356 research outputs found

    Novel Josephson effects between multi-gap and single-gap superconductors

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    Multi-gap superconductors can exhibit qualitatively new phenomena due to existence of multiple order parameters. Repulsive electronic interactions may give rise to a phase difference of π\pi between the phases of the order parameters. Collective modes due to the oscillation of the relative phases of these order parameters are also possible. Here we show that both these phenomena are observable in Josephson junctions between a single-gap and a multi-gap superconductor. In particular, a non-monotonic temperature dependence of the Josephson current through the junction reveals the existence of the π\pi phase differences in the multi-gap superconductor. This mechanism may be relevant for understanding several experiments on the Josephson junctions with unconventional superconductors. We also discuss how the presence of the collective mode resonantly enhances the DC Josephson current when the voltage across the junction matches the mode frequency. We suggest that our results may apply to MgB2_2, 2H-NbSe2_2, spin ladder and bilayer cuprates.Comment: 4 pages, 2 figure

    Analysis of soybean non-nodulation mutants by DNA amplification fingerprinting and bulked segregant analysis

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    In this study, two techniques were combined in order to create a more efficient means to isolate molecular markers for two unlinked non-nodulation loci in soybean. These two techniques had not previously been used in unison but have been shown to have characteristics sufficient to meet the goal. These techniques are: 1) DNA Amplification Fingerprinting (DAF) and 2) Bulked Segregant Analysis (BSA). DAF is a technique that employs the use of arbitrary primers to amplify many regions of genomic DNA. BSA is a technique of pooling individuals from a population into bulks based on a phenotypic trait that can be scored. In using these techniques together, BSA was supposed to isolate molecular markers in one bulk so that DAF could be used to detect that difference. The results were not as expected and no linked markers were isolated. The focus then turned to analyzing the experimental design to find exactly why the anticipated results were not obtained. It was found that the nature of the genome contributed most of the problems. The fact that these loci are in regions of conservation and that the soybean genome is most likely duplicated are major contributions to the pitfalls of the project design. Competition during amplification of the DNA also seems to have some effects. Suggestions to make the next effort in isolating markers more successful included the removal of the BSA technique from the project design

    Quantile estimation using auxiliary information with applications to soil texture data

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    In the Major Land Resource Area (MLRA) 107 pilot project, a multi-phase probability sampling design for updating soil surveys was implemented in western Iowa. In general, multi-phase designs are used when a variable of interest is expensive to measure, but is strongly related to another (auxiliary) variable which is inexpensive to observe. In a multi-phase design, the auxiliary variable is observed for a sample and the study variable is observed for a relatively small sub-sample. In the estimation stage, the auxiliary information is used to improve estimators of distributional quantities relating to the study variable. In particular, we consider estimation of quantiles in this context;Chambers and Dunstan (1986) (CD) presented an estimator for a finite population distribution function which incorporates auxiliary information. A linear relationship between the study variable and the auxiliary information is assumed. The residuals in the linear model are assumed to be homoskedastic. We derive a Bahadur-like representation for the quantile estimator corresponding to the CD distribution function estimator. This expression is used to derive an expression for the asymptotic variance of the quantile estimator;We consider estimation of quantiles for soil texture profiles using data from the MLRA 107 pilot project. The laboratory determination of soil texture is the variable of interest. Auxiliary information is available in the form of field determinations of soil texture. Due to the multi-phase sampling design used for data collection, field determinations are available at more sites than laboratory determinations. The CD quantile estimator is modified to incorporate sampling weights and to allow heteroskedasticity in the assumed linear model;A Bayesian approach to this estimation problem is also considered. A hierarchical model is used to describe the relationships between observed data and unknown parameters. Soil horizon profiles are modeled as realizations of Markov chains. Transformed textures are modeled with Gaussian mixtures. The posterior distribution of soil texture profiles is numerically approximated using a Gibbs sampler. The hierarchical model provides a comprehensive framework which may be useful for analyzing other variables collected in the pilot project. The two approaches are compared using simulated and real data

    Earth resources interactive processing system requirements

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    There are no author-identified significant results in this report

    Calibration of a tunable excimer laser using the optogalvanic effect

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    A device for the calibration of a tunable excimer laser is currently under development. The laser provides UV radiation at three principal wavelengths, 193, 248, and 308 nm and is tunable over a range of 1 nm at each of these wavelengths. The laser is used as a non-intrusive optical probe to excite electronic transitions, and thereby induce fluorescence, of the principle molecules or atoms of interest in supersonic flowfields, both reacting and nonreacting. The fluorescence resulting from the excitation is observed with an intensified camera. Over the range of tunability at the three wavelengths are a number of transitions that can be observed. The intensity of the fluorescence depends in part on the local temperature and density. The nature of this thermodynamic dependence is variable among transitions; thus, identification of the transition under observation is required. The specific transition excited corresponds directly to the wavelength of the radiation. The present technique used for transition identification consists of scanning the laser across the range of tunability and observing the fluorescence resulting from various molecular transitions

    Role of Endoplasmic Reticulum Stress Response in Parainfluenza Virus Acute to Persistent Infections

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    Persistent viral infections are a major health concern, with persistently infected (PI) cells being a source of continued shedding of virus and generation of viral mutants. Here, we hypothesized that cells persistently infected with the enveloped virus parainfluenza virus 5 (PIV5) would show altered expression of endoplasmic reticulum (ER) stress proteins and increased resistance to death caused by drug-induced ER stress. To test this, lysates of mock-infected, PIV5 acute-infected, and PIV5 PI human lung A549 cells were collected and levels of ER stress proteins were compared. Western blotting revealed that immunoglobulin heavy chain binding protein (BiP/GRP78) was present in higher levels in acute-infected and PI cells compared to naïve cells, indicating increased ER stress in both acutely infected and PI cells. Interestingly, basal levels of the ER stress-sensing protein IRE1-alpha were upregulated in PI compared to naïve and acutely infected cells, but PI cells showed decreased activation of IRE1-alpha compared to acutely infected cells. Naïve, acute-infected, and PI A549-NLR cells were treated with ER stress-inducing drugs tunicamycin, thapsigargin, and epigallocatechin gallate and monitored in real-time viability assays for drug-induced cell death. PI cells showed lower levels of stress-induced cell death compared to naive cells, whereas acute-infected cells experienced the greatest extent of cell death when challenged with ER stress-inducing drugs. Together, these results support the hypothesis that PIV5 persistently infected cells display altered ER stress response pathways and that PI cells are more resistant to death caused by ER stress-inducing drugs. Additionally, these results suggest that IRE1-alpha plays a key role in the shift from acute to persistent infection. These results have implications for the treatment of persistent viral infections, as well as the potential for these viruses to be used for oncolytic virotherapy in the future

    Open Educational Resources and their Implementation at Miami University

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    A white paper submitted on 9/8/2015 by the members of the 2014 –2015 Faculty Learning Community Exploring Open Educational Resources at Miami University. Covers OER definition, best practices, benefits and evidence, OER as a strategy to meet 2020 goals, implementing an OER culture at Miami University, and a preliminary plan.Center for Teaching Excellence (CTE) at Miami University Miami University Librarie

    Protecting Endangered Species: Do the Main Legislative Tools Work?

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    It is critical to assess the effectiveness of the tools used to protect endangered species. The main tools enabled under the U.S. Endangered Species Act (ESA) to promote species recovery are funding, recovery plan development and critical habitat designation. Earlier studies sometimes found that statistically significant effects of these tools could be detected, but they have not answered the question of whether the effects were large enough to be biologically meaningful. Here, we ask: how much does the recovery status of ESA-listed species improve with the application of these tools? We used species' staus reports to Congress from 1988 to 2006 to quantify two measures of recovery for 1179 species. We related these to the amount of federal funding, years with a recovery plan, years with critical habitat designation, the amount of peer-reviewed scientific information, and time listed. We found that change in recovery status of listed species was, at best, only very weakly related to any of these tools. Recovery was positively related to the number of years listed, years with a recovery plan, and funding, however, these tools combined explain <13% of the variation in recovery status among species. Earlier studies that reported significant effects of these tools did not focus on effect sizes; however, they are in fact similarly small. One must conclude either that these tools are not very effective in promoting species' recovery, or (as we suspect) that species recovery data are so poor that it is impossible to tell whether the tools are effective or not. It is critically important to assess the effectiveness of tools used to promote species recovery; it is therefore also critically important to obtain population status data that are adequate to that task
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