In this paper, we consider a multi-server queuing system in which additional servers are allowed for a longer queue to reduce the customer’s balking and reneging behavior. The customers are assumed to arrive in Poisson fashion and their service- times follow exponential distribution. The number of servers in long run depends on the queue-length. We obtain equilibrium queue size distribution. Th...

Simultaneous measurements of biomass and excretion of macroplankton-micronekton lead to similar results in tropical Atlantic and Pacific Oceans. Ratios are thus proposed to roughly estimate regenerated production in oligotrophic tropical waters from biomass data: biomass figures (mg dry wt m-') should be multiplied by 0.32 to estimate the amount of total nitrogen excreted (p,g at m-' day-') and...

INTRODUCTION For survival data the coefficient of determination cannot be used to describe how good a model fits to the data. Therefore, several measures of explained variation for survival data have been proposed in recent years. METHODS We analyse an existing measure of explained variation with regard to minimisation aspects and demonstrate that these are not fulfilled for the measure. RE...

CONTEXT Ongoing efforts to improve the quality of reporting for randomized controlled trials (RCTs) include the Consolidated Standards of Reporting Trials (CONSORT) statement. We examined the frequency of explicit reporting of the number needed to treat (NNT) and the absolute risk reduction (ARR) in RCTs. METHODS Five frequently cited journals were investigated: Annals of Internal Medicine, B...

Informed participation in population based screening programmes requires an explicit sharing of information about risks and benefits. However, many factors influence perceptions of risk and the value of risk reduction promised through screening. Campaigns that selectively quote incidence to “frighten” women into undergoing mammography have been criticised. Perceived risk, not objective risk, ex...

BACKGROUND Guidelines on cardiovascular disease (CVD) risk reassessment intervals are unclear, potentially leading to detrimental practice variation: too frequent can result in overtreatment and greater strain on the healthcare system; too infrequent could result in the neglect of high risk patients who require medication. This study aimed to understand the different factors that general practi...

BACKGROUND Many risk factors for fractures have been documented, including low bone-mineral density (BMD) and a history of fractures. However, little is known about the short-term absolute risk (AR) of fractures and the timing of clinical fractures. Therefore, we assessed the risk and timing of incident clinical fractures, expressed as 5-year AR, in postmenopausal women. METHODS In total, 10 ...

BACKGROUND Debate exists regarding to whether thiopurine therapy is as effective in ulcerative colitis (UC) as it is in Crohn's disease. AIM To review systematically the efficacy of azathioprine (AZA) and mercaptopurine (MP) in UC, and to conduct a meta-analysis of randomized clinical trials evaluating the efficacy of AZA/MP for the induction or maintenance of UC clinical remission. METHODS...

BACKGROUND National estimates of 'heart age' by government health organisations in the US, UK and China show most people have an older heart age than current age. While most heart age calculators are promoted as a communication tool for lifestyle change, they may also be used to justify medication when clinical guidelines advocate their use alongside absolute risk assessment. However, only thos...

Assume that M is a compact Riemannian manifold of bounded geometry given by restrictions on its diameter, Ricci curvature and injectivity radius. Assume we are given, with some error, the first eigenvalues of the Laplacian ∆ on M as well as the corresponding eigenfunctions restricted on an open set in M . We then construct a stable approximation to the manifold (M,g). Namely, we construct a met...