We calculate the eigenspectrum of random walks on the Eden tree in two and three dimensions. From this, we calculate the spectral dimension ds and the walk dimension dw and test the scaling relation ds = 2df/dw (= 2d/dw for an Eden tree). Finite-size induced crossovers are observed, whereby the system crosses over from a short-time regime where this relation is violated (particularly in two dim...

The authors compared a case-crossover design, a case-time-control design, and a cohort design to evaluate the effect of nurse staffing level on the risk of nosocomial infections. They evaluated two strategies, conditional logistic regression and generalized estimating equation, to analyze the case-crossover study. The study was performed among critically ill patients in the medical intensive ca...

OBJECTIVE To test the verbal memory of older volunteers given citicoline. DESIGN A randomized, double-blind, placebo-controlled, parallel group design was employed in the initial study. After data analysis, a subgroup was identified whose members had relatively inefficient memories. These subjects were recruited for a second study that used a crossover design. The subjects took either placebo...

Interlocus gene conversion is a major evolutionary force that drives the concerted evolution of duplicated genomic regions. Theoretical models successfully have addressed the effects of interlocus gene conversion and the importance of crossover in the evolutionary fate of gene families and duplications but have not considered complex recombination scenarios, such as the presence of hotspots. To...

OBJECTIVE To evaluate the characteristics of the design, analysis, and reporting of crossover trials for inclusion in a meta-analysis of treatment for primary open-angle glaucoma and to provide empirical evidence to inform the development of tools to assess the validity of the results from crossover trials and reporting guidelines. METHODS We searched MEDLINE, EMBASE, and Cochrane's CENTRAL r...

background: the efficacy of amlodipine, a calcium channel blocker, in treating systemic hypertension is well established but the most efficacious brand of this drug is still uncertain. the cost of different brands of amlodipine is tremendously different which may affect decision-making in hypertension treatment. the purpose of this study was to compare the efficacy and safety of different brand...

The traditional crossover operator used in genetic search exhibits a position-dependent bias called the dcfining-length bias. We show how this bias results in hidden biases that are difficult to anticipate and compensate for. We introduce a new crossover operator, shuffle crossover, that eliminates the position dependent bias of the traditional crossover operator by shuffling the representation...

An analytical study is presented of the crossover in the gapless attractive XXZ chain from antiferromagnetic to ferromagnetic behaviour at low to high temperature, respectively. In particular, an analytic formula for the crossover in the long distance asymptotics and explicit results for the nearest-neighbour longitudinal correlation are obtained. We also provide results for the specific heat a...