6,436 research outputs found
Using the maternal immune stimulation model of schizophrenia to investigate the therapeutic efficacy of neuromodulation techniques
The present work used a neurodevelopmental rodent model of schizophrenia, namely the maternal immune stimulation (MIS) model, to study the potency of electrical neuromodulation techniques to ameliorate and even prevent schizophrenia-relevant behavioral and neurobiological abnormalities. Acute and focal deep brain stimulation (DBS) to the medial prefrontal cortex (mPFC) was found to be therapeutically relevant as it successfully normalized deficits in sensorimotor gating and attention selectivity apparent in the adult MIS animals. Using a longitudinal approach the development of sensorimotor gating deficits in the MIS model was traced and was found to exhibit a maturational delay, in accordance with the clinical situation. Further, this approach revealed aberrant neurochemistry profile in the mPFC during the pre-symptomatic period of adolescence, prior to the outbreak of the behavioral deficits. Thus, chronic DBS to the mPFC of adolescent MIS animals was tested and revealed that this approach could prevent the development of deficits in sensorimotor gating, attentional selectivity and reversal learning. Along with these effects, DBS was able to prevent increased lateral ventricles volume and neurochemical alterations as well as the prevention of altered microglia in this model. Finally, a non-invasive neuromodulation technique in the form of transcranial direct current stimulation (tDCS) was chronically applied during adolescence to the prefrontal cortex and revealed that tDCS prevented behavioral deficits belonging to the positive-symptomatology of schizophrenia, along with abnormal lateral ventricles volume. Taken together, this pre-clinical, translational-directed work points to the plausible efficacy of early, non-invasive, neuromodulation approach as a preventive measure for the development of schizophrenia
Near-extremal black holes at late times, backreacted
Black holes display universal behavior near extremality. One such feature is
the late-time blowup of derivatives of linearized perturbations across the
horizon. For generic initial data, this instability is regulated by
backreaction, and the final state is a near-extremal black hole. The aim of
this paper is to study the late time behavior of such black holes analytically
using the weakly broken conformal symmetry of their near-horizon region. In
particular, gravitational backreaction is accounted for within the
Jackiw-Teitelboim model for near-horizon, near-extremal dynamics coupled to
bulk matter.Comment: v2: published versio
Fast plunges into Kerr black holes
Most extreme-mass-ratio-inspirals of small compact objects into supermassive
black holes end with a fast plunge from an eccentric last stable orbit. For
rapidly rotating black holes such fast plunges may be studied in the context of
the Kerr/CFT correspondence because they occur in the near-horizon region where
dynamics are governed by the infinite dimensional conformal symmetry. In this
paper we use conformal transformations to analytically solve for the radiation
emitted from fast plunges into near-extreme Kerr black holes. We find perfect
agreement between the gravity and CFT computations.Comment: 16 pages, 2 figure
Exact Gravitational Wave Signatures from Colliding Extreme Black Holes
The low-energy dynamics of any system admitting a continuum of static
configurations is approximated by slow motion in moduli (configuration) space.
Here, following Ferrell and Eardley, this moduli space approximation is
utilized to study collisions of two maximally charged Reissner--Nordstr{\"o}m
black holes of arbitrary masses, and to compute analytically the gravitational
radiation generated by their scattering or coalescence. The motion remains slow
even though the fields are strong, and the leading radiation is quadrupolar. A
simple expression for the gravitational waveform is derived and compared at
early and late times to expectations.Comment: 6 page
A New Model for Equitable and Efficient Resource Allocation to Schools: The Israeli Case
This paper sets out a new budget allocation formula for schools, designed to achieve a more equitable distribution of educational achievement. In addition to needs-based elements, the suggested composite allocation formula includes an improvement component, whereby schools receive budgetary allocations based on a new incentive measure developed in this paper (Improvement in the Educational Achievement Distribution, or IEAD). The development of the budget allocation formula is demonstrated utilizing Israeli data. Large scale, nationwide data sets relating students’ academic achievement to student background variables, teacher profiles and school characteristics, were analyzed to identify appropriate needs-based formula components and to estimate their weights. The results are compared with the funding formulas currently used in Israel.school finance, formular funding, needs-based funding, schools resource allocation, Israel
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