Learn Twice Invited Brief: Experiential Learning

This article provides a review of the concept of experiential learning, an overview of the theory, its benefits, and a range of examples both inside and outside the classroom. It concludes with a discussion of the steps that teachers can take to create experiential learning opportunities

Bicycle Handlebar Width Does Not Affect Spirometry, Ventilation, or Gas Exchange

Bicycle fit may affect comfort, aerodynamics, efficiency, ventilation, and power generation. Handlebars determine how the rider interacts with the bicycle. A wide range of handlebar widths are commercially available, but it is unclear if the resultant position affects lung function, ventilation, gas exchange, or efficiency. PURPOSE We aimed to measure the effects of handlebar widths on ventilation, gas exchange, spirometry, and comfort during moderate constant power exercise. METHODS Twenty-four recreationally active adults completed the study (32 ± 5 yrs., 175 ± 9 cm, 74 ± 12 kg, 8 women, 16 men). Participants completed three moderate constant power bouts of exercise on a cycle ergometer (Lode Excalibur PFM) while using handlebars set equivalent to, or ± 4cm in width to the participant shoulder width. We used a one-way RMANOVA to compare the three handlebar widths. RESULTS There was no difference in gas exchange and ventilation between the three handlebar widths: V̇O2 (F[2, 23] = 0.99, p = 0.38), V̇CO2 (F[1.47, 23] = 0.39, p = 0.62), V̇E (F[2, 23] = 0.53, p = 0.59], VT (F[2, 23] = 0.44, p = 0.65], fBr (F[2, 23] = 0.17, p = 0.84], PetO2(F[2, 23] = 0.45, p = 0.64), PetCO2 (F[2, 23] = 0.25, p=0.78]. Similarly, there were no differences in inspiratory capacity during the bout (F[1.49, 22] = 1.34, p = 0.27) or any spirometry variables immediately following exercise: FVC (F[1.43, 22] = 0.88, p = 0.39], FEV1 (F[2, 22] = 0.30, p = 0.74], FEV1/FVC (F[2, 22] = 0.18, p = 0.84], PEF (F[2, 22] = 0.14, p = 0.87]. There was no difference in the overall comfort (F[2, 23] = 0.90, p = 0.41] or shoulder discomfort (F [2, 23] = 0.90, p = 0.42). CONCLUSIONS Bicycle handlebar widths within 4 cm shoulder width do not result in changes to ventilation, gas exchange, efficiency, spirometry, or comfort during moderate power cycling exercise. Within the limits of rider preference, comfort, and safety, handlebar width can be adjusted substantially for aerodynamic purposes without affecting rider physiology

Influence of solvent in controlling peptide−surface interactions

Protein binding to surfaces is an important phenomenon in biology and in modern technological applications. Extensive experimental and theoretical research has been focused in recent years on revealing the factors that govern binding affinity to surfaces. Theoretical studies mainly focus on examining the contribution of the individual amino acids or, alternatively, the binding potential energies of the full peptide, which are unable to capture entropic contributions and neglect the dynamic nature of the system. We present here a methodology that involves the combination of nonequilibrium dynamics simulations with strategic mutation of polar residues to reveal the different factors governing the binding free energy of a peptide to a surface. Using a gold-binding peptide as an example, we show that relative binding free energies are a consequence of the balance between strong interactions of the peptide with the surface and the ability for the bulk solvent to stabilize the peptide

Invariant Peano curves of expanding Thurston maps

We consider Thurston maps, i.e., branched covering maps $f\colon S^2\to S^2$ that are postcritically finite. In addition, we assume that $f$ is expanding in a suitable sense. It is shown that each sufficiently high iterate $F=f^n$ of $f$ is semi-conjugate to $z^d\colon S^1\to S^1$, where $d$ is equal to the degree of $F$. More precisely, for such an $F$ we construct a Peano curve $\gamma\colon S^1\to S^2$ (onto), such that $F\circ \gamma(z) = \gamma(z^d)$ (for all $z\in S^1$).Comment: 63 pages, 12 figure

Diaphragm Force and Mitochondrial Function Ex Vivo Following GSNOR Inhibition In Vivo Preceding Mechanical Ventilation

During mechanical ventilation (MV), force developed by the diaphragm is decreased over time much faster than locomotor muscles. This is known as ventilator-induced diaphragm dysfunction (VIDD), and VIDD may be accelerated by intramyofiber oxidative stress. An important free radical used for the treatment of acute respiratory distress syndrome (ARDS) is nitric oxide (NO) which can diffuse to diaphragm myofibers during treatment. However, little is known whether NO or NO by-products such as S-nitrosothiols (RSNO), can accelerate or prevent VIDD. PURPOSE: To investigate whether inhibiting S-nitrosoglutathione reductase (GSNORi) during MV could affect ex vivo diaphragm force and mitochondrial respiration. METHODS: Male (C57BL6J) mice (n=27) were anesthetized and subjected to MV for 2, 4, or 6h, and non-MV mice (0 h) were used as controls. Alternatively, mice were treated with PBS/10% DMSO (n=6) or 25 µg SPL-334 (GSNORi, n=6) or 25 µg SPL-334 + 1.7 mg isosorbide dinitrate (ISDN; n=6), and then subjected to MV for 2 h. After MV, mice were euthanized, and diaphragm strips were used for force or for mitochondrial oxidative phosphorylation and reactive oxygen species generation measurements. RESULTS: Peak tetanic force was decreased by MV starting at 4 h (30 ± 2 N/cm2 vs 26 ± 1 N/cm2 vs 23 ± 2 N/cm2 vs 18 ± 4 N/cm2, for 0 vs 2 vs 4 vs 6h MV, P=0.0097 one-way ANOVA). Peak force was not different between DMSO vs GSNORi (P=0.3834). Leak respiration (Mann-Whitney p=0.26; CI95 7, 45 vs 10, 68 pmol/s/mg), coupled-phosphorylating mitochondrial respiration (Mann-Whitney p=0.91; CI95 121, 180 vs 107, 215 pmol/s/mg), and H2O2 flux in any of the respiratory states (e.g. coupled-phosphorylating Mann-Whitney p=0.26; CI95 30, 245 vs 4, 543 fmol/s/mg), were not different between DMSO vs GSNORi. CONCLUSION: VIDD was developed at 4 hours MV, but GSNORi treatment for 2 h did not produce any changes to VIDD and to mitochondrial function. These data suggest that if exogenous NO is not provided, inhibiting GSNOR in vivo alone does not affect diaphragm function ex vivo. Support: SDSU 2023 SEED Grant (to L.N.

Testing beat perception without sensory cues to the beat: the Beat-Drop Alignment Test (BDAT)

Beat perception can serve as a window into internal time-keeping mechanisms, auditory–motor interactions, and aspects of cognition. One aspect of beat perception is the covert continuation of an internal pulse. Of the several popular tests of beat perception, none provide a satisfying test of this faculty of covert continuation. The current study proposes a new beat-perception test focused on covert pulse continuation: The Beat-Drop Alignment Test (BDAT). In this test, participants must identify the beat in musical excerpts and then judge whether a single probe falls on or off the beat. The probe occurs during a short break in the rhythmic components of the music when no rhythmic events are present, forcing participants to judge beat alignment relative to an internal pulse maintained in the absence of local acoustic timing cues. Here, we present two large (N > 100) tests of the BDAT. In the first, we explore the effect of test item parameters (e.g., probe displacement) on performance. In the second, we correlate scores on an adaptive version of the BDAT with the computerized adaptive Beat Alignment Test (CA-BAT) scores and indices of musical experience. Musical experience indices outperform CA-BAT score as a predictor of BDAT score, suggesting that the BDAT measures a distinct aspect of beat perception that is more experience-dependent and may draw on cognitive resources such as working memory and musical imagery differently than the BAT. The BDAT may prove useful in future behavioral and neural research on beat perception, and all stimuli and code are freely available for download

The impact of future offshore wind farms on wind power generation in Great Britain

In the coming years the geographical distribution of wind farms in Great Britain is expected to change significantly. Following the development of the “round 3” wind zones (circa 2025), most of the installed capacity will be located in large offshore wind farms. However, the impact of this change in wind-farm distribution on the characteristics of national wind generation is largely unknown. This study uses a 34-year reanalysis dataset (Modern-Era Retrospective Analysis for Research and Applications (MERRA) from National Aeronautics and Space Administration, Global Modeling and Assimilation Office (NASA-GMAO)) to produce a synthetic hourly time series of GB-aggregated wind generation based on: (1) the “current” wind farm distribution; and (2) a “future” wind farm distribution scenario. The derived data are used to estimate a climatology of extreme wind power events in Great Britain for each wind farm distribution. The impact of the changing wind farm distribution on the wind-power statistics is significant. The annual mean capacity factor increased from 32.7% for the current wind farm distribution to 39.7% for the future distribution. In addition, there are fewer periods of prolonged low generation and more periods of prolonged high generation. Finally, the frequency and magnitude of ramping in the nationally aggregated capacity factor remains largely unchanged. However, due to the increased capacity of the future distribution, in terms of power output, the magnitude of the ramping increases by a factor of 5

A meshless method for an inverse two-phase one-dimensional nonlinear Stefan problem

We extend a meshless method of fundamental solutions recently proposed by the authors for the one-dimensional two-phase inverse linear Stefan problem, to the nonlinear case. In this latter situation the free surface is also considered unknown which is more realistic from the practical point of view. Building on the earlier work, the solution is approximated in each phase by a linear combination of fundamental solutions to the heat equation. The implementation and analysis are more complicated in the present situation since one needs to deal with a nonlinear minimization problem to identify the free surface. Furthermore, the inverse problem is ill-posed since small errors in the input measured data can cause large deviations in the desired solution. Therefore, regularization needs to be incorporated in the objective function which is minimized in order to obtain a stable solution. Numerical results are presented and discussed