264 research outputs found

    The SEE-IT Trial: emergency medical services Streaming Enabled Evaluation In Trauma: a feasibility randomised controlled trial

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    © The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/BACKGROUND: Use of bystander video livestreaming from scene to Emergency Medical Services (EMS) is becoming increasingly common to aid decision making about the resources required. Possible benefits include earlier, more appropriate dispatch and clinical and financial gains, but evidence is sparse. METHODS: A feasibility randomised controlled trial with an embedded process evaluation and exploratory economic evaluation where working shifts during six trial weeks were randomised 1:1 to use video livestreaming during eligible trauma incidents (using GoodSAM Instant-On-Scene) or standard care only. Pre-defined progression criteria were: (1) ≄ 70% callers (bystanders) with smartphones agreeing and able to activate live stream; (2) ≄ 50% requests to activate resulting in footage being viewed; (3) Helicopter Emergency Medical Services (HEMS) stand-down rate reducing by ≄ 10% as a result of live footage; (4) no evidence of psychological harm in callers or staff/dispatchers. Observational sub-studies included (i) an inner-city EMS who routinely use video livestreaming to explore acceptability in a diverse population; and (ii) staff wellbeing in an EMS not using video livestreaming for comparison to the trial site. RESULTS: Sixty-two shifts were randomised, including 240 incidents (132 control; 108 intervention). Livestreaming was successful in 53 incidents in the intervention arm. Patient recruitment (to determine appropriateness of dispatch), and caller recruitment (to measure potential harm) were low (58/269, 22% of patients; 4/244, 2% of callers). Two progression criteria were met: (1) 86% of callers with smartphones agreed and were able to activate livestreaming; (2) 85% of requests to activate livestreaming resulted in footage being obtained; and two were indeterminate due to insufficient data: (3) 2/6 (33%) HEMS stand down due to livestreaming; (4) no evidence of psychological harm from survey, observations or interviews, but insufficient survey data from callers or comparison EMS site to be confident. Language barriers and older age were reported in interviews as potential challenges to video livestreaming by dispatchers in the inner-city EMS. CONCLUSIONS: Progression to a definitive RCT is supported by these findings. Bystander video livestreaming from scene is feasible to implement, acceptable to both 999 callers and dispatchers, and may aid dispatch decision-making. Further assessment of unintended consequences, benefits and harm is required. TRIAL REGISTRATION: ISRCTN 11449333 (22 March 2022). https://www.isrctn.com/ISRCTN11449333.Peer reviewe

    Further evidence of the link between activity and metallicity using the flaring properties of stars in the Kepler field

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    The magnetic activity level of low-mass stars is known to vary as a function of the physical properties of the star. Many studies have shown that the stellar mass and rotation are both important parameters that determine magnetic activity levels. In contrast, the impact of a star's chemical composition on magnetic activity has received comparatively little attention. Data sets for traditional activity proxies, e.g. X-ray emission or calcium emission, are not large enough to search for metallicity trends in a statistically meaningful way. Recently, studies have used the photometric variability amplitude as a proxy for magnetic activity to investigate the role of metallicity because it can be relatively easily measured for large samples of stars. These studies find that magnetic activity and metallicity are positively correlated. In this work, we investigate the link between activity and metallicity further by studying the flaring properties of stars in the Kepler field. Similar to the photometric variability, we find that flaring activity is stronger in more metal-rich stars for a fixed mass and rotation period. This result adds to a growing body of evidence that magnetic field generation is correlated with metallicity.Comment: 6 pages, 5 figures, accepted for publication in MNRA

    Comparative Study between the Overall Production Time of Digitally Versus Conventionally Produced Indirect Orthodontic Bonding Trays

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    Objective:The purpose of this study was to compare the production time for indirect digitally and laboratory-produced orthodontic bonding trays.Methods:Orthodontic study casts were used in this study (n=40). The specimens were equally and randomly divided. In the digitally produced indirect bonding tray (DIBT) group (n=20), the brackets were set virtually using the Orthoanalyzer program (3Shape, Copenhagen, Denmark) to produce an indirect bonding tray that was virtually designed and 3D printed using VarseoWaxŸ Splint material with a Varseo S 3D printer (Bego, Bremen, Germany). In the laboratory-produced indirect bonding tray (LIBT) group, the brackets were adhesively bonded to the study casts in the dental laboratory (Danube Private University, Krems, Austria), and a transfer bonding silicone tray was manufactured.Results:The t-test results showed a significant difference between the passive time during the production of DIBTs (153.8±32.8 min) and LIBTs (7 min). However, the active production time was 13.6±0.8 min for DIBTs and 17.7±1.9 min for LIBTs. Every individual process step in both groups was measured in minutes, and statistical analysis was performed.Conclusion:The total production time, including active working and passive non-working time, was higher for DIBTs than for LIBTs. However, the actual active production time for DIBTs was shorter than that for LIBTs. Within the study limitations, the digital planning and production of indirect orthodontic trays can be considered a time-efficient production method

    The Quantized O(1,2)/O(2)×Z2O(1,2)/O(2)\times Z_2 Sigma Model Has No Continuum Limit in Four Dimensions. II. Lattice Simulation

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    A lattice formulation of the O(1,2)/O(2)×Z2O(1,2)/O(2)\times Z_2 sigma model is developed, based on the continuum theory presented in the preceding paper. Special attention is given to choosing a lattice action (the ``geodesic'' action) that is appropriate for fields having noncompact curved configuration spaces. A consistent continuum limit of the model exists only if the renormalized scale constant ÎČR\beta_R vanishes for some value of the bare scale constant~ÎČ\beta. The geodesic action has a special form that allows direct access to the small-ÎČ\beta limit. In this limit half of the degrees of freedom can be integrated out exactly. The remaining degrees of freedom are those of a compact model having a ÎČ\beta-independent action which is noteworthy in being unbounded from below yet yielding integrable averages. Both the exact action and the ÎČ\beta-independent action are used to obtain ÎČR\beta_R from Monte Carlo computations of field-field averages (2-point functions) and current-current averages. Many consistency cross-checks are performed. It is found that there is no value of ÎČ\beta for which ÎČR\beta_R vanishes. This means that as the lattice cutoff is removed the theory becomes that of a pair of massless free fields. Because these fields have neither the geometry nor the symmetries of the original model we conclude that the O(1,2)/O(2)×Z2O(1,2)/O(2)\times Z_2 model has no continuum limit.Comment: 32 pages, 7 postscript figures, UTREL 92-0

    Magic N=2 supergravities from hyper-free superstrings

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    We show by explicit construction the existence of various four dimensional models of type II superstrings with N=2 supersymmetry, purely vector multiplet spectrum and no hypermultiplets. Among these, two are of special interest, at the field theory level they correspond to the two exceptional N=2 supergravities of the magic square that have the same massless scalar field content as pure N=6 supergravity and N=3 supergravity coupled to three extra vector multiplets. The N=2 model of the magic square that is associated to N=6 supergravity is very peculiar since not only the scalar degrees of freedom but all the bosonic massless degrees of freedom are the same in both theories. All presented hyper-free N=2 models are based on asymmetric orbifold constructions with N=(4,1) world-sheet superconformal symmetry and utilize the 2d fermionic construction techniques. The two exceptional N=2 models of the magic square are constructed via a "twisting mechanism" that eliminates the extra gravitini of the N=6 and N=3 extended supergravities and creates at the same time the extra spin-1/2 fermions and spin-1 gauge bosons which are necessary to balance the numbers of bosons and fermions. Theories of the magic square with the same amount of supersymmetry in three and five space-time dimensions are constructed as well, via stringy reduction and oxidation from the corresponding four-dimensional models.Comment: 27 page

    Quantum Physics and Human Language

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    Human languages employ constructions that tacitly assume specific properties of the limited range of phenomena they evolved to describe. These assumed properties are true features of that limited context, but may not be general or precise properties of all the physical situations allowed by fundamental physics. In brief, human languages contain `excess baggage' that must be qualified, discarded, or otherwise reformed to give a clear account in the context of fundamental physics of even the everyday phenomena that the languages evolved to describe. The surest route to clarity is to express the constructions of human languages in the language of fundamental physical theory, not the other way around. These ideas are illustrated by an analysis of the verb `to happen' and the word `reality' in special relativity and the modern quantum mechanics of closed systems.Comment: Contribution to the festschrift for G.C. Ghirardi on his 70th Birthday, minor correction

    A Super-Oxidized Radical Cationic Icosahedral Boron Cluster

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    While the icosahedral closo-[B₁₂H₁₂]ÂČ⁻ cluster does not display reversible electrochemical behavior, perfunctionalization of this species via substitution of all 12 B–H vertices with alkoxy or benzyloxy (OR) substituents engenders reversible redox chemistry, providing access to clusters in the dianionic, monoanionic, and neutral forms. Here, we evaluated the electrochemical behavior of the electron-rich B₁₂(O-3-methylbutyl)₁₂ (1) cluster and discovered that a new reversible redox event that gives rise to a fourth electronic state is accessible through one-electron oxidation of the neutral species. Chemical oxidation of 1 with [N(2,4-Br₂C₆H₃)₃]·âș afforded the isolable [1]·âș cluster, which is the first example of an open-shell cationic B₁₂ cluster in which the unpaired electron is proposed to be delocalized throughout the boron cluster core. The oxidation of 1 is also chemically reversible, where treatment of [1]·âș with ferrocene resulted in its reduction back to 1. The identity of [1]·âș is supported by EPR, UV–vis, multinuclear NMR (ÂčH, ÂčÂčB), and X-ray photoelectron spectroscopic characterization
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