A model for evolution and extinction

We present a model for evolution and extinction in large ecosystems. The model incorporates the effects of interactions between species and the influences of abiotic environmental factors. We study the properties of the model by approximate analytic solution and also by numerical simulation, and use it to make predictions about the distribution of extinctions and species lifetimes that we would expect to see in real ecosystems. It should be possible to test these predictions against the fossil record. The model indicates that a possible mechanism for mass extinction is the coincidence of a large coevolutionary avalanche in the ecosystem with a severe environmental disturbance.Comment: Postscript (compressed etc. using uufiles), 16 pages, with 15 embedded figure

Emergence of immediate funds transfer as a general-purpose means of payment

Immediate funds transfer (IFT) is a highly convenient, certain, secure, and economical means of payment using bank money. IFT is not available in the U.S. banking system, except for large-value business payments, interbank transfers, and specialized financial market transactions. This article examines the successful experience with IFT in Mexico, South Africa, Switzerland, and the UK and concludes that payment system governance is the principal barrier to IFT innovation in the U.S.Payment systems ; Electronic funds transfers

A feasibility study of wearable activity monitors for pre-adolescent school-age children.

IntroductionUnderstanding physical activity is key in the fight against childhood obesity. The objective of this study was to examine the feasibility of using certain wearable devices to measure physical activity among children.MethodsA qualitative study was conducted with 25 children aged 7 to 10 years to assess acceptability and compliance of wearable activity devices in this age group. During March through August 2012, children participated in a 4-week study of 3 accelerometer models and a heart rate monitor. Children were asked to use a different device each week for 7 consecutive days. Children and their parents completed structured interviews after using each device; they also completed a final exit interview.ResultsThe wrist-worn Polar Active was the device most preferred by children and was associated with the highest level of compliance. Devices that are comfortable to wear, fit properly, have engaging features, and are waterproof increase feasibility and are associated with higher levels of compliance.ConclusionThe wrist-worn device was the most feasible for measuring physical activity among children aged 7 to 10 years. These findings will inform researchers in selecting tools for measuring children's physical activity

VALUATION OF CROP AND LIVESTOCK REPORTS: METHODOLOGICAL ISSUES AND QUESTIONS

Demand and Price Analysis,

Evolution of Cooperative Thought, Theory, and Purpose

The evolution of agricultural cooperative thought, theory, and purpose in the United States is reviewed from the standpoint of the reemergence of interest in how cooperatives can provide some of the security and benefits that might be lost with gradual phasing out of federal government farm support programs. By accomplishing group action for self-help, the early development of cooperatives drew considerable attention from economists, social theorists, and politicians. Alternative schools of cooperative thought developed, but most proponents of cooperatives regarded them as having enormous potential to provide a public service role in building a more economically stable and democratic society This paper also surveys how cooperative theory was developed more rigorously in the post-WWII period. It has provided better analytical tools for understanding how and why cooperatives have changed in response to technological and economic developments, as well as to social trends, like individualism. Given the new perspectives on cooperative theory and the scope of changes in how cooperatives operate and are structured, cooperatives have even greater potential for coordinating self-help actions, but this potential needs the support of cooperative education services.Agribusiness,

The Suffolk Bank and the Panic of 1837

The Suffolk Bank in Boston is well known as having been the clearinghouse for virtually all the banknotes that circulated in New England between 1836 and 1858. An examination of 19th century bank balance sheets shows that during and after the U.S. banking Panic of 1837, this private commercial bank also provided some services that today are provided by central banks. These include lending reserves to other banks (providing a discount window) and keeping the payments system operating. Because of Suffolk's activities, banks in New England fared better than banks elsewhere during the Panic of 1837. And after the panic, when much of the United States suffered a prolonged economic slowdown, New England fared better than the rest of the country, at least partly because of Suffolk’s central bank-like activities.Bank notes ; Banks and banking - History

INTERREGIONAL COMPETITION IN THE U.S. SWINE-PORK INDUSTRY: AN ANALYSIS OF OKLAHOMA'S AND THE SOUTHERN STATES' EXPANSION POTENTIAL

Community/Rural/Urban Development,

Lessons from a laissez-faire payments system: the Suffolk Banking System (1825-58)

A classic example of a privately created interbank payments system was operated by the Suffolk Bank of New England (1825–58). Known as the Suffolk Banking System, it was the nation’s first regionwide net-clearing system for bank notes. While it operated, notes of all New England banks circulated at par throughout the region. Some have concluded from this experience that unfettered competition in the provision of payments services can produce an efficient payments system. But another look at the history of the Suffolk Banking System questions this conclusion. The Suffolk Bank earned extraordinary profits, and note-clearing may have been a natural monopoly. There is no consensus in the literature about whether unfettered operation of markets with natural monopolies produces an efficient allocation of resources. ; Reprinted in Quarterly Review, Fall 2002 (v. 26. no. 4)Suffolk Banking System ; Payment systems