1,984 research outputs found
Recommended from our members
Volumetric laser endomicroscopy and its application to Barrett's esophagus: results from a 1,000 patient registry.
Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291
Probabilistic and Distributed Control of a Large-Scale Swarm of Autonomous Agents
We present a novel method for guiding a large-scale swarm of autonomous
agents into a desired formation shape in a distributed and scalable manner. Our
Probabilistic Swarm Guidance using Inhomogeneous Markov Chains (PSG-IMC)
algorithm adopts an Eulerian framework, where the physical space is partitioned
into bins and the swarm's density distribution over each bin is controlled.
Each agent determines its bin transition probabilities using a
time-inhomogeneous Markov chain. These time-varying Markov matrices are
constructed by each agent in real-time using the feedback from the current
swarm distribution, which is estimated in a distributed manner. The PSG-IMC
algorithm minimizes the expected cost of the transitions per time instant,
required to achieve and maintain the desired formation shape, even when agents
are added to or removed from the swarm. The algorithm scales well with a large
number of agents and complex formation shapes, and can also be adapted for area
exploration applications. We demonstrate the effectiveness of this proposed
swarm guidance algorithm by using results of numerical simulations and hardware
experiments with multiple quadrotors.Comment: Submitted to IEEE Transactions on Robotic
Modelos discriminantes para predecir la pérdida de peso. Proyecto PROgramas de Nutrición y Actividad Física para el tratamiento de la obesidad (PRONAF)
El objetivo del trabajo fue crear modelos discriminantes para estimar el porcentaje de pérdida de peso tras una intervención de seis meses, determinando la importancia de cada variable estudiada. La muestra, formada por 89 participantes en sobrepeso (18–50 años; IMC >25 y <29.9 kg/m2), fue distribuida en cuatro grupos de intervención: entrenamiento con cargas (S, n=22); entrenamiento aeróbico (E, n=25); entrenamiento combinado cargas + aeróbico (SE, n=23) y recomendaciones de ejercicio físico (C, n=19).
Los grupos de entrenamiento entrenaron 3 veces/semana durante 24 semanas. Todos los grupos siguieron una restricción calórica del 25% del gasto energético diario. Tres modelos discriminantes fueron obtenidos para estimar el porcentaje de pérdida de peso, determinando que el peso, la masa grasa y el peso magro son las variables más importantes para discriminar la pérdida de peso. Los tres modelos discriminantes consiguen un elevado porcentaje de clasificación correcta.
Registrado en Clinical Trials Gov.: número NCT01116856
Webliography of African-American Champaign-Urbana
This Lab Note reflects one part of a year-long project called eBlackChampaign-Urbana. Our interest here is to provide better access to the dispersed documentation of local African-American history and culture in ChampaignUrbana, using digital technology to aggregate and enliven historical and contemporary information. Although this
webliography focuses primarily on substantial, in-depth texts documenting local African-American life, we are also
aggregating into the eBlackCU.net website URLs for local African-American websites, facebook pages, photographs,
newspaper clippings, flyers, posters and other ephemeral documentation of Champaign-Urbana's Black heritage.published or submitted for publicationnot peer reviewe
Improved micro-contact resistance model that considers material deformation, electron transport and thin film characteristics
This paper reports on an improved analytic model forpredicting micro-contact resistance needed for designing microelectro-mechanical systems (MEMS) switches. The originalmodel had two primary considerations: 1) contact materialdeformation (i.e. elastic, plastic, or elastic-plastic) and 2) effectivecontact area radius. The model also assumed that individual aspotswere close together and that their interactions weredependent on each other which led to using the single effective aspotcontact area model. This single effective area model wasused to determine specific electron transport regions (i.e. ballistic,quasi-ballistic, or diffusive) by comparing the effective radius andthe mean free path of an electron. Using this model required thatmicro-switch contact materials be deposited, during devicefabrication, with processes ensuring low surface roughness values(i.e. sputtered films). Sputtered thin film electric contacts,however, do not behave like bulk materials and the effects of thinfilm contacts and spreading resistance must be considered. Theimproved micro-contact resistance model accounts for the twoprimary considerations above, as well as, using thin film,sputtered, electric contact
- …