Calibration of hip accelerometers for measuring physical activity and sedentary behaviours in adults with Down syndrome.

BACKGROUND: The knowledge base on physical activity and sedentary behaviour in adults with Down syndrome (DS) may advance by accelerometer calibration studies. This study aimed to develop cut-points for sedentary behaviour and moderate-to-vigorous physical activity (MVPA) for adults with DS based on output from accelerometers worn on the dominant and non-dominant hips. METHODS: Sixteen adults with DS (10 men; age 31 ± 15 years) performed 12 tasks including sedentary behaviours and physical activities. We obtained metabolic equivalents (METs) with indirect calorimetry and vector magnitude (VM) output from triaxial accelerometers (wGT3X-BT, ActiGraph) worn on the dominant and non-dominant hips. Receiver operating characteristic curves were used to identify optimal VM cut-points that maximised sensitivity and specificity. RESULTS: Overall classification accuracy was very high (area under the ROC curve: 0.95 and 0.92 for sedentary and MVPA models, respectively). For the non-dominant hip, the optimal VM cut-points were (1) sedentary behaviour ≤236 counts·min-1 and (2) MVPA ≥2167 counts·min-1 . For the dominant hip, optimal cut-points were (1) sedentary behaviour ≤243 counts·min-1 and (2) MVPA ≥2092 counts·min-1 . CONCLUSIONS: The presented VM cut-points for sedentary behaviour and MVPA for adults with DS had high classification accuracy. There were small differences in accelerometer cut-points between the dominant and non-dominant hip.

Accelerometer-based estimation of oxygen uptake in adults with Down syndrome: vector magnitude vs. vertical axis.

BACKGROUND: Triaxial accelerometer output [vector magnitude (VM) counts] may better estimate physical activity intensity as reflected in the rate of oxygen uptake (V̇O2 ) than the traditional vertical axis (VA) counts in adults with Down syndrome (DS). This study examined the accuracy of VM vs. VA counts in estimating V̇O2 in adults with and without DS across different physical activities and sedentary behaviours. METHODS: Sixteen adults with DS (10 men and 6 women; 31 ± 15 years) and 19 adults without DS (10 men and 9 women; 24 ± 5 years) performed 12 tasks. V̇O2 was measured by portable spirometer (K4b2 , Cosmed) and VM and VA with an accelerometer (wGT3X-BT, Actigraph). RESULTS: Vector magnitude and VA were significant predictors of V̇O2 in adults with DS (P < 0.001; R2  = 0.74 and 0.65, respectively) and adults without DS (P < 0.001; P < 0.001; R2  = 0.75 and 0.61, respectively). Absolute error of prediction was significantly smaller for VM than VA for sitting, playing app, drawing, sweeping, standing and basketball (P ≤ 0.005), but smaller for VA than VM for walking at 0.8 m·s-1 (P = 0.005). Bland-Altman plots for adults with and without DS indicated narrower limits of agreement for VM than VA (-5.57 to 5.57 and -6.44 to 6.44 mL·kg-1 ·min-1 ; -6.21 to 6.17 and -7.75 to 7.74 mL·kg-1 ·min-1 , respectively). CONCLUSIONS: Vector magnitude and VA are significant predictors of V̇O2 in adults with and without DS, yet VM more accurately estimated V̇O2 than VA for most tasks. Development of accelerometer-based prediction of physical activity levels in adults with and without DS may improve by utilising VM counts.

Analgesic activity of diterpene alkaloids from Aconitum baikalensis.

We compared analgesic activities of individual alkaloids extracted from Baikal aconite (Aconitum baikalensis): napelline, hypaconitine, songorine, mesaconitine, 12-epinapelline N-oxide. The detected analgesic activity was comparable to that of sodium metamizole. The mechanisms of analgesia were different in diterpene alkaloids of different structure. The antinociceptive effect of atisine alkaloids (12-epinapelline N-oxide, songorine) was naloxonedependent and realized via opioid receptor modulation.

Equivalence of alternate subtests for the Russell Revision of the Wechsler Memory Scale.

Two studies were conducted to examine the adequacy of the Visual Reproduction and Logical Memory Subtests of Form II of the Wechsler Memory Scale (WMS-II) as an alternate form for Russell's Revision of the WMS (RWMS). An archival data study on 46 inpatient alcoholics revealed greater pre-/post-treatment differences on Immediate Figural Recall scores for participants tested first on the RWMS, compared with participants tested first on the alternate subtests. In a second study, both forms were administered to 60 noninstitutionalized examinees. Immediate Figural Recall was again higher for subtests from WMS-II; Immediate and Delayed Semantic Recall were higher for RWMS. Data indicate apparent problems in the use of subtests of WMS-II as an alternate form for RWMS.

Limitations in equivalence of alternate subtests for Russell's Revision of the Wechsler Memory Scale: causes and solutions.

Reasons for limited equivalence of Form II of the Wechsler Memory Scale (WMS-II) Figural Memory Subtest as an alternate form for the Russell's Revision of the Wechsler Memory Scale (RWMS) Figural Memory Subtest were investigated. Thirty college students rated figural stimuli from RWMS and WMS-II on dimensions related to memory. Raters judged figural stimuli from RWMS to be less memorable, more complex, and more difficult to label verbally. Forms can be made more equivalent by either changes in scoring or the interchanging of stimuli across forms.

Depth of processing by mentally retarded and MA-matched nonretarded individuals.

Mildly mentally retarded and MA-matched nonretarded individuals were tested for speed and accuracy in responding to questions requiring different processing depth in the Craik and Tulving paradigm and then given an unexpected recognition task. Retarded individuals required progressively more encoding time relative to nonretarded individuals as processing depth increased. Both encoding and recognition accuracy, however, was equivalent for both groups; greater elaboration improved recognition in both groups. Implications for the study of retardation were presented.

Proactive effects in memory for stories.

Selective omissions in the recall of longer prose passages have been interpreted as evidence of abstractive processes during encoding. Presumably, the additional information in longer passages produces an information overload which necessitates selective attention. Learners in three experiments were tested on their recognition or recall of a short passage that either was or was not preceded by a long introductory segment. An encoding-based view predicts that increased passage length should diminish both recognition and recall. However, increased passage length decreased recall, but not recognition, demonstrating that passage length effects are dependent upon the type of cues available during retrieval. A further study demonstrated that ideas of greater thematic importance were recognized better than ideas of lesser thematic importance, even after a negligible retention interval. Abstractive processes deal with the relative importance of ideas but not the amount of information.