A cryptic promoter in potato virus X vector interrupted plasmid construction

BACKGROUND: Potato virus X has been developed into an expression vector for plants. It is widely used to express foreign genes. In molecular manipulation, the foreign genes need to be sub-cloned into the vector. The constructed plasmid needs to be amplified. Usually, during amplification stage, the foreign genes are not expressed. However, if the foreign gene is expressed, the construction work could be interrupted. Two different viral genes were sub-cloned into the vector, but only one foreign gene was successfully sub-cloned. The other foreign gene, canine parvovirus type 2 (CPV-2) VP1 could not be sub-cloned into the vector and amplified without mutation (frame shift mutation). RESULTS: A cryptic promoter in the PVX vector was discovered with RT-PCR. The promoter activity was studied with Northern blots and Real-time RT-PCR. CONCLUSION: It is important to recognize the homologous promoter sequences in the vector when a virus is developed as an expression vector. During the plasmid amplification stage, an unexpected expression of the CPV-2 VP1 gene (not in the target plants, but in E. coli) can interrupt the downstream work

Water-Driven Assembly of Laser Ablation-Induced Au Condensates as Mesomorphic Nano- and Micro-Tubes

Reddish Au condensates, predominant atom clusters and minor amount of multiply twinned particles and fcc nanoparticles with internal compressive stress, were produced by pulsed laser ablation on gold target in de-ionized water under a very high power density. Such condensates were self-assembled as lamellae and then nano- to micro-diameter tubes with multiple walls when aged at room temperature in water for up to 40 days. The nano- and micro-tubes have a lamellar- and relaxed fcc-type wall, respectively, both following partial epitaxial relationship with the co-existing multiply twinned nanoparticles. The entangled tubes, being mesomorphic with a large extent of bifurcation, flexibility, opaqueness, and surface-enhanced Raman scattering, may have potential encapsulated and catalytic/label applications in biomedical systems

Potential Implications of Mail Delivery Conversion on Older Adults’ Risk of Falls in The Winter

In December 2013, Canada Post announced they would be converting approximately five million households from door-to-door mail delivery to community mailboxes (CMB). The decision was made to address decreasing letter mail volume and operating losses experienced by the crown corporation. The CMBs will be phased in over the five years mainly in urban areas across the country. The decision to convert to CMBs makes Canada the only among the G8 countries to end home delivery of mail. As a result, no research exists on the implications of the change. Particular concern has been raised over how the conversion will affect older adults. One area that needs examination is the consequences of the CMBs delivery model on fall rates among older adults in the winter. Falls are common among seniors, with 20-30% community dwelling older adults falling each year. The risk of falling is increased in the winter when there is snow and ice on the ground. Injuries dues to falls consume a great deal of healthcare resources. The purpose of this scoping literature review was to determine: What are the implications for the elderly population of Canada Post’s decision to convert home delivery of mail to community mailbox delivery? Specifically, the review focused on how the conversion may impact fall rates among older adults in the winter