background: closure of patent ductus arteriosus (pda), ventricular septal defect (vsd) and atrial septal defect (asd) can be done surgically or by device. this study was designed to compare the total cost of surgical or device closures of pda, asd or vsd for iranian patients. methods: this is a cross-sectional study, conducted from january 1, 2005 until january 1, 2006 in two large heart center...

Activities of advanced applications can be modeled by interrelated transactions. These relations can be described by diierent kinds of transaction dependencies. The notion of transaction closure is a generalization of nested transactions providing means to describe complex activities such as transactional workkows. In this paper, our main focus lies on execution dependencies for describing cert...

In integer programming, the elementary closure associated with a family of cuts is the convex set de ned by the intersection of all the cuts in the family. In this paper, we compare the elementary closures arising from several classical families of cuts: three versions of Gomory's fractional cuts, three versions of Gomory's mixed integer cuts, two versions of intersection cuts and their strengt...

We study the mixed-integer rounding (MIR) closures of polyhedral sets. The MIR closure of a polyhedral set is equal to its split closure and the associated separation problem is NP-hard. We describe a mixed-integer programming (MIP) model with linear constraints and a non-linear objective for separating an arbitrary point from the MIR closure of a given mixed-integer set. We linearize the objec...

A relevant amount of work has been devoted very recently to modeling and (heuristically) solving the NP-hard separation problem of famous classes of valid inequalities for mixed integer linear programs (MIPs). This task has been accomplished by using, in turn, mixed-integer linear models for the separation problem, and a general-purpose solver to actually find violated cuts—the so-called MIPpin...

Alkaloid-modified, voltage-dependent sodium channels from lobster walking leg nerves were studied in planar neutral lipid bilayers. In symmetrical 0.5 M NaCl the single channel conductance of veratridine (VTD) (10 pS) was less than that of batrachotoxin (BTX) (16 pS) modified channels. At positive potentials, VTD- but not BTX-modified channels remained open at a flickery substate. VTD-modified ...

Every action in a conservation plan has a different level of effect and consequently contributes differentially to conservation. We examined how several community-based, marine, management actions differed in their contribution to national-level conservation goals in Fiji. We held a workshop with experts on local fauna and flora and local marine management actions to translate conservation goal...