Yoga practice in the UK: a cross- sectional survey of motivation, health benefits and behaviours

Objectives Despite the popularity of yoga and evidence of its positive effects on physical and mental health, little is known about yoga practice in the UK. This study investigated the characteristics of people who practise yoga, reasons for initiating and maintaining practice, and perceived impact of yoga on health and well-being. Design, setting and participants A cross-sectional online anonymous survey distributed through UK-based yoga organisations, studios and events, through email invites and flyers. 2434 yoga practitioners completed the survey, including 903 yoga teachers: 87% were women, 91% white and 71% degree educated; mean age was 48.7 years. Main outcome measures Perceived impact of yoga on health conditions, health outcomes and injuries. Relationships between yoga practice and measures of health, lifestyle, stress and well-being. Results In comparison with national population norms, participants reported significantly higher well-being but also higher anxiety; lower perceived stress, body mass index and incidence of obesity, and higher rates of positive health behaviours. 47% reported changing their motivations to practise yoga, with general wellness and fitness key to initial uptake, and stress management and spirituality important to current practice. 16% of participants reported starting yoga to manage a physical or mental health condition. Respondents reported the value of yoga for a wide range of health conditions, most notably for musculoskeletal and mental health conditions. 20.7% reported at least one yoga-related injury over their lifetime. Controlling for demographic factors, frequency of yoga practice accounted for small but significant variance in health-related regression models (p<0.001). Conclusion The findings of this first detailed UK survey were consistent with surveys in other Western countries. Yoga was perceived to have a positive impact on physical and mental health conditions and was linked to positive health behaviours. Further investigation of yoga’s role in self-care could inform health-related challenges faced by many countries

Determinants of the Timing and Incidence of Exploratory Drilling on Offshort Wildcat Tracts

This paper documents exploratory drilling activity on offshore wildcat oil and gas leases in the Gulf of Mexico that were sold between 1954 and 1990, with emphasis on the period before 1980. For each year of the lease, we study the determinants of the decision whether or not to begin exploratory drilling, and the outcome of any drilling activity. Our results indicate that equilibrium predictions of plausible noncooperative models are reasonably accurate, and more descriptive than those of cooperative models of drilling timing. We discuss why noncooperative behavior may occur, and the potential gains from coordination.

Patterns of Trade in the Market for Used Durables: Theory and Evidence

The consumption value of a durable good diminishes as it ages due to physical deterioration and consumers' preference for the new. We develop a model of consumer specialization and trade in the market for used durables based on imperfect substitutability. Imperfect substitutability across vintages is reflected in a declining market price over time. Heterogeneous consumers maximize utility by specializing in durables of differing ages. Consumers must trade to acquire their preferred vintage each period. When there are transaction costs in the secondhand market, the volume of trade due to specialization increases with imperfect substitutability. We examine the determinants of vehicle ownership transfers in Illinois, a measure of trade volume. Observed patterns of trade across automobile model years are consistent with our model, and inconsistent with a model of adverse selection.

A homotopy double groupoid of a Hausdorff space II: a van Kampen theorem

This paper is the second in a series exploring the properties of a functor which assigns a homotopy double groupoid with connections to a Hausdorff space. We show that this functor satisfies a version of the van Kampen theorem, and so is a suitable tool for nonabelian, 2-dimensional, local-to-global problems. The methods are analogous to those developed by Brown and Higgins for similar theorems for other higher homotopy groupoids. An integral part of the proof is a detailed discussion of commutative cubes in a double category with connections, and a proof of the key result that any composition of commutative cubes is commutative. These results have recently been generalised to all dimensions by Philip Higgins.Comment: 19 pages, uses picte

Ohio School Milk Markets: An Analysis of Bidding

We examine the institutional details of the school milk procurement process, bidding data, statements of dairy executives, and supply characteristics in Ohio during the 1980's. We compare the bidding behavior of a group of firms to a control group. We find that the behavior of each of the firms differs from that of the control group. We argue that the behavior of these firms is consistent with collusion. The estimated average effect of collusion on market prices is about six and one half percent, or roughly the cost of shipping school milk about 50 miles.

Development of a rotary fluid transfer coupling and support mechanism for space station

A design was developed for a rotary fluid coupling to transfer coolant fluids (primarily anhydrous ammonia) across rotating joints of the space station. Development testing using three conceptual designs yielded data which were used to establish the design of a multipass fluid coupling capable of handling three fluid circuits. In addition, a mechanism to support the fluid coupling and allow an astronaut to replace the coupling quickly and easily was designed

Empirical Implications of Equilibrium Bidding in First-Price, Symmetric, Common Value Auctions

This paper studies federal auctions for wildcat leases on the Outer Continental Shelf from 1954 to 1970. These are leases where bidders privately acquire (at some cost) noisy, but equally informative, signals about the amount of oil and gas that may be present. We develop a test of equilibrium bidding in a common values model that is implemented using data on bids and ex post values. We compute bid markups and rents under the alternative hypotheses of private and common values and find that the data are more consistent with the latter hypothesis. Finally, we use data on tract location and ex post values to test the comparative static prediction in common value auctions that bidders may bid less aggressively when they expect more competition.

Evaluation of the gust-alleviation characteristics and handling qualities of a free-wing aircraft

Dynamic characteristics of aircraft with wings free to pivot spanwise axi