Sequence organization of feline leukemis virus DNA in infected cells

A restriction site map has been deduced of unintegrated and integrated FeLV viral DNA found in human RD cells after experimental infection with the Gardner-Arnstein strain of FeLV. Restriction fragments were ordered by single and double enzyme digests followed by Southern transfer (1) and hybridization with 32P-labeled viral cDNA probes. The restriction map was oriented with respect to the 5' and 3' ends of viral RNA by using a 3' specific hybridization probe. The major form of unintegrated viral DNA found was a 8.7 kb linear DNA molecule bearing a 450 bp direct long terminal redundancy (LTR) derived from both 5' and 3' viral RNA sequences. Minor, circular forms, 8.7 kb and 8.2 kb in length were also detected, the larger one probably containing two adjacent copies of the LTR and the smaller one containing one copy of the LTR. Integrated copies of FeLV are colinear with the unintegrated linear form and contain the KpnI and SmaI sites found in each LTR

Exploring The “Mojo” Of Presidential Awards For Excellence In Mathematics And Science Teaching (PAEMST) Recipients

The purpose of this dissertation was to determine how extraordinary science teachers develop their teaching mojo. The teachers investigated were recipients of the prestigious Presidential Award for Excellence in Math and Science Teaching (PAEMST). This investigation focuses specifically on science instruction. The method used for this investigation was individual and group interviews conducted with eight PAEMST recipients. Five themes emerged from these interviews: 1. Science is a natural motivator for learning; 2. Students need to be scientifically literate citizens; 3. A critical “trigger event” propelled each of these teachers towards great science instruction; 4. Each sought out and engaged in ongoing, challenging professional development; 5. Despite isolation and inconsistent administrative support, all became and remain rock-solid advocates for science instruction. Recommendations for district-level administration and principals to identify, support, and sustain exemplary science teachers include: 1. Embrace science as a natural motivator for learning; 2. Increase support for science instruction as related to science, technology, engineering and math (STEM) curricula and instruction; 3. Provide exceptional professional development in best practices in science curriculum and instruction for both teachers and administrators; 4. Make this professional development hands-on and rigorous; 5. When seeking to identify possible science teachers in your school or district, look for those individuals who have demonstrated a strong desire to extend themselves professionally

Just luck: an experimental study of risk taking and fairness

Choices involving risk significantly affect the distribution of income and wealth in society. This paper reports the results of the first experiment, to our knowledge, to study fairness views about risk-taking, specifically whether such views are based chiefly on ex ante opportunities or on ex post outcomes. We find that, even though many participants focus exclusively on ex ante opportunities, most favor some redistribution ex post. Many participants also make a distinction between ex post inequalities that reflect differences in luck and ex post inequalities that reflect differences in choices. These findings apply to both stakeholders and impartial spectators.fairness; justice; risk

Frequency division multiplexing for interferometric planar Doppler velocimetry

A new method of acquiring simultaneously the signal and reference channels used for interferometric planar Doppler velocimetry is proposed and demonstrated. The technique uses frequency division multiplexing (FDM) to facilitate the capture of the requisite images on a single camera, and is suitable for time-averaged flow measurements. Furthermore, the approach has the potential to be expanded to allow the multiplexing of additional measurement channels for multicomponent velocity measurement. The use of FDM for interferometric referencing is demonstrated experimentally with measurements of a single velocity component of a seeded axisymmetric air jet. The expansion of the technique to include multiple velocity components was then investigated theoretically and experimentally to account for bandwidth, crosstalk, and dynamic range limitations. The technique offers reduced camera noise, automatic background light suppression, and crosstalk levels of typically <10%. Furthermore, as this crosstalk is dependent upon the channel modulations applied, it can be corrected for in postprocessing

Range-resolved signal processing for fibre segment interferometry applied to dynamic long-gauge length strain sensing

A range-resolved interferometric signal processing technique using sinusoidal optical frequency modulation is applied to fibre segment interferometry. Here, six optical fibre segments of gauge length 12.5 cm are used as interferometric strain sensors and are formed between seven weak, broadband fibre Bragg gratings, acting as in-fibre partial reflectors. In a very simple and cost-effective optical setup using injection current modulation of a laser diode source, interferometric measurement of acoustic wave propagation in a metal rod is used to demonstrate the capabilities of the technique

Acquisition of Energy Resources Under The Pacific Northwest Electric Power Planning and Conservation Act: A Look At The Future

This article addresses the impact of the Pacific Northwest Electric Power Planning and Conservation Act, focusing on two issues: (1) proposed administrative procedures, and (2) the BPA purchase authority. Purchase authority permits the BPA to purchase additional electric energy beyond the hydroelectric and thermal power it already markets. Purchase authority was at the heart of the debate over the regional power legislation. The administrative procedures the agency may adopt will establish the framework for many of the BPA\u27s majority policy decision. Discussion of these issues necessarily involves an analysis of how the legislation will affect the BPA\u27s actions