Unfortunately, it was not possible to compare the crows' behaviour with those of other studies where complex cognition has been suggested because of methodological issues such as the use of juveniles [14], lack of controls for neophobia, competition and social learning [7] and small sample size [9].
Such exposure circumstances represent a challenge to epidemiology, because of methodological issues such as limited power to detect small risks, exposure misclassification, and residual confounding.
In advanced colorectal cancer, reports on the correlation of patient outcomes with FDG-PET/CT-based metabolic response assessment after 1 or 2 months of chemotherapy are inconsistent [ 21- 23], probably partially because of methodological issues in multi-metastatic assessment.
It might therefore be expected that carers would visit their GPs more than the population as a whole, although the evidence here is inconclusive, possibly in part because of methodological issues [ 14].
Although useful, C4d has significant limitations for the diagnosis of ABMR, not least because of methodological issues (immunoperoxidase vs. immunofluorescence, frozen vs. paraffin), poor understanding of the meaning of minimal and focal staining, and its waxing and waning deposition.
However, even though it is clear that individual medical bills differ by age group, few studies have investigated age-specific medical expenses because of methodological issues, such as insufficient sample sizes and inappropriate statistical models.
The study that first proposed the theory of CCSVI, carried out in 2008 by Paolo Zamboni, was interesting but had a number of methodological issues.
A number of methodological issues arise from this pioneering study.
In addition the journal offers discussion of methodological issues involving the variety of approaches appropriate for addressing these problems.
In addition the journal welcomes discussions of methodological issues that involve the variety of approaches appropriate for addressing these problems.
However, there are a number of methodological issues with these early studies to consider.
