Beyond lesson recipes: first steps towards a repertoire for teaching primary computing

In 2014, the UK government introduced a new National Curriculum for state schools in England with a greater emphasis on computer science and computational thinking. Teaching this new curriculum presented challenges to many primary school teachers and led to a demand for professional development and exemplar teaching resources. This paper argues that many of the resources created in response to the revised curriculum are ‘recipes’ for lessons that fail to prepare teachers to teach challenging and purposeful computing lessons. It argues that, instead of providing recipes, we need to develop teachers’ ‘repertoire’ of strategies for teaching computing and that our approach to doing this should take account of the context in which primary teachers now work. The paper describes professional development practices designed to help less confident teachers take their first steps away from model lessons and towards computing projects that reflect the needs and interests of the pupils they teach. In particular, this paper will focus on two aspects of these practices: a teaching sequence intended to scaffold teachers in planning and teaching computing, and an approach to meeting the needs of the range of learners in a primary classroom through self-directed challenges. These were intended to support primary school teachers in improving their confidence and capability to plan and teach computer programming

Robustness of the Thirty Meter Telescope Primary Mirror Control System

The primary mirror control system for the Thirty Meter Telescope (TMT) maintains the alignment of the 492 segments in the presence of both quasi-static (gravity and thermal) and dynamic disturbances due to unsteady wind loads. The latter results in a desired control bandwidth of 1Hz at high spatial frequencies. The achievable bandwidth is limited by robustness to (i) uncertain telescope structural dynamics (control-structure interaction) and (ii) small perturbations in the ill-conditioned influence matrix that relates segment edge sensor response to actuator commands. Both of these effects are considered herein using models of TMT. The former is explored through multivariable sensitivity analysis on a reduced-order Zernike-basis representation of the structural dynamics. The interaction matrix ("A-matrix") uncertainty has been analyzed theoretically elsewhere, and is examined here for realistic amplitude perturbations due to segment and sensor installation errors, and gravity and thermal induced segment motion. The primary influence of A-matrix uncertainty is on the control of "focusmode"; this is the least observable mode, measurable only through the edge-sensor (gap-dependent) sensitivity to the dihedral angle between segments. Accurately estimating focus-mode will require updating the A-matrix as a function of the measured gap. A-matrix uncertainty also results in a higher gain-margin requirement for focus-mode, and hence the A-matrix and CSI robustness need to be understood simultaneously. Based on the robustness analysis, the desired 1 Hz bandwidth is achievable in the presence of uncertainty for all except the lowest spatial-frequency response patterns of the primary mirror

Search for gamma-ray emission from pp-wave dark matter annihilation in the Galactic Center

Indirect searches for dark matter through Standard Model products of its annihilation generally assume a cross-section which is dominated by a term independent of velocity ($s$-wave annihilation). However, in many DM models an $s$-wave annihilation cross-section is absent or helicity suppressed. To reproduce the correct DM relic density in these models, the leading term in the cross section is proportional to the DM velocity squared ($p$-wave annihilation). Indirect detection of such $p$-wave DM is difficult because the average velocities of DM in galaxies today are orders of magnitude slower than the DM velocity at the time of decoupling from the primordial thermal plasma, suppressing the annihilation cross-section today by some five orders of magnitude relative to its value at freeze out. Thus $p$-wave DM is out of reach of traditional searches for DM annihilations in the Galactic halo. Near the region of influence of a central supermassive black hole, such as Sgr A$^*$, however, DM can form a localized over-density known as a `spike'. In such spikes the DM is predicted to be both concentrated in space and accelerated to higher velocities, allowing the $\gamma$-ray signature from its annihilation to potentially be detectable above the background. We use the $Fermi$ Large Area Telescope to search for the $\gamma$-ray signature of $p$-wave annihilating DM from a spike around Sgr A$^*$ in the energy range 10 GeV-600 GeV. Such a signal would appear as a point source and would have a sharp line or box-like spectral features difficult to mimic with standard astrophysical processes, indicating a DM origin. We find no significant excess of $\gamma$ rays in this range, and we place upper limits on the flux in $\gamma$-ray boxes originating from the Galactic Center. This result, the first of its kind, is interpreted in the context of different models of the DM density near Sgr A$^*$.Comment: 16 pages, 7 figure

‘Grounding a PIE in the sky’:Laying empirical foundations for a psychologically informed environment (PIE) to enhance well-being and practice in a homeless organisation

While psychologically informed environments (PIEs) are gaining in prominence in efforts to improve well-being and practice in the homeless sector, their empirical foundations remain tenuous. We present a unique scoping needs analysis of staff and client well-being, staff attitudes and the social–therapeutic climate in a UK-based homeless prevention organisation (prior to PIE implementation). Our aims were: (a) to apply a robust framework to pinpoint need and target forthcoming PIE initiatives and (b) to establish a validated needs baseline that informs and measures efficacy of PIE for its future development. Four established personal and practice well-being measures were administered to 134 (predominantly ‘frontline’) staff and 50 clients. Staff completed the: Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS), Professional Quality of Life Scale (measuring compassion satisfaction [CS], burnout [BO] and secondary traumatic stress [STS]), Attitudes related to Trauma-informed Care Scale (ARTIC-10; measuring practice attitudes towards trauma-informed values) and the Essen Climate Evaluation Schema (EssenCES; measuring perceptions of client cohesion, safety and practitioner relationships in housing projects). Clients completed the WEMWBS and EssenCES. Vulnerability to STS was evident in nearly two-thirds of frontline staff and it was a statistically significant predictor of BO. It was not, however, associated with lesser levels of CS. We discuss this complex dynamic in relation to highlighted strategic recommendations for the PIE framework, and the identified potential challenges in implementing trauma-informed and reflective practice in the organisation. We conclude with a critique of the value and the lessons learnt from our efforts to integrate stronger empirical substance into the PIE approach

Intensive Archeological Survey: State Highway 34 at Kings Creek, Kaufman County, Texas

On behalf of the Texas Department of Transportation (TxDOT), SWCA Environmental Consultants (SWCA) conducted an intensive cultural resources survey on January 3, 2018, of 111.45 acres of existing right-of-way (ROW) along State Highway (SH) 34 at the Kings Creek in Kaufman County, Texas. As the project will receive funding from the Federal Highways Administration, it qualifies as an undertaking as defined in Title 36 Code of Federal Regulations (CFR) Part 800.16(y); therefore, the archeological survey was conducted in compliance with Section 106 of the National Historic Preservation Act (54 U.S. Code 306108). Furthermore, the project must also comply with the Antiquities Code of Texas (9 Natural Resources Code 191). Jon Budd served as Principal Investigator under Texas Antiquities Permit No. 8225. The area of potential effects (APE) is defined as the existing SH 34 TxDOT ROW between 120 to 330 feet (36.6 to 100.6 meters [m]) wide beginning at County Road 4094 and extending 3.22 miles northeast to Farm-to-Market Road 1388. Depth of construction impacts are typically 4 feet (1.20 m), with a maximum of 30 feet (9.14 m). The APE consists of approximately 111.45 acres. Background research identified three previous cultural resources surveys that cross the APE, but no archeological sites, recorded landmarks, cemeteries, National Register of Historic Places districts or properties, or historical markers were identified within or immediately adjacent to the project area. The nearest site, 41KF74, is a sparse prehistoric lithic scatter located approximately 0.4 mile south of the proposed project’s southern terminus. Two potentially historic structures were identified just beyond the APE during the historic map review. The existing ROW has been extensively modified by the construction of SH 34, numerous existing overhead and buried utilities, intersecting roadways, ditches, driveways, and major flood control structures, such as levees and channelized drainages. Since much of the area is a wide, low-lying alluvial setting, fill sections elevating the roadway above the floodplain are pervasive throughout the APE. The field investigation consisted of a pedestrian survey of the entire APE augmented with nine shovel tests along adjacent terraces and seven backhoe trenches at drainage crossings. Fill sections and buried utilities, including fiber optic lines on both sides of the APE, precluded subsurface investigations in many areas. The pedestrian survey, along with shovel tests and backhoe trenches, identified no cultural materials or features within the project APE. The cumulative impacts from the roadway and existing utilities, as well as frequent inundation, indicate a negligible potential for intact archeological resources within the APE. SWCA made a reasonable and good faith effort per 36 CFR Part 800.4(b)(1) to identify and locate prehistoric and historic archeological properties within the proposed project APE. The field investigation discovered no cultural resources; therefore, SWCA recommends that a finding of “no historic properties affected” be made for the current undertaking

In-plane effects on segmented-mirror control

Extremely large optical telescopes are being designed with primary mirrors composed of hundreds of segments. The “out-of-plane” piston, tip, and tilt degrees of freedom of each segment are actively controlled using feedback from relative height measurements between neighboring segments. The “in-plane” segment translations and clocking (rotation) are not actively controlled; however, in-plane motions affect the active control problem in several important ways, and thus need to be considered. We extend earlier analyses by constructing the “full” interaction matrix that relates the height, gap, and shear motion at sensor locations to all six degrees of freedom of segment motion, and use this to consider three effects. First, in-plane segment clocking results in height discontinuities between neighboring segments that can lead to a global control system response. Second, knowledge of the in-plane motion is required both to compensate for this effect and to compensate for sensor installation errors, and thus, we next consider the estimation of in-plane motion and the associated noise propagation characteristics. In-plane motion can be accurately estimated using measurements of the gap between segments, but with one unobservable mode in which every segment clocks by an equal amount. Finally, we examine whether in-plane measurements (gap and/or shear) can be used to estimate out-of-plane segment motion; these measurements can improve the noise multiplier for the “focus-mode” of the segmented-mirror array, which involves pure dihedral angle changes between segments and is not observable with only height measurements