2,555 research outputs found
Stochastic Analysis of Subcritical Amplification of Magnetic Energy in a Turbulent Dynamo
We present and analyze a simplified stochastic dynamo model
which is designed to assess the influence of additive and multiplicative
noises, non-normality of dynamo equation, and nonlinearity of the %
effect and turbulent diffusivity, on the generation of a large-scale magnetic
field in the subcritical case. Our model incorporates random fluctuations in
the parameter and additive noise arising from the small-scale
fluctuations of magnetic and turbulent velocity fields. We show that the noise
effects along with non-normality can lead to the stochastic amplification of
the magnetic field even in the subcritical case. The criteria for the
stochastic instability during the early kinematic stage are established and the
critical value for the intensity of multiplicative noise due to fluctuations is found. We obtain numerical solutions of non-linear stochastic
differential equations and find the series of phase transitions induced by
random fluctuations in the parameter.Comment: 21pages,7 figure
Superconducting Magnetization above the Irreversibility Line in Tl2Ba2CuO6
Piezolever torque magnetometry has been used to measure the magnetization of
superconducting Tl2Ba2CuO6. Three crystals with different levels of oxygen
overdoping were investigated in magnetic fields up to 10 Tesla. In all cases,
the magnetization above the irreversibility line was found to depart from the
behaviour M ~ ln(Hc2/H) of a simple London-like vortex liquid. In particular,
for a strongly overdoped (Tc = 15K) crystal, the remnant superconducting order
above the irreversibility line is characterized by a linear diamagnetic
response (M ~ H) that persists well above Tc and also up to the highest field
employed.Comment: RevTeX, 11 pages, 7 encapsulated PostScript figures, submitted to
Physical Review
Disrupted Superior Collicular Activity May Reveal Crvical Dystonia Disease Pathomechanisms
Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures afecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in afected patients and in relatives harbouring a disease-specifc endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unafected frst-degree relatives with abnormal temporal discrimination, 16 unafected frst-degree relatives with normal temporal discrimination and 16 healthy controls. The response of participant’s superior colliculi to looming stimuli was assessed by functional magnetic resonance imaging. Cervical dystonia patients and relatives with abnormal temporal discrimination demonstrated (i) signifcantly reduced superior collicular activation for whole brain and region of interest analysis; (ii) a statistically signifcant negative correlation between temporal discrimination threshold and superior collicular peak values. Our results support the hypothesis that disrupted superior collicular processing is involved in the pathogenesis of cervical dystonia. These fndings, which align with animal models of cervical dystonia, shed new light on pathomechanisms in humans
Schema therapy for emotional dysregulation: Theoretical implication and clinical applications
The term emotional dysregulation refers to an impaired ability to regulate unwanted
emotional states. Scientific evidence supports the idea that emotional dysregulation
underlies several psychological disorders as, for example: personality disorders, bipolar
disorder type II, interpersonal trauma, anxiety disorders, mood disorders and posttraumatic
stress disorder. Emotional dysregulation may derive from early interpersonal
traumas in childhood. These early traumatic events create a persistent sensitization of
the central nervous system in relation to early life stressing events. For this reason,
some authors suggest a common endophenotypical origin across psychopathologies.
In the last 20 years, cognitive behavioral therapy has increasingly adopted an interactiveontogenetic
view to explain the development of disorders associated to emotional
dysregulation. Unfortunately, standard Cognitive Behavior Therapy (CBT) methods are
not useful in treating emotional dysregulation. A CBT-derived new approach called
Schema Therapy (ST), that integrates theory and techniques from psychodynamic and
emotion focused therapy, holds the promise to fill this gap in cognitive literature. In this
model, psychopathology is viewed as the interaction between the innate temperament
of the child and the early experiences of deprivation or frustration of the subject\u2019s
basic needs. This deprivation may lead to develop early maladaptive schemas (EMS),
and maladaptive Modes. In the present paper we point out that EMSs and Modes
are associated with either dysregulated emotions or with dysregulatory strategies that
produce and maintain problematic emotional responses. Thanks to a special focus on
the therapeutic relationship and emotion focused-experiential techniques, this approach
successfully treats severe emotional dysregulation. In this paper, we make several
comparisons between the main ideas of ST and the science of emotion regulation, and
we present how to conceptualize pathological phenomena in terms of failed regulation
and some of the ST strategies and techniques to foster successful regulation in patients
Disrupted Superior Collicular Activity May Reveal Cervical Dystonia Disease Pathomechanisms
Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures affecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in affected patients and in relatives harbouring a disease-specific endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unaffected first-degree relatives with abnormal temporal discrimination, 16 unaffected first-degree relatives with normal temporal discrimination and 16 healthy controls. The response of participant’s superior colliculi to looming stimuli was assessed by functional magnetic resonance imaging. Cervical dystonia patients and relatives with abnormal temporal discrimination demonstrated (i) significantly reduced superior collicular activation for whole brain and region of interest analysis; (ii) a statistically significant negative correlation between temporal discrimination threshold and superior collicular peak values. Our results support the hypothesis that disrupted superior collicular processing is involved in the pathogenesis of cervical dystonia. These findings, which align with animal models of cervical dystonia, shed new light on pathomechanisms in humans
Inflammation and Metabolism of Influenza-Stimulated Peripheral Blood Mononuclear Cells From Adults With Obesity Following Bariatric Surgery
BACKGROUND: Obesity dysregulates immunity to influenza infection. Therefore, there is a critical need to investigate how obesity impairs immunity and to establish therapeutic approaches that mitigate the impact of increased adiposity. One mechanism by which obesity may alter immune responses is through changes in cellular metabolism. METHODS: We studied inflammation and cellular metabolism of peripheral blood mononuclear cells (PBMCs) isolated from individuals with obesity relative to lean controls. We also investigated if impairments to PBMC metabolism were reversible upon short-term weight loss following bariatric surgery. RESULTS: Obesity was associated with systemic inflammation and poor inflammation resolution. Unstimulated PBMCs from participants with obesity had lower oxidative metabolism and adenosine triphosphate (ATP) production compared to PBMCs from lean controls. PBMC secretome analyses showed that ex vivo stimulation with A/Cal/7/2009 H1N1 influenza led to a notable increase in IL-6 with obesity. Short-term weight loss via bariatric surgery improved biomarkers of systemic metabolism but did not improve markers of inflammation resolution, PBMC metabolism, or the PBMC secretome. CONCLUSIONS: These results show that obesity drives a signature of impaired PBMC metabolism, which may be due to persistent inflammation. PBMC metabolism was not reversed after short-term weight loss despite improvements in measures of systemic metabolism
Whither Critical Masculinity Studies? Notes on Inclusive Masculinity Theory, Postfeminism, and Sexual Politics
Inclusive masculinity theory has recently been proposed as a new approach to theo- rizing contemporary masculinities. Focusing particularly on the work of the theory’s key exponent, Eric Anderson, this article offers a critical reading of inclusive masculinity theory in relation to the context of contemporary postfeminism. Building on feminist scholarship that analyzes the emergence of a distinctive postfeminist sensibility within the academy, I consider how inclusive masculinity theory both reflects and reproduces certain logics of postfeminism. My central concern is the manner in which this scho- larship deemphasizes key issues of sexual politics and promotes a discourse of optimism about men, masculinities, and social change. Against this view, I argue that critical masculinity studies must foreground the analysis of gendered power relations and posit that the interrogation of contemporary postfeminism is critical to this endeavor
Disrupted Superior Collicular Activity May Reveal Cervical Dystonia Disease Pathomechanisms
Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures affecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in affected patients and in relatives harbouring a disease-specific endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unaffected first-degree relatives with abnormal temporal discrimination, 16 unaffected first-degree relatives with normal temporal discrimination and 16 healthy controls. The response of participant’s superior colliculi to looming stimuli was assessed by functional magnetic resonance imaging. Cervical dystonia patients and relatives with abnormal temporal discrimination demonstrated (i) significantly reduced superior collicular activation for whole brain and region of interest analysis; (ii) a statistically significant negative correlation between temporal discrimination threshold and superior collicular peak values. Our results support the hypothesis that disrupted superior collicular processing is involved in the pathogenesis of cervical dystonia. These findings, which align with animal models of cervical dystonia, shed new light on pathomechanisms in humans
Nonlinear Hydrodynamics of Disentangled Flux-Line Liquids
In this paper we use non-Gaussian hydrodynamics to study the magnetic
response of a flux-line liquid in the mixed state of a type-II superconductor.
Both the derivation of our model, which goes beyond conventional Gaussian flux
liquid hydrodynamics, and its relationship to other approaches used in the
literature are discussed. We focus on the response to a transverse tilting
field which is controlled by the tilt modulus, c44, of the flux array. We show
that interaction effects can enhance c44 even in infinitely thick clean
materials. This enhancement can be interpreted as the appearance of a
disentangled flux-liquid fraction. In contrast to earlier work, our theory
incorporates the nonlocality of the intervortex interaction in the field
direction. This nonlocality is crucial for obtaining a nonvanishing
renormalization of the tilt modulus in the thermodynamic limit of thick
samples.Comment: 20 pages, 3 figures (submitted to PRB
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