885 research outputs found
Recommended from our members
Mechanisms of cognitive-behavioral therapy for obsessive-compulsive disorder involve robust and extensive increases in brain network connectivity.
Cognitive-behavioral therapy (CBT) is effective for obsessive compulsive disorder (OCD); however, little is understood about its mechanisms related to brain network connectivity. We examined connectivity changes from resting-state functional magnetic resonance imaging data pre-to-post-CBT in 43 OCD participants, randomized to receive either 4 weeks of intensive CBT or 4 weeks waitlist followed by 4 weeks of CBT, and 24 healthy controls before and after 4 weeks of no treatment. Network-based-statistic analysis revealed large-magnitude increases in OCD connectivity in eight networks. Strongest increases involved connectivity between the cerebellum and caudate/putamen, and between the cerebellum and dorsolateral/ventrolateral prefrontal cortices. Connectivity increases were associated with increased resistance to compulsions. Mechanisms of CBT may involve enhanced cross-network integration, both within and outside of classical cortico-striatal-thalamo-cortical regions; those involving cerebellar to striatal and prefrontal regions may reflect acquisition of new non-compulsive goal-directed behaviors and thought patterns. Our findings have implications for identifying targets for enhancing treatment efficacy and monitoring treatment progress
F. John's stability conditions vs. A. Carasso's SECB constraint for backward parabolic problems
In order to solve backward parabolic problems F. John [{\it Comm. Pure. Appl.
Math.} (1960)] introduced the two constraints "" and where satisfies the backward heat equation for
with the initial data
The {\it slow-evolution-from-the-continuation-boundary} (SECB) constraint has
been introduced by A. Carasso in [{\it SIAM J. Numer. Anal.} (1994)] to attain
continuous dependence on data for backward parabolic problems even at the
continuation boundary . The additional "SECB constraint" guarantees a
significant improvement in stability up to In this paper we prove that
the same type of stability can be obtained by using only two constraints among
the three. More precisely, we show that the a priori boundedness condition
is redundant. This implies that the Carasso's SECB condition
can be used to replace the a priori boundedness condition of F. John with an
improved stability estimate. Also a new class of regularized solutions is
introduced for backward parabolic problems with an SECB constraint. The new
regularized solutions are optimally stable and we also provide a constructive
scheme to compute. Finally numerical examples are provided.Comment: 15 pages. To appear in Inverse Problem
Vertical flow in the Southern Ocean estimated from individual moorings
In this study, we demonstrate that oceanic vertical velocities can be estimated from individual mooring measurements, even for non-stationary flow. This result is obtained under three assumptions: i. weak diffusion (PĂ©clet number â«1), ii. weak friction (Reynolds number â«1), and iii. small inertial terms (Rossby number âȘ1). The theoretical framework is applied to a set of 4 moorings located in the Southern Ocean. For this site, the diagnosed vertical velocities are highly variable in time, their standard deviation being one-to-two orders of magnitude greater than their mean. We demonstrate that the time-averaged vertical velocities are largely induced by geostrophic flow, and can be estimated from the time-averaged density and horizontal velocities. This suggests that local time-mean vertical velocities are primarily forced by the time-mean ocean dynamics, rather than by e.g. transient eddies or internal waves. We also show that, in the context of these four moorings, the time-mean vertical flow is consistent with stratified Taylor column dynamics in the presence of a topographic obstacle
Evolution of the AO Spine Sacral and Pelvic Classification System: a systematic review.
OBJECTIVE
The purpose of this study was to describe the genesis of the AO Spine Sacral and Pelvic Classification System in the context of historical sacral and pelvic grading systems.
METHODS
A systematic search of MEDLINE, EMBASE, Google Scholar, and Cochrane databases was performed consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all existing sacral and pelvic fracture classification systems.
RESULTS
A total of 49 articles were included in this review, comprising 23 pelvic classification systems and 17 sacral grading schemes. The AO Spine Sacral and Pelvic Classification System represents both the evolutionary product of these historical systems and a reinvention of classic concepts in 5 ways. First, the classification introduces fracture types in a graduated order of biomechanical stability while also taking into consideration the neurological status of patients. Second, the traditional belief that Denis central zone III fractures have the highest rate of neurological deficit is not supported because this subgroup often includes a broad spectrum of injuries ranging from a benign sagittally oriented undisplaced fracture to an unstable "U-type" fracture. Third, the 1990 Isler lumbosacral system is adopted in its original format to divide injuries based on their likelihood of affecting posterior pelvic or spinopelvic stability. Fourth, new discrete fracture subtypes are introduced and the importance of bilateral injuries is acknowledged. Last, this is the first integrated sacral and pelvic classification to date.
CONCLUSIONS
The AO Spine Sacral and Pelvic Classification is a universally applicable system that redefines and reorders historical fracture morphologies into a rational hierarchy. This is the first classification to simultaneously address the biomechanical stability of the posterior pelvic complex and spinopelvic stability, while also taking into consideration neurological status. Further high-quality controlled trials are required prior to the inclusion of this novel classification within a validated scoring system to guide the management of sacral and pelvic injuries
Movement disorder and neuronal migration disorder due to ARFGEF2 mutation
We report a child with a severe choreadystonic movement disorder, bilateral periventricular nodular heterotopia (BPNH), and secondary microcephaly based on compound heterozygosity for two new ARFGEF2 mutations (c.2031_2038dup and c.3798_3802del), changing the limited knowledge about the phenotype. The brain MRI shows bilateral hyperintensity of the putamen, BPNH, and generalized atrophy. Loss of ARFGEF2 function affects vesicle trafficking, proliferation/apoptosis, and neurotransmitter receptor function. This can explain BPNH and microcephaly. We hypothesize that the movement disorder and the preferential damage to the basal ganglia, specifically to the putamen, may be caused by an increased sensitivity to degeneration, a dynamic dysfunction due to neurotransmitter receptor mislocalization or a combination of both
Particles at oilâair surfaces : powdered oil, liquid oil marbles, and oil foam
The type of material stabilized by four kinds of fluorinated particles (sericite and bentonite platelet clays and spherical zinc oxide) in airâoil mixtures has been investigated. It depends on the particle wettability and the degree of shear. Upon vigorous agitation, oil dispersions are formed in all the oils containing relatively large bentonite particles and in oils of relatively low surface tension (Îłla < 26 mN mâ»Âč) like dodecane, 20 cS silicone, and cyclomethicone containing the other fluorinated particles. Particle-stabilized oil foams were obtained in oils having Îłla > 26 mN mâ»Âč where the advancing airâoilâsolid contact angle Ξ lies between ca. 90° and 120°. Gentle shaking, however, gives oil-in-air liquid marbles with all the oilâparticle systems except for cases where Ξ is <60°. For oils of tension >24 mN mâ»Âč with omniphobic zinc oxide and sericite particles for which advancing Ξ â„ 90°, dry oil powders consisting of oil drops in air which do not leak oil could be made upon gentle agitation up to a critical oil:particle ratio (COPR). Above the COPR, catastrophic phase inversion of the dry oil powders to air-in-oil foams was observed. When sheared on a substrate, the dry oil powders containing at least 60 wt % of oil release the encapsulated oil, making these materials attractive formulations in the cosmetic and food industries
The Look-back Time Evolution of Far-Ultraviolet Flux from the Brightest Cluster Elliptical Galaxies at z < 0.2
We present the GALEX UV photometry of the elliptical galaxies in Abell
clusters at moderate redshifts (z < 0.2) for the study of the look-back time
evolution of the UV upturn phenomenon. The brightest elliptical galaxies (M_r <
-22) in 12 remote clusters are compared with the nearby giant elliptical
galaxies of comparable optical luminosity in the Fornax and Virgo clusters. The
sample galaxies presented here appear to be quiescent without signs of massive
star formation or strong nuclear activity, and show smooth, extended profiles
in their UV images indicating that the far-UV (FUV) light is mostly produced by
hot stars in the underlying old stellar population. Compared to their
counterparts in nearby clusters, the FUV flux of cluster giant elliptical
galaxies at moderate redshifts fades rapidly with ~ 2 Gyrs of look-back time,
and the observed pace in FUV - V color evolution agrees reasonably well with
the prediction from the population synthesis models where the dominant FUV
source is hot horizontal-branch stars and their progeny. A similar amount of
color spread (~ 1 mag) in FUV - V exists among the brightest cluster elliptical
galaxies at z ~ 0.1, as observed among the nearby giant elliptical galaxies of
comparable optical luminosity.Comment: Accepted for publication in the Special GALEX ApJ Supplement,
December 200
Recommended from our members
Fieldable Fourier Transform Spectrometer: System Construction, Background Variability Measurements, and Chemical Attack Warning Experiments
The infrared sensors task at the Pacific Northwest National Laboratory (PNNL) is focused on the science and technology of remote and in-situ chemical sensors for detecting proliferation and countering terrorism. Missions to be addressed by remote chemical sensor development will include detecting proliferation of nuclear or chemical weapons, and providing warning of terrorist use of chemical weapons. Missions to be addressed by in-situ chemical sensor development include countering terrorism by screening luggage, personnel, and shipping containers for explosives, firearms, narcotics, chemical weapons, or chemical weapons residues, and mapping contaminated areas. The science and technology relevant to these primary missions is also likely to be useful for battlefield chemical weapons defense, air operations support, monitoring emissions from chemical weapons destruction facilities or industrial chemical plants, and law enforcement applications. PNNL will seek to serve organizations with direct interest in these missions through collaborative research and development efforts approved by NA-22. During FY02, PNNL began assembling a remote IR detection capability that would allow field experiments to be conducted. The capability consists of a commercially available FTIR (Fourier Transform Infrared) emission spectrometer and a frequency-modulation differential-absorption LIDAR (FM-DIAL) system being developed at PNNL. To provide environmental protection for these systems, a large, well insulated, temperature controlled trailer was specified and procured. While the FTIR system was field-ready, the FM-DIAL system required many modifications to prepare for field deployment. This document provides an overview of the FTIR system, summarizes the modifications made to the FM-DIAL system, and describes the salient features of the remote systems trailer
- âŠ