10,822 research outputs found
International Partnerships: A Model for Educational Organizations
Opportunities exist for faculty and students within educational leadership preparation programs to participate in international initiatives within developing countries. One way to do this is through collaboration with organizations that already have an established presence in the country. Working within these organizations provides opportunities for learning and research for the educational leadership program. If done well, such work also helps host organizations meet their mission and goals. An understanding of effective behaviors in international partnerships may benefit educational leadership programs that develop these types of service opportunities. The behaviors mirror the scholar-practitioner philosophy, of which some prominent educational leadership programs adhere, through addressing pragmatic needs within a local context
Effects of impurity atoms on sputtered GMR multilayers
We have investigated the effects of residual
gas impurity atoms on interlayer exchange coupling
and giant magnetoresistance (GMR) in Co(9Ä)/Cu(9Ä)
multilayers. Structural analysis was performed by Co(59)
NMR. We deposited sub-monolayer quantities of residual
gases at different points in the Co/Cu bilayer; the
interfaces, or the middle of the Cu spacers or CO magnetic
layers. Impurities at the interface lower the GMR
and increase remenant fraction and saturation field. We
are able to model these results phenomenologically by
adding biquadratic coupling. Impurities in the bulk of
the Cu layers lower GMR still further, and such samples
are well described by models containing almost
100% biquadratic coupling. We have demonstrated that
the ttansport parameters in our samples are largely
unaffected by small quantities of impurities, but that
the interlayer coupling is extremely sensitive to them,
particularly in the bulk of the Cu spacer layers
Thermodynamics of Quadrature Trajectories in Open Quantum Systems
We apply a large-deviation method to study the diffusive trajectories of the
quadrature operators of light within a reservoir connected to dissipative
quantum systems. We formulate the study of quadrature trajectories in terms of
characteristic operators and show that in the long time limit the statistics of
such trajectories obey a large-deviation principle. We take our motivation from
homodyne detection schemes which allow the statistics of quadrature operator of
the light field to be measured. We illustrate our approach with four examples
of increasing complexity: a driven two-level system, a `blinking' three-level
system, a pair of weakly-coupled two-level driven systems, and the micromaser.
We discuss how quadrature operators can serve as alternative order parameters
for the classification of dynamical phases, which is particularly useful in
cases where the statistics of quantum jumps cannot distinguish between such
phases. The formalism we introduce also allows us to analyse the properties of
the light emitted by quantum jump trajectories which fluctuate far from the
typical dynamics.Comment: 17 pages, 20 figure
Fuel quality/processing study. Volume 4: On site processing studies
Fuel treated at the turbine and the turbine exhaust gas processed at the turbine site are studied. Fuel treatments protect the turbine from contaminants or impurities either in the upgrading fuel as produced or picked up by the fuel during normal transportation. Exhaust gas treatments provide for the reduction of NOx and SOx to environmentally acceptable levels. The impact of fuel quality upon turbine maintenance and deterioration is considered. On site costs include not only the fuel treatment costs as such, but also incremental costs incurred by the turbine operator if a turbine fuel of low quality is not acceptably upgraded
The effect of genomic information on optimal contribution selection in livestock breeding programs
BACKGROUND: Long-term benefits in animal breeding programs require that increases in genetic merit be balanced with the need to maintain diversity (lost due to inbreeding). This can be achieved by using optimal contribution selection. The availability of high-density DNA marker information enables the incorporation of genomic data into optimal contribution selection but this raises the question about how this information affects the balance between genetic merit and diversity. METHODS: The effect of using genomic information in optimal contribution selection was examined based on simulated and real data on dairy bulls. We compared the genetic merit of selected animals at various levels of co-ancestry restrictions when using estimated breeding values based on parent average, genomic or progeny test information. Furthermore, we estimated the proportion of variation in estimated breeding values that is due to within-family differences. RESULTS: Optimal selection on genomic estimated breeding values increased genetic gain. Genetic merit was further increased using genomic rather than pedigree-based measures of co-ancestry under an inbreeding restriction policy. Using genomic instead of pedigree relationships to restrict inbreeding had a significant effect only when the population consisted of many large full-sib families; with a half-sib family structure, no difference was observed. In real data from dairy bulls, optimal contribution selection based on genomic estimated breeding values allowed for additional improvements in genetic merit at low to moderate inbreeding levels. Genomic estimated breeding values were more accurate and showed more within-family variation than parent average breeding values; for genomic estimated breeding values, 30 to 40% of the variation was due to within-family differences. Finally, there was no difference between constraining inbreeding via pedigree or genomic relationships in the real data. CONCLUSIONS: The use of genomic estimated breeding values increased genetic gain in optimal contribution selection. Genomic estimated breeding values were more accurate and showed more within-family variation, which led to higher genetic gains for the same restriction on inbreeding. Using genomic relationships to restrict inbreeding provided no additional gain, except in the case of very large full-sib families
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