993 research outputs found

    Assessing the genetic diversity of cultivars and wild soybeans using SSR markers

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    Increasing the diversity of the soybean germplasm base could introduce new genes affecting agronomic traits. In this study, we demonstrated the differences of genetic diversity level among 40 soybean accessions of cultivars, landraces and wild soybeans collected in the Shanxi Agricultural University using 40 simple sequence repeat (SSR) primer pairs. The structure based on model result showed that the cultivars, landraces and wild soybeans could be divided into three groups. Comparison of three types of soybeans showed that wild soybeans and landraces showed higher genetic diversity level than cultivars. The average genetic diversity index of wild soybeans and landraces was 1.5421 and 1.2864, while that of cultivars was 1.0981. A total number of alleles in wild soybeans were 224, while those in cultivars and landraces were 182 and 148, respectively, which were 81.25 and 66.07% of wild soybeans. The higher genetic distance (0.6414) and genetic differentiation (0.1200) and the lower genetic identity (0.5265) and gene flow (1.8338) between wild soybeans and cultivars were found. The proportion of low frequency alleles (allele frequency < 0.15) was the highest in wild soybeans (57.5%), followed by landraces (42%) and cultivars (29.8%). The UPGMA results also showed that wide soybean were of more abundant genetic diversity than cultivars. These results indicated that wild soybeans and landraces possessed greater allelic diversity than cultivars and might contain alleles not present in the cultivars which can strengthen further conservation and utilization.Key words: Soybean, simple sequence repeat, genetic diversity

    The Landscape of Inappropriate Laboratory Testing: A 15-Year Meta-Analysis

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    Background: Laboratory testing is the single highest-volume medical activity and drives clinical decision-making across medicine. However, the overall landscape of inappropriate testing, which is thought to be dominated by repeat testing, is unclear. Systematic differences in initial vs. repeat testing, measurement criteria, and other factors would suggest new priorities for improving laboratory testing. Methods: A multi-database systematic review was performed on published studies from 1997โ€“2012 using strict inclusion and exclusion criteria. Over- vs. underutilization, initial vs. repeat testing, low- vs. high-volume testing, subjective vs. objective appropriateness criteria, and restrictive vs. permissive appropriateness criteria, among other factors, were assessed. Results: Overall mean rates of over- and underutilization were 20.6% (95% CI 16.2โ€“24.9%) and 44.8% (95% CI 33.8โ€“55.8%). Overutilization during initial testing (43.9%; 95% CI 35.4โ€“52.5%) was six times higher than during repeat testing (7.4%; 95% CI 2.5โ€“12.3%; P for stratum difference <0.001). Overutilization of low-volume tests (32.2%; 95% CI 25.0โ€“39.4%) was three times that of high-volume tests (10.2%; 95% CI 2.6โ€“17.7%; P<0.001). Overutilization measured according to restrictive criteria (44.2%; 95% CI 36.8โ€“51.6%) was three times higher than for permissive criteria (12.0%; 95% CI 8.0โ€“16.0%; P<0.001). Overutilization measured using subjective criteria (29.0%; 95% CI 21.9โ€“36.1%) was nearly twice as high as for objective criteria (16.1%; 95% CI 11.0โ€“21.2%; P = 0.004). Together, these factors explained over half (54%) of the overall variability in overutilization. There were no statistically significant differences between studies from the United States vs. elsewhere (P = 0.38) or among chemistry, hematology, microbiology, and molecular tests (P = 0.05โ€“0.65) and no robust statistically significant trends over time. Conclusions: The landscape of overutilization varies systematically by clinical setting (initial vs. repeat), test volume, and measurement criteria. Underutilization is also widespread, but understudied. Expanding the current focus on reducing repeat testing to include ordering the right test during initial evaluation may lead to fewer errors and better care

    Strong quantum fluctuation of vortices in the new superconductor MgB2MgB_2

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    By using transport and magnetic measurement, the upper critical field Hc2(T)H_{c2}(T) and the irreversibility line Hirr(T)H_{irr}(T) has been determined. A big separation between Hc2(0)H_{c2}(0) and Hirr(0)H_{irr}(0) has been found showing the existence of a quantum vortex liquid state induced by quantum fluctuation of vortices in the new superconductor MgB2MgB_2. Further investigation on the magnetic relaxation shows that both the quantum tunneling and the thermally activated flux creep weakly depends on temperature. But when the melting field HirrH_{irr} is approached, a drastic rising of the relaxation rate is observed. This may imply that the melting of the vortex matter at a finite temperature is also induced by the quantum fluctuation of vortices.Comment: 4 pages, 4 figure

    Detecting unambiguously non-Abelian geometric phases with trapped ions

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    We propose for the first time an experimentally feasible scheme to disclose the noncommutative effects induced by a light-induced non-Abelian gauge structure with trapped ions. Under an appropriate configuration, a true non-Abelian gauge potential naturally arises in connection with the geometric phase associated with two degenerated dark states in a four-state atomic system interacting with three pulsed laser fields. We show that the population in atomic state at the end of a composed path formed by two closed loops C1C_1 and C2C_2 in the parameter space can be significantly different from the composed counter-ordered path. This population difference is directly induced by the noncommutative feature of non-Abelian geometric phases and can be detected unambiguously with current technology.Comment: 6 page

    Capsomer Vaccines Protect Mice from Vaginal Challenge with Human Papillomavirus

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    Capsomers were produced in bacteria as glutathione-S-transferase (GST) fusion proteins with human papillomavirus type 16 L1 lacking the first nine and final 29 residues (GST-HPV16L1ฮ”) alone or linked with residues 13โ€“47 of HPV18, HPV31 and HPV45 L2 in tandem (GST-HPV16L1ฮ”-L2x3). Subcutaneous immunization of mice with GST-HPV16L1ฮ” or GST-HPV16L1ฮ”-L2x3 in alum and monophosphoryl lipid A induced similarly high titers of HPV16 neutralizing antibodies. GST-HPV16L1ฮ”-L2x3 also elicited moderate L2-specific antibody titers. Intravaginal challenge studies showed that immunization of mice with GST-HPV16 L1ฮ” or GST-HPV16L1ฮ”-L2x3 capsomers, like Cervarixยฎ, provided complete protection against HPV16. Conversely, vaccination with GST-HPV16 L1ฮ” capsomers failed to protect against HPV18 challenge, whereas mice immunized with either GST-HPV16L1ฮ”-L2x3 capsomers or Cervarixยฎ were each completely protected. Thus, while the L2-specific response was moderate, it did not interfere with immunity to L1 in the context of GST-HPV16L1ฮ”-L2x3 and is sufficient to mediate L2-dependent protection against an experimental vaginal challenge with HPV18

    Quantum tunneling of two coupled single-molecular magnets

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    Two single-molecule magnets are coupled antiferromagnetically to form a supramolecule dimer. We study the coupling effect and tunneling process by means of the numerical exact diagonalization method, and apply them to the recently synthesized supramoleculer dimer [Mn4]2 The model parameters are calculated for the dimer based on the tunneling process. The absence of tunneling at zero field and sweeping rate effect on the step height in the hysterisis loops are understood very well in this theory.Comment: 4 pages including 3 figure and 1 tabl
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