Taking A Stand: The Effects Of Standing Desks On Task Performance And Engagement

Time spent sitting is associated with negative health outcomes, motivating some individuals to adopt standing desk workstations. This study represents the first investigation of the effects of standing desk use on reading comprehension and creativity. In a counterbalanced, within-subjects design, 96 participants completed reading comprehension and creativity tasks while both sitting and standing. Participants self-reported their mood during the tasks and also responded to measures of expended effort and task difficulty. In addition, participants indicated whether they expected that they would perform better on work-relevant tasks while sitting or standing. Despite participants’ beliefs that they would perform worse on most tasks while standing, body position did not affect reading comprehension or creativity performance, nor did it affect perceptions of effort or difficulty. Mood was also unaffected by position, with a few exceptions: Participants exhibited greater task engagement (i.e., interest, enthusiasm, and alertness) and less comfort while standing rather than sitting. In sum, performance and psychological experience as related to task completion were nearly entirely uninfluenced by acute (~30-min) standing desk use. View Full-Tex

Solutions of the Yang-Baxter equation: descendants of the six-vertex model from the Drinfeld doubles of dihedral group algebras

The representation theory of the Drinfeld doubles of dihedral groups is used to solve the Yang-Baxter equation. Use of the 2-dimensional representations recovers the six-vertex model solution. Solutions in arbitrary dimensions, which are viewed as descendants of the six-vertex model case, are then obtained using tensor product graph methods which were originally formulated for quantum algebras. Connections with the Fateev-Zamolodchikov model are discussed.Comment: 34 pages, 2 figure

Characteristics of Innovation in a Non-Metropolitan Area: The Okanagan Valley of British Columbia

This paper addresses the characteristics of innovation in industrial clusters in a Non-Metropolitan area of British Columbia. The Okanagan houses strong high technology, agrifood, forest products, and construction sectors. These sectors were surveyed for common characteristics indicative of a strong industrial cluster

ALTERATIONS IN GROUND REACTION FORCES DURING TETHERED WALKING

This study examined t h e e f f e c t s of tethering conditions on ground forces while walking a t 2.5 mph. Six males w e r e unweighted 0%, 25%, 50% and 75% of t h e i r BWT while supported i n a Kinney upper body vest by an active traction prototype (Conva-Lift). They walked 10 min. a t each randomly selected unweighting condition in a 12 f t . dia. c i r c l e . Ten right and l e f t s t r i d e impacts w e r e collected a t 1000 Hz with an Ariel APAS system using a K i s t l e r force plate during each condition a t 2.5 mph (27%). Walking velocity was verified by an infra-red timing system. 5 right and l e f t s t r i d e s in which the velocity was closest t o 2.5 mph w e r e selected for analysis. The s t r i d e was delineated into the phases of heelstrike (HS), midfoot support (MFS), and toe-off (TO). The v e r t i c a l forces (F,) a t the 3 phases, the fore-aft forces (Fy) a t HS and TO and the contact time w e r e calculated. A 4x2x5 ANOVA (WtxFtxLeg) with repeated measures on a l l factors was used t o analyze (F,) forces a t HS, MFS, and TO, fore-aft forces (Fy) a t HS, TO, and contact t i m e . The v e r t i c a l forces (Fz) a t HS w e r e 902.0+112.9 Nt(76% BWT), and 389.3276.8 Nt(45% BWT) for the unweighting conditions. The i n i t i a l impact forces w e r e consistent with normal overland walking and the F, forces w e r e significantly reduced when the subject was unweighted a t 50% and 75% of t h e i r BWT. The forea f t forces representing the decelerative forces w e r e 16%, 16%, lo%, and 4% BWT for the weight conditions. Significant differences w e r e found t o exist between the i n i t i a l contact force a t 0% ( f u l l BWT) and 75% unweighting. The MFS v e r t i c a l forces (F,) w e r e 682.7±73.4, 595.7±73.3, 395.9±49.8, and 234.3±28.7 N t for the loading conditions. The midfoot forces represented about a 30% reduction or absorption of the i n i t i a l impact forces, while the 75% condition exhibited only a 18% reduction in the impact force which would suggest that weight bearing mechanism of the arch of the foot functioned differently when unloaded. The F, forces a t TO significantly differed from 869.1±118.5, 76.56±105.4, 537.9±91.8, and 281.4±78.2 f o r t h e conditions. The percentage of reduction of F, forces a t HS and TO for the unweighting conditions, and the v e r t i c a l forces a t TO w e r e decreased more for a similar degree of unweighting. This finding would suggest that t h i s active traction prototype might be beneficial in t h e r e h a b i l i t a t i o n of posterior compartment injuries. When examining the reduction i n the fore-aft accelerative forces a t TO, the % BWT w e r e similar t o the F, forces a t HS for similar unloading conditions. The s t r i d e contact times significantly differed between ,705±03 sec for t h e r i g h t s t r i d e s and ,68±.04 sec for the l e f t s t r i d e s and no differences existed for the weighting condition. Significant time differences w e r e attributable t o the outside leg having t o travel a greater distance in the same t i m e a s t h e inner leg, while walking in a c i r c l e . The Conva-Lift's travel direction is reversible t o prevent any imbalances due t o circular walking. The significant differences in the ground reaction forces in the v e r t i c a l and fore-aft direction as the subjects w e r e unweighted would indicate that the Conva-Lift is a viable means of reducing ground reaction forces while ambulating

Grothendieck's constant and local models for noisy entangled quantum states

We relate the nonlocal properties of noisy entangled states to Grothendieck's constant, a mathematical constant appearing in Banach space theory. For two-qubit Werner states \rho^W_p=p \proj{\psi^-}+(1-p){\one}/{4}, we show that there is a local model for projective measurements if and only if $p \le 1/K_G(3)$, where $K_G(3)$ is Grothendieck's constant of order 3. Known bounds on $K_G(3)$ prove the existence of this model at least for $p \lesssim 0.66$, quite close to the current region of Bell violation, $p \sim 0.71$. We generalize this result to arbitrary quantum states.Comment: 6 pages, 1 figur

BIOMECHANICAL SPORT ANALYSIS THROUGH DATA INTEGRATION

This project consisted of the utilisation of a synchronised time base data software program (Ariel APASview), capable of dynamically integrating video, kinematic, kinetic, EMG, and force plate data for the analysis of selected sports under different competitive conditions (practice, Olympic and collegiate competitions). Biomechanical analysis through data integration was performed on discus throwing, basketball free throw shooting, and high jumping. Visual records from multiple perspectives and quantitative feedback were provided to the coaches and athletes for effective evaluation of their sport performance

Evidence of Variable Zn/Fe in Zinc-Ferrites Produced From Roasting of Zinc Sulphide Concentrate

Zn-Fe-O phases formed during roasting of concentrates from zinc sulfide ores produce soluble zinc oxide, oxy-sulfates and insoluble ferrite compounds. The ferrites have a general formula ZnOFe2O3. However, these ferrites have a range of magnetic properties, suggesting variable stoichiometry. Scanning electron microscopy has been used to obtain the general relationship between the Zn/Fe ratio of the ferrites and their magnetic susceptibility