Jet-Surface Interaction: High Aspect Ratio Nozzle Test, Nozzle Design and Preliminary Data

The Jet-Surface Interaction High Aspect Ratio (JSI-HAR) nozzle test is part of an ongoing effort to measure and predict the noise created when an aircraft engine exhausts close to an airframe surface. The JSI-HAR test is focused on parameters derived from the Turbo-electric Distributed Propulsion (TeDP) concept aircraft which include a high-aspect ratio mailslot exhaust nozzle, internal septa, and an aft deck. The size and mass flow rate limits of the test rig also limited the test nozzle to a 16:1 aspect ratio, half the approximately 32:1 on the TeDP concept. Also, unlike the aircraft, the test nozzle must transition from a single round duct on the High Flow Jet Exit Rig, located in the AeroAcoustic Propulsion Laboratory at the NASA Glenn Research Center, to the rectangular shape at the nozzle exit. A parametric nozzle design method was developed to design three low noise round-to-rectangular transitions, with 8:1, 12:1, and 16: aspect ratios, that minimizes flow separations and shocks while providing a flat flow profile at the nozzle exit. These designs validated using the WIND-US CFD code. A preliminary analysis of the test data shows that the actual flow profile is close to that predicted and that the noise results appear consistent with data from previous, smaller scale, tests. The JSI-HAR test is ongoing through October 2015. The results shown in the presentation are intended to provide an overview of the test and a first look at the preliminary results

Ultrasound-Assisted Peripheral Venous Access in Young Children: A Randomized Controlled Trial and Pilot Feasibility Study

OBJECTIVES: Intravenous (IV) access in children treated in the emergency department (ED) is frequently required and often difficult to obtain. While it has been shown that ultrasound can be useful in adults for both central and peripheral venous access, research regarding children has been limited. We sought to determine if the use of a static ultrasound technique could, a) allow clinicians to visualize peripheral veins and b) improve success rates of peripheral venous cannulation in young children in the ED.METHODS: We performed a randomized clinical trial of children < 7 years in an academic pediatric ED who required IV access and who had failed the first IV attempt. We randomized patients to either continued standard IV attempts or ultrasound-assisted attempts. Clinicians involved in the study received one hour of training in ultrasound localization of peripheral veins. In the ultrasound group, vein localization was performed by an ED physician who marked the skin overlying the target vessel. Intravenous cannulation attempts were then immediately performed by a pediatric ED nurse who relied on the skin mark for vessel location. We allowed for technique cross-over after two failed IV attempts. We recorded success rate and location of access attempts. We compared group success rates using differences in 95% confidence intervals (CI).RESULTS: We enrolled 44 children over a one-year period. The median age of enrollees was 9.5 months. We visualized peripheral veins in all patients in the ultrasound group (n=23) and in those who crossed over to ultrasound after failed standard technique attempts (n= 8). Venipuncture was successful on the first attempt in the ultrasound group in 13/23 (57%, CI, 35% to 77%), versus 12/21 (57%, CI, 34% to 78%) in the standard group, difference between groups 0.6% (95% CI -30% to 29%). First attempt cannulation success in the ultrasound group was 8/23 (35%, CI, 16% to 57%), versus 6/21 (29%, CI, 11% to 52%) in the standard group, difference between groups 6% (95% CI -21% to 34%).CONCLUSION: Ultrasound allows physicians to visualize peripheral veins of young children in the ED. We were unable to demonstrate, however, a clinically important benefit to a static ultrasound aided vein cannulation technique performed by clinicians with limited ultrasound training over standard technique after one failed IV attempt in an academic pediatric ED

Bose-Einstein correlations for Levy stable source distributions

The peak of the two-particle Bose-Einstein correlation functions has a very interesting structure. It is often believed to have a multivariate Gaussian form. We show here that for the class of stable distributions, characterized by the index of stability $0 < \alpha \le 2$, the peak has a stretched exponential shape. The Gaussian form corresponds then to the special case of $\alpha = 2$. We give examples for the Bose-Einstein correlation functions for univariate as well as multivariate stable distributions, and check the model against two-particle correlation data.Comment: 30 pages, 1 figure, an important misprint in former eqs. (37-38) and other minor misprints are corrected, citations update

How to… support others in developing a career in clinical education research

The Incubator for Clinical Education Research (ClinEdR) is a UK-wide network, established with support from the National Institute for Health Research, to lead initiatives to build capacity in the field. A key barrier identified by this group is that many experienced educators, clinicians, and researchers, who may be committed to supporting others, have little guidance on how best to do this. In this “How to …” paper, we draw on relevant literature and our individual and collective experiences as members of the National Institute for Health Research ClinEdR incubator to offer suggestions on how educators can support others to develop successful careers involving ClinEdR. This article offers guidance and inspiration for all professionals whose role involves research and scholarship and who encounter aspiring or developing clinical education researchers in the course of their work. It will also be of interest to researchers who are starting out and progressing in the field

Fungal-derived cues promote ocular autoimmunity through a Dectin-2/Card9-mediated mechanism

This work was supported by National Institutes of Health (RO1 EY025250) and Intramural funding (NEI Project# EY00184), along with Department of Veterans Affairs Biomedical Laboratory Research & Development Service (Merit Review Award I01 BX002180) and Australian Research Council (F130101648). The authors thank Dr. Ruth J. Napier (VA Portland Health Care System & School of Medicine, Oregon Health & Science University, Portland, OR, USA) along with Dr. Tiffany Hughes and Anthony Smith (Immunology, Allergy & Arthritis, Flinders University School of Medicine) for their helpful discussions. We are also grateful to Rachel Penchoen-Lin at VA Portland Health Care System for her technical contributions.Peer reviewedPostprin

The effect of finite-range interactions in classical transport theory

The effect of scattering with non-zero impact parameters between consituents in relativistic heavy ion collisions is investigated. In solving the relativistic Boltzmann equation, the characteristic range of the collision kernel is varied from approximately one fm to zero while leaving the mean-free path unchanged. Modifying this range is shown to significantly affect spectra and flow observables. The finite range is shown to provide effective viscosities, shear, bulk viscosity and heat conductivity, with the viscous coefficients being proportional to the square of the interaction range

Is whole-colon investigation by colonoscopy, computerised tomography colonography or barium enema necessary for all patients with colorectal cancer symptoms, and for which patients would flexible sigmoidoscopy suffice? A retrospective cohort study.

BACKGROUND: For patients referred to hospital with suspected colorectal cancer (CRC), it is current standard clinical practice to conduct an examination of the whole colon and rectum. However, studies have shown that an examination of the distal colorectum using flexible sigmoidoscopy (FS) can be a safe and clinically effective investigation for some patients. These findings require validation in a multicentre study. OBJECTIVES: To investigate the links between patient symptoms at presentation and CRC risk by subsite, and to provide evidence of whether or not FS is an effective alternative to whole-colon investigation (WCI) in patients whose symptoms do not suggest proximal or obstructive disease. DESIGN: A multicentre retrospective study using data collected prospectively from two randomised controlled trials. Additional data were collected from trial diagnostic procedure reports and hospital records. CRC diagnoses within 3 years of referral were sourced from hospital records and national cancer registries via the Health and Social Care Information Centre. SETTING: Participants were recruited to the two randomised controlled trials from 21 NHS hospitals in England between 2004 and 2007. PARTICIPANTS: Men and women aged ≥ 55 years referred to secondary care for the investigation of symptoms suggestive of CRC. MAIN OUTCOME MEASURE: Diagnostic yield of CRC at distal (to the splenic flexure) and proximal subsites by symptoms/clinical signs at presentation. RESULTS: The data set for analysis comprised 7380 patients, of whom 59% were women (median age 69 years, interquartile range 62-76 years). Change in bowel habit (CIBH) was the most frequently presenting symptom (73%), followed by rectal bleeding (38%) and abdominal pain (29%); 26% of patients had anaemia. CRC was diagnosed in 551 patients (7.5%): 424 (77%) patients with distal CRC, 122 (22%) patients with cancer proximal to the descending colon and five patients with both proximal and distal CRC. Proximal cancer was diagnosed in 96 out of 2021 (4.8%) patients with anaemia and/or an abdominal mass. The yield of proximal cancer in patients without anaemia or an abdominal mass who presented with rectal bleeding with or without a CIBH or with a CIBH to looser and/or more frequent stools as a single symptom was low (0.5%). These low-risk groups for proximal cancer accounted for 41% (3032/7380) of the cohort; only three proximal cancers were diagnosed in 814 low-risk patients examined by FS (diagnostic yield 0.4%). LIMITATIONS: A limitation to this study is that changes to practice since the trial ended, such as new referral guidelines and improvements in endoscopy quality, potentially weaken the generalisability of our findings. CONCLUSIONS: Symptom profiles can be used to determine whether or not WCI is necessary. Most proximal cancers were diagnosed in patients who presented with anaemia and/or an abdominal mass. In patients without anaemia or an abdominal mass, proximal cancer diagnoses were rare in those with rectal bleeding with or without a CIBH or with a CIBH to looser and/or more frequent stools as a single symptom. FS alone should be a safe and clinically effective investigation in these patients. A cost-effectiveness analysis of symptom-based tailoring of diagnostic investigations for CRC is recommended. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95152621. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 66. See the NIHR Journals Library website for further project information