755 research outputs found

    A genetic polymorphism and its genetic effects on goat myogenin gene in intron 1

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    Single nucleotide polymorphisms (SNPs) of the myogenin (MyoG) gene were tested using primer induced restriction fragment length polymorphism assay-polymerase chain reaction (PIRA-PCR) from Bore goat and its upgrading offspring to Tangshan diary goat (including F1, F2 and F3). The effects of the myogenin gene on the birth weight, 1-month body weight and the weaning weight were also analyzed. On the basis of the DNA sequence of the goat myogenin gene (FJ607135), primers were designed to amplify myogenin gene. The result showed that one polymorphism (transition of g.558C>T) was found in intron 1 of goat myogenin gene, in which two alleles (A and B) and three genotypes (AA, AB and BB) were examined. The distributions of three genotypes were basically identical in four goat populations, and allele A was the dominant gene. The effect of the myogenin genotypes on the birth weight, 1-month body weight and the weaning weight were all not significant (P > 0.05) due to the small number of BB gaots; however, the values of AA genotype goats and AB genotype goats were obviously higher than those of BB genotype goats for three growth traits, in the order of AA > AB > BB. These results suggest that the myogenin genotype has some effects on partial growth traits of goat, and selecting the individuals with A allele could be favorable to the birth weight, 1-month body weight and the weaning weight.Key words: goats, myogenin gene, primer induced restriction fragment length polymorphism assay-polymerase chain reaction (PIRA-PCR), genetic polymorphisms, genetic effects

    Teacher cognition in teaching intercultural communicative competence: A qualitative study on preservice Chinese language teachers in Hong Kong SAR, China

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    The purpose of this study is to examine preservice Chinese language teachers’ cognition in teaching intercultural communicative competence. In the study we collected data through in-depth interviews with seven preservice teachers in a Master of Education program (Teaching Chinese as a Second Language, TCSL) at a university in Hong Kong SAR, China. The findings indicated that the participants had a relatively positive attitude and inclination toward the development of students’ intercultural communicative competence, while their conceptualizations of culture tended to be static and ambiguous. In addition, the participants’ objectives in teaching intercultural communicative competence were found to be more attitude-than knowledge- or skill-oriented. The study offers valuable insights that preservice language teachers’ cognition plays a crucial role in their future professional development and calls for curricular innovations with intercultural aims in teacher education programs

    Rickettsiae Induce Microvascular Hyperpermeability via Phosphorylation of VE-Cadherins: Evidence from Atomic Force Microscopy and Biochemical Studies

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    The most prominent pathophysiological effect of spotted fever group (SFG) rickettsial infection of microvascular endothelial cells (ECs) is an enhanced vascular permeability, promoting vasogenic cerebral edema and non-cardiogenic pulmonary edema, which are responsible for most of the morbidity and mortality in severe cases. To date, the cellular and molecular mechanisms by which SFG Rickettsia increase EC permeability are largely unknown. In the present study we used atomic force microscopy (AFM) to study the interactive forces between vascular endothelial (VE)-cadherin and human cerebral microvascular EC infected with R. montanensis, which is genetically similar to R. rickettsii and R. conorii, and displays a similar ability to invade cells, but is non-pathogenic and can be experimentally manipulated under Biosafety Level 2 (BSL2) conditions. We found that infected ECs show a significant decrease in VE-cadherin-EC interactions. In addition, we applied immunofluorescent staining, immunoprecipitation phosphorylation assay, and an in vitro endothelial permeability assay to study the biochemical mechanisms that may participate in the enhanced vascular permeability as an underlying pathologic alteration of SFG rickettsial infection. A major finding is that infection of R. montanensis significantly activated tyrosine phosphorylation of VE-cadherin beginning at 48 hr and reaching a peak at 72 hr p.i. In vitro permeability assay showed an enhanced microvascular permeability at 72 hr p.i. On the other hand, AFM experiments showed a dramatic reduction in VE-cadherin-EC interactive forces at 48 hr p.i. We conclude that upon infection by SFG rickettsiae, phosphorylation of VE-cadherin directly attenuates homophilic protein–protein interactions at the endothelial adherens junctions, and may lead to endothelial paracellular barrier dysfunction causing microvascular hyperpermeability. These new approaches should prove useful in characterizing the antigenically related SFG rickettsiae R. conorii and R. rickettsii in a BSL3 environment. Future studies may lead to the development of new therapeutic strategies to inhibit the VE-cadherin-associated microvascular hyperpermeability in SFG rickettsioses

    Resonances in J/ψϕπ+πJ/\psi \to \phi \pi ^+\pi ^- and ϕK+K\phi K^+K^-

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    A partial wave analysis is presented of J/ψϕπ+πJ/\psi \to \phi \pi ^+\pi ^- and ϕK+K\phi K^+K^- from a sample of 58M J/ψJ/\psi events in the BES II detector. The f0(980)f_0(980) is observed clearly in both sets of data, and parameters of the Flatt\' e formula are determined accurately: M=965±8M = 965 \pm 8 (stat) ±6\pm 6 (syst) MeV/c2^2, g1=165±10±15g_1 = 165 \pm 10 \pm 15 MeV/c2^2, g2/g1=4.21±0.25±0.21g_2/g_1 = 4.21 \pm 0.25 \pm 0.21. The ϕππ\phi \pi \pi data also exhibit a strong ππ\pi \pi peak centred at M=1335M = 1335 MeV/c2^2. It may be fitted with f2(1270)f_2(1270) and a dominant 0+0^+ signal made from f0(1370)f_0(1370) interfering with a smaller f0(1500)f_0(1500) component. There is evidence that the f0(1370)f_0(1370) signal is resonant, from interference with f2(1270)f_2(1270). There is also a state in ππ\pi \pi with M=179030+40M = 1790 ^{+40}_{-30} MeV/c2^2 and Γ=27030+60\Gamma = 270 ^{+60}_{-30} MeV/c2^2; spin 0 is preferred over spin 2. This state, f0(1790)f_0(1790), is distinct from f0(1710)f_0(1710). The ϕKKˉ\phi K\bar K data contain a strong peak due to f2(1525)f_2'(1525). A shoulder on its upper side may be fitted by interference between f0(1500)f_0(1500) and f0(1710)f_0(1710).Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.

    Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0

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    Using 58 million J/psi and 14 million psi' decays obtained by the BESII experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous measurements.Comment: 9 pages, 8 figures, RevTex

    Search for K_S K_L in psi'' decays

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    K_S K_L from psi'' decays is searched for using the psi'' data collected by BESII at BEPC, the upper limit of the branching fraction is determined to be B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is compared with the prediction of the S- and D-wave mixing model of the charmonia, based on the measurements of the branching fractions of J/psi-->K_S K_L and psi'-->K_S K_L.Comment: 5 pages, 1 figur

    First Measurements of eta_c Decaying into K^+K^-2(pi^+pi^-) and 3(pi^+pi^-)

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    The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the first time using a sample of 5.8X10^7 J/\psi events collected by the BESII detector. The product branching fractions are determined to be B(J/\psi-->gamma eta_c)*B(eta_c-->K^+K^-pi^+pi^-pi^+pi^-)=(1.21+-0.32+- 0.23)X10^{-4},B(J/ψ>gammaetac)B(etac>K0Kˉ0pi+pi)=(1.29+0.43+0.32)X104,B(J/\psi-->gamma eta_c)*B(eta_c-->K^{*0}\bar{K}^{*0}pi^+pi^-)= (1.29+-0.43+-0.32)X10^{-4}, and (J/\psi-->gamma eta_c)* B(eta_c-->pi^+pi^-pi^+pi^-pi^+pi^-)= (2.59+-0.32+-0.48)X10^{-4}. The upper limit for eta_c-->phi pi^+pi^-pi^+pi^- is also obtained as B(J/\psi-->gamma eta_c)*B(eta_c--> phi pi^+pi^-pi^+pi^-)< 6.03 X10^{-5} at the 90% confidence level.Comment: 11 pages, 4 figure

    First observation of psi(2S)-->K_S K_L

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    The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC); the branching ratio is determined to be B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the prediction of the perturbative QCD ``12%'' rule. The result, together with the branching ratios of psi(2S) decays to other pseudoscalar meson pairs (\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let

    Study of psi(2S) decays to X J/psi

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    Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of psi(2S) -> pi^+ pi^- J/psi are measured. The results are B(psi(2S) -> eta J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.098 \pm 0.005 \pm 0.010, B(psi(2S) -> pi^0 pi^0 J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 0.570 \pm 0.009 \pm 0.026, and B(psi(2S) -> anything J/psi)/B(psi(2S) -> pi^+ pi^- J/psi) = 1.867 \pm 0.026 \pm 0.055.Comment: 13 pages, 8 figure

    Radiotherapy-induced cell death activates paracrine HMGB1-TLR2 signaling and accelerates pancreatic carcinoma metastasis

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    Background: Dying cells after irradiation could promote the repopulation of surviving cancer cells leading to tumor recurrence. We aim to define the role of dying cells in promoting pancreatic cancer cells metastasis following radiotherapy.Methods: Using the transwell system as the in vitro co-culture model, a small number of untreated pancreatic cancer cells were seeded in the upper chamber, while a larger number of lethally treated pancreatic cancer cells were seeded in the lower chamber. A series of experiments were conducted to investigate the role of dying-cell-derived HMGB1 on the invasion of pancreatic cancer in vitro and cancer metastasis in vivo. We then designed shRNA knockdown and Western blot assays to detect signaling activity.Results: We found that dying pancreatic cancer cells significantly promote the invasion of pancreatic cancer cells in vitro and cancer metastasis in vivo. HMGB1 gene knockdown attenuated the migration-stimulating effect of irradiated, dying cells on living pancreatic cancer cells. Finally, we showed that dying-cell-derived HMGB1 functions in a paracrine manner to affect cancer-cell migration dependent on acquiring an epithelial-mesenchymal transition (EMT) phenotype and PI3K/pAkt activation. This process is mediated by the receptor for TLR2.Conclusion: Our study indicates that, during radiotherapy, dying pancreatic cancer cells activate paracrine signaling events that promote the mobility of surviving tumor cells. We suggest a strategy to inhibit HMGB1 for preventing pancreatic carcinoma relapse and metastasis
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