Group theory is a branch of mathematics that studies, of course, the structure and behavior of "groups." A mathematical group is composed of a set of elements and a group operation (call it "multiplication" and denote it as *); the set is closed under multiplication--combining elements using multiplication never leads outside the group. It is a closed system. In addition to being closed, a grou...

In the current knowledge economy era, knowledge has become an organization’s primary resource due to the fact that an organization is an extension of an information society. Therefore, firms that are able to effectively manage their knowledge resources can expect to reap a wide range of benefits. Due to the diversity of organizational culture (which include results-oriented, tightly controlled,...

In a work of Just, Miller, Scheepers and Szeptycki it was asked whether certain diagonalization properties for sequences of open covers are provably closed under taking finite or countable unions. In a recent work, Scheepers proved that one of the properties in question is closed under taking countable unions. After surveying the known results, we show that none of the remaining classes is prov...

background: except in emergency cases, all patients should be seen first by a primary healthcare physician who decides whether a referral to secondary care is necessary. the present study examined the reasons for patient self-referral to specialists. methods: a random sample of 1036 individuals was selected from people attending public outpatient clinics and specialists’ offices in the private ...

The number of closed-circuit television (CCTV) cameras in British town centres has rapidly increased in recent years. These increases are mirrored in Europe and North America. In Britain many of these cameras videotape town centres, 24 hours a day, 365 days a year. How do CCTV systems account for the space of the town centres in which they operate? What theoretical sensibilities can we use to e...

Assuming spherical symmetry we analyse the dynamics of an inhomogeneous dark radiation vaccum on a Randall and Sundrum 3-brane world. Under certain natural conditions we show that the effective Einstein equations on the brane form a closed system. On a de Sitter brane and for negative dark energy density we determine exact dynamical and inhomogeneous solutions which depend on the brane cosmolog...

In this paper we will continue the study of p-closed spaces. This class of spaces is strictly placed between the class of strongly compact spaces and the class of quasi-Hclosed spaces. We will provide new characterizations of p-closed spaces and investigate their relationships with some other classes of topological spaces.

Clinical research requires a secure working environment for data management tasks. Traditionally, this was achieved by using closed systems not accessible via network communication. More recently, however, as research projects especially in the academic setting take on more distributed forms with partners working in different institutions and/or locations, closed environments may no longer be f...