Difference-based clustering of short time-course microarray data with replicates

<p>Abstract</p> <p>Background</p> <p>There are some limitations associated with conventional clustering methods for short time-course gene expression data. The current algorithms require prior domain knowledge and do not incorporate information from replicates. Moreover, the results are not always easy to interpret biologically.</p> <p>Results</p> <p>We propose a novel algorithm for identifying a subset of genes sharing a significant temporal expression pattern when replicates are used. Our algorithm requires no prior knowledge, instead relying on an observed statistic which is based on the first and second order differences between adjacent time-points. Here, a pattern is predefined as the sequence of symbols indicating direction and the rate of change between time-points, and each gene is assigned to a cluster whose members share a similar pattern. We evaluated the performance of our algorithm to those of K-means, Self-Organizing Map and the Short Time-series Expression Miner methods.</p> <p>Conclusions</p> <p>Assessments using simulated and real data show that our method outperformed aforementioned algorithms. Our approach is an appropriate solution for clustering short time-course microarray data with replicates.</p

Dimeric SecA Couples the Preprotein Translocation in an Asymmetric Manner

The Sec translocase mediates the post-translational translocation of a number of preproteins through the inner membrane in bacteria. In the initiatory translocation step, SecB targets the preprotein to the translocase by specific interaction with its receptor SecA. The latter is the ATPase of Sec translocase which mediates the post-translational translocation of preprotein through the protein-conducting channel SecYEG in the bacterial inner membrane. We examined the structures of Escherichia coli Sec intermediates in solution as visualized by negatively stained electron microscopy in order to probe the oligomeric states of SecA during this process. The symmetric interaction pattern between the SecA dimer and SecB becomes asymmetric in the presence of proOmpA, and one of the SecA protomers predominantly binds to SecB/proOmpA. Our results suggest that during preprotein translocation, the two SecA protomers are different in structure and may play different roles

Teachers and Mindful Colouring to Tackle Burnout and Increase Mindfulness, Resiliency and Wellbeing

The number of teachers leaving the profession continues to increase at a worrying rate. Factors contributing to this include burnout, heightened levels of stress, anxiety and depression. The current study tested whether the use of mindful colouring would translate to improvements in wellbeing. Teachers from the UK (n = 35) were randomly assigned to a colouring mindfulness-based intervention or waitlist group. Participants completed four scales (burnout, wellbeing, resilience and mindfulness) and participated in a 5-day intervention of daily mindfulness colouring or continued their working week as usual. Results of repeated-measures ANOVA showed statistically significant lower levels of burnout, stress, depressive symptoms and anxiety in the mindfulness colouring condition, as well as increased levels of resilience and mindfulness. Findings from the current study support the use of mindfulness colouring to significantly enhance levels of wellbeing in teachers. The study also presents an inexpensive, highly accessible and effective self-help tool for this targeted non-clinical population

Microalgae as second generation biofuel. A review

International audienc