Replicate high-density rat genome oligonucleotide microarrays reveal hundreds of regulated genes in the dorsal root ganglion after peripheral nerve injury.

BACKGROUND: Rat oligonucleotide microarrays were used to detect changes in gene expression in the dorsal root ganglion (DRG) 3 days following sciatic nerve transection (axotomy). Two comparisons were made using two sets of triplicate microarrays, naïve versus naïve and naïve versus axotomy. RESULTS: Microarray variability was assessed using the naïve versus naïve comparison. These results support use of a P < 0.05 significance threshold for detecting regulated genes, despite the large number of hypothesis tests required. For the naïve versus axotomy comparison, a 2-fold cut off alone led to an estimated error rate of 16%; combining a >1.5-fold expression change and P < 0.05 significance reduced the estimated error to 5%. The 2-fold cut off identified 178 genes while the combined >1.5-fold and P < 0.05 criteria generated 240 putatively regulated genes, which we have listed. Many of these have not been described as regulated in the DRG by axotomy. Northern blot, quantitative slot blots and in situ hybridization verified the expression of 24 transcripts. These data showed an 83% concordance rate with the arrays; most mismatches represent genes with low expression levels reflecting limits of array sensitivity. A significant correlation was found between actual mRNA differences and relative changes between microarrays (r(2 )= 0.8567). Temporal patterns of individual genes regulation varied. CONCLUSIONS: We identify parameters for microarray analysis which reduce error while identifying many putatively regulated genes. Functional classification of these genes suggest reorganization of cell structural components, activation of genes expressed by immune and inflammatory cells and down-regulation of genes involved in neurotransmission

‘The Use of Social Media to Foster Trust, Mentorship, and Collaboration in Scientific Organizations

Many domains are well known for their resistance to social media. Currently, there is a dearth of literature that explores social media use in these contexts. This study seeks to help address this gap by evaluating the use of social media within a scientific organization (anonymized as SciCity) that has a strong virtual presence and quarterly face-to-face meet-ups. We evaluated SciCity’s use of social media to foster trust, collaboration, and mentorship. We found that the prominent social media platform Twitter fosters trust among organizational members and plays a role in creating and maintaining lightweight collaborative relationships. Additionally, Twitter-based relationships often act as precursors to collaborations that occur face-to-face. However, Twitter, by itself, was not found to be successful in promoting formal collaborations. Though the medium did facilitate sporadic mentoring, supplementary non-social media-based communication was needed to form mentorship relationships. Twitter was also found to serve as a “social lubricant,” making contact easier and faster, thereby helping foster a scientific social network. Though minor in its role in specifically fostering scientific collaboration, the use of social media by SciCity indicates a shift toward acceptable uses of social media for scientific organizations that have traditionally been hesitant to use social media

Stimulation of colonic motility by oral PEG electrolyte bowel preparation assessed by MRI : comparison of split vs single dose

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