1,993 research outputs found

    Gene regulation: A chromatin thermostat.

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    As environmental temperatures rise, plants seek help from their core molecular mechanisms to adapt. One molecule that comes to the rescue, regulating gene expression, is the chromatin protein H2A.Z

    Capturing the dynamic epigenome

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    Traditional methods for epigenomic analysis provide a static picture of chromatin, which is actually a highly dynamic assemblage. Recent approaches have allowed direct measurements of chromatin dynamics, providing deeper insights into processes such as transcription, DNA replication and epigenetic inheritance

    Using MaxMSP to Integrate Learning of Physics and Music

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    poster abstractThis project integrates musical activity with the learning of concepts in areas such as physics and computer science. While the expression of musical ideas utilizes the laws of physics on many levels, the study of the two fields often is disparate. Traditional music education does little to promote understanding of the scientific concepts behind disciplines such as acoustics. Similarly, the field of acoustics only tangentially addresses issues relatable to a student educated in the traditional U.S. music system. The goal of this research is to develop a computer software application that will more closely integrate learning and understanding of both music and the physics of sound, which is the scientific field of acoustics. This work will take place utilizing the MaxMSP programming environment, which enables the construction of small applications known as Max Patches. These patches can be tailored in an infinite number of ways for teaching, study, and musical expression. The Max patch to be developed will include a virtual keyboard, an oscillator, and a series of computer objects that will visually output mathematical information based on the waveform that is created by the notes on the keyboard. Hence the virtual keyboard will provide understanding into basic acoustics through the exposition of the fundamental musical waveforms and the underlying principles of their nature. Playing the notes on the keyboard serves two purposes. First, it will help participants grasp basic musical concepts such as note memorization and relative pitch. Simultaneously, it will expose subjects to a visual approach to understanding the physics of the notes being played. The goal is to more closely integrate scientific understanding of sound while teaching the user to engage those concepts in a musical fashion

    Thunderstorm hazards flight research: Storm hazards 1980 overview

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    A highly instrumented NASA F-106B aircraft, modified for the storm hazards mission and protected against direct lightning strikes, was used in conjunction with various ground based radar and lightning measurement systems to collect data during thunderstorm penetration flights. During 69 thunderstorm penetrations, there were 10 direct lightning strikes to the aircraft. No problems were encountered with any of the aircraft's systems as a result of the strikes and the research instrumentation performed as designed. Electromagnetic characteristics of nine strikes were recorded, and the results of other experiments confirm the theory that X-ray radiation and nitrous oxide gas are being produced by processes associated directly with thunderstorm electric fields and lightning discharges. A better understanding of aircraft lightning attachment mechanisms and strike zones is being accomplished by careful inspection, identification, and documentation of lightning attachment points and swept stroke paths following each strike to the aircraft

    Reciprocity relationships in vector acoustics and their application to vector field calculations

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    The article of record as published may be found at 10.1121/1.4996458The reciprocity equation commonly stated in underwater acoustics relates pressure fields and monopole sources. It is often used to predict the pressure measured by a hydrophone for multiple source locations by placing a source at the hydrophone location and calculating the field everywhere for that source. A similar equation that governs the orthogonal components of the particle velocity field is needed to enable this computational method to be used for acoustic vector sensors. This paper derives a general reciprocity equation that accounts for both monopole and dipole sources. This vector-scalar reciprocity equation can be used to calculate individual components of the received vector field by altering the source type used in the propagation calculation. This enables a propagation model to calculate the received vector field components for an arbitrary number of source locations with a single model run for each vector field component instead of requiring one model run for each source location. Application of the vector-scalar reciprocity principle is demonstrated with analytic solutions for a range-independent environment and with numerical solutions for a range-dependent environment using a parabolic equation model

    Artsmesh- An Incremental Development in Telematic Art

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    poster abstractWithin the past two decades, telematic art has pushed technological boundaries and created opportunities for artists to collaborate in ways that were not once possible. For example, Auksalaq, a telematic opera created by Scott Deal, DMA, in 2011, incorporates both JackTrip Audio and ConferenceXP Video. Some social media platforms such as Skype and Google Hangouts have also integrated audio and video within their interfaces in order to explore these possibilities; however, there are limitations that some practices have failed to address such as compressed (lossy) formats of audio and/or video. Similarly, other barriers such as high latency and minimal navigation control have often made network music performance (NMP) a limited experience and not an equal alternative to traditional, real-time performance. The purpose of this project is to help test a beta prototype of Artsmesh, a protocol that integrates high quality audio and video for live peer-to-peer (P2P) NMP. Artsmesh contains fourteen panels that are customizable to fit a wide range of network setups. It also incorporates Internet Protocol version 6 (IPv6), Open Sound Control (OSC), Jacktrip, ffmpeg, Youtube, along with other features, making it the ideal choice for artists that have focused/professional needs. The ability for Artsmesh to precisely route high quality audio also makes it a preferable option for recording and mixing engineers who participate in telematic collaborations. Artsmesh is a step forward for creating an environment that integrates necessary features for an optimal NMP platform

    Barrier Lowering and Field Penetration at Metal-Dielectric Interfaces

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    We report here photoemission measurements on Si-SiO_2-Al structures in which the metal-SiO_2 barrier energy has been determined as a function of the electric field strength E in the dielectric. The expected barrier lowering is the sum of two terms: a) the Schottky term, proportional to E^(1/2) and b) a term due to the penetration of the electric field into the metal electrode, proportional to E. The experimental results are in good agreement with the model, where the Schottky effect involves the optical value of the dielectric constant of the oxide and the Thomas-Fermi screening distance in the metal is 1 Ã…. To our knowledge this represents the first unambiguous quantitative determination of either effect in a polar dielectric, although the Schottky effect alone has been observed in silicon

    Storm hazards '79: F-106B operations summary

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    Preliminary flight tests with a F-106B aircraft were made on the periphery of isolated thunder cells using weather radar support. In addition to storm hazards correlation research, a direct-strike lightning measurement experiment and an atmospheric chemistry experiment were conducted. Two flights were made to close proximity to lightning generating cumulonimbus clouds; however, no direct lightning strikes were experienced. Although no discernible lightning transients were recorded, many operational techniques were identified and established

    Development of a multimedia tutorial to educate how to assess the critical view of safety in laparoscopic cholecystectomy using expert review and crowd-sourcing

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    We sought to determine the feasibility of developing a multimedia educational tutorial to teach learners to assess the critical view of safety using input from expert surgeons, non-surgeons and crowd-sourcing. We intended to develop a tutorial that would teach learners how to identify the basic anatomy and physiology of the gallbladder, identify the components of the critical view of safety criteria, and understand its significance for performing a safe gallbladder removal. Using rounds of assessment with experts, laypersons and crowd-workers we developed an educational video with improving comprehension after each round of revision. We demonstrate that the development of a multimedia educational tool to educate learners of various backgrounds is feasible using an iterative review process that incorporates the input of experts and crowd sourcing. When planning the development of an educational tutorial, a step-wise approach as described herein should be considered
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