50,504 research outputs found

    Design and performance of an adaptive MFSK HF terminal.

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    The paper describes the implementation of a real-time integrated modem/codec system for long-range radio communications, e.g. HF. The system has been developed by the Hull-Lancaster Communication Research Group. The system has been implemented using a proprietary DSP-based architecture which uses the AT&T DSP32C digital signal processor and the transmission format comprises MFSK modulation combined with RS coding. The main features of the system are described and results from on-air HF trials over both static and aeromobile channels are presente

    Promoting resilience in occupational therapy rducation, a scoping literature review

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    Psychological and emotional resilience are important Occupational Therapy (OT) graduate skills. Occupational Therapists often embark on varied careers in highly demanding and challenging work environments. Theoretically, teaching and learning resilience during training affords protective advantages including safeguarding effects, which promote wellness and a sense of “I can do this, I will survive”. However, OT educators face significant challenges knowing how best to promote resilience through self-directed learning (SDL) approaches. In the UK, there is a strong focal shift towards producing resilient, autonomous life-long learners.  This review was undertaken to inform current education practices in the field

    The effect of clinical decision making for initiation of systemic anticancer treatments in response to the COVID-19 pandemic in England: a retrospective analysis

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    BACKGROUND: Cancer services worldwide had to adapt in response to the COVID-19 pandemic to minimise risk to patients and staff. We aimed to assess the national impact of COVID-19 on the prescribing of systemic anticancer treatment in England, immediately after lockdown and after the introduction of new treatments to reduce patient risk. METHODS: We did a retrospective analysis using data from a central National Health Service England web database mandated for clinicians to register intention to start all new systemic anticancer treatments approved for use in England since 2016. We analysed the monthly number of treatment registrations in April, 2020, after the implementation of societal lockdown on March 23, 2020, and after implementation of treatment options to reduce patient risk such as oral or less immunosuppressive drugs, in May and June, 2020. We compared the number of registrations in April-June, 2020, with the mean number of registrations and SD during the previous 6 months of unaffected cancer care (September, 2019, to February, 2020). We calculated the percentage change and absolute difference in SD units for the number of registrations overall, by tumour type, and by type and line of therapy. FINDINGS: In April, 2020, 2969 registrations were recorded, representing 1417 fewer registrations than in the control period (monthly mean 4386; 32% reduction, absolute difference 4·2 SDs, p<0·0001). In May, 2020, total registrations increased to 3950, representing a 10% reduction compared with the control period (absolute difference 1·3 SDs, p<0·0001). In June, 2020, 5022 registrations were recorded, representing a 15% increase compared with the control period (absolute difference 1·9 SDs; p<0·0001]). INTERPRETATION: After the onset of the COVID-19 pandemic, there was a reduction in systemic anticancer treatment initiation in England. However, following introduction of treatment options to reduce patient risk, registrations began to increase in May, 2020, and reached higher numbers than the pre-pandemic mean in June, 2020, when other clinical and societal risk mitigation factors (such as telephone consultations, facemasks and physical distancing) are likely to have contributed. However, outcomes of providing less treatment or delaying treatment initiation, particularly for advanced cancers and neoadjuvant therapies, require continued assessment. FUNDING: None

    Probing the Super Star Cluster Environment of NGC 1569 Using FISICA

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    We present near-IR JH spectra of the central regions of the dwarf starburst galaxy NGC 1569 using the Florida Image Slicer for Infrared Cosmology and Astrophysics (FISICA). The dust-penetrating properties and available spectral features of the near-IR, combined with the integral field unit (IFU) capability to take spectra of a field, make FISICA an ideal tool for this work. We use the prominent [He I] (1.083\mu m) and Pa\beta (1.282 \mu m) lines to probe the dense star forming regions as well as characterize the general star forming environment around the super star clusters (SSCs) in NGC 1569. We find [He I] coincident with CO clouds to the north and west of the SSCs, which provides the first, conclusive evidence for embedded star clusters here.Comment: 6 pages, 3 figures, accepted for publication in the MNRA

    Beta lives - some statistical perspectives on the capital asset pricing model

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    This note summarizes some technical issues relevant to the use of the idea of excess return in empirical modelling. We cover the case where the aim is to construct a measure of expected return on an asset and a model of the CAPM type is used. We review some of the problems and show examples where the basic CAPM may be used to develop other results which relate the expected returns on assets both to the expected return on the market and other factors

    Effect of Cluster Formation on Isospin Asymmetry in the Liquid-Gas Phase Transition Region

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    Nuclear matter within the liquid-gas phase transition region is investigated in a mean-field two-component Fermi-gas model. Following largely analytic considerations, it is shown that: (1) Due to density dependence of asymmetry energy, some of the neutron excess from the high-density phase could be expelled into the low-density region. (2) Formation of clusters in the gas phase tends to counteract this trend, making the gas phase more liquid-like and reducing the asymmetry in the gas phase. Flow of asymmetry between the spectator and midrapidity region in reactions is discussed and a possible inversion of the flow direction is indicated.Comment: 9 pages,3 figures, RevTe

    Magnetospheric considerations for solar system ice state

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    The current lattice configuration of the water ice on the surfaces of the inner satellites of Jupiter and Saturn is likely shaped by many factors. But laboratory experiments have found that energetic proton irradiation can cause a transition in the structure of pure water ice from crystalline to amorphous. It is not known to what extent this process is competitive with other processes in solar system contexts. For example, surface regions that are rich in water ice may be too warm for this effect to be important, even if the energetic proton bombardment rate is very high. In this paper, we make predictions, based on particle flux levels and other considerations, about where in the magnetospheres of Jupiter and Saturn the ∼MeV proton irradiation mechanism should be most relevant. Our results support the conclusions of Hansen and McCord (2004), who related relative level of radiation on the three outer Galilean satellites to the amorphous ice content within the top 1 mm of surface. We argue here that if magnetospheric effects are considered more carefully, the correlation is even more compelling. Crystalline ice is by far the dominant ice state detected on the inner Saturnian satellites and, as we show here, the flux of bombarding energetic protons onto these bodies is much smaller than at the inner Jovian satellites. Therefore, the ice on the Saturnian satellites also corroborates the correlation

    Switching dynamics of surface stabilized ferroelectric liquid crystal cells: effects of anchoring energy asymmetry

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    We study both theoretically and experimentally switching dynamics in surface stabilized ferroelectric liquid crystal cells with asymmetric boundary conditions. In these cells the bounding surfaces are treated differently to produce asymmetry in their anchoring properties. Our electro-optic measurements of the switching voltage thresholds that are determined by the peaks of the reversal polarization current reveal the frequency dependent shift of the hysteresis loop. We examine the predictions of the uniform dynamical model with the anchoring energy taken into account. It is found that the asymmetry effects are dominated by the polar contribution to the anchoring energy. Frequency dependence of the voltage thresholds is studied by analyzing the properties of time-periodic solutions to the dynamical equation (cycles). For this purpose, we apply the method that uses the parameterized half-period mappings for the approximate model and relate the cycles to the fixed points of the composition of two half-period mappings. The cycles are found to be unstable and can only be formed when the driving frequency is lower than its critical value. The polar anchoring parameter is estimated by making a comparison between the results of modelling and the experimental data for the shift vs frequency curve. For a double-well potential considered as a deformation of the Rapini-Papoular potential, the branch of stable cycles emerges in the low frequency region separated by the gap from the high frequency interval for unstable cycles.Comment: 35 pages, 15 figure
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