Study of the association between gait variability and physical activity

Background

Gait variability can be considered an indirect measure of gait stability, in particular regarding temporal or spatial variability assessment. Physical activity, such as walking, is advised for the elderly and can be improved by gait stability. The aim of this study was to investigate the associations between gait stability and physical activity in women of different age ranges.

Methods

Forty-two healthy women of different age ranges (18-40 yrs. and 65-75 yrs.) were recruited in the study. To assess physical activity, the subjects wore a multi-sensor activity monitor for a whole week, inferring the time spent in moderate to vigorous physical activity (MVPA). MVPA were analysed in bouts of at least 10 subsequent minutes (MVPA_bouts) and in overall minutes (MVPA_tot). A kinematic analysis was performed with an optoelectronic system to calculate gait variability - expressed as standard deviation (SD) and coefficient of variability (CV) of step width, stride length, stance and swing time (during treadmill walking at different speeds).

Results

Elderly women, with high walking speed (5 km/h), and moderate step width variability (CV = 8–27%), met the recommended levels of physical activity (MVPA_tot and MVPA_bouts). Furthermore, gait variability, adjusted for age and number of falls, was significantly and negatively associated with MVPA_tot only at 3.5 km/h, and with MVPA_bouts only at 4 km/h.

Conclusions

In a population of healthy elderly women, gait variability was significantly and negatively associated with the level of physical activity. Healthy elderly women, with moderate gait variability (step width variability), and high preferred walking speed, seem to be able to meet the recommended levels of physical activity.

     

The seasonality of conception

Individual data on menstrual cycles of noncontracepting women living in Western countries were used in order to verify whether the biological seasonality of conception persists after sexual behavior is controlled for. Episodes of intercourse were recorded daily, and the time of ovulation was detected by a marker We find that the seasonality of conception changes with woman's age and frequency of episodes of sexual intercourse. In particular; for women aged 27-31 having only one act of intercourse during the six most fertile days of the menstrual cycle, the seasonality of fecundability is stronger In this age group in the Northern Hemisphere, if seasonality of acts of sexual intercourse is controlled, the monthly distribution of probability of conception is bimodal, with two maxima (September and January) and two minima (December and March). When unobserved characteristics of the couples are considered, this seasonal pattern of conception persists.     

Working systemically following abuse: exploring safe uncertainty

This paper explores systemic practice and ‘safe uncertainty’ in work with parents who do not accept responsibility following child abuse. The prevailing view has been that little positive work can be carried out with families where responsibility is denied. Our work is offered to add to the small yet growing number of publications which challenge the dominant discourse relating to child protection work. A case study is illustrated within which the issue of assessment versus therapy emerges. The Legal Department of the Local Authority Social Services requested an assessment from child and family psychiatry. Concern developed regarding the point at which assessment ended and therapy began. The authors offer a systemic model in exploring the importance of a safe multi‐disciplinary framework within which uncertainty can be tolerated and therapy/change work can be affected. A framework within which parents can be supported in developing skills to meet the needs of children is presented. These issues are central to the professional and legal systems relating to child protection in the UK. Copyright © 1999 John Wiley & Sons, Ltd.     

Complexity properties of complementary prisms

The complementary prism \(G\bar{G}\) of a graph G arises from the disjoint union of the graph G and its complement \(\bar{G}\) by adding the edges of a perfect matching joining pairs of corresponding vertices of G and \(\bar{G}\). Haynes, Henning, Slater, and van der Merwe introduced the complementary prism and as a variation of the well-known prism. We study algorithmic/complexity properties of complementary prisms with respect to cliques, independent sets, k-domination, and especially \(P_3\)-convexity. We establish hardness results and identify some efficiently solvable cases.     

Education and Union Formation as Simultaneous in Italy and Spain

Both the time spent in education and the age at first union have substantially increased in Italy and Spain. We show that exit from education and union formation are simultaneous processes. We use the European Community Household Panel providing standardised information. The effect of unobserved characteristics on both processes is controlled for using simultaneous hazard modelling. We find that the exit from education increases the risk of entering the first union, and that individual unobserved characteristics influence the occurrence of the two processes simultaneously. Ignoring these characteristics would overestimate the effect of exit from education on union formation.     

USING BASEBALL CARD PRICES TO MEASURE STAR QUALITY AND MONOPSONY

Baseball card prices are used to capture star quality in a new measure of productivity in Major League Baseball. Star quality, which impacts revenues, is determined from a player's baseball card price as the residual in a fit of card prices to performance statistics. This measure is entered into the computation of individual player marginal revenue product and compared to players' salaries using data from the four years leading up to the 1994 MLB strike. Results are examined for monopsonistic exploitation by market size, free agency status, type of player, and other relevant categories. Underpaid and overpaid players are identified.     

Talking about Beauty: A Study of Everyday Aesthetics among Low‐Income Citizens of Milan

This paper reports on research undertaken into the aesthetics of the everyday. As well as the subject matter of aesthetic philosophy, art criticism and of the sociology of art, beauty, and beautiful are of course very ordinary matters too. To shed light on the meanings of beauty as used in everyday settings and in natural language, we use the data collected in a study conducted with a group of low‐income residents of the city of Milan. In this study we were interested in analyzing their lifestyle in terms of their relationship with aesthetics, i.e., with “beautiful” objects and/or experiences. Participants' self‐reported aesthetic appreciations suggest that conceptions of “beauty” are used as devices to narrate pieces of identity, memories, experiences, etc. Their aesthetic judgements take on an anthropological function, creating a framework of meanings that help the participants make sense of the world of objects and of their own lives with/through them.     

“Me and the Law is Not Friends”: How Former Prisoners Make Sense of Reentry

This article examines how former prisoners of color conceptualize their political, social, and economic futures and how these conceptualizations relate to the racialized social structural obstacles encountered upon reentry and decisions to re-engage criminal labor. I find that, presented with similar post-prison challenges, excarcerated men take several approaches when reentering society. I argue that the differences among their approaches lie in their varying interpretations of how they can act as individuals against and within their social structural limitations. Their decisions to rejoin or forfeit participation in criminal economies are thus shaped by experiences confronting the limitations of material conditions but also emerge from their critiques of racialized structures.