Goal-setting behaviour in Massive Open Online Courses (MOOCs)

Massive Open Online Courses (MOOCs) represent a new and increasingly popular model of online learning course where the learner’s ability sets their learning goals and the emphasis is on creating new knowledge rather than on ’working through structured course materials’. This study set out to investigate the skills and attributes learners need to possess to participate effectively in a MOOC, and in particular: ‘How do participants plan and reflect upon their learning goals within the Change 11 MOOC?’ Participants for this primarily qualitative study were recruited from the Change 11 course cohort. Participants were first invited to complete a self-report instrument to establish a measure of their self-regulation. Semi-structured in-depth interviews (n=27) exploring goal-setting and other learning behaviours were then conducted. Anonymised interviews were analysed and a combination of pre-defined and emergent codes used to categorise the data. Interview data was then analysed against the SR scores derived from the survey instrument. Findings from the study highlight that learners with different self-regulated learning profiles differ in their approach to goal setting and learning in a MOOC, but that other factors are also important with the topic and precise format of the course in particular mediating individual approaches to goal-setting. These findings can help practitioners design more supportive learning environments and learning designs which take account of different learner approaches to goal-setting in MOOCs which, while presently under-researched, are rapidly gaining prominence as a mechanism for delivering learning online

The light speed vs the observer: the Kennedy-Thorndike test from GRAAL-ESRF

High precision tests of the light speed constancy for all observers as of empirical basis of the Special Relativity have continuously been among the goals of advanced experimental studies. Based on the Compton Edge method proposed by us [1], a constraint on the one-way light speed isotropy and the Lorentz invariance violation has been obtained at the dedicated GRAAL experiment at European Synchrotron Radiation Facility (ESRF, Grenoble) [2-5]. Using the GRAAL's data we now get a new constraint on one of key tests of Special Relativity - the Kennedy-Thorndike experiment [6] - in probing the light speed invariance with respect to the velocity of the observer (apparatus). Our analysis takes advantage of GRAAL's setup where two separate energy scales are involved: first, via the position of the Compton Edge determining the light speed in the reference frame of incident 6 GeV electrons within the tagging system, second, in the calorimeter via the 1.27 MeV photons of the ^22 Na source. The two energy scales are engaged to each other through production of $\eta$ mesons by tagged laser Compton backscattered $\gamma$-rays. Accuracy of the calibration and stability of energies reached in each section enable us to obtain the limit 7 10^-12 for the Kennedy-Thorndike test, which improves the currently existing limits by three orders of magnitude.Comment: To appear in Eur Phys J C; 6 pages, 3 figure

Elastic Compton Scattering from 3He and the Role of the Delta

We report observables for elastic Compton scattering from $^3$He in Chiral Effective Field Theory with an explicit $\Delta(1232)$ degree of freedom ($\chi$EFT) for energies between 50 and 120 MeV. The $\gamma\,{}^3$He amplitude is complete at N3LO, $\mathcal{O}(e^2\delta^3)$, and in general converges well order by order. It includes the dominant pion-loop and two-body currents, as well as the Delta excitation in the single-nucleon amplitude. Since the cross section is two to three times that for deuterium and the spin of polarised $^3$He is predominantly carried by its constituent neutron, elastic Compton scattering promises information on both the scalar and spin polarisabilities of the neutron. We study in detail the sensitivities of 4 observables to the neutron polarisabilities: the cross section, the beam asymmetry and two double asymmetries resulting from circularly polarised photons and a longitudinally or transversely polarised target. Including the Delta enhances those asymmetries from which neutron spin polarisabilities could be extracted. We also correct previous, erroneous results at N2LO, i.e.~without an explicit Delta, and compare to the same observables on proton, neutron and deuterium targets. An interactive Mathematica notebook of our results is available from [email protected]: 37 pages LaTeX2e (pdflatex) including 16 figures as .pdf files using includegraphics; minor corrections, triggered by referee comments, plus typographical errors; text-identical to version published as EPJA 54 (2018) 12

Quantum Memory for Photons in Case of Many Close Lying Exciton Resonances in Solids

The possibility of storage of quantum information with photons is studied in the case of resonant transitions via many close lying exciton levels in a solid with impurity Lambda-atoms. The upper levels of the impurity atom form resonant Fano states, similar to the autoionization atomic states, due to the configuration interaction with the continuum of the exciton band. In this case slowing of light pulses is shown to be realistic, in the presence of the control field, down to the group velocity much lower than that in vacuum. The possibility of storage and reconstruction of a quantum pulse is studied in the case of the instantaneous switching on/off of the control field. It is shown that the signal quantum pulse cannot be stored undistorted for differing values of Fano parameters and for non-zero two-photon detuning and decay rate between the lower levels (decoherence). However, for small difference of the Fano parameters and for small values of the two-photon detuning and the decoherence there is no distortion in the case where the length of the pulse is much longer than the linear absorption (amplification) length, so the shape and quantum state of the light pulse can be restored.Comment: 15 pages, 3 figure

Sub-10 ps time tagging of electromagnetic showers with scintillating glasses and SiPMs

The high energy physics community has recently identified an $e^+e^-$ Higgs factory as one of the next-generation collider experiments, following the completion of the High Luminosity LHC program at CERN.The moderate radiation levels expected at such colliders compared to hadron colliders, enable the use of less radiation tolerant but cheaper technologies for the construction of the particle detectors. This opportunity has triggered a renewed interest in the development of scintillating glasses for the instrumentation of large detector volumes such as homogeneous calorimeters. While the performance of such scintillators remains typically inferior in terms of light yield and radiation tolerance compared to that of many scintillating crystals, substantial progress has been made over the recent years. In this paper we discuss the time resolution of cerium-doped Alkali Free Fluorophosphate scintillating glasses, read-out with silicon photo-multipliers in detecting single charged tracks and at different positions along the longitudinal development of an electromagnetic shower, using respectively 150~GeV pions and 100~GeV electron beams at the CERN SPS H2 beam line. A single sensor time resolution of 14.4~ps and 5-7~ps was measured respectively in the two cases. With such a performance the present technology has the potential to address an emerging requirement of future detectors at collider experiments: measuring the time-of-flight of single charged particles as well as that of neutral particles showering inside the calorimeter and the time development of showers

Armenian grapevines: cytoembryological, morphological and chemical analysis

The objectives of our study was to phenotype Armenian grapevines on the base of cytoembryological, morphometric and phenolic content analysis of 10 wine and 10 table cultivars (Vitis vinifera L.). The presented results suggest that Armenian table grape cultivars have higher level of abnormalities in the process of seed formation than wine cultivars. However, during ovule development, the observed differences between table and wine varieties were not significant. The berry morphometric analysis demonstrated that table cultivars formed significantly larger and heavier berries than wine cultivars. The obtained results show that wine grapes contained significantly higher phenol concentrations than table grapes, in both colored and white grapevine cultivars. The study of phenol composition, an important chemical descriptor in grapevine phenotyping, provides oenological information useful to improve the wine quality. Cultivar characterization could be used as marker for the selection of table and wine grape breeding programs. These results will be upgraded in the database for Armenian grapevine varieties. In future Armenian germplasm will be compared with datasets of neighboring countries, to determine the varietal origins relationships