52 research outputs found
Resonant nucleation of spatio-temporal order via parametric modal amplification
We investigate, analytically and numerically, the emergence of
spatio-temporal order in nonequilibrium scalar field theories. The onset of
order is triggered by destabilizing interactions (DIs), which instantaneously
change the interacting potential from a single to a double-well, tunable to be
either degenerate (SDW) or nondegenerate (ADW). For the SDW case, we observe
the emergence of spatio-temporal coherent structures known as oscillons. We
show that this emergence is initially synchronized, the result of parametric
amplification of the relevant oscillon modes. We also discuss how these ordered
structures act as bottlenecks for equipartition. For ADW potentials, we show
how the same parametric amplification mechanism may trigger the rapid decay of
a metastable state. For a range of temperatures, the decay rates associated
with this resonant nucleation can be orders of magnitude larger than those
computed by homogeneous nucleation, with time-scales given by a simple power
law, , where depends weakly on the
temperature and is the free-energy barrier of a critical
fluctuation.Comment: 38 pages, 20 figures now included within the tex
Decreased olfactory discrimination is associated with impulsivity in healthy volunteers
In clinical populations, olfactory abilities parallel executive function, implicating shared
neuroanatomical substrates within the ventral prefrontal cortex. In healthy individuals, the relationship
between olfaction and personality traits or certain cognitive and behavioural characteristics remains
unexplored. We therefore tested if olfactory function is associated with trait and behavioural impulsivity
in nonclinical individuals. Eighty-three healthy volunteers (50 females) underwent quantitative
assessment of olfactory function (odour detection threshold, discrimination, and identifcation). Each
participant was rated for trait impulsivity index using the Barratt Impulsiveness Scale and performed
a battery of tasks to assess behavioural impulsivity (Stop Signal Task, SST; Information Sampling
Task, IST; Delay Discounting). Lower odour discrimination predicted high ratings in non-planning
impulsivity (Barratt Non-Planning impulsivity subscale); both, lower odour discrimination and detection
threshold predicted low inhibitory control (SST; increased motor impulsivity). These fndings extend
clinical observations to support the hypothesis that defcits in olfactory ability are linked to impulsive
tendencies within the healthy population. In particular, the relationship between olfactory abilities and
behavioural inhibitory control (in the SST) reinforces evidence for functional overlap between neural
networks involved in both processes. These fndings may usefully inform the stratifcation of people at
risk of impulse-control-related problems and support planning early clinical interventions
Behavioural and Developmental Interventions for Autism Spectrum Disorder: A Clinical Systematic Review
Background: Much controversy exists regarding the clinical efficacy of behavioural and developmental interventions for improving the core symptoms of autism spectrum disorders (ASD). We conducted a systematic review to summarize the evidence on the effectiveness of behavioural and developmental interventions for ASD. Methods and Findings: Comprehensive searches were conducted in 22 electronic databases through May 2007. Further information was obtained through hand searching journals, searching reference lists, databases of theses and dissertations, and contacting experts in the field. Experimental and observational analytic studies were included if they were written in English and reported the efficacy of any behavioural or developmental intervention for individuals with ASD. Two independent reviewers made the final study selection, extracted data, and reached consensus on study quality. Results were summarized descriptively and, where possible, meta-analyses of the study results were conducted. One-hundred-and-one studies at predominantly high risk of bias that reported inconsistent results across various interventions were included in the review. Meta-analyses of three controlled clinical trials showed that Lovaas treatment was superior to special education on measures of adaptive behaviour, communication and interaction, comprehensive language, daily living skills, expressive language, overall intellectual functioning and socialization. High-intensity Lovaas was superior to low-intensity Lovaas on measures of intellectual functioning in two retrospective cohort studies. Pooling the results of two randomized controlle
Introducing Smirk 2
We introduce a new open source windows based lecture capture solution called Smirk 2. We describe the motivations for writing the tool, a comparison with other such programs on the market, and explain the mechanism of downloading Smirk on to a machine, either to use or to amend it. It also proposes potential projects that could be built on top of the Smirk platform β and also offers a justification of why academics should be involved in the creation not just the use, of learning technology.Peer reviewedFinal Accepted Versio
Mafic-dominated volcanogenic sulphide deposits in the Troodos ophiolite, Cyprus Part 1 β The deposits of the Solea graben
Dating Fill Deposits and Pithouses in the Mimbres Area Through Two Ceramic Seriation Techniques: An Example from the Lake Roberts Vista Site
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