1,249 research outputs found

    Time dependent CP asymmetry in B0→ρ0ÎłB^0 \to \rho^0 \gamma decay to probe the origin of CP violation

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    Since the CP violation in the BB system has been investigated up to now only through processes related to the BB--Bˉ\bar{B} mixing, urgently required is new way of study for the CP violation and establishing its origin in the BB system independent of the mixing process. In this work, we explore the exclusive B0→ρ0Îł B^0 \to \rho^0 \gamma decay to obtain the time-dependent CP asymmetry in b→db \to d decay process in the standard model and the supersymmetric model. We find that the complex RL and RR mass insertion to the squark sector in the MSSM can lead to a large CP asymmetry in b→dÎłb \to d \gamma decay through the gluino-squark diagrams, which is not predicted in the Standard Model induced by the BB--Bˉ\bar{B} mixing.Comment: 10 pages, 4 eps figure

    Faddeev-Jackiw Analysis of Topological Mass Generating Action

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    We analyze the gauge symmetry of a topological mass generating action in four dimensions which contains both a vector and a second rank antisymmetric tensor fields. In the Abelian case, this system induces an effective mass for the vector gauge field via a topological coupling B∧FB \wedge F in the presence of a kinetic term for the antisymmetric tensor field BB, while maintaining a gauge symmetry. On the other hand, for the non-Abelian case the BB field does not have a gauge symmetry unless an auxiliary vector field is introduced to the system. We analyze this change of symmetry in the Faddeev-Jackiw formalism, and show how the auxiliary vector field enhances the symmetry. At the same time this enhanced gauge symmetry becomes reducible. We also show this phenomenon in this analysis.Comment: 20 pages, REVTe

    Understanding CD4+ T cells in autoimmune bullous diseases

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    Autoimmune bullous diseases (AIBDs) are a group of life-threatening blistering diseases caused by autoantibodies that target proteins in the skin and mucosa. Autoantibodies are the most important mediator in the pathogenesis of AIBDs, and various immune mechanisms contribute to the production of these pathogenic autoantibodies. Recently, significant progress has been made in understanding how CD4+ T cells drive autoantibody production in these diseases. Here, we review the critical role of CD4+ T cells in the production of pathogenic autoantibodies for the initiation and perpetuation of humoral response in AIBDs. To gain an in-depth understanding of CD4+ T-cell pathogenicity, antigen specificity, and mechanisms of immune tolerance, this review covers comprehensive mouse and human studies of pemphigus and bullous pemphigoid. Further exploration of pathogenic CD4+ T cells will potentially provide immune targets for improved treatment of AIBDs

    Strongly Localized Electrons in a Magnetic Field: Exact Results on Quantum Interference and Magnetoconductance

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    We study quantum interference effects on the transition strength for strongly localized electrons hopping on 2D square and 3D cubic lattices in a magnetic field B. In 2D, we obtain closed-form expressions for the tunneling probability between two arbitrary sites by exactly summing the corresponding phase factors of all directed paths connecting them. An analytic expression for the magnetoconductance, as an explicit function of the magnetic flux, is derived. In the experimentally important 3D case, we show how the interference patterns and the small-B behavior of the magnetoconductance vary according to the orientation of B.Comment: 4 pages, RevTe

    LHC Signature of Mirage Mediation

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    We study LHC phenomenology of mirage mediation scenario in which anomaly and modulus contributions to soft SUSY breaking terms are comparable to each other. A Monte Carlo study of mirage mediation, with model parameters α=1\alpha=1,M0=500 M_0=500 GeV, nM=1/2n_M=1/2, nH=1n_H=1 and tanÎČ=10\rm{tan}\beta=10, is presented. It is shown that masses of supersymmetric particles can be measured in a model independent way, providing information on SUSY breaking sector. In particular, the mass ratio of gluino to the lightest neutralino for the benchmark scenario is determined to be 1.9 \lesssim m_{\tildeg}/m_{\tilde\chi_1^0} \lesssim 3.1, well reproducing theoretical input value of mg~/mχ~10≃2.5m_{\tilde g}/m_{\tilde\chi_1^0} \simeq 2.5 which is quite distinctive from the predictions mg~/mχ~10≳6m_{\tilde g}/m_{\tilde\chi_1^0} \gtrsim 6 of other SUSY scenarios in which gaugino masses are unified at the GUT scale. The model parameters of mirage mediation can be also determined from various kinematic distributions

    Serum Tau Proteins as Potential Biomarkers for the Assessment of Alzheimer's Disease Progression

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    Total tau (t‐tau) and phosphorylated tau (p‐tau) protein elevations in cerebrospinal fluid (CFS) are well‐established hallmarks of Alzheimer’s disease (AD), while the associations of serum t‐tau and p‐tau levels with AD have been inconsistent across studies. To identify more accessible non‐invasive AD biomarkers, we measured serum tau proteins and associations with cognitive function in age‐matched controls (AMC, n = 26), mild cognitive impairment group (MCI, n = 30), and mild‐AD group (n = 20) according to the Mini‐mental State Examination (MMSE), Clinical Dementia Rating (CDR), and Global Deterioration Scale (GDS) scores. Serum t‐tau, but not p‐tau, was significantly higher in the mild‐AD group than AMC subjects (p < 0.05), and there were significant correlations of serum t‐tau with MMSE and GDS scores. Receiver operating characteristic (ROC) analysis distinguished mild‐AD from AMC subjects with moderate sensitivity and specificity (AUC = 0.675). We speculated that tau proteins in neuronal cell‐derived exosomes (NEX) isolated from serum would be more strongly associated with brain tau levels and disease characteristics, as these exosomes can penetrate the blood‐brain barrier. Indeed, ELISA and Western blotting indicated that both NEX t‐tau and p‐tau (S202) were significantly higher in the mild‐AD group compared to AMC (p < 0.05) and MCI groups (p < 0.01). In contrast, serum amyloid ÎČ (AÎČ1–42) was lower in the mild‐AD group compared to MCI groups (p < 0.001). During the 4‐year follow‐up, NEX t‐tau and p‐tau (S202) levels were correlated with the changes in GDS and MMSE scores. In JNPL3 transgenic (Tg) mice expressing a human tau mutation, t‐tau and p‐tau expression levels in NEX increased with neuropathological progression, and NEX tau was correlated with tau in brain tissue exosomes (tEX), suggesting that tau proteins reach the circulation via exosomes. Taken together, our data suggest that serum tau proteins, especially NEX tau proteins, are useful biomarkers for monitoring AD progression. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.1

    Key Intrinsic Connectivity Networks for Individual Identification With Siamese Long Short-Term Memory

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    In functional magnetic resonance imaging (fMRI) analysis, many studies have been conducted on inter-subject variability as well as intra-subject reproducibility. These studies indicate that fMRI could have unique characteristics for individuals. In this study, we hypothesized that the dynamic information during 1 min of fMRI was unique and repetitive enough for each subject, so we applied long short-term memory (LSTM) using initial time points of dynamic resting-state fMRI for individual identification. Siamese network is used to obtain robust individual identification performance without additional learning on a new dataset. In particular, by adding a new structure called region of interest–wise average pooling (RAP), individual identification performance could be improved, and key intrinsic connectivity networks (ICNs) for individual identification were also identified. The average performance of individual identification was 97.88% using the test dataset in eightfold cross-validation analysis. Through the visualization of features learned by Siamese LSTM with RAP, ICNs spanning the parietal region were observed as the key ICNs in identifying individuals. These results suggest the key ICNs in fMRI could represent individual uniqueness

    Effective Interventions and Decline of Antituberculosis Drug Resistance in Eastern Taiwan, 2004–2008

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    BACKGROUND: The Taiwan health authority recently launched several tuberculosis (TB) control interventions, which may have an impact on the epidemic of drug-resistant TB. We conducted a population-based antituberculosis drug resistance surveillance program in Eastern Taiwan to measure the proportions of notified TB patients with anti-TB drug resistance and the trend from 2004 to 2008. METHODS AND FINDINGS: All culture-positive TB patients were enrolled. Drug susceptibility testing results of the first isolate of each TB patient in each treatment course were analyzed. In total, 2688 patients were included, of which 2176 (81.0%) were new TB cases and 512 (19.0%) were previously treated cases. Among the 2176 new TB cases, 97 (4.5%) were retreated after the first episode of TB treatment within the study period. The proportion of new patients with any resistance, isoniazid resistance but not multidrug-resistant TB (resistant to at least isoniazid and rifampin, MDR-TB), and MDR-TB was 16.4%, 7.5%, and 4.0%, respectively, and that among previously treated cases was 30.9%, 7.9%, and 17.6%, respectively. The combined proportion of any resistance decreased from 23.3% in 2004 to 14.3% in 2008, and that of MDR-TB from 11.5% to 2.4%. CONCLUSIONS: The proportion of TB patients with drug-resistant TB in Eastern Taiwan remains substantial. However, an effective TB control program has successfully driven the proportion of drug resistance among TB patients downward
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