4,111 research outputs found

    Mean Hα+[N ii]+[S ii] EW inferred for star-forming galaxies at z  ∼ 5.1–5.4 using high-quality Spitzer /IRAC photometry

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    Recent Spitzer/InfraRed Array Camera (IRAC) photometric observations have revealed that rest-frame optical emission lines contribute significantly to the broad-band fluxes of high-redshift galaxies. Specifically, in the narrow redshift range z ∼ 5.1–5.4 the [3.6]–[4.5] colour is expected to be very red, due to contamination of the 4.5 μm band by the dominant Hα line, while the 3.6 μm filter is free of nebular emission lines. We take advantage of new reductions of deep Spitzer/IRAC imaging over the Great Observatories Origins Deep Survey-North+South fields (Labbé et al. 2015) to obtain a clean measurement of the mean Hα equivalent width (EW) from the [3.6]–[4.5] colour in the redshift range z = 5.1–5.4. The selected sources either have measured spectroscopic redshifts (13 sources) or lie very confidently in the redshift range z = 5.1–5.4 based on the photometric redshift likelihood intervals (11 sources). Our zphot = 5.1–5.4 sample and zspec = 5.10–5.40 spectroscopic sample have a mean [3.6]–[4.5] colour of 0.31 ± 0.05 and 0.35 ± 0.07 mag, implying a rest-frame EW (Hα+[N II]+[S II]) of 665 ± 53 and 707 ± 74 Å, respectively, for sources in these samples. These values are consistent albeit slightly higher than derived by Stark et al. at z ∼ 4, suggesting an evolution to higher values of the Hα+[N II]+[S II] EW at z > 2. Using the 3.6 μm band, which is free of emission line contamination, we perform robust spectral energy distribution fitting and find a median specific star formation rate of sSFR = 17+2−517−5+2 Gyr−1, 7+1−2×7−2+1× higher than at z ∼ 2. We find no strong correlation (<2σ) between the Hα+[N II]+[S II] EW and the stellar mass of sources. Before the advent of JWST, improvements in these results will come through an expansion of current spectroscopic samples and deeper Spitzer/IRAC measurements

    Implications of large dimuon CP asymmetry in B_{d,s} decays on minimal flavor violation with low tan beta

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    The D0 collaboration has recently announced evidence for a dimuon CP asymmetry in B_{d,s} decays of order one percent. If confirmed, this asymmetry requires new physics. We argue that for minimally flavor violating (MFV) new physics, and at low tan beta=v_u/v_d, there are only two four-quark operators (Q_{2,3}) that can provide the required CP violating effect. The scale of such new physics must lie below 260 GeV sqrt{tan beta}. The effect is universal in the B_s and B_d systems, leading to S_{psi K}~sin(2beta)-0.15 and S_{psi phi}~0.25. The effects on epsilon_K and on electric dipole moments are negligible. The most plausible mechanism is tree-level scalar exchange. MFV supersymmetry with low tan beta will be excluded. Finally, we explain how a pattern of deviations from the Standard Model predictions for S_{psi phi}, S_{psi K} and epsilon_K can be used to test MFV and, if MFV holds, to probe its structure in detail.Comment: 11 pages. v2: References adde

    Business process modelling and visualisation to support e-government decision making: Business/IS alignment

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    © 2017 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/978-3-319-57487-5_4.Alignment between business and information systems plays a vital role in the formation of dependent relationships between different departments in a government organization and the process of alignment can be improved by developing an information system (IS) according to the stakeholders’ expectations. However, establishing strong alignment in the context of the eGovernment environment can be difficult. It is widely accepted that business processes in the government environment plays a pivotal role in capturing the details of IS requirements. This paper presents a method of business process modelling through UML which can help to visualise and capture the IS requirements for the system development. A series of UML models have been developed and discussed. A case study on patient visits to a healthcare clinic in the context of eGovernment has been used to validate the models

    Homogeneous Open Quantum Random Walks on a lattice

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    We study Open Quantum Random Walks for which the underlying graph is a lattice, and the generators of the walk are translation-invariant. We consider the quantum trajectory associated with the OQRW, which is described by a position process and a state process. We obtain a central limit theorem and a large deviation principle for the position process, and an ergodic result for the state process. We study in detail the case of homogeneous OQRWs on a lattice, with internal space h=C2h={\mathbb C}^2

    TEMPRANILLO is a regulator of juvenility in plants

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    Many plants are incapable of flowering in inductive daylengths during the early juvenile vegetative phase (JVP). Arabidopsis mutants with reduced expression of TEMPRANILLO (TEM), a repressor of FLOWERING LOCUS T (FT) had a shorter JVP than wild-type plants. Reciprocal changes in mRNA expression of TEM and FT were observed in both Arabidopsis and antirrhinum, which correlated with the length of the JVP. FT expression was induced just prior to the end of the JVP and levels of TEM1 mRNA declined rapidly at the time when FT mRNA levels were shown to increase. TEM orthologs were isolated from antirrhinum (AmTEM) and olive (OeTEM) and were expressed most highly during their juvenile phase. AmTEM functionally complemented AtTEM1 in the tem1 mutant and over-expression of AmTEM prolonged the JVP through repression of FT and CONSTANS (CO). We propose that TEM may have a general role in regulating JVP in herbaceous and woody species

    Ricci Flow Gravity

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    A theory of gravitation is proposed, modeled after the notion of a Ricci flow. In addition to the metric an independent volume enters as a fundamental geometric structure. Einstein gravity is included as a limiting case. Despite being a scalar-tensor theory the coupling to matter is different from Jordan-Brans-Dicke gravity. In particular there is no adjustable coupling constant. For the solar system the effects of Ricci flow gravity cannot be distinguished from Einstein gravity and therefore it passes all classical tests. However for cosmology significant deviations from standard Einstein cosmology will appear.Comment: 15 pages. V2: improved presentation, in particular Jordan vs. Brans-Dicke and on viability. Added section on physical interpretation. V3: more references. Reworked to agree with published versio

    The Universal One-Loop Effective Action

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    We present the universal one-loop effective action for all operators of dimension up to six obtained by integrating out massive, non-degenerate multiplets. Our general expression may be applied to loops of heavy fermions or bosons, and has been checked against partial results available in the literature. The broad applicability of this approach simplifies one-loop matching from an ultraviolet model to a lower-energy effective field theory (EFT), a procedure which is now reduced to the evaluation of a combination of matrices in our universal expression, without any loop integrals to evaluate. We illustrate the relationship of our results to the Standard Model (SM) EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.Comment: 30 pages, v2 contains additional comments and corrects typos, version accepted for publication in JHE

    BLM and RMI1 alleviate RPA inhibition of topoIIIα decatenase activity

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    RPA is a single-stranded DNA binding protein that physically associates with the BLM complex. RPA stimulates BLM helicase activity as well as the double Holliday junction dissolution activity of the BLM-topoisomerase IIIα complex. We investigated the effect of RPA on the ssDNA decatenase activity of topoisomerase IIIα. We found that RPA and other ssDNA binding proteins inhibit decatenation by topoisomerase IIIα. Complex formation between BLM, TopoIIIα, and RMI1 ablates inhibition of decatenation by ssDNA binding proteins. Together, these data indicate that inhibition by RPA does not involve species-specific interactions between RPA and BLM-TopoIIIα-RMI1, which contrasts with RPA modulation of double Holliday junction dissolution. We propose that topoisomerase IIIα and RPA compete to bind to single-stranded regions of catenanes. Interactions with BLM and RMI1 enhance toposiomerase IIIα activity, promoting decatenation in the presence of RPA

    The effects of rational and irrational coach team talks on the cognitive appraisal and achievement goal orientation of varsity football athletes

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    The effects of rational and irrational coach team talks on cognitive appraisal and achievement goal orientation were examined. During the half-time interval of a 60-minute football match, 25 male varsity football athletes (Mage = 20.20; SD ± 1.38 years) received a rational (n = 13) or an irrational (n = 12) team talk from a coach. Irrational and rational beliefs were measured before the football match. Task engagement, cognitive appraisal (challenge and threat), and achievement goal orientation (approach and avoidance) regarding second-half football performance were measured following team-talk delivery. Athletes in the rational team talk condition reported significantly lower threat appraisal and avoidance goal orientation than athletes in the irrational team talk condition. No significant between-condition differences emerged for challenge appraisal and approach goal orientation. For coaching practice, data suggest that communicating rational or irrational beliefs to football athletes through a half time team talk will influence appraisal and achievement goal orientation regarding upcoming performance. Keywords Rational emotive behaviour therapy, irrational beliefs, rational beliefs, appraisal, achievement goal
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