DNA sequence of the mouse H-2Dd transplantation antigen gene

The inbred BALB/c mouse has three transplantation antigens, H2-Kd, H2-Ld, and H2-Dd. We present the complete nucleotide sequence of the H2-Dd gene as well as 777 residues of previously unpublished H-2Dd protein sequence. These data complete the sequences of all the BALB/c transplantation antigen genes and permit detailed comparison with each other and with their counterparts from the inbred C57BL/10 mouse. Transplantation antigens may differ from one another by as much as 5%-15% of their amino acid sequence for the external domains. These extensive differences may arise by gene conversion. The H-2D region of the BALB/c mouse encodes the H2-Dd and the H2-Ld genes. Serologic data suggest that at least two additional transplantation antigen molecules, H2-Rd and H2-Md, are encoded in the H-2D region of the major compatibility complex. Paradoxically, gene cloning studies have only identified the H2-Dd and the H2-Ld genes in the H-2D region. A complete DNA sequence of the H2-Dd gene shows that a variety of alternative splice sites exist throughout the gene, which may lead to additional gene products and may explain the multiplicity of H-2D-encoded polypeptides

Sacrificial charge and the spectral resolution performance of the Chandra Advanced CCD Imaging Spectrometer

Soon after launch, the Advanced CCD Imaging Spectrometer (ACIS), one of the focal plane instruments on the Chandra X-ray Observatory, suffered radiation damage from exposure to soft protons during passages through the Earth's radiation belts. The ACIS team is continuing to study the properties of the damage with an emphasis on developing techniques to mitigate charge transfer inefficiency (CTI) and spectral resolution degradation. A post-facto CTI corrector has been developed which can effectively recover much of the lost resolution. Any further improvements in performance will require knowledge of the location and amount of sacrificial charge - charge deposited along the readout path of an event which fills electron traps and changes CTI. We report on efforts by the ACIS Instrument team to characterize which charge traps cause performance degradation and the properties of the sacrificial charge seen on-orbit. We also report on attempts to correct X-ray pulseheights for the presence of sacrificial charge.Comment: 9 pages, 7 figures to be published in Proc. SPIE 485

Biology Laboratories at a Distance: A Case Study and Experiment of Ecology and Evolution Labs with Community College Students

Community colleges deliver more courses online; laboratory-based courses face challenges in how to do this. This study examined how ecology and evolution laboratories could effectively be delivered in an online biology community college course. Virtual simulations and hands-on, at-home kits were used in two groups. Results showed that students using the virtual simulations had higher learning gains and more positive perceptions towards their laboratory experiences than those students using athome kits. By evaluating learning gains on a pretest/posttest and utilizing interviews and focus groups, this research concluded that virtual simulations offered a superior learning experience for online learners. The results suggest that laboratory experiences offered students important advantages: course engagement, opportunities to think about the processes of science, and opportunities to engage with difficult or abstract content. Students expected laboratories to be streamlined. The results of this research suggest that instructors and administrators at community colleges critically examine the use of virtual simulations for abstract or difficult content as virtual simulations provided opportunities for greater student success than traditional, hands-on labs when delivered online. Virtual simulations provide viable alternatives to traditional laboratories for online students

Shopping Center Parking Lot Liability

More than sixty-eight million automobiles were registered in the United States in 1963 alone. This horde of automobiles, along with the mass exodus to the suburbs, has caused shopping centers to become integral parts of community living, and has made facilities for parking around them of principal importance. The resultant revolution in merchandising has extended the property owner\u27s duty of care to include such parking areas

You Don\u27t Belong: Exploring Luxury Branding Strategy

Luxury branding strategies create impressions of exclusivity which is transmitted into the brand’s products and retail spaces. Exclusivity is a necessary component to create consumer desire despite limitations of accessibility, time, effort, and pricing. A new population of aspirational shoppers, known as Chandlers, highly value exclusive brands as they increase perceptions of social status. This study will examine the impact of loud vs. discrete luxury branding on perceptions of brand status and browsing intentions, and the moderating impact of the Chandler effect