Electroweak Model Independent Tests for SU(3) Symmetry in Hadronic B Decays

We study effects of new physics beyond the Standard Model on SU(3) symmetry in charmless hadronic two body B decays. It is found that several equalities for some of the decay amplitudes, such as $A(B_d (B_u) \to \pi^+\pi^-,\pi^+ K^- (\pi^- \bar K^0)) =A(B_s \to K^+ \pi^-, K^- K^+ (K^0 \bar K^0))$, $A(B_d \to \pi^+\rho^-, \pi^- \rho^+, K^-\rho^+, \pi^+ K^{*-}) = A(B_s \to K^+ \rho^-, \pi^- K^{*+}, K^- K^{*+}, K^+ K^{*-})$, $A(B_d (B_u) \to \rho^+\rho^-, \rho^+ K^{*-}(\rho^- \bar K^{*0})) =A(B_s \to K^{*+} \rho^-, K^{*-} K^{*+} (K^{*0} \bar K^{*0}))$, predicted by SU(3) symmetry in the SM are not affected by new physics. These relations provide important electroweak model independent tests for SU(3) symmetry in B decays.Comment: 4 pages, revte

Constraints on SUSY Gluonic Dipole Interaction from B\to K\pi Decays

In low energy SUSY theories exchange of gluino and squark with left-right mixing can produce a large gluonic dipole interaction. In this paper we study the effects of this interaction on $B\to K \pi$ using QCD improved factorization method. The Standard Model predicts a smaller branching ratio for $B^0 \to \bar K^0 \pi^0$ than experimental measured one. We find that within the parameter space allowed from $B\to \gamma X_s$ constraint, the SUSY dipole interaction can enhance this branching ratio to agree with the experimental measurement. Combining recent data for all the four $\bar B^0 \to K^- \pi^+, \bar K^0 \pi^0$ and $B^- \to K^- \pi^0, \bar K^0 \pi^-$ decay modes, we find that the allowed parameter space is reduced significantly compared with that using $B\to X_s \gamma$ data alone. It is found that even with these constraints, the predictions for CP violation in these modes can be dramatically different from those of the SM predictions.Comment: 22 pages, 22 figures. Major revise for B to K pi correctio

A peridynamic based machine learning model for one-dimensional and two-dimensional structures

With the rapid growth of available data and computing resources, using data-driven models is a potential approach in many scientific disciplines and engineering. However, for complex physical phenomena that have limited data, the data-driven models are lacking robustness and fail to provide good predictions. Theory-guided data science is the recent technology that can take advantage of both physics-driven and data-driven models. This study presents a novel peridynamics based machine learning model for one and two-dimensional structures. The linear relationships between the displacement of a material point and displacements of its family members and applied forces are obtained for the machine learning model by using linear regression. The numerical procedure for coupling the peridynamic model and the machine learning model is also provided. The numerical procedure for coupling the peridynamic model and the machine learning model is also provided. The accuracy of the coupled model is verified by considering various examples of a one-dimensional bar and two-dimensional plate. To further demonstrate the capabilities of the coupled model, damage prediction for a plate with a pre-existing crack, a two-dimensional representation of a three-point bending test, and a plate subjected to dynamic load are simulated

The Microbiome and Hematopoietic Cell Transplantation: Past, Present, and Future

N/

Disparities in appendicitis rupture rate among mentally ill patients

<p>Abstract</p> <p>Background</p> <p>Many studies have been carried out that focus on mental patients' access to care for their mental illness, but very few pay attention on these same patients' access to care for their physical diseases. Acute appendicitis is a common surgical emergency. Our population-based study was to test for any possible association between mental illness and perforated appendicitis. We hypothesized that there are significant disparities in access to timely surgical care between appendicitis patients with and without mental illness, and more specifically, between patients with schizophrenia and those with another major mental illness.</p> <p>Methods</p> <p>Using the National Health Insurance (NHI) hospital-discharge data, we compared the likelihood of perforated appendix among 97,589 adults aged 15 and over who were hospitalized for acute appendicitis in Taiwan between the years 1997 to 2001. Among all the patients admitted for appendicitis, the outcome measure was the odds of appendiceal rupture vs. appendicitis that did not result in a ruptured appendix.</p> <p>Results</p> <p>After adjusting for age, gender, ethnicity, socioeconomic status (SES) and hospital characteristics, the presence of schizophrenia was associated with a 2.83 times higher risk of having a ruptured appendix (odds ratio [OR], 2.83; 95% confidence interval [CI], 2.20–3.64). However, the presence of affective psychoses (OR, 1.15; 95% CI: 0.77–1.73) or other mental disorders (OR, 1.58; 95% CI: 0.89–2.81) was not a significant predictor for a ruptured appendix.</p> <p>Conclusion</p> <p>These findings suggest that given the fact that the NHI program reduces financial barriers to care for mentally ill patients, they are still at a disadvantage for obtaining timely treatment for their physical diseases. Of patients with a major mental illness, schizophrenic patients may be the most vulnerable ones for obtaining timely surgical care.</p

Aurora-A overexpression enhances cell-aggregation of Ha-ras transformants through the MEK/ERK signaling pathway

<p>Abstract</p> <p>Background</p> <p>Overexpression of Aurora-A and mutant Ras (Ras^V12) together has been detected in human bladder cancer tissue. However, it is not clear whether this phenomenon is a general event or not. Although crosstalk between Aurora-A and Ras signaling pathways has been reported, the role of these two genes acting together in tumorigenesis remains unclear.</p> <p>Methods</p> <p>Real-time PCR and sequence analysis were utilized to identify Ha- and Ki-<it>ras </it>mutation (Gly -> Val). Immunohistochemistry staining was used to measure the level of Aurora-A expression in bladder and colon cancer specimens. To reveal the effect of overexpression of the above two genes on cellular responses, mouse NIH3T3 fibroblast derived cell lines over-expressing either Ras^V12and wild-type Aurora-A (designated WT) or Ras^V12and kinase-inactivated Aurora-A (KD) were established. MTT and focus formation assays were conducted to measure proliferation rate and focus formation capability of the cells. Small interfering RNA, pharmacological inhibitors and dominant negative genes were used to dissect the signaling pathways involved.</p> <p>Results</p> <p>Overexpression of wild-type Aurora-A and mutation of Ras^V12were detected in human bladder and colon cancer tissues. Wild-type Aurora-A induces focus formation and aggregation of the Ras^V12transformants. Aurora-A activates Ral A and the phosphorylation of AKT as well as enhances the phosphorylation of MEK, ERK of WT cells. Finally, the Ras/MEK/ERK signaling pathway is responsible for Aurora-A induced aggregation of the Ras^V12transformants.</p> <p>Conclusion</p> <p>Wild-type-Aurora-A enhances focus formation and aggregation of the Ras^V12transformants and the latter occurs through modulating the Ras/MEK/ERK signaling pathway.</p