The Leisure Of Learning: Students’ Perceptions Of Learntertainment’ As An Instructional Method

With present-day classrooms becoming increasingly diverse, educational institutions, teachers and university administrators are looking to teaching and learning strategies that provide for a variety of learning profiles and styles. Many educators start their class with a ‘big bang’- an interesting ice breaker- to raise excitement in their students, but due to the use of the lecture method, the interest in class soon regresses, and the attention of the learner begins to wane. This has the negative impact of affecting what is learned and the extent of knowledge gained as a result of the teaching-learning process. Consequently, learntertainment, a new teaching approach is being presented as an alternative to the lecture method. The purpose of this paper is identifying what the benefits of Learntertainment teaching strategies are and to explore students’ perception of Learntertainment. A qualitative approach is considered to be appropriate for this paper and will be based on Strauss and Corbin (1998) grounded theory modified slightly to incorporate constructivist grounded theory espoused by Charmaz (2000)

Hidden Symmetries and Integrable Hierarchy of the N=4 Supersymmetric Yang-Mills Equations

We describe an infinite-dimensional algebra of hidden symmetries of N=4 supersymmetric Yang-Mills (SYM) theory. Our derivation is based on a generalization of the supertwistor correspondence. Using the latter, we construct an infinite sequence of flows on the solution space of the N=4 SYM equations. The dependence of the SYM fields on the parameters along the flows can be recovered by solving the equations of the hierarchy. We embed the N=4 SYM equations in the infinite system of the hierarchy equations and show that this SYM hierarchy is associated with an infinite set of graded symmetries recursively generated from supertranslations. Presumably, the existence of such nonlocal symmetries underlies the observed integrable structures in quantum N=4 SYM theory.Comment: 24 page

Construction and characterization of a large insert porcine YAC library

The recent construction of genetic linkage maps of the porcine genome (Rohrer et al. 1994, 1996; Ellegren et al. 1994; Archibald et al. 1995) allows the assignment of loci affecting heritable traits of economic importance (ETLs; Lander and Botstein 1989) to specific chromosomal segments. Markers can thus be identified that may be useful in marker-assisted selection (MAS) to increase the frequency of favorable allele(s) in resource populations (reviewed in Soller 1994). In addition, mapping of these loci creates the opportunity to identify gene(s) influencing a trait, through positional cloning or positional cnadidate gene approaches (Grootscholten et al. 1991). A positional cloning strategy requires the construction of contigs that physically span large sections of chromosomes. In the human and mouse systems, contig construction has depended on the availability of multiple YAC libraries that provide depth of coverage to minimize the impact of chimeric and deleted clones inherent in these libraries. A single porcine genomic YAC library has been reported (Leeb et al. 1995), but contains only one genome coverage, which limits the ability to make large contigs. We report the construction of a porcine YAC library, with approximately 5.5-fold coverage of the genome and a low rate of chimerism, that provides an additional resource for contig construction and positional cloning

Fano hypersurfaces and Calabi-Yau supermanifolds

In this paper, we study the geometrical interpretations associated with Sethi's proposed general correspondence between N = 2 Landau-Ginzburg orbifolds with integral \hat{c} and N = 2 nonlinear sigma models. We focus on the supervarieties associated with \hat{c} = 3 Gepner models. In the process, we test a conjecture regarding the superdimension of the singular locus of these supervarieties. The supervarieties are defined by a hypersurface \widetilde{W} = 0 in a weighted superprojective space and have vanishing super-first Chern class. Here, \widetilde{W} is the modified superpotential obtained by adding as necessary to the Gepner superpotential a boson mass term and/or fermion bilinears so that the superdimension of the supervariety is equal to \hat{c}. When Sethi's proposal calls for adding fermion bilinears, setting the bosonic part of \widetilde{W} (denoted by \widetilde{W}_{bos}) equal to zero defines a Fano hypersurface embedded in a weighted projective space. In this case, if the Newton polytope of \widetilde{W}_{bos} admits a nef partition, then the Landau-Ginzburg orbifold can be given a geometrical interpretation as a nonlinear sigma model on a complete intersection Calabi-Yau manifold. The complete intersection Calabi-Yau manifold should be equivalent to the Calabi-Yau supermanifold prescribed by Sethi's proposal.Comment: 24 pages, uses JHEP3.cls; v2: minor corrections, references adde

Predicting ambulatory energy expenditure in lower limb amputees using multi-sensor methods

PurposeTo assess the validity of a derived algorithm, combining tri-axial accelerometry and heart rate (HR) data, compared to a research-grade multi-sensor physical activity device, for the estimation of ambulatory physical activity energy expenditure (PAEE) in individuals with traumatic lower-limb amputation.MethodsTwenty-eight participants [unilateral (n = 9), bilateral (n = 10) with lower-limb amputations, and non-injured controls (n = 9)] completed eight activities; rest, ambulating at 5 progressive treadmill velocities (0.48, 0.67, 0.89, 1.12, 1.34m.s-1) and 2 gradients (3 and 5%) at 0.89m.s-1. During each task, expired gases were collected for the determination of and subsequent calculation of PAEE. An Actigraph GT3X+ accelerometer was worn on the hip of the shortest residual limb and, a HR monitor and an Actiheart (AHR) device were worn on the chest. Multiple linear regressions were employed to derive population-specific PAEE estimated algorithms using Actigraph GT3X+ outputs and HR signals (GT3X+HR). Mean bias±95% Limits of Agreement (LoA) and error statistics were calculated between criterion PAEE (indirect calorimetry) and PAEE predicted using GT3X+HR and AHR.ResultsBoth measurement approaches used to predict PAEE were significantly related (Pr = 0.92, bilateral; r = 0.93, and control; r = 0.91, and AHR; unilateral; r = 0.86, bilateral; r = 0.81, and control; r = 0.67). Mean±SD percent error across all activities were 18±14%, 15±12% and 15±14% for the GT3X+HR and 45±20%, 39±23% and 34±28% in the AHR model, for unilateral, bilateral and control groups, respectively.ConclusionsStatistically derived algorithms (GT3X+HR) provide a more valid estimate of PAEE in individuals with traumatic lower-limb amputation, compared to a proprietary group calibration algorithm (AHR). Outputs from AHR displayed considerable random error when tested in a laboratory setting in individuals with lower-limb amputation.</div

From Yang-Mills Lagrangian to MHV Diagrams

We prove the equivalence of a recently suggested MHV-formalism to the standard Yang-Mills theory. This is achieved by a formally non-local change of variables. In this note we present the explicit formulas while the detailed proofs are postponed to a future publication.Comment: Latex,11 pages, minor changes, reference added, version to appear in JHE

Towards a Stringy Resolution of the Cosmological Singularity

We study cosmological solutions to the low-energy effective action of heterotic string theory including possible leading order $\alpha'$ corrections and a potential for the dilaton. We consider the possibility that including such stringy corrections can resolve the initial cosmological singularity. Since the exact form of these corrections is not known the higher-derivative terms are constructed so that they vanish when the metric is de Sitter spacetime. The constructed terms are compatible with known restrictions from scattering amplitude and string worldsheet beta-function calculations. Analytic and numerical techniques are used to construct a singularity-free cosmological solution. At late times and low-curvatures the metric is asymptotically Minkowski and the dilaton is frozen. In the high-curvature regime the universe enters a de Sitter phase.Comment: 6 pages, 2 Figures; minor revisions; references added; REVTeX 4; version to appear in Phys. Rev.

The portal of Neviaser: a valid option for antegrade nailing of humerus fractures

Introduction: The objective of this retrospective non-randomized study was to evaluate the portal of Neviaser (PN) as an alternative approach in antegrade humeral nailing. Methods: The surgical approach for the straight antegrade intramedullary nail (SAIN) was either the anterolateral delta-split (group 2, n = 79) or the portal of Neviaser (group 3, n = 27). Length of surgery and time of radiation were extracted from charts. Patients stabilized using the PN were followed for a clinical and radiological exam. At follow-up we evaluated the DASH (Disability of the Arm, Shoulder and Hand) and CMS (Constant-Murley Score). Results: Between 10.2015 and 12.2018 191 proximal and diaphyseal humeral fractures were operated using either an angular stable extramedullary device (group 1, PHILOS®, n = 85) or a straight humeral nail (MultiLoc®, n = 106). Time of radiation and intervention followed a normal distribution. The mean length of surgery was 172.9 min (SD 91.5) in group 1, 121.5 min (SD 54.1) in group 2 and 96.4 min (SD 33.7) in group 3 (p < 0.01). Time of radiation was significantly different with 1.1 min (SD 0.6: group 1), 3.1 min (SD 1.6: group 2) and 2.9 min (SD 1.7: group 3) (p < 0.01). After a mean interval of 21.5 months (range 6–43 months) 14 / 27 patients of group 3 were available for a clinical and radiological follow-up. The mean DASH in group 3 was 25, the CMS reached 70. The age and sex weighted CMS mean value was 96%. Forward flexion was 131°, abduction 125°. The ratio of strength affected versus non-affected side was 4.4: 6.2 kg. Conclusions: The portal of Neviaser is a feasible and safe approach and is an alternative to the anterolateral delta-split. Length of surgery and time of radiation were significantly shorter. Level of evidence: IV