It is common for large population-based surveys to select a sample from a population using a complex design. A simulation study was conducted to compare the estimates from the stratified proportional hazards model with the weighted estimates of the Binder method, when a stratified random sample of the population is used. The SAS PHREG procedure performs regression analysis of survival data base...

Networks have in recent years emerged as an invaluable tool for describing and quantifying complex systems in many branches of science. Recent studies suggest that network often exhibit hierarchical organization, where vertices divide into groups that further subdivided into groups of groups, and so forth over multiple scales. In this paper, we introduce a novel algorithm that searches for the ...

a new sensitive, simple and rapid method for determination of methotrexate (mtx) was developed based on quenching effects of mtx on the fluorescence intensity of tb3+-1,10-phenanthroline complex. the fluorescence intensity was measured with excitation wavelength of 300 nm and emission wavelength of 545 nm and the quenched fluorescence intensity is proportional to the concentration of mtx in tris...

Correspondence to Dr Michael Nurmohamed; [email protected] ABSTRACT Objective: To assess the effects of treatment with antitumour necrosis factor (TNF) agents, methotrexate, or other non-biological disease-modifying antirheumatic drugs (DMARDs) on cardiovascular event risks among patients with rheumatoid arthritis (RA). Methods: We conducted a retrospective study using data from the MarketScan...

deregulation policy has caused some changes in the concepts of power systems reliability assessment and enhancement. in this paper, generation reliability is considered, and a method for its assessment using intelligent systems is proposed. also, because of power market and generators’ forced outages stochastic behavior, monte carlo simulation is used for reliability evaluation. generation reli...

We benchmark the dynamical simplex evolution (DSE) method with several of the currently available algorithms to detect communities in complex networks by comparing correctly identified nodes for different levels of "fuzziness" of random networks composed of well-defined communities. The potential benefits of the DSE method to detect hierarchical substructures in complex networks are discussed.

A new sensitive, simple and rapid method for determination of methotrexate (MTX) was developed based on quenching effects of MTX on the fluorescence intensity of Tb3+-1,10-phenanthroline complex. The fluorescence intensity was measured with excitation wavelength of 300 nm and emission wavelength of 545 nm and the quenched fluorescence intensity is proportional to the concentration of MTX in Tris...

Proportional damping is a widely used approach to model dissipative forces in complex engineering structures and it has been used in various dynamic problems for more than ten decades. A major limitation of the mass and stiffness proportional damping approximation is the lack of generality of the model to allow for experimentally observed variation of damping factors with respect to vibration f...