Learning Group Formation Factors in a Career and Technical Education Networking Program

Team based learning based on the transformation of permanent student groups into powerful learning teams is widely and successfully used as an instructional strategy in postsecondary career and technical education. Failure of groups to reach the learning team status is a major learning drawback of this approach. Factors affecting the transformation of groups to teams are applied consistently to the whole class, with the exception of group formation and membership. Career and technical education populations differ from other postsecondary populations and examination of group formation factors may result in improvement of student results.Abstract / Introduction / Problem Statement / Purpose of Study / Literature Review / Method / Results / Conclusion / References / Appendix 1 - Consent Form / Appendix 2 Student Questionnaire - Group Selection / Appendix 3 Student Response Dat

Convergence rates for finite element problems with singularities. Part 1: Antiplane shear

The problem of a finite crack in an infinite medium under antiplane shear load is considered. It is shown that the nodal forces at the tip of the crack accurately gives the order of singularity, that n energy release methods can give the strength to better than 1 percent with element size 1/10 the crack length, and that nodal forces give a much better estimate of the stress field than do the elements themselves. The finite element formulation and the factoring of tridiagonal matrices are discussed

Possible energy-dependence of Theta_13 in neutrino oscillations

A simple three-flavor neutrino-oscillation model is discussed which has both nonzero mass differences and timelike Fermi-point splittings, together with a combined bi-maximal and trimaximal mixing pattern. One possible consequence would be new effects in \nu_{\mu} \to \nu_{e} oscillations, characterized by an energy-dependent effective mixing angle \Theta_{13}. Future experiments such as T2K and NOvA, and perhaps even the current MINOS experiment, could look for these effects.Comment: 15 pages with revtex4; title changed in journa

Fe I and Fe II Abundances of Solar-Type Dwarfs in the Pleiades Open Cluster

We have derived Fe abundances of 16 solar-type Pleiades dwarfs by means of an equivalent width analysis of Fe I and Fe II lines in high-resolution spectra obtained with the Hobby - Eberly Telescope and High Resolution Spectrograph. Abundances derived from Fe II lines are larger than those derived from Fe I lines (herein referred to as over-ionization) for stars with Teff < 5400 K, and the discrepancy (deltaFe = [Fe II/H] - [Fe I/H]) increases dramatically with decreasing Teff, reaching over 0.8 dex for the coolest stars of our sample. The Pleiades joins the open clusters M 34, the Hyades, IC 2602, and IC 2391, and the Ursa Major moving group, demonstrating ostensible over-ionization trends. The Pleiades deltaFe abundances are correlated with Ca II infrared triplet and Halpha chromospheric emission indicators and relative differences therein. Oxygen abundances of our Pleiades sample derived from the high-excitation O I triplet have been previously shown to increase with decreasing Teff, and a comparison with the deltaFe abundances suggests that the over-excitation (larger abundances derived from high excitation lines relative to low excitation lines) and over-ionization effects that have been observed in cool open cluster and disk field main sequence (MS) dwarfs share a common origin. Star-to-star Fe I abundances have low internal scatter, but the abundances of stars with Teff < 5400 K are systematically higher compared to the warmer stars. The cool star [Fe I/H] abundances cannot be connected directly to over-excitation effects, but similarities with the deltaFe and O I triplet trends suggest the abundances are dubious. Using the [Fe I/H] abundances of five stars with Teff > 5400 K, we derive a mean Pleiades cluster metallicity of [Fe/H] = +0.01 +/- 0.02.Comment: 32 pages, 7 figures, 7 tables; accepted by PAS

Evolution of virulence: triggering host inflammation allows invading pathogens to exclude competitors.

Virulence is generally considered to benefit parasites by enhancing resource-transfer from host to pathogen. Here, we offer an alternative framework where virulent immune-provoking behaviours and enhanced immune resistance are joint tactics of invading pathogens to eliminate resident competitors (transferring resources from resident to invading pathogen). The pathogen wins by creating a novel immunological challenge to which it is already adapted. We analyse a general ecological model of 'proactive invasion' where invaders not adapted to a local environment can succeed by changing it to one where they are better adapted than residents. However, the two-trait nature of the 'proactive' strategy (provocation of, and adaptation to environmental change) presents an evolutionary conundrum, as neither trait alone is favoured in a homogenous host population. We show that this conundrum can be resolved by allowing for host heterogeneity. We relate our model to emerging empirical findings on immunological mediation of parasite competition

Three-dimensional coronal slow modes: toward three-dimensional seismology

On 2008 January 10, the twin Solar Terrestrial Relations Observatory (STEREO) A and B spacecraft conducted a high time cadence study of the solar corona with the Extreme UltraViolet Imager (EUVI) instruments with the aim of investigating coronal dynamics. Observations of the three-dimensional propagation of waves within active region coronal loops and a measurement of the true coronal slow mode speed are obtained. Intensity oscillations with a period of approximately 12 minutes are observed to propagate outwards from the base of a loop system, consistent with the slow magnetoacoustic mode. A novel analysis technique is applied to measure the wave phase velocity in the observations of the A and B spacecraft. These stereoscopic observations are used to infer the three-dimensional velocity vector of the wave propagation, with an inclination of 37 +- 6 deg to the local normal and a magnitude of 132 +- 9 and 132 +- 11 km s-1, giving the first measurement of the true coronal longitudinal slow mode speed, and an inferred temperature of 0.84 +- 12 MK and 0.84 +- 15 MK

Comprehensive Observations of a Solar Minimum CME with STEREO

We perform the first kinematic analysis of a CME observed by both imaging and in situ instruments on board STEREO, namely the SECCHI, PLASTIC, and IMPACT experiments. Launched on 2008 February 4, the CME is tracked continuously from initiation to 1 AU using the SECCHI imagers on both STEREO spacecraft, and is then detected by the PLASTIC and IMPACT particle and field detectors on board STEREO-B. The CME is also detected in situ by ACE and SOHO/CELIAS at Earth's L1 Lagrangian point. The CME hits STEREO-B, ACE, and SOHO on 2008 February 7, but misses STEREO-A entirely. This event provides a good example of just how different the same event can look when viewed from different perspectives. We also demonstrate many ways in which the comprehensive and continuous coverage of this CME by STEREO improves confidence in our assessment of its kinematic behavior, with potential ramifications for space weather forecasting. The observations provide several lines of evidence in favor of the observable part of the CME being narrow in angular extent, a determination crucial for deciding how best to convert observed CME elongation angles from Sun-center to actual Sun-center distances.Comment: 27 pages, 10 figures, AASTEX v5.2, accepted by Ap

A Search for Ultra-High Energy Counterparts to Gamma-Ray Bursts

A small air shower array operating over many years has been used to search for ultra-high energy (UHE) gamma radiation ($\geq 50$ TeV) associated with gamma-ray bursts (GRBs) detected by the BATSE instrument on the Compton Gamma-Ray Observatory (CGRO). Upper limits for a one minute interval after each burst are presented for seven GRBs located with zenith angles $\theta < 20^{\circ}$. A $4.3\sigma$ excess over background was observed between 10 and 20 minutes following the onset of a GRB on 11 May 1991. The confidence level that this is due to a real effect and not a background fluctuation is 99.8\%. If this effect is real then cosmological models are excluded for this burst because of absorption of UHE gamma rays by the intergalactic radiation fields.Comment: 4 pages LaTeX with one postscript figure. This version does not use kluwer.sty and will allow automatic postscript generatio