32 research outputs found
Neuropsychological functioning and social anhedonia: Three-year follow-up data from a longitudinal community high risk study
Social anhedonia is a promising vulnerability marker for schizophrenia-spectrum pathology. Prior research has demonstrated that individuals with psychometrically-defined social anhedonia show a range of âschizophrenia-likeâ neurocognitive abnormalities. However, this research is limited in that it is based largely on the study of college students. The present article reports findings from a longitudinal study of social anhedonia recruited from a community sample. As part of this study, a neurocognitive battery was administered at baseline and at three-year follow-up sessions to participants with (n = 78) vs. without (n = 77) social anhedonia. Additional measures of global functioning and schizotypal, schizoid and paranoid schizophrenia-spectrum symptoms were also administered. Across groups, subjects showed significant improvement in neurocognitive functioning over time. Compared to controls, at follow-up, individuals with social anhedonia showed significantly poorer attentional vigilance and simple processing speed, but failed to evidence impairments in immediate or delayed verbal memory, immediate or delayed visual memory, visual or verbal working memory, olfaction or executive abilities. At follow-up, within the social anhedonia group, schizoid (and to a lesser extent, schizotypal) symptom severity was associated with a range of neurocognitive impairments. Neurocognitive impairments were generally not associated with paranoid symptoms or global functioning. Baseline neurocognitive performance was not significantly predictive of follow-up symptom severity or functioning. Collectively, these findings suggest that neurocognitive dysfunctions only characterize a subset of individuals with social anhedonia
Attainment of high confinement in neutral beam heated divertor discharges in the PDX tokamak
The PDX divertor configuration has recently been converted from an open to a closed geometry to inhibit the return of neutral gas from the divertor region to the main chamber. Since then, operation in a regime with high energy confinement in neutral beam heated discharges (ASDEX H-mode) has been routine over a wide range of operating conditions. These H-mode discharges are characterized by a sudden drop in divertor density and H/sub ..cap alpha../ emission and a spontaneous rise in main chamber plasma density during neutral beam injection. The confinement time is found to scale nearly linearly with plasma current, but it can be degraded due to either the presence of edge instabilities or heavy gas puffing. Detailed Thomson scattering temperature profiles show high values of Te near the plasma edge (approx. 450 eV) with sharp radial gradients (approx. 400 eV/cm) near the separatrix. Density profiles are broad and also exhibit steep gradients close to the separatrix
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Depletion of Endothelial-Derived 2-AG Reduces Blood-Endothelial Barrier Integrity via Alteration of VE-Cadherin and the Phospho-Proteome
Mounting evidence supports the role of the endocannabinoid system in neurophysiology, including bloodâbrain barrier (BBB) function. Recent work has demonstrated that activation of endocannabinoid receptors can mitigate insults to the BBB during neurological disorders like traumatic brain injury, cortical spreading depression, and stroke. As alterations to the BBB are associated with worsening clinical outcomes in these conditions, studies herein sought to examine the impact of endocannabinoid depletion on BBB integrity. Barrier integrity was investigated in vitro via bEnd.3 cell monolayers to assess endocannabinoid synthesis, barrier function, calcium influx, junctional protein expression, and proteome-wide changes. Inhibition of 2-AG synthesis using DAGLα inhibition and siRNA inhibition of DAGLα led to loss of barrier integrity via altered expression of VE-cadherin, which could be partially rescued by exogenous application of 2-AG. Moreover, the deleterious effects of DAGLα inhibition on BBB integrity showed both calcium and PKC (protein kinase C)-dependency. These data indicate that disruption of 2-AG homeostasis in brain endothelial cells, in the absence of insult, is sufficient to disrupt BBB integrity thus supporting the role of the endocannabinoid system in neurovascular disorders. © 2023 by the authors.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Characteristics of low-q disruptions in PBX
The results of this study indicate that even within the relatively narrow low-q/sub /psi// operating space, there is a continuum in the characteristics of the low-q/sub /psi// disruptions with a primary dependence on the value of . While the ideal external kink instability may give rise to the growing oscillations that lead up to the ultimate disruption, the instabilities are weighted towards the edge only at the lowest-q/sub /psi// (less than or equal to 3) and highest . At even slightly higher q/sub /psi//, the oscillations are also seen, at the same frequency, in the interior of the plasma. The results further indicate that effects outside the scope of ideal MHD theory may play a significant role in low-q/sub /psi// disruptions. 34 refs., 19 figs