Flows in inkjet-printed aqueous rivulets

We used optical microscopy to investigate flows inside water rivulets that were inkjet-printed onto different surfaces and under different ambient conditions. The acquired fluid dynamics videos were submitted to the 2013 Gallery of Fluid Motion.Comment: This article accompanies a fluid dynamics video submitted to the 2013 Gallery of Fluid Motion of the 66th Annual Meeting of the APS Division of Fluid Dynamic

Empirical Evaluation of the Parallel Distribution Sweeping Framework on Multicore Architectures

In this paper, we perform an empirical evaluation of the Parallel External Memory (PEM) model in the context of geometric problems. In particular, we implement the parallel distribution sweeping framework of Ajwani, Sitchinava and Zeh to solve batched 1-dimensional stabbing max problem. While modern processors consist of sophisticated memory systems (multiple levels of caches, set associativity, TLB, prefetching), we empirically show that algorithms designed in simple models, that focus on minimizing the I/O transfers between shared memory and single level cache, can lead to efficient software on current multicore architectures. Our implementation exhibits significantly fewer accesses to slow DRAM and, therefore, outperforms traditional approaches based on plane sweep and two-way divide and conquer.Comment: Longer version of ESA'13 pape

A New HDG Method for Dirichlet Boundary Control of Convection Diffusion PDEs II: Low Regularity

In the first part of this work, we analyzed a Dirichlet boundary control problem for an elliptic convection diffusion PDE and proposed a new hybridizable discontinuous Galerkin (HDG) method to approximate the solution. For the case of a 2D polygonal domain, we also proved an optimal superlinear convergence rate for the control under certain assumptions on the domain and on the target state. In this work, we revisit the convergence analysis without these assumptions; in this case, the solution can have low regularity and we use a different analysis approach. We again prove an optimal convergence rate for the control, and present numerical results to illustrate the convergence theory

A Bulk-Parallel Priority Queue in External Memory with STXXL

We propose the design and an implementation of a bulk-parallel external memory priority queue to take advantage of both shared-memory parallelism and high external memory transfer speeds to parallel disks. To achieve higher performance by decoupling item insertions and extractions, we offer two parallelization interfaces: one using "bulk" sequences, the other by defining "limit" items. In the design, we discuss how to parallelize insertions using multiple heaps, and how to calculate a dynamic prediction sequence to prefetch blocks and apply parallel multiway merge for extraction. Our experimental results show that in the selected benchmarks the priority queue reaches 75% of the full parallel I/O bandwidth of rotational disks and and 65% of SSDs, or the speed of sorting in external memory when bounded by computation.Comment: extended version of SEA'15 conference pape

Air entrainment through free-surface cusps

In many industrial processes, such as pouring a liquid or coating a rotating cylinder, air bubbles are entrapped inside the liquid. We propose a novel mechanism for this phenomenon, based on the instability of cusp singularities that generically form on free surfaces. The air being drawn into the narrow space inside the cusp destroys its stationary shape when the walls of the cusp come too close. Instead, a sheet emanates from the cusp's tip, through which air is entrained. Our analytical theory of this instability is confirmed by experimental observation and quantitative comparison with numerical simulations of the flow equations

Mathematical Modeling and Simulation of Biologically Inspired Hair Receptor Arrays in Laminar Unsteady Flow Separation

Bats possess arrays of distributed ow-sensitive hair-like mechanoreceptors on their dorsal and ventral wing surfaces. It is generally hypothesized that the hair sensor array provides air ow feedback during ight. Speci cally, the sensing of leading and trailing edge vortices that are shed during apping ight has been proposed. In this work, we consider the mechanics of exible hair-like structures for the time accurate measurement and visualization of hydrodynamic images associated with unsteady near surface ow phenomena. A nonlinear viscoelastic model of a hair-like structure coupled to an unsteady nonuniform ow environment is proposed. Writing the hair model in nondimensional form, we perform an order of magnitude analysis of the physical forces involved in the uid-structure hair response. Through the proper choice of hair material, we show how the time accurate measurement of near surface ow velocity may be obtained from hair tip displacement and resultant moment. Furthermore, we show how a surface mounted hair array may provide a time accurate hydrodynamic image of a laminar unsteady ow separation over a cylinder.This is the publisher’s final pdf. The published article is copyrighted by Elsevier and can be found at: http://www.elsevier.com/Keywords: low Reynolds number, bats, micro air vehicles, nite element

A scoping review of the changing landscape of geriatric medicine in undergraduate medical education: curricula, topics and teaching methods

Purpose The world’s population is ageing. Therefore, every doctor should receive geriatric medicine training during their undergraduate education. This review aims to summarise recent developments in geriatric medicine that will potentially inform developments and updating of undergraduate medical curricula for geriatric content. Methods We systematically searched the electronic databases Ovid Medline, Ovid Embase and Pubmed, from 1st January 2009 to 18th May 2021. We included studies related to (1) undergraduate medical students and (2) geriatric medicine or ageing or older adults and (3) curriculum or curriculum topics or learning objectives or competencies or teaching methods or students’ attitudes and (4) published in a scientific journal. No language restrictions were applied. Results We identified 2503 records and assessed the full texts of 393 records for eligibility with 367 records included in the thematic analysis. Six major themes emerged: curriculum, topics, teaching methods, teaching settings, medical students’ skills and medical students’ attitudes. New curricula focussed on minimum Geriatrics Competencies, Geriatric Psychiatry and Comprehensive Geriatric Assessment; vertical integration of Geriatric Medicine into the curriculum has been advocated. Emerging or evolving topics included delirium, pharmacotherapeutics, healthy ageing and health promotion, and Telemedicine. Teaching methods emphasised interprofessional education, senior mentor programmes and intergenerational contact, student journaling and reflective writing, simulation, clinical placements and e-learning. Nursing homes featured among new teaching settings. Communication skills, empathy and professionalism were highlighted as essential skills for interacting with older adults. Conclusion We recommend that future undergraduate medical curricula in Geriatric Medicine should take into account recent developments described in this paper. In addition to including newly emerged topics and advances in existing topics, different teaching settings and methods should also be considered. Employing vertical integration throughout the undergraduate course can usefully supplement learning achieved in a dedicated Geriatric Medicine undergraduate course. Interprofessional education can improve understanding of the roles of other professionals and improve team-working skills. A focus on improving communication skills and empathy should particularly enable better interaction with older patients. Embedding expected levels of Geriatric competencies should ensure that medical students have acquired the skills necessary to effectively treat older patients

New horizons in geriatric medicine education and training: the need for pan-European education and training standards

The ageing population ought to be celebrated as evidence for the efficacy of modern medicine, but the challenge that this demographic shift presents for 21st century healthcare systems, with increasing numbers of people living with multi-morbidity and frailty, cannot be ignored. There is therefore a need to ensure that all healthcare professionals grasp the basic principles of care of older people. In this paper, we make a case for the development of pan-European education and training standards for the field of geriatric medicine. Firstly, the challenges which face the implementation and delivery of geriatric medicine in a systematic way across Europe are described – these include, but are not limited to; variance in geriatric medicine practice across Europe, insecurity of the specialty in some countries and significant heterogeneity in geriatric medicine training programs across Europe. The opportunities for geriatric medicine are then presented and we consider how engendering core geriatric medicine competencies amongst nongeriatricians has potential to bridge existing gaps in service provision across Europe. Finally, we consider how work can proceed to teach sufficient numbers of doctors and health professionals in the core knowledge, skills and attitudes required to do this. To safeguard the future of the specialty across Europe, we contend that there is a need to strive towards harmonisation of post-graduate geriatric medicine training across Europe, through the establishment of pan-European education and training standards in the specialty

Validation, reproducibility and safety of trans dermal electrical stimulation in chronic pain patients and healthy volunteers

<p>Abstract</p> <p>Background</p> <p>Surrogate pain models have been extensively tested in Normal Human Volunteers (NHV). There are few studies that examined pain models in chronic pain patients. Patients are likely to have altered pain mechanisms. It is of interest to test patient pain responses to selective pain stimuli under controlled laboratory conditions.</p> <p>Methods</p> <p>The Institutional Ethic Committee approved the study. 16 patients with chronic neuropathic radiculopathy and 16 healthy volunteers were enrolled to the study after obtaining informed consent. During electrical stimulation (150 minutes for volunteers and 75 minutes for patients) the following parameters were measured every 10 minutes:</p> <p>Ongoing pain: Visual Analogue Scale (VAS) and Numeric Rate Scale (NRS)</p> <p>Allodynia (soft foam brush)</p> <p>Hyperalgesia (von Frey monofilament 20 g)</p> <p>Flare</p> <p>For each endpoint, the area under the curve (AUC) was estimated from the start of stimulation to the end of stimulation by the trapezoidal rule. The individual AUC values for both periods were plotted to show the inter- and intra-subject variability. For each endpoint a mixed effect model was fitted with random effect subject and fixed effect visit. The estimate of intra-subject variance and the mean value were then used to estimate the sample size of a crossover study required to have a probability of 0.80 to detect a 25% change in the mean value. Analysis was done using GenStat 8^thedition.</p> <p>Results</p> <p>Each endpoint achieved very good reproducibility for patients and NHV. Comparison between groups revealed trends towards:</p> <p>Faster habituation to painful stimuli in patients</p> <p>Bigger areas of hyperalgesia in patients</p> <p>Similar area of allodynia and flare (no statistical significance)</p> <p>Conclusion</p> <p>The differences demonstrated between patients and NHVs suggest that the electrical stimulation device used here may stimulate pathways that are affected in the pathological state.</p