Helicopter Wake Encounters in the Context of RECAT-EU

This work presents a first attempt to apply the RECAT-EU (European Wake Turbulence Categorisation and Separation Minima) methodology of fixed-wing aircraft separation to helicopters. The approach is based on a classification of helicopters in categories using their rotor diameter and weight combined with wake comparisons between different classes of fixed-wing aircraft and helicopters. Where necessary the upset caused by a wake encounter to a simple helicopter model is used to establish safe separation distances. The work is based on a very limited amount of data for wake strengths but shows that the principles of the RECAT-EU methodology are directly applicable to helicopters at least for landing and take-off. This research calls for further measurements of helicopter wakes with modern methods so that the suggested separation distances can be further ascertained and ultimately refined allowing for better and safer integration of fixed and rotary-wing traffic at airports

Nigrosine staining of wheat endosperm proteolipid patterns on starch gels

We have previously characterized a group of proteolipids from wheat endosperm, designated CM proteins, which are soluble in chloroformmethanol (2:1, v/v) and have a molecular weight lower than 25,000 daltons (1-3). These have been also studied by Redman and Ewart (4). The CM proteins are suitably fractionated into several components by starch gel electrophoresis at pH 3.2 (1). A sensitive staining procedure was required in connection with genetic studies of these proteins because phenotypes had to be ascertained in small endosperm fractions dissected without impairing normal germination and plant development. We report here on Nigrosine staining conditions for CM proteins under which high sensitivity and selectivity are achieve

Exploring the Early Universe with Gaia and THEIA

It has recently been pointed out that Gaia is capable of detecting a stochastic gravitational wave background in the sensitivity band between the frequency of pulsar timing arrays and LISA. We argue that Gaia and THEIA has great potential for early universe cosmology, since such a frequency range is ideal for probing phase transitions in asymmetric dark matter, SIMP and the cosmological QCD transition. Furthermore, there is the potential for detecting primordial black holes in the solar mass range produced during such an early universe transition and distinguish them from those expected from the QCD epoch. Finally, we discuss the potential for Gaia and THEIA to probe topological defects and the ability of Gaia to potentially shed light on the recent NANOGrav results.Comment: 26 pages, 6 figure

BCG Cell Imaging Using Scanning Probe Microscopy

Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) were used to obtain images of the surface of whole, intact BCG (bacille Calmette Guerin, a mycobacterium) cells in air and under solution by immobilizing the cells onto glass slides (AFM only) or highly oriented pyrolytic graphite. The technique used for AFM imaging involved depositing a submonolayer of cells under a centrifugal force followed by fixation/dehydration using polar organic solvents. AFM images agree well with images from light and electron microscopy and showed large numbers of BCG cells in their distinctive cord arrangement. The AFM also proved useful for identifying extracellular microgranules which cannot be seen with light microscopy. For STM imaging, the hydrophobicity of BCG enabled strong adhesion from aqueous solution onto graphite. STM images of BCG could only be obtained while scanning in aqueous solution, and the cells showed a large variation in contrast when different samples were imaged. The STM provided greater detail of surface features than the AFM and was able to produce images of periodic layers corroborating observations made by transmission electron microscopy

A Graph Aided Strategy to Produce Good Recursive Towers over Finite Fields

International audienceWe propose a systematic method to produce potentially good recursive towers over finite fields. The graph point of view, so as some magma and sage computations are used in this process.We also establish some theoretical functional criterion ensuring the existence of many rational points on a recursive tower. Both points are illustrated by an example, from the production process, to the theoretical study

Interactive teaching environment for diagnostic radiography with real-time X-ray simulation and patient positioning

PURPOSE: Traditional undergraduate radiographer training mixes academic lectures and clinical practice. Our goal is to bridge the current disconnection between theory and practice in a safe environment, avoiding the risk of radiation for both practitioners and patients. To this end, this research proposes a new software to teach diagnostic radiography using real-time interactive X-ray simulation and patient positioning. METHODS: The proposed medical simulator is composed of three main modules. A fast and accurate character animation technique is in charge of simulating the patient positioning phase and adapts their internal anatomy accordingly. gVirtualXRay is an open-source X-ray simulation library and generates the corresponding radiographs in real time. Finally, the courseware allows going through all the diagnostic radiology steps from the patient positioning and the machine configuration to the final image enhancing. RESULTS: A face and content validation study has been conducted; 18 radiology professionals were recruited to evaluate our software using a questionnaire. The results show that our tool is realistic in many ways (72% of the participants agreed that the simulations are visually realistic), useful (67%) and suitable (78%) for teaching X-ray radiography. CONCLUSIONS: The proposed tool allows simulating the most relevant steps of the projectional radiography procedure. The virtual patient posing system and X-ray simulation module execute at interactive rates. These features enable the lectures to show their students the results of good and bad practices in a classroom environment, avoiding radiation risk

Understanding cultural barriers and opportunities for developing new apprenticeship programmes

There is increasing interest in many countries in training models that are practice-oriented and correspond to the needs of the labour market. The new Spanish dual system of apprenticeship (FP Dual) for teaching and learning was first implemented in the Valencia Community in 2012. Although FP Dual enjoys considerable support from institutions and from politicians who believe it has the potential to reduce youth unemployment, the dual system is still in a pilot stage. This report is based on research based in Valencia, to explore the cultural and organisational norms and the barriers and opportunities these afford to introducing apprenticeship. The research included interviews with different stakeholders. The findings reported here are seen as the precursor to a longer-term study. Existe hoy en muchos países un interés creciente por modelos de formación que estén orientados por la práctica y respondan a las necesidades del mercado de trabajo. El nuevo sistema de Aprendizaje Dual (FP Dual) para enseñar y aprender, se implantó en la Comunidad Valenciana en 2012. Si bien la FP Dual goza de considerable apoyo por parte de instituciones y de políticos que creen en su potencial para reducir el desempleo juvenil, el hecho es que se encuentra todavía en una fase piloto. Este informe se basa en la investigación llevada a cabo en Valencia (2016/2017) con objeto de explorar las normas culturales y organizacionales y las barreras y las oportunidades que pueden afectar y/o contribuir a su introducción. La investigación, fase inicial de proyecto más amplio, incluye entrevistas con las diferentes partes interesadas. Existeix avui en molts països un interès creixent per models de formació que estiguin orientats cap a la pràctica i responguin a les necessitats del mercat de treball. El nou sistema d'Aprenentatge Dual (FP Dual) per a ensenyar i aprendre, es va implantar a la Comunitat Valenciana en 2012. Si bé la FPdual gaudeix de considerable suport  per institucions i per polítics que creuen en el seu potencial per reduir la desocupació juvenil, el fet es que es troba encara en una fase pilot. El present informe es basa i dóna compter de la investigació realitzada a València (2016-2017) al objecte d?explorar les normes culturals i organitzacionals  així com les barreres i les oportunitats que puguen afectar i/o contribuir a la seva introducció, La investigació, fase inicial de projecte més ampli,  inclou entrevistes amb les diferents parts interessades