1,754 research outputs found

    NRL tethered balloon measurements at San Nicolas Island during FIRE IFO 1987

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    An overview is given of the tethered balloon measurements made during the First ISCCP Regional Experiment (FIRE) marine stratocumulus intensive field observations (IFO) at San Nicolas Island in 1987. The instrument utilized on the balloon flights, the 17 flights over a 10 day period, the state of the data analysis, and some preliminary results are described. A goal of the measurements with the Naval Research Laboratory (NRL) balloon was to give a unique and greatly improved look at the microphysics of the clear and cloud-topped boundary layer. For this goal, collocated measurements were made of turbulence, aerosol, cloud particles, and meteorology. Two new instruments which were expected to make significant contributions to this effort were the saturation hygrometer, capable of measuring 95 percent less than RH 105 percent (with an accuracy of 0.05 percent near 100 percent) and used for the first time in clouds; and the forward scatter meter which gives in situ LWC measurements at more than 10 Hz. The data set, while unfortunately only partially simultaneous with the bulk of the FIRE stratocumulus observations, is unique and worthwhile in its own right. For the first time accurate RH measurements near 100 percent have been made in-cloud; although, the use of the saturation hygrometer reflected a learning experience which will result is substantially better performance the next time. These measurements were made in conjunction with other microphysical measurements such as aerosol and cloud droplet spectra, and perhaps most important of all, they were all collocated with bivane turbulence measurements thus permitting flux calculations. Thus the analysis of this data set, which consisted of about 50 percent stratocumulus cases including increasing and decreasing partial cloud cover, should lead to new insights on the physical mechanisms which drive the boundary-layer/cloud/turbulence system

    ASSESSMENT OF KINEMATIC CMJ DATA USING A DEEP LEARNING ALGORITHM-BASED MARKERLESS MOTION CAPTURE SYSTEM

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    The purpose of this study was to compare the performance of a video-based markerless motion capture system to a conventional marker-based approach during a counter movement jump (CMJ). Twenty-three healthy participants performed CMJ while data was collected simultaneously via a marker-based (Oqus) and a 2D video-based motion capture system (Miqus, both: Qualisys). The video data was further processed to 3D-data using Theia3D (Theia Markerless Inc.). Excellent agreement between systems with ICCs \u3e0.99 exists for jump height (mean average error of -0.27 cm) and sagittal ankle and knee plane angles (RMSD \u3c 5°). The hip joint showed an average RMSD of 21° with a strong correlation of 0.80. As such the markerless system is capable of detecting jump height, sagittal ankle and knee joint angles and 3D joint positions of a CMJ to a high accurac

    Memory disorders in children

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    Memory disorders are a frequent consequence of a variety of childhood neurological conditions. We will review the characteristics of memory disorders as a function of the main four memory systems: short-term memory, episodic memory, semantic memory, and procedural memory. For each system, we will identify the most typical cerebral and/or genetic correlates, and we will discuss the impact of impairment of each memory system on everyday life functioning. © 2013 Elsevier B.V

    Scientific and Technical Advisory Committee Review of the Chesapeake Bay Program Partnership’s Climate Change Assessment Framework and Programmatic Integration and Response Efforts

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    [From the Executive Summary] The following report presents a synthesis of reviewer responses from the Scientific and Technical Advisory Committee’s (STAC) panel on the Chesapeake Bay Program Partnership’s Climate Change Assessment Framework (CCAF) and Programmatic Integration and Response Efforts. The enclosed findings and recommendations are in response to the 16 questions delivered to the panel (Appendix A). In summary, given the current state of knowledge, the combination of using climate model projections and downscaling provides an acceptable baseline for estimating changing climate conditions for the Chesapeake Bay, and the panel finds the CCAF approach to be fundamentally sound. However, the panel members have a number of concerns pertaining primarily to the current lack of complete formal documentation on the details of the approach. In the responses to the questions that follow in the body of the report, the panel has outlined several areas where more details or further investigations are suggested and has also provided some specific recommendations for CBP consideration in regard to future use and application of the CCAF

    Traditionally taught students learn; actively engaged students remember

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    A common narrative in physics education research is that students taught in lecture-based classes learn less than those taught with activity-based reformed methods. We show this narrative is simplistic and misses important dynamics of student learning. In particular, we find students of both methods show equal short-term learning gains on a conceptual question dealing with electric potential. For traditionally taught students, this learning rapidly decays on a time scale of weeks, vanishing by the time of the typical end-of-term post-test. For students in reform-based classes, however, the knowledge is retained and may even be enhanced by subsequent instruction. This difference explains the many previous pre- and post-test studies that have found minimal learning gains in lecture-based courses. Our findings suggest a more nuanced model of student learning, one that is sensitive to time-dependent effects such as forgetting and interference. In addition, the findings suggest that lecture-based courses, by incorporating aspects designed to reinforce student understanding of previously covered topics, might approach the long-term learning found in research-based pedagogies

    Mechanical and hydrologic basis for the rapid motion of a large tidewater glacier: 1. Observations

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    Measurements of glacier flow velocity and basal water pressure at two sites on Columbia Glacier, Alaska, are combined with meteorological and hydrologic data to provide an observational basis for assessing the role of water storage and basal water pressure in the rapid movement of this large glacier. During the period from July 5 to August 31, 1987, coordinated observations were made of glacier surface motion and of water level in five boreholes drilled to (or in one case near to) the glacier bed at two sites, 5 and 12 km from the terminus. Glacier velocities increased downglacier in this reach from about 4 m d^−1 to about 7 m d^−1. Three types of time variation in velocity and other variables were revealed: (1) Diurnal fluctuation in water input/output, borehole water level, and ice velocity (fluctuation amplitude 5 to 8%); (2) Speed-up events in glacier motion (15–30% speed up), lasting about 3 days, and occurring at times of enhanced input of water, in some cases from rain and in others from ice ablation enhanced by strong, warm winds; (3) “Extra-slowdown” events, in which, after a speed-up event, the ice velocity decreased in about 3 days to a level consistently lower than that prior to the speed-up event. All of the time variations in velocity were due, directly or indirectly, to variations in water input to the glacier. The role of basal water in causing the observed glacier motions is interpreted by Kamb et al. (this issue)

    Generalized Euler Angle Paramterization for SU(N)

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    In a previous paper (math-ph/0202002) an Euler angle parameterization for SU(4) was given. Here we present the derivation of a generalized Euler angle parameterization for SU(N). The formula for the calculation of the Haar measure for SU(N) as well as its relation to Marinov's volume formula for SU(N) will also be derived. As an example of this parameterization's usefulness, the density matrix parameterization and invariant volume element for a qubit/qutrit, three qubit and two three-state systems, also known as two qutrit systems, will also be given.Comment: 36 pages, no figures; added qubit/qutrit work, corrected minor definition problems and clarified Haar measure derivation. To be published in J. Phys. A: Math. and Ge

    Hidden spin-isospin exchange symmetry

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    The strong interactions among nucleons have an approximate spin-isospin exchange symmetry that arises from the properties of quantum chromodynamics in the limit of many colors, NcN_c. However this large-NcN_c symmetry is well hidden and reveals itself only when averaging over intrinsic spin orientations. Furthermore, the symmetry is obscured unless the momentum resolution scale is close to an optimal scale that we call ΛlargeNc\Lambda_{{\rm large-}N_c}. We show that the large-NcN_c derivation requires a momentum resolution scale of ΛlargeNc500\Lambda_{{\rm large-}N_c} \sim 500 MeV. We derive a set of spin-isospin exchange sum rules and discuss implications for the spectrum of 30^{30}P and applications to nuclear forces, nuclear structure calculations, and three-nucleon interactions.Comment: 5 pages (main) + 3 pages (supplemental materials), 1 figure (main) + 4 figures (supplemental materials), final version to appear in Phys. Rev. Let

    Field performance of transgenic sugarcane produced using Agrobacterium and biolistics methods.

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    Future genetic improvement of sugarcane depends, in part, on the ability to produce high-yielding transgenic cultivars with improved traits such as herbicide and insect resistance. Here, transgenic sugarcane plants generated by different transformation methods were assessed for field performance over 3 years. Agrobacterium-mediated (Agro) transgenic events (35) were produced using four different Agrobacterium tumefaciens strains, while biolistic (Biol) transgenic events (48) were produced using either minimal linearized DNA (LDNA) transgene cassettes with 5', 3' or blunt ends or whole circular plasmid (PDNA) vectors containing the same transgenes. A combined analysis showed a reduction in growth and cane yield in Biol, Agro as well as untransformed tissue culture (TC) events, compared with the parent clone (PC) Q117 (no transformation or tissue culture) in the plant, first ratoon and second ratoon crops. However, when individual events were analysed separately, yields of some transgenic events from both Agro and Biol were comparable to PC, suggesting that either transformation method can produce commercially suitable clones. Interestingly, a greater percentage of Biol transformants were similar to PC for growth and yield than Agro clones. Crop ratoonability and sugar yield components (Brix%, Pol%, and commercial cane sugar (CCS)) were unaffected by transformation or tissue culture. Transgene expression remained stable over different crop cycles and increased with plant maturity. Transgene copy number did not influence transgene expression, and both transformation methods produced low transgene copy number events. No consistent pattern of genetic changes was detected in the test population using three DNA fingerprinting techniques

    ISBS 2018 AUCKLAND CONFERENCE OPENING CEREMONY ORDER OF PROCEEDINGS

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    The Master of Ceremony Professor Patria Hume will ask delegates to stand at the commencement of the opening for the procession of the dignitaries to the auditorium. Dignitaries will be called into the auditorium via the Māori traditional karanga, and will proceed to their seats. The first formal address will be given by kaihāpai Dr Valance Smith and commence with a Karakia (Blessing) and Mihi Whakatau welcoming dignitaries, guests and delegates to the ISBS 2018 Conference. Derek McCormack, the AUT Vice-Chancellor, will address the assembled company and welcome them to AUT for the conference hosted in partnership by AUT, AUTM, HPSNZ, ATEED and ISBS. The conference logo was designed by Professor Patria Hume and Dr Valance Smith based on: the adaption of the AUT SPRINZ logo (taking steps to research-education-service excellence – sprinting up the NZ fern); and the goals of conference reflected in Māori culture “Te hōkai tapuwae” means “The breadth of stride”. Within the Māori Karakia (prayer) ‘Tenei au tenei au’ is the line ‘te hōkai nei i o taku tapuwae’ – The breadth of stride as Tane ascends to the heavens to retrieve the three baskets of knowledge. This embodies human movement and the pursuit of knowledge – the goals of ISBS. The AUT Faculty of Health and Environmental Sciences Dean and Pro-Vice Chancellor, in absentia, welcomes the assembled company and encourages them to experience the research-education-service focus at AUT. Mike Stanley, the AUT Millennium (AUT Millennium) Chief Executive & New Zealand Olympic Committee (NZOC) President, will address the assembled company and welcome them to AUTM for the conference applied programme. Michael Scott, the High Performance Sport New Zealand (HPSNZ) Chief Executive, will address the assembled company and outline the importance of biomechanics and integrated sport science in supporting high performance athletes. Pam Ford, General Manager Economic Development, Auckland Tourism, Events Economic Development (ATEED), will address the assembled company and outline the importance of the conference to Auckland and New Zealand. Thanks will be given to the industry partners for their active contribution to the conference. The Conference Flag Ceremony and Official Opening of the Conference by the ISBS President. The delegates selected to participate as flag bearers during the opening ceremony as they were the first from their country to register for the conference, will proceed to the stage. (We apologise to delegates from countries who do not have a flag represented in the flag bearing ceremony due to logistics). The conference will be officially opened by President Young-Hoo with the unfurling of the ISBS banner. The ISBS President Professor Young-Hoo Kwon will address the assembled company on behalf of the International Society of Biomechanics in Sports and its Board of Directors, to welcome delegates to the 36th ISBS Annual Conference and to the city of Auckland. The details of this ISBS 2018 Conference inaugural Presidents Award are confidential until it is awarded. The recipient does not know they are receiving this award. The citation will be read by Dr Laura-Anne Furlong, ISBS Board member. The ISBS President Professor Young-Hoo Kwon and AUT Vice Chancellor Derek McCormack will present the ISBS 2018 conference travel grants to the recipients. NZ$20,000 is being awarded. The Kaikōrero Dr Valance Smith will perform the traditional Māori blessing of the gifts for dignitaries. Master wood carver Jarrod Hume was commissioned to create hand carved pohutukawa, puriri, and kauri (native NZ trees) items for dignitaries. Jarrod reclaimed the wood from fallen trees at Kawau Island in Auckland’s Hauraki Gulf. He dried the wood for two years, hand carved each item, and added Pasifika art work of his own creation using pyrography. The AUT kapahaka group, Tītahi ki Tua, will again perform for the assembled company. ISBS Geoffrey Dyson Awardee Professor Hermann Schwameder will be introduced by ISBS President Professor Young-Hoo Kwon. The prestigious Geoffrey Dyson Lecture is an invited presentation given by scientists who have made an outstanding contribution to ISBS and the field of sports biomechanics. As the Industry Partners Representative, Imogen Moorhouse (VICON’S CEO) from the ISBS 2018 Auckland Conference Platinum Industry Partner VICON, will address the assembled company and invite them to the opening Industry Playground Event immediately following the procession of the delegates from the theatre into the Sir Paul Reeves Atrium. The delegates will be requested to rise and remain standing for the procession of the dignitaries from the auditorium. All delegates will then proceed to the Kiwiana Opening Reception in the Sir Paul Reeves Atrium, where they will be greeted by Kelly Sheerin, and Alex Muir from VICON, on behalf of the industry partner medallists participating in the Playing Field Events
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