488 research outputs found

    Group Support Systems (GSS)

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    Groupware is a term describing an emerging computer software technology enhancing the ability of people to work together as a group, (a software driven 'group support system'). This project originated at the beginning of 1992 and reports were issued describing the activity through May 1995. These reports stressed the need for process as well as technology. That is, while the technology represented a computer assisted method for groups to work together, the Group Support System (GSS) technology als required an understanding of the facilitation process electronic meetings demand. Even people trained in traditional facilitation techniques did not necessarily aimlessly adopt groupware techniques. The latest phase of this activity attempted to (1) improve the facilitation process by developing training support for a portable groupware computer system, and (2) to explore settings and uses for the portable groupware system using different software, such as Lotus Notes

    Heat transfer measurement of turbulent spots in a hypersonic blunt-body boundary layer

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    This paper presents data on turbulent-spot propagation in the hypersonic boundary-layer flow over a blunted cylindrical body. Data are based on the measurement of time-dependent surface heat transfer rates using gauges positioned as arrays in either th

    Correlated Quantum Transport of Density Wave Electrons

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    Recently observed Aharonov-Bohm quantum interference of period h/2e in charge density wave rings strongly suggest that correlated density wave electron transport is a cooperative quantum phenomenon. The picture discussed here posits that quantum solitons nucleate and transport current above a Coulomb blockade threshold field. We propose a field-dependent tunneling matrix element and use the Schrodinger equation, viewed as an emergent classical equation as in Feynman's treatment of Josephson tunneling, to compute the evolving macrostate amplitudes, finding excellent quantitative agreement with voltage oscillations and current-voltage characteristics in NbSe3. A proposed phase diagram shows the conditions favoring soliton nucleation versus classical depinning. (Published in Phys. Rev. Lett. 108, 036404 (2012).)Comment: 9 pages, 4 figures, (5 pages & 3 figures for main article), includes Supplemental Material with 1 figure. Published version: Physical Review Letters, vol. 108, p. 036404 (2012

    Non-invasive detection of animal nerve impulses with an atomic magnetometer operating near quantum limited sensitivity

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    Magnetic fields generated by human and animal organs, such as the heart, brain and nervous system carry information useful for biological and medical purposes. These magnetic fields are most commonly detected using cryogenically-cooled superconducting magnetometers. Here we present the frst detection of action potentials from an animal nerve using an optical atomic magnetometer. Using an optimal design we are able to achieve the sensitivity dominated by the quantum shot noise of light and quantum projection noise of atomic spins. Such sensitivity allows us to measure the nerve impulse with a miniature room-temperature sensor which is a critical advantage for biomedical applications. Positioning the sensor at a distance of a few millimeters from the nerve, corresponding to the distance between the skin and nerves in biological studies, we detect the magnetic field generated by an action potential of a frog sciatic nerve. From the magnetic field measurements we determine the activity of the nerve and the temporal shape of the nerve impulse. This work opens new ways towards implementing optical magnetometers as practical devices for medical diagnostics.Comment: Main text with figures, and methods and supplementary informatio

    Does artificial intelligence have a role in the IVF clinic?

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    Funding: K R D is supported by a Mid-Career Fellowship from the Hospital Research Foundation (C-MCF-58-2019). K D is supported by the UK Engineering and Physical Sciences Research Council (grants EP/P030017/1 and EP/R004854/1).Lay summary The success of IVF has remained stagnant for a decade. The focus of a great deal of research is to improve on the current ~30% success rate of IVF. Artificial intelligence (AI), or machines that mimic human intelligence, has been gaining traction for its potential to improve outcomes in medicine, such as cancer diagnosis from medical images. In this commentary, we discuss whether AI has the potential to improve fertility outcomes in the IVF clinic. Based on existing research, we examine the potential of adopting AI within multiple facets of an IVF cycle, including egg/sperm and embryo selection, as well as formulation of an IVF treatment regimen. We discuss both the potential benefits and concerns of the patient and clinician in adopting AI in the clinic. We outline hurdles that need to be overcome prior to implementation. We conclude that AI has an important future in improving IVF success.Publisher PDFPeer reviewe

    Noise normalizes firing output of mouse lateral geniculate nucleus neurons.

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    The output of individual neurons is dependent on both synaptic and intrinsic membrane properties. While it is clear that the response of an individual neuron can be facilitated or inhibited based on the summation of its constituent synaptic inputs, it is not clear whether subthreshold activity, (e.g. synaptic "noise"--fluctuations that do not change the mean membrane potential) also serve a function in the control of neuronal output. Here we studied this by making whole-cell patch-clamp recordings from 29 mouse thalamocortical relay (TC) neurons. For each neuron we measured neuronal gain in response to either injection of current noise, or activation of the metabotropic glutamate receptor-mediated cortical feedback network (synaptic noise). As expected, injection of current noise via the recording pipette induces shifts in neuronal gain that are dependent on the amplitude of current noise, such that larger shifts in gain are observed in response to larger amplitude noise injections. Importantly we show that shifts in neuronal gain are also dependent on the intrinsic sensitivity of the neuron tested, such that the gain of intrinsically sensitive neurons is attenuated divisively in response to current noise, while the gain of insensitive neurons is facilitated multiplicatively by injection of current noise- effectively normalizing the output of the dLGN as a whole. In contrast, when the cortical feedback network was activated, only multiplicative gain changes were observed. These network activation-dependent changes were associated with reductions in the slow afterhyperpolarization (sAHP), and were mediated at least in part, by T-type calcium channels. Together, this suggests that TC neurons have the machinery necessary to compute multiple output solutions to a given set of stimuli depending on the current level of network stimulation

    Experimentally unsupervised deconvolution for light-sheet microscopy with propagation-invariant beams

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    This project was funded by the UK Engineering and Physical Sciences Research Council (grants EP/P030017/1 and EP/R004854/1), and has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement (EC-GA 871212) and H2020 FETOPEN project "Dynamic” (EC-GA 863203). P.W. was supported by the 1851 Research Fellowship from the Royal Commission. KRD was supported by a Mid-Career Fellowship from the Hospital Research Foundation (C-MCF-58-2019). K.D. acknowledges support from the Australian Research Council through a Laureate Fellowship. S.S. was funded by BBSRC (BB/M00905X/1).Deconvolution is a challenging inverse problem, particularly in techniques that employ complex engineered point-spread functions, such as microscopy with propagation-invariant beams. Here, we present a deep-learning method for deconvolution that, in lieu of end-to-end training with ground truths, is trained using known physics of the imaging system. Specifically, we train a generative adversarial network with images generated with the known point-spread function of the system, and combine this with unpaired experimental data that preserve perceptual content. Our method rapidly and robustly deconvolves and super-resolves microscopy images, demonstrating a two-fold improvement in image contrast to conventional deconvolution methods. In contrast to common end-to-end networks that often require 1000–10,000s paired images, our method is experimentally unsupervised and can be trained solely on a few hundred regions of interest. We demonstrate its performance on light-sheet microscopy with propagation-invariant Airy beams in oocytes, preimplantation embryos and excised brain tissue, as well as illustrate its utility for Bessel-beam LSM. This method aims to democratise learned methods for deconvolution, as it does not require data acquisition outwith the conventional imaging protocol.Publisher PDFPeer reviewe

    A BASIC STUDY CARRIED OUT TO OBSERVE THE LAND USE AND THE VEGETATION TYPE OF FOREST RESERVE AT RITIGALA

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    The Ritigala Strict Nature Reserve has an ideal setting for ethno botanicstudies on account of its unique features. It is a living folder of informationregarding bio diversity and is regarded as an 'oasis of vegetation'. Thereforeprotection and conservation of its flora and fauna is of vital importance.As this area extends over 1528 hectares, observation of encroachments is adifficult task. Forest clearance can be clearly observed by using aerialphotographs of consecutive years. The aerial photographs may providesufficient data to observe the land uses and vegetation types of the StrictNature Reserve.Aerial photographs of 1982 and 1992 were used as a tool to observe theusable pattern of the forest. The texture of the aerial photographs was studiedand qualitatively it could be divided into three categories. Textural variationswere significant. Restrictions of some textures could be observed to somespecific areas, which can be explained as an effect of the Northeast monsoonrains.The aerial photographs show improvement of the natural habitat of the forestarea within a period of ten years from 1982 to 1992. No constructions wereseen within the limits of the Strict Nature Reserve until 1992.The study of aerial photographs indicated different patterns in the canopycover. For instance, temporal changes observed in white canopies appearedsignificant. It is surmised that these white crowns are those of Mangiferazeylanica (Bl.) Hook.f (Etamba) in bloom
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