University of Memphis

About: University of Memphis is a education organization based out in Memphis, Tennessee, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 7710 authors who have published 20082 publications receiving 611618 citations. The organization is also known as: U of M.

Oscillation in ergodic theory

Abstract: In this paper we establish a variety of square function inequalities and study other operators which measure the oscillation of a sequence of ergodic averages. These results imply the pointwise ergodic theorem and give additional information such as control of the number of upcrossings of the ergodic averages. Related results for differentiation and for the connection between differentiation operators and the dyadic martingale are also established.

Advancing the Science of mHealth

Abstract: Mobile health (mHealth) technologies have the potential to greatly impact health research, health care, and health outcomes, but the exponential growth of the technology has outpaced the science. This article outlines two initiatives designed to enhance the science of mHealth. The mHealth Evidence Workshop used an expert panel to identify optimal methodological approaches for mHealth research. The NIH mHealth Training Institutes address the silos among the many academic and technology areas in mHealth research and is an effort to build the interdisciplinary research capacity of the field. Both address the growing need for high quality mobile health research both in the United States and internationally. mHealth requires a solid, interdisciplinary scientific approach that pairs the rapid change associated with technological progress with a rigorous evaluation approach. The mHealth Evidence Workshop and the NIH mHealth Training Institutes were both designed to address and further develop this scientific app...

Validity and reliability of activity measures in African-American girls for GEMS.

Abstract: TREUTH, M. S., N. E. SHERWOOD, N. F. BUTTE, B. MCCLANAHAN, E. OBARZANEK, A. ZHOU, C. AYERS, A. ADOLPH, J. JORDAN, D. R. JACOBS, JR., and J. ROCHON. Validity and Reliability of Activity Measures in African-American Girls for GEMS. Med. Sci. Sports Exerc., Vol. 35, No. 3, pp. 532–539, 2003. Purpose: To determine the reliability and validity of physical activity monitors and self-report instruments suitable for young African-American girls. Methods: A validation study was conducted by the Girls health Enrichment Multi-site Studies (GEMS) research team to compare an accelerometer with a pedometer and two self-report instruments for assessing physical activity in African-American girls, age 8 –9 yr. Girls ( N 68) attended two clinic visits spaced 4 d apart. Each girl wore a MTI/CSA accelerometer (used as the criterion standard for validity) and a pedometer simultaneously for four consecutive days. Girls completed on two occasions a 24-h physical activity checklist of yesterday and usual activities, including sedentary activities (GEMS Activity Questionnaire, GAQ), and a 3-d computerized self-report instrument (Activitygram). Results: Girls were (mean SD) 9.0 0.6 yr old and had a body mass index of 19.4 kg·m 2 . Reliability measured by intraclass correlations (ICC) and Pearson correlation coefficients (r) were calculated for the MTI/CSA (ICC 0.37, P 0.0001), pedometer (ICC 0.08, P 0.094), Activitygram (ICC 0.24) (P 0.005), and GAQ for physical (r 0.80, P 0.0001) and sedentary (r 0.3– 0.5, P 0.005) activities. Significant Pearson correlations between the MTI/CSA and the other instruments, as a measure of validity, were observed for the 4-d average pedometer score (r 0.47, P 0.0001), 3-d average Activitygram score (r 0.37, P 0.002), and the average of the two yesterday and two usual GAQ activity scores for a subset of 18 physical activities questions (r 0.27, P 0.03; and r 0.29, P 0.02, respectively). The MTI/CSA was uncorrelated with single day scores from the three other instruments. Conclusion: The reliability of the instruments tested was acceptable, except the pedometer. Validity correlations were significant when more than one day was used. Self-report instruments need further development for improved reliability and validity. Key Words: ACCELEROMETER, PEDOMETER, PHYSICAL ACTIVITY ASSESSMENT, SELF-REPORT QUESTIONNAIRES, CHILDREN, INACTIVITY

Empirically supported treatments or type I errors? Problems with the analysis of data from group-administered treatments.

Abstract: When treatments are administered in groups, clients interact in ways that lead to violations of a key assumption of most statistical analyses-the assumption of independence of observations. The resulting dependencies, when not properly accounted for, can increase Type I errors dramatically. Of the 33 studies of group-administered treatment on the empirically supported treatments list, none appropriately analyzed their data. The current authors provide corrections that can be applied to improper analyses. After the corrections, only 12.4% to 68.2% of tests that were originally reported as significant remained significant, depending on what assumptions were made about how large the dependencies among observations really are. Of the 33 studies, 6-19 studies no longer had any significant results after correction. The authors end by providing recommendations for researchers planning group-administered treatment research.