Digital Games in the Science Classroom: Leveraging Internal and External Scaffolds during Game Play

We have developed a disciplinarily integrated game (DIG) to support students in interpreting, translating, and manipulating across formal representations in the domain of Newtonian kinematics. In this study, we seek to understand what game play looks like in a classroom context with particular attention given to how students leverage internal and external scaffolds to progress through the game and deepen their conceptual knowledge. We investigate the following questions: (1) In what ways do students interact with the game, with each other, and with their teacher when they play SURGE Symbolic in a classroom environment? (2) How do game scaffolds, both within and outside of the game, support or impede student learning and game play? (3) What are the implications of these observations for teachers and game designers? We found that although most students used internal scaffolds in some way to assist their game play, many found that these scaffolds were insufficient to get through challenges. They quickly sought help from external resources available to them outside the game to help them advance in the game. The source of information they needed to make progress came from various people or resources outside the game, what we are calling “knowers.

771-3 Direct Characterization of F1ecalnide Binding Rates from Use-Dependent Conduction Delay In Canine Purkinje Fibers

To quantitatively characterize flecainide-induced channel blockade from usedependent conduction delay (CD), 12 canine purkinje fibers were studied using a dual microelectrode technique. During 60 sec of pacing at interstimulus intervals (ISI) of 1.25–0.4 sec with 2μM flecainide (FLEC), incremental CD followed a monoexponential time course, the rates of which were linearly related to the interpulse recovery interval (tr=ISI — action potential duration). Steady state block was an exponential function of the recovery rates. Use-dependent block derived from incremental CD and decremental squared conduction velocity (θ2) was characterized by the forward (k) and reverse (I) rate constants for the activated (a) and resting (r) states:ka (× 106) (mol-1 s-1)la (s-1)kr (× 102) (mol-1 s-1)Ir (s-1)CD7.0±2.612.0±4.40.6±1.74.01±1.63θ210.0±3.414.7±2.52.8±5.73.66±1.40Vmax(prox)6.8±2.315.9±5.05.1±10.34.22±1.11These rates reflect marked open state Na+ channel block and closed channel trapping at resting membrane potentials with FLEC. The addition of 1μM isoproterenol (ISO) to FLEC-superfused fibers reversed the FLEC-induced reduction of θ2 from 1.79±0.7 to 1.89±0.89 (m/s)2 (p=0.017) without changing V˙max. The rate constants for FLEC binding and unbinding were not altered by ISO. Thus FLEC's apparent binding rates can be quantified from its use-{jependent effects on conduction. Both ISO's selective reversal of FLEC effect on θ2 but not V˙max and the absence of changes in the rate constants suggest that the modulation of FLEC effect is due to an alteration in passive membrane properties. These characterizations will facilitate subsequent comparisons of FLEC interactions in pathologic and hyperadrenergic states in vivo

Invariant expectations and vanishing of bounded cohomology for exact groups

We study exactness of groups and establish a characterization of exact groups in terms of the existence of a continuous linear operator, called an invariant expectation, whose properties make it a weak counterpart of an invariant mean on a group. We apply this operator to show that exactness of a finitely generated group $G$ implies the vanishing of the bounded cohomology of $G$ with coefficients in a new class of modules, which are defined using the Hopf algebra structure of $\ell_1(G)$.Comment: Final version, to appear in the Journal of Topology and Analysi

Using Common Gardens and AFLP Analyses to Identify Metapopulations of Indigenous Plant Materials for Rangeland Revegetation in Western USA

Past mismanagement, overgrazing, invasive weedy species, wildfires, marginal crop production, mineral and energy extraction, recreation and global climate change are challenges currently facing rangelands (Pierson et al. 2011). These disturbances may lead to long-term reductions in biodiversity, altered nutrient and water cycling, diminished forage production for livestock and wildlife, increased wildfire frequency and increased soil erosion and stream sedimentation (Sheley et al. 2008). Rangeland revegetation with desirable plant materials may be required to improve degraded conditions, speed recovery, and prevent further erosion and degradation. There is a critical need for plant materials to restore and revegetate rangeland ecosystems. Legumes indigenous to western North America are of particular interest for revegetation because they provide biologically fixed nitrogen, increase plant production, enhance forage quality and provide food sources for grazing animals and pollinators. Some land managers in the USA are concerned with the genetic identity of populations used for revegetation. To balance concerns of genetic identity, ecological adaptation, and economical seed production, we assessed genetic variation and its phenotypic expression in Astragalus filipes Torr. ex A. Gray (basalt milkvetch), Dalea ornata (Douglas) Eaton & Wright (western prairie clover) and D. searlsiae (A. Gray) Barneby (Searls’ prairie clover) using common-garden and AFLP (amplified fragment length polymorphism) techniques. These data were used to define population structures (genetically differentiated groups) within each species, which served as a basis for commercial release and rangeland revegetation (Johnson et al. 2012)

Feminist Scholarship Review: Women and Music

Published from 1991 through 2007 at Trinity College, Hartford, Connecticut, the Feminist Scholarship Review is a literary journal that describes women\u27s experiences around the world. FSR began as a review of feminist scholarly material, but evolved into a journal for poetry and short storie

Dedication

This issue of the Nebraska Law Review is dedicated to the Honorable Earl Warren, Chief Justice of the United States, upon his retirement

Elemental Uptake in Relation to Root Characteristics of Tall Fescue

HiMag, an accession of tall fescue (Festuca arundinacea Schreb.), was selected for high magnesium (Mg) concentration in leaves to reduce grass tetany risk to ruminants. However, the mechanism for enhanced Mg uptake in HiMag leaves has not been determined. The objective was to investigate if increased Mg uptake in HiMag could be explained by differences in elemental distribution among plant parts, root characteristics, or organic acid concentrations compared to its parental cultivars, ‘‘Kentucky 31’’ (KY31) and ‘‘Missouri 96’’ (MO96). The study was conducted on a surface-irrigated calcareous Portneuf silt loam (coarse-silty, mixed, mesic, Durinodic Xeric Haplocalcid). Vegetation and soil cores of 7.6-cm diameter were sampled to a 45-cm soil depth in 15-cm increments. Mass and ash were determined for leaves, crowns, and roots. Leaf area, root length, root area, root length density, elemental concentration, and uptake [potassium (K), calcium (Ca), Mg, sodium (Na), and phosphorus (P)], and malate and citrate concentrations also were determined. Leaf Mg concentration was higher in HiMag than parental cultivars. HiMag generally did not differ in crown and root elemental concentrations from its parents. Risk of causing grass tetany, indicated by leaf K/(Ca+Mg), was lower in HiMag than KY31 and MO96 in both 1994 (P=0.03) and 1995 (P=0.01). Root length, area, and mass were not related to cation concentrations in the three tall fescue accessions, suggesting that HiMag may have an active uptake or transport mechanism for Mg

Chronic traumatic encephalopathy is a common co-morbidity, but less frequent primary dementia in former soccer and rugby players

Chronic traumatic encephalopathy (CTE) is reported at high prevalence in selected autopsy case series of former contact sports athletes. Nevertheless, the contribution of CTE pathology to clinical presentation and its interaction with co-morbid neurodegenerative pathologies remain unclear. To address these issues, we performed comprehensive neuropathology assessments on the brains of former athletes with dementia and considered these findings together with detailed clinical histories to derive an integrated clinicopathological diagnosis for each case. Consecutive, autopsy-acquired brains from former soccer and rugby players with dementia were assessed for neurodegenerative pathologies using established and preliminary consensus protocols. Thereafter, next of kin interviews were conducted to obtain detailed accounts of the patient’s clinical presentation and course of disease to inform a final, integrated clinicopathological diagnosis. Neuropathologic change consistent with CTE (CTE-NC) was confirmed in five of seven former soccer and three of four former rugby players’ brains, invariably in combination with mixed, often multiple neurodegenerative pathologies. However, in just three cases was the integrated dementia diagnosis consistent with CTE, the remainder having alternate diagnoses, with the most frequent integrated diagnosis Alzheimer’s disease (AD) (four cases; one as mixed AD and vascular dementia). This consecutive autopsy series identifies neuropathologic change consistent with preliminary diagnostic criteria for CTE (CTE-NC) in a high proportion of former soccer and rugby players dying with dementia. However, in the majority, CTE-NC appears as a co-morbidity rather than the primary, dementia causing pathology. As such, we suggest that while CTE-NC might be common in former athletes with dementia, in many cases its clinical significance remains uncertain