BACKGROUND Most animal species display Sexual Size Dimorphism (SSD): males and females consistently attain different sizes, most frequently with females being larger than males. However the selective mechanisms driving patterns of SSD remain controversial. 'Rensch's rule' proposes a general scaling phenomenon for all taxa, whereby SSD increases with average body size when males are larger than ...

PURPOSE To study the effect of pupil size on the relationship between refractive astigmatism and uncorrected distance visual acuity (UDVA) and pseudoaccommodation in pseudophakic eyes. METHODS Thirty-six eyes from 36 patients who underwent phacoemulsification and intraocular lens (IOL) implantation were included. All eyes were divided into two groups based on the presence of postoperative-wit...

Sexual size dimorphism (SSD) is almost universal in animals. Rensch’s rule proposes that SSD increases with increasing average body size in taxa where males are larger than females (malebiased SSD; MBSSD) and decreases when females are larger (femalebiased SSD; FBSSD). Although it was proposed that both patterns are part of the same evolutionary trend, there is more evidence for Rensch’s rule i...

Understanding the ecological impacts of climate change is a crucial challenge of the twenty-first century. There is a clear lack of general rules regarding the impacts of global warming on biota. Here, we present a metaanalysis of the effect of climate change on body size of ectothermic aquatic organisms (bacteria, phyto- and zooplankton, and fish) from the community to the individual level. Us...

Rensch's rule states that sexual size dimorphism (SSD) increases with body size in taxa where males are larger, and decreases when females are larger. The dominant explanation for the trend is currently that competitive advantage for males is greater in larger individuals, whereas female size is constrained by the energetics of rearing offspring. This rule holds for a variety of vertebrate taxa...

SAMPLE SIZE MUST BE PLANNED carefully to ensure that the research time, patient effort and support costs invested in any clinical trial are not wasted. Item 7 of the CONSORT statement relates to the sample size and stopping rules of studies (see Box 1); it states that the choice of sample size needs to be justified. 1 Ideally, clinical trials should be large enough to detect reliably the smalle...

Sample size justification is an important consideration when planning a clinical trial, not only for the main trial but also for any preliminary pilot trial. When the outcome is a continuous variable, the sample size calculation requires an accurate estimate of the standard deviation of the outcome measure. A pilot trial can be used to get an estimate of the standard deviation, which could then...

OBJECTIVE To characterise the percentage of available outcome data being presented in reports of randomised clinical trials with continuous outcome measures, thereby determining the potential for incomplete reporting bias. DESIGN Descriptive cross sectional study. DATA SOURCES A random sample of 200 randomised trials from issues of 20 medical journals in a variety of specialties during 2007...