Intronless mRNA transport elements may affect multiple steps of pre-mRNA processing.

We have reported recently that a small element within the mouse histone H2a-coding region permits efficient cytoplasmic accumulation of intronless beta-globin cDNA transcripts. This sequence lowers the levels of spliced products from intron-containing constructs and can functionally replace Rev and the Rev-responsive element (RRE) in the nuclear export of unspliced HIV-1-related mRNAs. In work reported here, we further investigate the molecular mechanisms by which this element might work. We demonstrate here through both in vivo and in vitro assays that, in addition to promoting mRNA nuclear export, this element acts as a polyadenylation enhancer and as a potent inhibitor of splicing. Surprisingly, two other described intronless mRNA transport elements (from the herpes simplex virus thymidine kinase gene and hepatitis B virus) appear to function in a similar manner. These findings prompt us to suggest that a general feature of intronless mRNA transport elements might be a collection of phenotypes, including the inhibition of splicing and the enhancement of both polyadenylation and mRNA export

Shady Oak Lake Feasibility Study of Best Management Practices

Report and presentation completed by students enrolled in CE 5511: Urban Hydrology and Land Development, taught by Dr. John Gulliver in spring 2013.This project was completed as part of the 2012-2013 Resilient Communities Project (rcp.umn.edu) partnership with the City of Minnetonka. To improve water quality in Shady Oak Lake, Minnetonka project lead and water resource engineer Liz Stout worked with a team of students in CE 5511: Urban Hydrology and Land Development, to identify potential best management practices for the watershed. The BMPs considered in the study included in-lake treatment, street sweeping, sumps, swales, bio- infiltration, and changes to city ordinances. Based on the analysis, it was determined that increasing the frequency of street sweeping in the lakeshed would be the most effective best management practice.The students' final report and presentation are available.This project was supported by the Resilient Communities Project (RCP), a program at the University of Minnesota whose mission is to connect communities in Minnesota with U of MN faculty and students to advance local sustainability and resilience through collaborative, course-based projects. RCP is a program of the Center for Urban and Regional Affairs (CURA). More information at http://www.rcp.umn.edu

Novel intermetallic-reinforced near-α Ti alloys manufactured by spark plasma sintering

Near-$α$ Ti alloys are ideal candidates for high-temperature aerospace, automotive and nautical propulsion systems due to their high strength, low density and good corrosion resistance. However, the maximum service temperature of the well-known near-$α$ alloy Ti6242S is limited to about 540 °C. By adding, for example, intermetallic $γ$-TiAl based alloy particles to Ti6242S powder a significant increase in yield strength up to 650 °C can be achieved by means of spark plasma sintering, along with sufficient room temperature ductility. In this study, investigations on the underlying strengthening mechanisms were carried out. For this purpose, mechanical tests and detailed microstructural characterization were performed.Spark plasma sintering at 1150 °C of powder blends with 10 m.% spherical $γ$-TiAl based powder (<20 μm) leads to a homogeneous dissolution of the TiAl particles in the matrix material and a refinement of the lamellar microstructure. Due to the formation of ordered intermetallic α$_2$-Ti$_3$Al precipitates, which are completely stable up to 670 °C in the newly evolved Ti-8.3Al-1.8Sn-3.7Zr-2.0Mo-0.9Nb-0.08Si alloy (m.%), the creep resistance at 600 °C has been increased significantly. In the B containing variant, it was found that finely distributed titanium borides TiB formed in the Ti6242 matrix and led to an even more pronounced refinement of the microstructure. For B additions of 1 m.%, however, the creep resistance at 600 °C is reduced compared to the other alloys, but the strength is increased up to 500 °C