The other metabolic function that can affect PHA levels in cells is the rate of polymer turnover, which is catalyzed by PHA depolymerase, encoded by phaZ genes. These are difficult enzymes to assay because of the polymeric nature of their substrates, but evidence suggests that they are associated with the carbonosome granules, and cells express a set of paralogs that display different substrate specificities. Finally, our results indicate that PHA content enhances growth rate of R. rubrum. Though the underlying mechanism of this phenomenon is still unclear, previous studies have shown that PHA enhances resistance to stresses, and this resistance may be mediated by increasing of the levels of the growth regulator guanosinetetraphosphate, which enhances PHA degradation during the stress of Pseudomonas oleovorans. Visual analogue scales are commonly used in clinical trials and other studies as primary or secondary outcomes or as a tool to derive a health utility index. The VAS is a 10 cm long straight line, marked at each end with labels which anchor the scale. Vertical and horizontal presentations have been developed, although the horizontal version is the most common. In the context of pain, patients are asked to place a mark on the line at a point representing the severity of their pain where the anchors are ��no pain�� and ��pain as bad as it could be��. Scores are noted in millimetres thus giving a total score range of 0�C100 millimetres. Consequently, the VAS is often treated as an interval level scale and subjected to arithmetical operations and parametric statistics. However, just because clinicians and researchers assume that the score in millimetres is interval in nature, this does not necessarily mean that patients score it as an interval scale. Indeed, some CCG215022 research suggests that patients find it difficult to judge how to rate their pain on the pain VAS line, finding it ��not very accurate��, ��sort of random��, ��almost guesswork�� or having to ��work it into numbers first��. A study on business travellers also revealed that scores on a VAS cluster into much BMS-935177 inhibitor smaller groups. A wide range of Minimally Important Differences in change scores on the pain VAS have been reported, ranging from nine to 30 millimetres in emergency departments. Elsewhere changes of 33% and 3.11 cm have been shown as clinically meaningful post-operatively.