While virtual communities (VCs) have been used mainly for information sharing and social networking, little is known as to how online vendors can derive benefits from them in practice. VCs are particularly successful in attracting and retaining members. Online vendors have attempted to capitalize on this characteristic of a virtual community (VC) for obtaining numerous commercial benefits, such...

Branner-Hubbard motion is a systematic way of deforming an attracting holomorphic dynamical system f into a family (fs)s∈L, via a holomorphic motion which is also a group action. We establish the analytic dependence of fs on s (a result first stated by Lyubich) and the injectivity of fs on f . We prove that the stabilizer of f (in terms of s) is either the full group L (rigidity), or a discrete...

In recent years the major developments in employee-benefit plans sponsored or underwritten by private organizations have been reported regularly in the Social Xecurity Bulletin. Thiis year the report is in two parts. Part I, which appeared in the April issue of the Bulletin, included 1959 data on coverage, contributions, and benefits under health, welfare, and retirement plans. In addition it d...

From time to time the Bulletin carries reports on operations in the five States that supplement the unemployment insurance benefit with a small allowance for dependents of beneficiaries . This article discusses sources from which data on the dependents of wage earners can be obtained and the use of such information in estimating the extent to which inclusion of dependents’ allowances aflects th...

The purpose of this study is to present the information on the duration of treatment and the cost of work-related low back pain. Using the compensation-database for 1997 work-related low back pain (n=9,277), this study estimated the duration of treatment, the cost of work-related low back pain, the relationship between them, and probability of being off treatment at different intervals. The mea...