mexico, Nicaragua and Chile. Local stakeholders participated: decision-makers in key informant interviews, front-line clinicians in focus groups and other stakeholders through a survey. The analysis was conducted within site and then across sites. A total of 22 semi-structured interviews, three focus groups and 27 questionnaires (52% response rate) were conducted. Participants recognized a strong need to evaluate different areas of CMHC in Latin America, including access, types and quality of services, human resources and outcomes related to mental disorders, including addiction. A priority was to evaluate collaboration within the health system, including the referral system. Issues of feasibility, including the weaknesses of information systems, were also identified. Local stakeholders strongly supported the development of a comprehensive evaluation framework for CMHC in Latin America and cited several dimensions and contextual factors critical for inclusion. Implementation must allow flexibility and adaptation to the local context. © 2015 John Wiley & Sons Ltd.

Special Education Teacher Preparation in Classroom Management: Implications for Students with Emotional and Behavioral Disorders

ERIC Educational Resources Information Center

Oliver, Regina M.; Reschly, Daniel J.

2010-01-01

Special education teachers' skills with classroom organization and behavior management affect the emergence and persistence of behavior problems as well as the success of inclusive practice for students with emotional and behavioral disorders (EBD). Adequate special education teacher preparation and strong classroom organization and behavior…

Evaluating the Consistency of Scales Used in Adult Attention Deficit Hyperactivity Disorder Assessment of College-Aged Adults

ERIC Educational Resources Information Center

Saleh, Ayman; Fuchs, Catherine; Taylor, Warren D.; Niarhos, Frances

2018-01-01

Objective: Neurocognitive evaluations are commonly integrated with clinical assessment to evaluate adult Attention Deficit Hyperactivity Disorder (ADHD). Study goal is to identify measures most strongly related to ADHD diagnosis and to determine their utility in screening processes. Participants: 230 students who were evaluated at the Vanderbilt…

Gene Disrupting Mutations Associated with Regression in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Goin-Kochel, Robin P.; Trinh, Sandy; Barber, Shelley; Bernier, Raphael

2017-01-01

Approximately one-third of children with autism spectrum disorder (ASD) reportedly lose skills within the first 3 years, yet a causal mechanism remains elusive. Considering evidence of strong genetic effects for ASD and findings that distinct phenotypes in ASD associate with specific genetic events, we examined rates of parent-reported regression…

Development of a Continuum of Services for Children and Adults with Autism and Other Severe Behavior Disorders.

ERIC Educational Resources Information Center

Luce, Stephen C.; And Others

1992-01-01

Key elements of a continuum of services for individuals with autism and other severe behavior disorders are described, focusing on development of a strong central organization; funding; staff recruitment, training, supervision, and evaluation; program evaluation; outreach parent training; home-based early intervention; vocational training;…

Longitudinal Comparison between Male and Female Preschool Children with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Postorino, Valentina; Fatta, Laura Maria; De Peppo, Lavinia; Giovagnoli, Giulia; Armando, Marco; Vicari, Stefano; Mazzone, Luigi

2015-01-01

Epidemiological studies have highlighted a strong male bias in autism spectrum disorder (ASD), however few studies have examined gender differences in autism symptoms, and available findings are inconsistent. The aim of the present study is to investigate the longitudinal gender differences in developmental profiles of 30 female and 30 male…

Selective Auditory Attention and Children with Attention-Deficit Hyperactivity Disorder: Effects of Repeated Measurement with and without Methylphenidate.

ERIC Educational Resources Information Center

Dalebout, Susan D.; And Others

1991-01-01

Twelve children (ages 7-8) with attention deficit hyperactive disorder were administered the Selective Auditory Attention Test twice: after the administration of methylphenidate and after the administration of a placebo. Results revealed no simple drug effect but a strong order effect. (Author/JDD)

Anxiety and Depressive Symptoms and Medical Illness Among Adults with Anxiety Disorders

PubMed Central

Niles, Andrea N.; Dour, Halina J.; Stanton, Annette L.; Roy-Byrne, Peter P.; Stein, Murray B.; Sullivan, Greer; Sherbourne, Cathy D.; Rose, Raphael D.; Craske, Michelle G.

2014-01-01

Objective Anxiety is linked to a number of medical conditions, yet few studies have examined how symptom severity relates to medical comorbidity. Purpose The current study assessed associations between severity of anxiety and depression and presence of medical conditions in adults diagnosed with anxiety disorders. Method Nine-hundred eighty-nine patients diagnosed with panic, generalized anxiety, social anxiety, and posttraumatic stress disorders reported on the severity of anxiety and depressive symptoms and on diagnoses of 11 medical conditions. Results Severity of anxiety and depressive symptoms was strongly associated with having more medical conditions over and above control variables, and the association was as strong as that between BMI and disease. Odds of having asthma, heart disease, back problems, ulcer, migraine headache and eyesight difficulties also increased as anxiety and depressive symptom severity increased. Anxiety symptoms were independently associated with ulcer, whereas depressive symptoms were independently associated with heart disease, migraine, and eyesight difficulties. Conclusions These findings add to a growing body of research linking anxiety disorders with physical health problems and indicate that anxiety and depressive symptoms deserve greater attention in their association with disease. PMID:25510186

A Cohort Study Comparing Women with Autism Spectrum Disorder with and without Generalized Joint Hypermobility

PubMed Central

Sharp, Julia L.; Edelson, Stephen M.; Kelly, Desmond P.; Casanova, Manuel F.

2018-01-01

Reports suggest comorbidity between autism spectrum disorder (ASD) and the connective tissue disorder, Ehlers-Danlos syndrome (EDS). People with EDS and the broader spectrum of Generalized Joint Hypermobility (GJH) often present with immune- and endocrine-mediated conditions. Meanwhile, immune/endocrine dysregulation is a popular theme in autism research. We surveyed a group of ASD women with/without GJH to determine differences in immune/endocrine exophenotypes. ASD women 25 years or older were invited to participate in an online survey. Respondents completed a questionnaire concerning diagnoses, immune/endocrine symptom history, experiences with pain, and seizure history. ASD women with GJH (ASD/GJH) reported more immune- and endocrine-mediated conditions than their non-GJH counterparts (p = 0.001). Autoimmune conditions were especially prominent in the ASD/GJH group (p = 0.027). Presence of immune-mediated symptoms often co-occurred with one another (p < 0.001–0.020), as did endocrine-mediated symptoms (p < 0.001–0.045), irrespective of the group. Finally, the numbers of immune- and endocrine-mediated symptoms shared a strong inter-relationship (p < 0.001), suggesting potential system crosstalk. While our results cannot estimate comorbidity, they reinforce concepts of an etiological relationship between ASD and GJH. Meanwhile, women with ASD/GJH have complex immune/endocrine exophenotypes compared to their non-GJH counterparts. Further, we discuss how connective tissue regulates the immune system and how the immune/endocrine systems in turn may modulate collagen synthesis, potentially leading to higher rates of GJH in this subpopulation. PMID:29562607

Comparison of simplified score with the revised original score for the diagnosis of autoimmune hepatitis: a new or a complementary diagnostic score?

PubMed

Gatselis, Nikolaos K; Zachou, Kalliopi; Papamichalis, Panagiotis; Koukoulis, George K; Gabeta, Stella; Dalekos, George N; Rigopoulou, Eirini I

2010-11-01

The International Autoimmune Hepatitis Group developed a simplified score for autoimmune hepatitis. We assessed this "new scoring system" and compared it with the International Autoimmune Hepatitis Group original revised score. 502 patients were evaluated namely, 428 had liver diseases of various etiology [hepatitis B (n=109), hepatitis C (n=100), hepatitis D (n=4), alcoholic liver disease (n=28), non-alcoholic fatty liver disease (n=55), autoimmune cholestatic diseases (n=77), liver disorders of undefined origin (n=32) and miscellaneous hepatic disorders (n=23)], 13 had autoimmune hepatitis/overlap syndromes, 18 had autoimmune hepatitis/concurrent with other liver diseases and 43 had autoimmune hepatitis. The specificity of the simplified score was similar to that of the revised score (97% vs. 97.9%). The sensitivity in unmasking autoimmune hepatitis in autoimmune hepatitis/overlap syndromes was also similar in both systems (53.8% and 61.5%). However, the sensitivity for autoimmune hepatitis diagnosis in autoimmune hepatitis patients with concurrent liver disorders was lower by the new score (p=0.001). Liver biopsy proved to be the only independent factor for unmasking autoimmune hepatitis component among patients (p=0.003). The simplified score is a reliable and simple tool for excluding autoimmune hepatitis. However, both systems cannot unmask autoimmune hepatitis component efficiently in autoimmune hepatitis patients with concurrent autoimmune or non-autoimmune liver diseases. This study also strongly reiterates the importance of liver biopsy in the work-up of patients. Copyright © 2010 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Strong disorder real-space renormalization for the many-body-localized phase of random Majorana models

NASA Astrophysics Data System (ADS)

Monthus, Cécile

2018-03-01

For the many-body-localized phase of random Majorana models, a general strong disorder real-space renormalization procedure known as RSRG-X (Pekker et al 2014 Phys. Rev. X 4 011052) is described to produce the whole set of excited states, via the iterative construction of the local integrals of motion (LIOMs). The RG rules are then explicitly derived for arbitrary quadratic Hamiltonians (free-fermions models) and for the Kitaev chain with local interactions involving even numbers of consecutive Majorana fermions. The emphasis is put on the advantages of the Majorana language over the usual quantum spin language to formulate unified RSRG-X rules.

Gender moderates the relationship between childhood abuse and internalizing and substance use disorders later in life: a cross-sectional analysis.

PubMed

Meng, Xiangfei; D'Arcy, Carl

2016-11-15

Although some studies examined the moderating role of gender in the relationship between childhood maltreatment and mental disorders later in life, a number of them examined the effects of only one or two types of maltreatment on an individual mental disorder, for instance, depression, substance use. It is of considerable clinical and theoretical importance to have in-depth understanding what roles of different types of childhood abuse play out in a wide range of mental disorders among women and men using well accepted instruments measuring abuse and mental disorders. The present study aimed to examine this issue using a large nationally representative population sample to explore the gender effect of different types of childhood abuse in mental disorders, and assess the moderating role of gender in the abuse-mental disorder relationship. Using data from the Canadian Community Health Survey 2012: Mental Health we sought to answer this question. Respondents with information on childhood maltreatment prior to age 16 were selected (N = 23, 395). We found: i) strong associations between childhood abuse frequency and gender; ii) significant differences between men and women in terms of mental disorders; iii) strong associations between childhood abuse and mental disorders; and, iv) gender moderated the role of childhood abuse history on adulthood mental disorders. Females with a history of sexual abuse and/or exposure to interpersonal violence were at a greater risk of alcohol abuse or dependence later in life. Intervention should occur as early as possible, and should help female victims of childhood sexual abuse and/or exposure to interpersonal violence, and their families to build more constructive ways to effectively reduce the negative affects of these experiences. Recognition of the moderating role of gender on the relationship between childhood abuse history and mental disorders later in life may aid clinicians and researchers in providing optimal health services.

Utilizing Telehealth to Support Treatment of Acute Stress Disorder in a Theater of War: Prolonged Exposure via Clinical Videoconferencing.

PubMed

Pelton, Dan; Wangelin, Bethany; Tuerk, Peter

2015-05-01

Posttraumatic stress disorder (PTSD) and acute stress disorder are prevalent mental health diagnoses associated with the military operations in Iraq and Afghanistan and are especially significant in service members returning from combat. Prolonged exposure (PE) therapy is a highly effective behavioral treatment for these symptoms, and providing this treatment as soon as possible, even in the midst of a soldier's combat deployment, has strong potential benefits. In the current case study, telehealth technology was used to support the delivery of PE therapy to treat a service member diagnosed with acute stress disorder in a war zone. PE was conducted face-to-face on the relatively secure Forward Operating Base for the first half of therapy and via clinical videoconferencing (CV) to the service member's remote combat outpost during the later stages of therapy. The service member exhibited marked improvements in symptoms over 10 sessions. Results are consistent with previous empirical findings and highlight the potential benefits of using telehealth to deliver evidenced-based treatment for traumatic stress disorders in a war zone. This case study provides a preliminary working model for delivering PE in a combat environment using multiple delivery systems. Benefits and clinical utility of CV-delivered exposure therapy are discussed, particularly for providers pending future operational deployments (e.g., including members of the military, independent government agencies, and first responders) and for those treating patients in remote locations.

Perceived incompetence moderates the relationship between maladaptive perfectionism and disordered eating.

PubMed

Ferrier-Auerbach, Amanda G; Martens, Matthew P

2009-01-01

Maladaptive perfectionism and perceived incompetence are two factors associated with disordered eating. In this study, we examined whether perceived incompetence moderated the relationship between maladaptive perfectionism and disordered eating. Three hundred fifteen college women completed surveys assessing eating habits and levels of perceived incompetence and perfectionism. Results supported a moderating effect of perceived incompetence such that as levels of perceived incompetence increased, the relationship between maladaptive perfectionism and disordered eating became increasingly strong. These results imply that clinicians may want to focus efforts on helping clients learn to set healthy goals and improve their perception of competence in life domains.

The role of quench rate in colloidal gels.

PubMed

Royall, C Patrick; Malins, Alex

2012-01-01

Interactions between colloidal particles have hitherto usually been fixed by the suspension composition. Recent experimental developments now enable the control of interactions in situ. Here we use Brownian dynamics simulations to investigate the effect of controlling interactions upon gelation, by "quenching" the system from an equilibrium fluid to a gel. We find that, contrary to the normal case of an instantaneous quench, where the local structure of the gel is highly disordered, controlled quenching results in a gel with a much higher degree of local order. Under sufficiently slow quenching, local crystallisation is found, which is strongly enhanced when a monodisperse system is used. The higher the degree of local order, the smaller the mean squared displacement, indicating an enhancement of gel stability.

Gauge theory for finite-dimensional dynamical systems.

PubMed

Gurfil, Pini

2007-06-01

Gauge theory is a well-established concept in quantum physics, electrodynamics, and cosmology. This concept has recently proliferated into new areas, such as mechanics and astrodynamics. In this paper, we discuss a few applications of gauge theory in finite-dimensional dynamical systems. We focus on the concept of rescriptive gauge symmetry, which is, in essence, rescaling of an independent variable. We show that a simple gauge transformation of multiple harmonic oscillators driven by chaotic processes can render an apparently "disordered" flow into a regular dynamical process, and that there exists a strong connection between gauge transformations and reduction theory of ordinary differential equations. Throughout the discussion, we demonstrate the main ideas by considering examples from diverse fields, including quantum mechanics, chemistry, rigid-body dynamics, and information theory.

Actual neurosis as the underlying psychic structure of panic disorder, somatization, and somatoform disorder: an integration of Freudian and attachment perspectives.

PubMed

Verhaeghe, Paul; Vanheule, Stijn; De Rick, Ann

2007-10-01

Starting from a contemporary critique of the DSM-IV, this paper argues that the diagnostic categories of panic disorder somatization, and undifferentiated somatoform disorders can be understood as belonging to a common type of psychopathology--i.e., the Freudian actual neuroses. In addition to their strong clinical similarity, these disorders share an etiological similarity; and the authors propose a combination of Freud's focus on this type of patient's inability to represent an endogenous drive arousal with the post-Freudian focus on separation anxiety. An etiological hypothesis is put forward based on contemporary psychoanalytic attachment theory, highlighting mentalization. Concrete implications for a psychoanalytically based treatment are proposed.

Density of states and magnetotransport in Weyl semimetals with long-range disorder

NASA Astrophysics Data System (ADS)

Pesin, D. A.; Mishchenko, E. G.; Levchenko, A.

2015-11-01

We study the density of states and magnetotransport properties of disordered Weyl semimetals, focusing on the case of a strong long-range disorder. To calculate the disorder-averaged density of states close to nodal points, we treat exactly the long-range random potential fluctuations produced by charged impurities, while the short-range component of disorder potential is included systematically and controllably with the help of a diagram technique. We find that, for energies close to the degeneracy point, long-range potential fluctuations lead to a finite density of states. In the context of transport, we discuss that a self-consistent theory of screening in magnetic field may conceivably lead to nonmonotonic low-field magnetoresistance.

Quantum Bath Refrigeration towards Absolute Zero: Challenging the Unattainability Principle

NASA Astrophysics Data System (ADS)

Kolář, M.; Gelbwaser-Klimovsky, D.; Alicki, R.; Kurizki, G.

2012-08-01

A minimal model of a quantum refrigerator, i.e., a periodically phase-flipped two-level system permanently coupled to a finite-capacity bath (cold bath) and an infinite heat dump (hot bath), is introduced and used to investigate the cooling of the cold bath towards absolute zero (T=0). Remarkably, the temperature scaling of the cold-bath cooling rate reveals that it does not vanish as T→0 for certain realistic quantized baths, e.g., phonons in strongly disordered media (fractons) or quantized spin waves in ferromagnets (magnons). This result challenges Nernst’s third-law formulation known as the unattainability principle.

Molecular nonlinear dynamics and protein thermal uncertainty quantification

PubMed Central

Xia, Kelin; Wei, Guo-Wei

2014-01-01

This work introduces molecular nonlinear dynamics (MND) as a new approach for describing protein folding and aggregation. By using a mode system, we show that the MND of disordered proteins is chaotic while that of folded proteins exhibits intrinsically low dimensional manifolds (ILDMs). The stability of ILDMs is found to strongly correlate with protein energies. We propose a novel method for protein thermal uncertainty quantification based on persistently invariant ILDMs. Extensive comparison with experimental data and the state-of-the-art methods in the field validate the proposed new method for protein B-factor prediction. PMID:24697365

Quantum bath refrigeration towards absolute zero: challenging the unattainability principle.

PubMed

Kolář, M; Gelbwaser-Klimovsky, D; Alicki, R; Kurizki, G

2012-08-31

A minimal model of a quantum refrigerator, i.e., a periodically phase-flipped two-level system permanently coupled to a finite-capacity bath (cold bath) and an infinite heat dump (hot bath), is introduced and used to investigate the cooling of the cold bath towards absolute zero (T=0). Remarkably, the temperature scaling of the cold-bath cooling rate reveals that it does not vanish as T→0 for certain realistic quantized baths, e.g., phonons in strongly disordered media (fractons) or quantized spin waves in ferromagnets (magnons). This result challenges Nernst's third-law formulation known as the unattainability principle.

Structural and dynamical trends in alkali-metal silanides characterized by neutron-scattering methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Wan Si; Dimitrievska, Mirjana; Chotard, Jean -Noel

Structural, vibrational, and dynamical properties of the mono- and mixed-alkali silanides (MSiH 3, where M = K, Rb, Cs, K 0.5Rb 0.5, K 0.5Cs 0.5, and Rb 0.5Cs 0.5) were investigated by various neutron experiments, including neutron powder diffraction (NPD), neutron vibrational spectroscopy (NVS), neutron-scattering fixed-window scans (FWSs), and quasielastic neutron scattering (QENS) measurements. Structural characterization showed that the mixed compounds exhibit disordered (α) and ordered (β) phases for temperatures above and below about 200–250 K, respectively, in agreement with their monoalkali correspondents. Vibrational and dynamical properties are strongly influenced by the cation environment; in particular, there is a redmore » shift in the band energies of the librational and bending modes with increasing lattice size as a result of changes in the bond lengths and force constants. Additionally, slightly broader spectral features are observed in the case of the mixed compounds, indicating the presence of structural disorder caused by the random distribution of the alkali-metal cations within the lattice. FWS measurements upon heating showed that there is a large increase in reorientational mobility as the systems go through the order–disorder (β–α) phase transition, and measurements upon cooling of the α-phase revealed the known strong hysteresis for reversion back to the β-phase. Interestingly, at a given temperature, among the different alkali silanide compounds, the relative reorientational mobilities of the SiH 3 – anions in the α- and β-phases tended to decrease and increase, respectively, with increasing alkali-metal mass. Lastly, this dynamical result might provide some insights concerning the enthalpy–entropy compensation effect previously observed for these potentially promising hydrogen storage materials.« less

Reduced Vglut2/Slc17a6 Gene Expression Levels throughout the Mouse Subthalamic Nucleus Cause Cell Loss and Structural Disorganization Followed by Increased Motor Activity and Decreased Sugar Consumption

PubMed Central

Smith-Anttila, Casey J.A.; Nordenankar, Karin; Arvidsson, Emma; Mahmoudi, Souha; Zampera, André; Wärner Jonsson, Hanna; Bergquist, Jonas; Lévesque, Daniel; Andersson, Malin; Dumas, Sylvie

2016-01-01

The subthalamic nucleus (STN) plays a central role in motor, cognitive, and affective behavior. Deep brain stimulation (DBS) of the STN is the most common surgical intervention for advanced Parkinson’s disease (PD), and STN has lately gained attention as target for DBS in neuropsychiatric disorders, including obsessive compulsive disorder, eating disorders, and addiction. Animal studies using STN-DBS, lesioning, or inactivation of STN neurons have been used extensively alongside clinical studies to unravel the structural organization, circuitry, and function of the STN. Recent studies in rodent STN models have exposed different roles for STN neurons in reward-related functions. We have previously shown that the majority of STN neurons express the vesicular glutamate transporter 2 gene (Vglut2/Slc17a6) and that reduction of Vglut2 mRNA levels within the STN of mice [conditional knockout (cKO)] causes reduced postsynaptic activity and behavioral hyperlocomotion. The cKO mice showed less interest in fatty rewards, which motivated analysis of reward-response. The current results demonstrate decreased sugar consumption and strong rearing behavior, whereas biochemical analyses show altered dopaminergic and peptidergic activity in the striatum. The behavioral alterations were in fact correlated with opposite effects in the dorsal versus the ventral striatum. Significant cell loss and disorganization of the STN structure was identified, which likely accounts for the observed alterations. Rare genetic variants of the human VGLUT2 gene exist, and this study shows that reduced Vglut2/Slc17a6 gene expression levels exclusively within the STN of mice is sufficient to cause strong modifications in both the STN and the mesostriatal dopamine system. PMID:27699212

Reduced Vglut2/Slc17a6 Gene Expression Levels throughout the Mouse Subthalamic Nucleus Cause Cell Loss and Structural Disorganization Followed by Increased Motor Activity and Decreased Sugar Consumption.

PubMed

Schweizer, Nadine; Viereckel, Thomas; Smith-Anttila, Casey J A; Nordenankar, Karin; Arvidsson, Emma; Mahmoudi, Souha; Zampera, André; Wärner Jonsson, Hanna; Bergquist, Jonas; Lévesque, Daniel; Konradsson-Geuken, Åsa; Andersson, Malin; Dumas, Sylvie; Wallén-Mackenzie, Åsa

2016-01-01

The subthalamic nucleus (STN) plays a central role in motor, cognitive, and affective behavior. Deep brain stimulation (DBS) of the STN is the most common surgical intervention for advanced Parkinson's disease (PD), and STN has lately gained attention as target for DBS in neuropsychiatric disorders, including obsessive compulsive disorder, eating disorders, and addiction. Animal studies using STN-DBS, lesioning, or inactivation of STN neurons have been used extensively alongside clinical studies to unravel the structural organization, circuitry, and function of the STN. Recent studies in rodent STN models have exposed different roles for STN neurons in reward-related functions. We have previously shown that the majority of STN neurons express the vesicular glutamate transporter 2 gene ( Vglut2/Slc17a6 ) and that reduction of Vglut2 mRNA levels within the STN of mice [conditional knockout (cKO)] causes reduced postsynaptic activity and behavioral hyperlocomotion. The cKO mice showed less interest in fatty rewards, which motivated analysis of reward-response. The current results demonstrate decreased sugar consumption and strong rearing behavior, whereas biochemical analyses show altered dopaminergic and peptidergic activity in the striatum. The behavioral alterations were in fact correlated with opposite effects in the dorsal versus the ventral striatum. Significant cell loss and disorganization of the STN structure was identified, which likely accounts for the observed alterations. Rare genetic variants of the human VGLUT2 gene exist, and this study shows that reduced Vglut2/Slc17a6 gene expression levels exclusively within the STN of mice is sufficient to cause strong modifications in both the STN and the mesostriatal dopamine system.

Structural and dynamical trends in alkali-metal silanides characterized by neutron-scattering methods

DOE PAGES

Tang, Wan Si; Dimitrievska, Mirjana; Chotard, Jean -Noel; ...

2016-09-02

Structural, vibrational, and dynamical properties of the mono- and mixed-alkali silanides (MSiH 3, where M = K, Rb, Cs, K 0.5Rb 0.5, K 0.5Cs 0.5, and Rb 0.5Cs 0.5) were investigated by various neutron experiments, including neutron powder diffraction (NPD), neutron vibrational spectroscopy (NVS), neutron-scattering fixed-window scans (FWSs), and quasielastic neutron scattering (QENS) measurements. Structural characterization showed that the mixed compounds exhibit disordered (α) and ordered (β) phases for temperatures above and below about 200–250 K, respectively, in agreement with their monoalkali correspondents. Vibrational and dynamical properties are strongly influenced by the cation environment; in particular, there is a redmore » shift in the band energies of the librational and bending modes with increasing lattice size as a result of changes in the bond lengths and force constants. Additionally, slightly broader spectral features are observed in the case of the mixed compounds, indicating the presence of structural disorder caused by the random distribution of the alkali-metal cations within the lattice. FWS measurements upon heating showed that there is a large increase in reorientational mobility as the systems go through the order–disorder (β–α) phase transition, and measurements upon cooling of the α-phase revealed the known strong hysteresis for reversion back to the β-phase. Interestingly, at a given temperature, among the different alkali silanide compounds, the relative reorientational mobilities of the SiH 3 – anions in the α- and β-phases tended to decrease and increase, respectively, with increasing alkali-metal mass. Lastly, this dynamical result might provide some insights concerning the enthalpy–entropy compensation effect previously observed for these potentially promising hydrogen storage materials.« less

Using Community Partnerships to Better Understand the Barriers to Using an Evidence-Based, Parent-Mediated Intervention for Autism Spectrum Disorder in a Medicaid System.

PubMed

Pickard, Katherine E; Kilgore, Amanda N; Ingersoll, Brooke R

2016-06-01

Service use disparities have been noted to impede under-resourced families' ability to access high-quality services for their child with autism spectrum disorder (ASD). These disparities are particularly relevant for parent-mediated interventions and may suggest a lack of fit between these interventions and the needs of under-resourced community settings. This study used Roger's Diffusion of Innovations theory to guide community partnerships aimed at understanding the perceived compatibility, complexity, and relative advantage of using an evidence-based, parent-mediated intervention (Project ImPACT) within a Medicaid system. Three focus groups were conducted with 16 Medicaid-eligible parents, and three focus groups were conducted with 16 ASD providers operating within a Medicaid system. Across all groups, parents and providers reported general interest in using Project ImPACT. However, primary themes emerged regarding the need to (a) reduce the complexity of written materials; (b) allow for a more flexible program delivery; (c) ensure a strong parent-therapist alliance; (d) involve the extended family; and (e) help families practice the intervention within their preexisting routines. Results are discussed as they relate to the design and fit of evidence-based, parent-mediated interventions for under-resourced community settings. © Society for Community Research and Action 2016.

Prediction of A2 to B2 Phase Transition in the High Entropy Alloy Mo-Nb-Ta-W

NASA Astrophysics Data System (ADS)

Huhn, William; Widom, Michael

2014-03-01

In this talk we show that an effective Hamiltonian fit with first principles calculations predicts an order/disorder transition occurs in the high entropy alloy Mo-Nb-Ta-W. Using the Alloy Theoretic Automated Toolset, we find T=0K enthalpies of formation for all binaries containing Mo, Nb, Ta, and W, and in particular we find the stable structures for binaries at equiatomic concentrations are close in energy to the associated B2 structure, suggesting that at intermediate temperatures a B2 phase is stabilized in Mo-Nb-Ta-W. Our ``hybrid Monte Carlo/molecular dynamics'' results for the Mo-Nb-Ta-W system are analyzed to identify certain preferred chemical bonding types. A mean field free energy model incorporating nearest neighbor bonds will be presented, allowing us to predict the mechanism of the order/disorder transition. We find the temperature evolution of the system is driven by strong Mo-Ta bonding. Comparison of the free energy model and our MC/MD results suggest the existence of additional low-temperature phase transitions in the system likely ending with phase segregation into binary phases. We would like to thank DOD-DTRA for funding this research under contract number DTRA-11-1-0064.