Can accelerometry be used to discriminate levels of activity?

The aims of this study were to investigate the associations between an activity logbook and the RT3 accelerometer and to assess whether the RT3 can discriminate activity levels in healthy adults. Ten participants completed two trials wearing an RT3 accelerometer over a 4-6 h period and completed a detailed activity log. Results showed a poor correlation between the RT3 in moderate activities (r = 0.22) in comparison to low (r = 0.52) and hard (r = 0.70) from the logbook. A significant difference was found in average RT3 vector magnitude (VM) counts/min in each activity level (p < 0.0001). Discriminant analysis demonstrated that an RT3VM counts/min value of approximately 500 was found to have high sensitivity (88%), and specificity (88%) for discriminating between low and moderate activity levels from the logbook. This study found that accelerometry has the potential to discriminate activity levels in free living. This study is the first to investigate whether tri-axial accelerometry can discriminate different levels of free-living activity recorded in an activity logbook. The RT3 accelerometer can discriminate between low and moderate physical activities and offers a methodology that may be applicable to future research in occupational settings.

Hypolipidemic 2-[4-(1,1-dimethylethyl)phenyl]-4H-3,1-benzoxazin-4-ones. Structure-activity relationships of a novel series of high-density lipoprotein elevators.

The preparation and plasma lipid altering characteristics of a series of 4H-3,1-benzoxazin-4-ones are described. Hypocholesterolemic, hypotriglyceridemic, and high-density-lipoprotein elevating properties are found for derivatives bearing a 4-(1,1-dimethylethyl)phenyl group at the 2-position, and this activity is displayed in both hypercholesterolemic and in normolipidemic rats when the ring system is substituted at position 6 with hydrogen, methyl, chloro, or iodo groups, and is optimal when the 6-position is substituted by a bromine atom. Evidence is presented suggesting that a metabolite or degradation product is responsible for the changes in lipoprotein concentration observed with active molecules of this type. Synthesis of anticipated degradation products of the active molecules gave products displaying the expected in vivo activity, but no improvement in the narrow therapeutic margin of the best compound, 6-bromo-2-[4-(1,1-dimethylethyl)phenyl]-4H-3,1-benzoxazin-4-one, was obtained.