Stabillity Ball Sitting Elevates Peak Arm Ergometry Oxygen Consumption and Heart Rate

International Journal of Exercise Science 5(4) : 360-366, 2012. This study compared sitting on a stability ball (B) to sitting on a chair (C) during arm ergometry to determine the impact on peak VO2, peak heart rate (HR), and exercise intensity prescription. Open-circuit spirometer, blood pressure, and HR were monitored during rest and continuous graded exercise test to exhaustion using an arm ergometer. Twenty-seven apparently healthy adults exercised twice, once at B and the other trial C (order randomized), with 60 minutes of rest between trials. ANOVA for repeated measures (a \u3c 0.05) and paired t testing using Holm\u27s-sequential Bonferroni were used to analyze results for 30 W, 45 W, Penultimate, and Peak stages of exercise. VO2 was significantly higher (8% to 12%, P \u3c 0.001) for all stages of exercise for B compared to C. HR was significantly higher (P \u3c 0.001) only at the Penultimate and Peak levels (3% and 2%, respectively) for B compared to C; all other sub-maximal HRs were not significantly different. There were no significant main effects or interactions (P\u3e 0.138) when VO2 and HR were expressed as percentage of maximum. Compared to chair sitting, the stability ball has a greater absolute metabolic response with little impact on HR. Prescribing exercise with absolute MET levels should consider this; however, intensity as a percentage of maximum may not be affected by the stability ball

Probing alkenoxy radical electronic structure using anion PEI spectroscopy

Photoelectron imaging spectra of three alkenoxide radical anions (3-buten-1-oxide, 3-buten-2-oxide, and 2-propenoxide) are presented and analyzed with supporting results of density functional theory calculations. In all spectra, intense detachment features are observed at approximately 2 eV electron binding energy, which is similar to the electron affinities of saturated neutral alkoxy radicals [Ramond et al., J. Chem. Phys. 112, 1158 (2000)]. Photoelectron angular distributions suggest the presence of several overlapping transitions which are assigned to the X̃ and à states of multiple energetically competitive conformers. The term energy of the à state of the 2-propenoxy radical, 0.17 eV, is higher than that of 3-buten-2-oxy (0.13 eV) and 3-buten-1-oxy (0.05 eV) radicals. Comparing the butenoxy radicals, we infer that stronger interactions between the non-bonding O 2p orbitals and the π bond increase the splitting between the ground and the first excited state in the 3-buten-2-oxy radical relative to the 3-buten-1-oxy radical

O₂^–·[Polar VOC] Complexes: H‑Bonding versus Charge–Dipole Interactions, and the Noninnocence of Formaldehyde

Anion photoelectron imaging was used to measure the photodetachment spectra of molecular complexes formed between O₂^– and a range of atmospherically relevant polar molecules, including species with a carbonyl group (acetone, formaldehyde) and alcohols (ethanol, propenol, butenol). Experimental spectra are analyzed using a combination of Franck–Condon simulations and electronic structure calculations. Strong charge–dipole interactions and H-bonding stabilize the complex anions relative to the neutrals, resulting in a <i>ca.</i> 1 eV increase in electron binding energy relative to bare O₂^–, an effect more pronounced in complexes with H-bonding. In addition, broken degeneracy of the O₂-local π_g orbitals in the complexes results in the stabilization of the low-lying excited O₂ (a ¹Δ_g)·[polar VOC] state relative to the ground O₂ (X ³Σ_g^–)·[polar VOC] state when compared to bare O₂. The spectra of the O₂^–·[polar VOC] complexes exhibit less pronounced laser photoelectron angular distribution (PADs). The spectrum of O₂^–·formaldehyde is unique in terms of both spectral profile and PAD. On the basis of these experimental results in addition to computational results, the complex anion cannot be described as a distinct O₂^– anion partnered with an innocent solvent molecule; the molecules are more strongly coupled through charge delocalization. Overall, the results underscore how the symmetry of the O₂ π_g orbitals is broken by different polar partners, which may have implications for atmospheric photochemistry and models of solar radiation absorption that include collision-induced absorption