Exact Potts Model Partition Functions for Strips of the Honeycomb Lattice

We present exact calculations of the Potts model partition function $Z(G,q,v)$ for arbitrary $q$ and temperature-like variable $v$ on $n$-vertex strip graphs $G$ of the honeycomb lattice for a variety of transverse widths equal to $L_y$ vertices and for arbitrarily great length, with free longitudinal boundary conditions and free and periodic transverse boundary conditions. These partition functions have the form $Z(G,q,v)=\sum_{j=1}^{N_{Z,G,\lambda}} c_{Z,G,j}(\lambda_{Z,G,j})^m$, where $m$ denotes the number of repeated subgraphs in the longitudinal direction. We give general formulas for $N_{Z,G,j}$ for arbitrary $L_y$. We also present plots of zeros of the partition function in the $q$ plane for various values of $v$ and in the $v$ plane for various values of $q$. Explicit results for partition functions are given in the text for $L_y=2,3$ (free) and $L_y=4$ (cylindrical), and plots of partition function zeros are given for $L_y$ up to 5 (free) and $L_y=6$ (cylindrical). Plots of the internal energy and specific heat per site for infinite-length strips are also presented.Comment: 39 pages, 34 eps figures, 3 sty file

A phase II study of neoadjuvant chemotherapy with docetaxel, cisplatin and trastuzumab for T2 breast cancers

Preclinical data indicate that the combination of docetaxel, cisplatin and trastuzumab (TCH) may have the potential for clinically significant activity against breast cancers that overexpress the her2/neu gene (HER2). An open-label phase II trial was designed to investigate the response rate and toxicity profile of TCH in breast cancer patients with a primary tumor 2-5 cm in diameter (T2) in its original size. Thirty breast cancer patients with HER2-overexpressing tumors were enrolled. Patients received 6 cycles of docetaxel at 60 mg/m(2) and cisplatin at 50 mg/m(2) given on day 1 and then every 21 days. Trastuzumab was given on day 1, cycle 1 (4 mg/kg), and then continued weekly at 2 mg/kg for 1 year or until disease progression. Tumor measurements were obtained at baseline as well as after 3 and 6 cycles of chemotherapy. We identified 29 breast cancer patients in Taiwan, of whom 13 (44.8%) had pathological complete responses. No cardiac toxicity was observed. Hematologic grade 4 or 3 toxicities were observed in 1 of 28 patients. Non-hematologic grade 4 or 3 toxicities with a reverse pattern were observed in 6 of 29 patients. The results of our study indicate that TCH neoadjuvant chemotherapy is feasible and active in T2 HER2-overexpressing breast cancer patients in terms of pathological complete response rate, complete response, partial response and manageable toxicities

Selection rules in three-body B decay from factorization

Extending the dynamics underlying the factorization calculation of two-body decays, we propose simple selection rules for nonresonant three-body B decays. We predict, for instance, that in the Dalitz plot of B^0-->D^0-bar\pi^+\pi^-, practically no events should be found in the corner of E(\pi^+) < \Lambda_{QCD} as compared with the corner of E(\pi^-) < \Lambda_{QCD}. We also predict that there should be very few three-body decay events with a soft meson resonance and two energetic mesons or meson resonances. The selection rules are quite different from the soft pion theorem, since they apply to different kinematical regions. For B^0 -->D^0-bar\pi^+\pi^-, the latter predicts that the decay matrix element vanishes in the zero-four-momentum limit of \pi^+ instead of \pi^-. Since this marked difference from the soft pion theorem is directly related to the issue of short-distance QCD dominance in the FSI of two-body B decays, experimental test of the selection rules will shed light on strong interaction dynamics of B decay.Comment: 12 pages in REVTEX including 3 eps figure

Genome-wide scan using DArT markers for selection footprints in six-rowed naked barley from the Tibetan Plateau

As one of the world’s earliest domesticated crops, barley is a model species for the study of evolution and domestication. Domestication is an evolutionary process whereby a population adapts, through selection; to new environments created by human cultivation. We describe the genome-scanning of molecular diversity to assess the evolution of barley in the Tibetan Plateau. We used 667 Diversity Arrays Technology (DArT) markers to genotype 185 barley landraces and wild barley accessions from the Tibetan Plateau. Genetic diversity in wild barley was greater than in landraces at both genome and chromosome levels, except for chromosome 3H. Landraces and wild barley accessions were clearly differentiated genetically, but a limited degree of introgression was still evident. Significant differences in diversity between barley subspecies at the chromosome level were observed for genes known to be related to physiological and phenotypical traits, disease resistance, abiotic stress tolerance, malting quality and agronomic traits. Selection on the genome of six-rowed naked barley has shown clear multiple targets related to both its specific end-use and the extreme environment in Tibet. Our data provide a platform to identify the genes and genetic mechanisms that underlie phenotypic changes, and provide lists of candidate domestication genes for modified breeding strategies

Study of Bc --> J/psi pi, etac pi decays with perturbative QCD approach

The Bc --> J/psi pi, etac pi decays are studied with the perturbative QCD approach. It is found that form factors and branching ratios are sensitive to the parameters w, v, f_J/psi and f_etac, where w and v are the parameters of the charmonium wave functions for Coulomb potential and harmonic oscillator potential, respectively, f_J/psi and f_etac are the decay constants of the J/psi and etac mesons, respectively. The large branching ratios and the clear signals of the final states make the Bc --> J/psi pi, etac pi decays to be the prospective channels for measurements at the hadron collidersComment: 21 pages, revtex

A Calibration of the K600 FPP from 120 to 200 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Search for Solar Axions Produced in the p+d→3He+Ap + d \rightarrow\rm{^3He}+ A Reaction

A search for the axioelectric absorption of 5.5-MeV solar axions produced in the $p+d\rightarrow \rm{^3He}+\gamma(5.5 \rm{MeV})$ reaction was performed with two BGO detectors placed inside a low-background setup. A model independent limit on axion-photon and axion-nucleon couplings was obtained: $|g_{Ae}\times g_{AN}| \leq 3.2\times 10^{-9} (m_A=0)$. Constraints on the axion-electron coupling constant were obtained for axions with masses in the $(0.1-1.0)$ MeV range: $g_{Ae}\leq (1.8-9.0)\times 10^{-7}$. The solar positron flux from $A\rightarrow e^-+e^+$ decay was determined for axions with masses $m_A > 2m_e$. Using the existing experimental data on the interplanetary positron flux, a new constraint on the axion-electron coupling constant for axions with masses in the $(1.2-5.4)$ MeV range was obtained: $g_{Ae} \leq (1-5)\times 10^{-17}$.Comment: 6 pages, 5 figure

Applicability of perturbative QCD to Λb→Λc\Lambda_b \to \Lambda_c decays

We develop perturbative QCD factorization theorem for the semileptonic heavy baryon decay $\Lambda_b \to \Lambda_c l\bar{\nu}$, whose form factors are expressed as the convolutions of hard $b$ quark decay amplitudes with universal $\Lambda_b$ and $\Lambda_c$ baryon wave functions. Large logarithmic corrections are organized to all orders by the Sudakov resummation, which renders perturbative expansions more reliable. It is observed that perturbative QCD is applicable to $\Lambda_b \to \Lambda_c$ decays for velocity transfer greater than 1.2. Under requirement of heavy quark symmetry, we predict the branching ratio $B(\Lambda_b \to \Lambda_c l{\bar\nu})\sim 2$, and determine the $\Lambda_b$ and $\Lambda_c$ baryon wave functions.Comment: 12 pages in Latex file, 3 figures in postscript files, some results are changed, but the conclusion is the sam

Detection of the tagged or untagged photons in acousto-optic imaging of thick highly scattering media by photorefractive adaptive holography

We propose an original adaptive wavefront holographic setup based on the photorefractive effect (PR), to make real-time measurements of acousto-optic signals in thick scattering media, with a high flux collection at high rates for breast tumor detection. We describe here our present state of art and understanding on the problem of breast imaging with PR detection of the acousto-optic signal

A Measurement of the Spin Transfer Observable D_NN' for p+p Elastic Scattering at T_p = 200MeV

This research was sponsored by the National Science Fooundation Grant NSF PHY-931478