Damped finite-time-singularity driven by noise

We consider the combined influence of linear damping and noise on a dynamical finite-time-singularity model for a single degree of freedom. We find that the noise effectively resolves the finite-time-singularity and replaces it by a first-passage-time or absorbing state distribution with a peak at the singularity and a long time tail. The damping introduces a characteristic cross-over time. In the early time regime the probability distribution and first-passage-time distribution show a power law behavior with scaling exponent depending on the ratio of the non linear coupling strength to the noise strength. In the late time regime the behavior is controlled by the damping. The study might be of relevance in the context of hydrodynamics on a nanometer scale, in material physics, and in biophysics.Comment: 9 pages, 4 eps-figures, revtex4 fil

The Two Fluid Drop Snap-off Problem: Experiments and Theory

We address the dynamics of a drop with viscosity $\lambda \eta$ breaking up inside another fluid of viscosity $\eta$. For $\lambda=1$, a scaling theory predicts the time evolution of the drop shape near the point of snap-off which is in excellent agreement with experiment and previous simulations of Lister and Stone. We also investigate the $\lambda$ dependence of the shape and breaking rate.Comment: 4 pages, 3 figure

Finite Element Methods for Elliptic Distributed Optimal Control Problems with Pointwise State Constraints

Finite element methods for a model elliptic distributed optimal control problem with pointwise state constraints are considered from the perspective of fourth order boundary value problems

Brownian transport in corrugated channels with inertia

The transport of suspended Brownian particles dc-driven along corrugated narrow channels is numerically investigated in the regime of finite damping. We show that inertial corrections cannot be neglected as long as the width of the channel bottlenecks is smaller than an appropriate particle diffusion length, which depends on the the channel corrugation and the drive intensity. Being such a diffusion length inversely proportional to the damping constant, transport through sufficiently narrow obstructions turns out to be always sensitive to the viscosity of the suspension fluid. The inertia corrections to the transport quantifiers, mobility and diffusivity, markedly differ for smoothly and sharply corrugated channels.Comment: 9 pages including figures. arXiv admin note: substantial text overlap with arXiv:1202.436

Self-Supervised Adversarial Shape Completion

The goal of this paper is 3D shape completion: given an incomplete instance of a known category, hallucinate a complete version of it that is geometrically plausible. We develop an adversarial framework that makes it possible to learn shape completion in a self-supervised fashion, only from incomplete examples. This is enabled by a discriminator network that rejects incomplete shapes, via a loss function that separately assesses local sub-regions of the generated example and accepts only regions with sufficiently high point count. This inductive bias against empty regions forces the generator to output complete shapes. We demonstrate the effectiveness of this approach on synthetic data from ShapeNet and ModelNet, and on a real mobile mapping dataset with nearly 9'000 incomplete cars. Moreover, we apply it to the KITTI autonomous driving dataset without retraining, to highlight its ability to generalise to different data characteristics

Development and Testing of The Gait Assessment and Intervention Tool (G.A.I.T.): A Measure of Coordinated Gait Components

Recent neuroscience methods have provided the basis upon which to develop effective gait training methods for recovery of the coordinated components of gait after neural injury. We determined that there was not an existing observational measure that was, at once, adequately comprehensive, scored in an objectively-based manner, and capable of assessing incremental improvements in the coordinated components of gait. Therefore, the purpose of this work was to use content valid procedures in order to develop a relatively inexpensive, more comprehensive measure, scored with an objectively-based system, capable of incrementally scoring improvements in given items, and that was both reliable and capable of discriminating treatment response for those who had a stroke. Eight neurorehabilitation specialists developed criteria for the gait measure, item content, and scoring method. In subjects following stroke (\u3e12 months), the new measure was tested for intra- and inter-rater reliability using the Intraclass Correlation Coefficient; capability to detect treatment response using Wilcoxon Signed Ranks Test; and discrimination between treatment groups, using the Plum Ordinal Regression. The Gait Assessment and Intervention Tool (G.A.I.T.) is a 31-item measure of the coordinated movement components of gait and associated gait deficits. It exhibited the following advantages: comprehensive, objective-based scoring method, incremental measurement of improvement within given items. The G.A.I.T. had good intra- and inter-rater reliability (ICC = .98, p = .0001, 95% CI = .95, .99; ICC = .83, p = .007, 95% CI = .32, .96, respectively. The inexperienced clinician who had training, had an inter-rater reliability with an experienced rater of ICC = .99 (p = .0001, CI = .97, .999). The G.A.I.T. detected improvement in response to gait training for two types of interventions: comprehensive gait training (z = −2.93, p = .003); and comprehensive gait training plus functional electrical stimulation (FES; z = −3.3, p = .001). The G.A.I.T. was capable of discriminating between two gait training interventions, showing an additive advantage of FES to otherwise comparable comprehensive gait training (parameter estimate = 1.72, p = .021; CI, .25, 3.1)

Development and Testing of The Gait Assessment and Intervention Tool (G.A.I.T.): A Measure of Coordinated Gait Components

Recent neuroscience methods have provided the basis upon which to develop effective gait training methods for recovery of the coordinated components of gait after neural injury. We determined that there was not an existing observational measure that was, at once, adequately comprehensive, scored in an objectively-based manner, and capable of assessing incremental improvements in the coordinated components of gait. Therefore, the purpose of this work was to use content valid procedures in order to develop a relatively inexpensive, more comprehensive measure, scored with an objectively-based system, capable of incrementally scoring improvements in given items, and that was both reliable and capable of discriminating treatment response for those who had a stroke. Eight neurorehabilitation specialists developed criteria for the gait measure, item content, and scoring method. In subjects following stroke (\u3e12 months), the new measure was tested for intra- and inter-rater reliability using the Intraclass Correlation Coefficient; capability to detect treatment response using Wilcoxon Signed Ranks Test; and discrimination between treatment groups, using the Plum Ordinal Regression. The Gait Assessment and Intervention Tool (G.A.I.T.) is a 31-item measure of the coordinated movement components of gait and associated gait deficits. It exhibited the following advantages: comprehensive, objective-based scoring method, incremental measurement of improvement within given items. The G.A.I.T. had good intra- and inter-rater reliability (ICC = .98, p = .0001, 95% CI = .95, .99; ICC = .83, p = .007, 95% CI = .32, .96, respectively. The inexperienced clinician who had training, had an inter-rater reliability with an experienced rater of ICC = .99 (p = .0001, CI = .97, .999). The G.A.I.T. detected improvement in response to gait training for two types of interventions: comprehensive gait training (z = −2.93, p = .003); and comprehensive gait training plus functional electrical stimulation (FES; z = −3.3, p = .001). The G.A.I.T. was capable of discriminating between two gait training interventions, showing an additive advantage of FES to otherwise comparable comprehensive gait training (parameter estimate = 1.72, p = .021; CI, .25, 3.1)

Increasing heat storage by wearing extra clothing during upper body exercise up-regulates heat shock protein 70 but does not modify the cytokine response

Plasma heat shock protein 70 (HSP70) concentrations rise during heat stress, which can independently induce cytokine production. Upper body exercise normally results in modest body temperature elevations. The aim of this study was to investigate the impacts of additional clothing on the body temperature, cytokine and HSP70 responses during this exercise modality. Thirteen males performed 45-min constant-load arm cranking at 63% maximum aerobic power (62 ± 7%V̇O2peak) in either a non-permeable whole-body suit (intervention, INT) or shorts and T-shirt (control, CON). Exercise resulted in a significant increase of IL-6 and IL-1ra plasma concentrations (P 0.19). The increase in HSP70 from pre to post was only significant for INT (0.12 ± 0.11ng∙mL−1, P < 0.01 vs. 0.04 ± 0.18 ng∙mL−1, P = 0.77). Immediately following exercise, Tcore was elevated by 0.46 ± 0.29 (INT) and 0.37 ± 0.23ºC (CON), respectively (P < 0.01), with no difference between conditions (P = 0.16). The rise in mean Tskin (2.88 ± 0.50 and 0.30 ± 0.89ºC, respectively) and maximum heat storage (3.24 ± 1.08 and 1.20 ± 1.04 J∙g−1, respectively) was higher during INT (P < 0.01). Despite large differences in heat storage between conditions, the HSP70 elevations during INT, even though significant, were very modest. Possibly, the Tcore elevations were too low to induce a more pronounced HSP70 response to ultimately affect cytokine productio

A Guide to Localized Frames and Applications to Galerkin-like Representations of Operators

This chapter offers a detailed survey on intrinsically localized frames and the corresponding matrix representation of operators. We re-investigate the properties of localized frames and the associated Banach spaces in full detail. We investigate the representation of operators using localized frames in a Galerkin-type scheme. We show how the boundedness and the invertibility of matrices and operators are linked and give some sufficient and necessary conditions for the boundedness of operators between the associated Banach spaces.Comment: 32 page