Abstract:This is a paper about multi-fractal scaling and dissipation in a shell model of turbulence, called the Gledzer-Ohkitani-Yamada model or GOY model. This set of equations describes a one dimensional cascade of energy towards higher wave vectors. When the model is chaotic, the high-wave-vector velocity is a product of roughly independent multipliers, one for each logarithmic momentum shell. The appropriate tool for studying the multifractal properties of this model is shown to be the energy ux on each shell rather than the velocity on each shell. Using this quantity, one can obtain better measurements of the deviations from Kolmogorov scaling (in the GOY dynamics) than were available up to now. These deviations are seen to depend upon the details of inertial-range structure of the model and hence are not universal. However, once the conserved quantities of the model are xed to have the same scaling structure as energy and helicity, these deviations seem to depend only weakly upon the scale parameter of the model. We analyze the connection between multifractality in the velocity distribution and multifractality in the dissipation. Our arguments suggest that the connection is universal for models of this character, but the model has a di erent behavior from that of real turbulence. We also predict the scaling behavior of time correlations of shell-velocities, of the dissipation, and of Lyapunov indices. These scaling arguments can be carried over, with little change, to multifractal models of real turbulence.

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One way to image the molecular pathology in Alzheimer’s disease (AD) is by positron emission tomography using probes that target amyloid fibrils. However, these fibrils are not closely linked to the development of the disease. It is now thought that early stage biomarkers that instigate memory loss comprise of Aβ oligomers (AβOs). Here we report a sensitive molecular magnetic resonance imaging (MRI) contrast probe that is specific for AβOs. We attach oligomer-specific antibodies onto magnetic nanostructures and show the complex is stable and it binds to AβOs on cells and brain tissues to give a MRI signal. When intranasally administered to an AD mouse model, the probe readily reached hippocampal AβOs. In isolated samples of human brain tissue, we observed an MRI signal that distinguished AD from controls. Such nanostructures that target neurotoxic AβOs are potentially useful for evaluating the efficacy of new drugs and ultimately for early-stage AD diagnosis and disease management.

Background Cardiovascular disease (CVD) is the leading cause of death worldwide. Despite strong evidence supporting the benefits of cardiac rehabilitation (CR), over 80% of eligible patients do not participate in CR. Digital health technologies (ie, the delivery of care using the internet, wearable devices, and mobile apps) have the potential to address the challenges associated with traditional facility-based CR programs, but little is known about the comprehensiveness of these interventions to serve as digital approaches to CR. Overall, there is a lack of a systematic evaluation of the current literature on digital interventions for CR. Objective The objective of this systematic literature review is to provide an in-depth analysis of the potential of digital health technologies to address the challenges associated with traditional CR. Through this review, we aim to summarize the current literature on digital interventions for CR, identify the key components of CR that have been successfully addressed through digital interventions, and describe the gaps in research that need to be addressed for sustainable and scalable digital CR interventions. Methods Our strategy for identifying the primary literature pertaining to CR with digital solutions (defined as technology employed to deliver remote care beyond the use of the telephone) included a consultation with an expert in the field of digital CR and searches of the PubMed (MEDLINE), Embase, CINAHL, and Cochrane databases for original studies published from January 1990 to October 2018. Results Our search returned 31 eligible studies, of which 22 were randomized controlled trials. The reviewed CR interventions primarily targeted physical activity counseling (31/31, 100%), baseline assessment (30/31, 97%), and exercise training (27/31, 87%). The most commonly used modalities were smartphones or mobile devices (20/31, 65%), web-based portals (18/31, 58%), and email-SMS (11/31, 35%). Approximately one-third of the studies addressed the CR core components of nutrition counseling, psychological management, and weight management. In contrast, less than a third of the studies addressed other CR core components, including the management of lipids, diabetes, smoking cessation, and blood pressure. Conclusions Digital technologies have the potential to increase access and participation in CR by mitigating the challenges associated with traditional, facility-based CR. However, previously evaluated interventions primarily focused on physical activity counseling and exercise training. Thus, further research is required with more comprehensive CR interventions and long-term follow-up to understand the clinical impact of digital interventions.

We study the two-dimensional localization problem for (i) a classical diffusing particle advected by a quenched random mean-zero vorticity field, and (ii) a quantum particle in a quenched random mean-zero magnetic field. Through a combination of numerical and analytical techniques we argue that both systems have extended eigenstates at a special point in the spectrum invariant under particle-hole symmetry, where a sublattice decomposition obtains. In a neighborhood of this point, the Lyapunov exponents of the transfer matrices acquire ratios characteristic of conformal invariance allowing an indirect determination of 1͞r for the typical spatial decay of eigenstates. PACS numbers: 46.10.+z, 05.40.+j, 05.45.+b In this paper we study two simple models for passive advection of a diffusing field: (I) a diffusing scalar density n͑x͒ advected by a quenched random velocity field A͑x͒ described by the Fokker-Planck equation [1]:where D is the diffusivity; and (II) the random-flux model [2] for a noninteracting quantum particle propagating in a spatially random, zero-mean magnetic fieldwhere A now denotes the vector potential, described by the Schrödinger equationc being the (complex) quantum wave function, p ϵ 2i= = = the momentum operator, and V ͑x͒ the (scalar) potential [3]. Model (II) has received much attention recently in the context of the quantum Hall effect at filling factor n 1 2[2]. An unresolved question is whether the system has properties of a Fermi liquid, and, in particular, extended states. Previous work has addressed the energy dependence of the localization length j͑E͒ moving inward from the band edge, with authors arriving at opposite conclusions. The most careful numerical study of model (II) to date concludes that all states are localized [2(b)], whereas others find a central band of extended states [2(a)]. An analytic calculation using a replicated nonlinear sigma model with a topological term [4] also obtains a band of extended states.Our purpose is twofold. First, we explore the consequences of particle-hole symmetry at the band center of these models, E c , and describe numerical and analytical evidence for a divergent localization length at this point. Previous studies [2(b),5] did not allow for this symmetry at the band center [6]. Second, we demonstrate that the properties of random flux that have drawn so much attention are exhibited by a much larger class of models, among them the passive scalar model (I).Magnetic field and vorticity are distinguished from potential fields by their transformation under time reversal [7]. Writing the velocity in model (I) as A = = =x 1 = = = 3 f, we observe that x, like V, is even under time reversal, whereas f, (the source of vorticity v = = = 3 A 2= 2 f), like B, is odd. A further physical similarity between the two models is that one expects transport to be dominated by the longest streamlines [1(b)] [8,9]; for the random-flux (passive scalar) model with vanishing mean magnetic field (vorticity), these rare streamlines run along the interfaces of opposi...

Importantly, our findings suggest that while a >1 mm margin is associated with better prognosis than a submillimeter margin, achieving a margin >1 cm may result in even better oncologic outcomes and should be considered if possible.

Our study demonstrates that PET is more accurate than CECT in LN staging NSCLC patients in Taiwan where TB is still prevalent. Semi-quantitative SUV method or DTPI with RI does not result in better diagnostic accuracy than visual analysis of PET images.

BackgroundAlthough numerous evidence-based and feasible interventions are available to treat pain from childhood vaccine injections, evidence indicates that children are not benefitting from this knowledge. Unrelieved vaccination pain puts children at risk for significant long-term harms including the development of needle fears and subsequent health care avoidance behaviours. Parents report that while they want to mitigate vaccination pain in their children, they lack knowledge about how to do so. An evidence-based clinical practice guideline for managing vaccination pain was recently developed in order to address this knowledge-to-care gap. Educational tools (pamphlet and video) for parents were included to facilitate knowledge transfer at the point of care. The objectives of this study were to evaluate usability and effectiveness in terms of knowledge acquisition from the pamphlet and video in parents of newly born infants.MethodsMixed methods design. Following heuristic usability evaluation of the pamphlet and video, parents of newborn infants reviewed revised versions of both tools and participated in individual and group interviews and individual knowledge testing. The knowledge test comprised of 10 true/false questions about the effectiveness of various pain management interventions, and was administered at three time points: at baseline, after review of the pamphlet, and after review of the video.ResultsThree overarching themes were identified from the interviews regarding usability of these educational tools: receptivity to learning, accessibility to information, and validity of information. Parents’ performance on the knowledge test improved (p≤0.001) from the baseline phase to after review of the pamphlet, and again from the pamphlet review phase to after review of the video.ConclusionsUsing a robust testing process, we demonstrated usability and conceptual knowledge acquisition from a parent-directed educational pamphlet and video about management of vaccination pain. Future studies are planned to determine the impact of these educational tools when introduced in clinical settings on parent behaviors during infant vaccinations.