8,451 research outputs found

    Chip-firing groups of iterated cones

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    Let Γ\Gamma be a finite graph and let Γn\Gamma_n be the "nnth cone over Γ\Gamma" (i.e., the join of Γ\Gamma and the complete graph KnK_n). We study the asymptotic structure of the chip-firing group Pic0(Γn)\text{Pic}^0(\Gamma_n).Comment: 8 pages. v4: added Remark 1.

    Approximating RR Lyrae light curves using cubic polynomials

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    In this paper, we use cubic polynomials to approximate RR Lyrae light curves and apply the method to HST data of RR Lyraes in the halo of M31. We compare our method to the standard method of Fourier decomposition and find that the method of cubic polynomials eliminates virtually all ringing effects and does so with significantly fewer parameters than the Fourier technique. Further, for RRc stars the parameters in the fit are all physical. Our study also reveals a number of additional periodicites in this data not found previously: we find 23 RRc stars, 29 RRab stars and 3 multiperiodic stars.Comment: 6 pages, MNRAS accepte

    The Hanbury Brown and Twiss Experiment with Fermions

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    We realized an equivalent Hanbury Brown and Twiss experiment for a beam of electrons in a two dimensional electron gas in the quantum Hall regime. A metallic split gate serves as a tunable beam splitter which is used to partition the incident beam into transmitted and reflected partial beams. The current fluctuations in the reflected and transmitted beam are fully anticorrelated demonstrating that fermions tend to exclude each other (anti-bunching). If the occupation probability of the incident beam is lowered by an additional gate, the anticorrelation is reduced and disappears in the classical limit of a highly diluted beam

    Innovation in the time of SARS-CoV-2: A collaborative journey between NHS clinicians, engineers, academics and industry.

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    During the pandemic healthcare faced great pressure on the availability of protective equipment. This paper describes the entire novel innovative process of design optimisation, production and deployment of face-visors to NHS frontline workers during SARS-CoV-2 pandemic. The described innovative journey spans collaboration between clinicians and academic colleagues for design to the implementation with industry partners of a face-visor for use in a healthcare setting. It identifies the enablers and barriers to development along with the strategies employed to produce a certified reusable, adjustable, high volume and locally produced face-visor. The article also explores aspects of value, scalability, spread and sustainability all of which are essential features of innovation

    Asking, Learning, Seeking Out : An Exploration of Data Literacy for Teaching

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    The current study explored preservice and inservice teachers’ perspectives on data literacy for teaching. Semi-structured interviews were employed with 12 teacher candidates in elementary and special education. The findings revealed participants’ misconceptions regarding formative and summative data; their understanding of the value of formative data; perceptions of challenges related to data literacy for teaching including time, making sense of data, and reliability and validity; and candidates’ preferences for authentic data literacy instruction

    Causality and the AdS Dirichlet problem

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    The (planar) AdS Dirichlet problem has previously been shown to exhibit superluminal hydrodynamic sound modes. This problem is defined by bulk gravitational dynamics with Dirichlet boundary conditions imposed on a rigid timelike cut-off surface. We undertake a careful examination of this set-up and argue that, in most cases, the propagation of information between points on the Dirichlet hypersurface is nevertheless causal with respect to the induced light cones. In particular, the high-frequency dynamics is causal in this sense. There are however two exceptions and both involve boundary gravitons whose propagation is not constrained by the Einstein equations. These occur in i) AdS3_3, where the boundary gravitons generally do not respect the induced light cones on the boundary, and ii) Rindler space, where they are related to the infinite speed of sound in incompressible fluids. We discuss implications for the fluid/gravity correspondence with rigid Dirichlet boundaries and for the black hole membrane paradigm.Comment: 29 pages, 5 figures. v2: added refs. v3: minor clarification

    Ranking Objections to Christian Theism: A Survey of Subjective Declarations and their Correlations with Expert Opinions

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    There have been numerous books written on the top objections to Christianity—sometimes stated as “common,” “major,” “frequent,” “every day,” “cultural,” “tough,” “difficult” objections. However, there is a dearth of behavioral studies in the literature that show how and given population ranks objections to Christianity. As such, the apologist has had to rely on expert opinions from the books that have been authored. These expert opinions are based on familiarity with the literature in the field and contact with laity from university, church, and other speaking engagements. The purpose of this study is to document trends in how people report the relative strength of objections to Christian theism.[1] We analyze whether these trends correlate with popular works of Christian apologists—our baseline for expert opinion. Further, we determine whether there are any statistically significant relationships between reported demographics, rankings, and attitudes. Summary of Results and Analysis. Subjective declarations of respondents of the questionnaire showed that most participants were either 18-24 (marginally more than 55-64 and 65-74), male (marginally more than female), had some college (marginally more than bachelor’s, master’s degrees), lived in a suburban community, or lived in the South. In comparing the expert opinion baseline with the aggregate survey ranking results, we see similar rankings between the objection that “God is unloving/immoral” and that the “Bible is not inerrant” (ranked by both as 1st and 2nd, respectively) at the higher end of the spectrum. We found that those identified as agnostic seem to have the closest potential correlation to expert opinion (baseline). The mean of their rankings produced four objections that closely approximated the baseline, one objection that was about one rank removed from the baseline, and three objections that were about two ranks from the baseline. For demographics and rankings, we found statistically significant relationships between religious identification and the objection “God does not exist” with those who identified as atheists, giving it an average ranking of 3.74 (on a scale of 1-13; 1 = highest, 13 = lowest). For demographics and attitudes, we found statistically significant relationships between religious identification and age, religious discussion importance, and attitude toward Christian theism. (See “Analysis” section.) [1] The study was done under the School of Divinity Department at Liberty University in compliance with Liberty University’s Internal Review Board (Research Ethics Office). IRB-FY21-22-12. Policy: Post-2018 Rule. Submitted 07-06-2021. Last approved 09-07-2021, no expiration date applicable

    Enhanced activation of an amino-terminally truncated isoform of the voltage-gated proton channel HVCN1 enriched in malignant B cells

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    The final published version can be found here: http://dx.doi.org/10.1073/pnas.1411390111M.C. is the recipient of a Bennett Fellowship from Leukaemia and Lymphoma Research (ref. 12002). M.A.B. is supported by a GlaxoSmithKline Oncology–Biotechnology and Biological Sciences Research Council Collaborative Awards in Science and Engineering PhD studentship. This work was supported by National Institutes of Health Grants GM087507 and GM102336 (to T.E.D.)
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