Stress-Energy Tensor Induced by Bulk Dirac Spinor in Randall-Sundrum Model

Motivated by the possible extension into a supersymmetric Randall-Sundrum (RS) model, we investigate the properties of the vacuum expectation value (VEV) of the stress-energy tensor for a quantized bulk Dirac spinor field in the RS geometry and compare it with that for a real scalar field. This is carried out via the Green function method based on first principles without invoking the degeneracy factor, whose validity in a warp geometry is a priori unassured. In addition, we investigate the local behavior of the Casimir energy near the two branes. One salient feature we found is that the surface divergences near the two branes have opposite signs. We argue that this is a generic feature of the fermionic Casimir energy density due to its parity transformation in the fifth dimension. Furthermore, we investigate the self-consistency of the RS metric under the quantum correction due to the stress-energy tensor. It is shown that the VEV of the stress-energy tensor and the classical one become comparable near the visible brane if k ~ M ~ M_Pl (the requirement of no hierarchy problem), where k is the curvature of the RS warped geometry and M the 5-dimensional Planck mass. In that case the self-consistency of RS model that includes bulk fields is in doubt. If, however, k <~ M, then an approximate self-consistency of the RS-type metric may still be satisfied.Comment: 7 pages with 2 figure

Probing neutrino mass hierarchies and ϕ13\phi_{13} with supernova neutrinos

We investigate the feasibility of probing the neutrino mass hierarchy and the mixing angle $\phi_{13}$ with the neutrino burst from a future supernova. An inverse power-law density $\rho \sim r^{n}$ with varying $n$ is adopted in the analysis as the density profile of a typical core-collapse supernova. The survival probabilities of $\nu_{e}$ and $\bar{\nu}_{e}$ are shown to reduce to two-dimensional functions of $n$ and $\phi_{13}$. It is found that in the $n-\sin^{2} \phi_{13}$ parameter space, the 3D plots of the probability functions exhibit highly non-trivial structures that are sensitive to the mass hierarchy, the mixing angle $\phi_{13}$, and the value of $n$. The conditions that lead to observable differences in the 3D plots are established. With the uncertainty of $n$ considered, a qualitative analysis of the Earth matter effect is also included.Comment: 16 pages, 3 figures. Ref [11] added, and some typos correcte

Site specific genetic incorporation of azidophenylalanine in Schizosaccharomyces pombe

The diversity of protein functions is impacted in significant part by the chemical properties of the twenty amino acids, which are used as building blocks for nearly all proteins. The ability to incorporate unnatural amino acids (UAA) into proteins in a site specific manner can vastly expand the repertoire of protein functions and also allows detailed analysis of protein function. In recent years UAAs have been incorporated in a site-specific manner into proteins in a number of organisms. In nearly all cases, the amber codon is used as a sense codon, and an orthogonal tRNA/aminoacyl-tRNA synthetase (RS) pair is used to generate amber suppressing tRNAs charged with the UAA. In this work, we have developed tools to incorporate the cross-linking amino acid azido-phenylalanine (AzF) through the use of bacterial tRNATyr and a modified version of TyrRS, AzFRS, in Schizosaccharomyces pombe, which is an attractive model organism for the study of cell behavior and function. We have incorporated AzF into three different proteins. We show that the majority of AzF is modified to amino-phenyl alanine, but protein cross-linking was still observed. These studies set the stage for exploitation of this new technology for the analysis of S. pombe proteins

Performance of Hamamatsu 64-anode photomultipliers for use with wavelength--shifting optical fibres

Hamamatsu R5900-00-M64 and R7600-00-M64 photomultiplier tubes will be used with wavelength--shifting optical fibres to read out scintillator strips in the MINOS near detector. We report on measurements of the gain, efficiency, linearity, crosstalk, and dark noise of 232 of these PMTs, of which 219 met MINOS requirements.Comment: 15 pages, 12 figures. Accepted by Nucl. Inst. Meth.

Simulation of High Conversion Efficiency and Open-circuit Voltages Of {\alpha}-si/poly-silicon Solar Cell

The P+ {\alpha}-Si /N+ polycrystalline solar cell is molded using the AMPS-1D device simulator to explore the new high efficiency thin film poly-silicon solar cell. In order to analyze the characteristics of this device and the thickness of N+ poly-silicon, we consider the impurity concentration in the N+ poly-silicon layer and the work function of transparent conductive oxide (TCO) in front contact in the calculation. The thickness of N+ poly-silicon has little impact on the device when the thickness varies from 20 {\mu}m to 300 {\mu}m. The effects of impurity concentration in polycrystalline are analyzed. The conclusion is drawn that the open-circuit voltage (Voc) of P+ {\alpha}-Si /N+ polycrystalline solar cell is very high, reaching 752 mV, and the conversion efficiency reaches 9.44%. Therefore, based on the above optimum parameters the study on the device formed by P+ {\alpha}-Si/N+ poly-silicon is significant in exploring the high efficiency poly-silicon solar cell.Comment: 8 pages 6figures, 1 table

The significance of acute-phase small-for-size liver graft injury in mobilization of circulating EPCs/MDSCs/Tregs after LDLT for HCC patients

Oral Presentation - Session O40 HCC and Living Donor Transplantation: O40.06INTRODUCTION AND OBJECTIVE: Higher incidence of tumor recurrence is a major obstacle of living donor liver transplanatation (LDLT) for the patients with hepatocellular carcinoma (HCC). We have already demonstrated that acute phase small-for-size liver graft injury plays important role on late phase tumor recurrence and metastases in a serial animal studies. Understanding the molecular mechanism of acute phase small-for-size liver graft injury is essential for development of therapeutic strategy to reduce the likelihood of tumor recurrence after LDLT. In the current clinical study, we aim to investigate the impact of acute-phase small-for-size graft injury on mobilization of circulating endothelial progenitor cells (EPCs), myeloid-derived suppressive cells (MDSCs) and regulatory T cells (Tregs) in HCC patients after liver transplantation and to explore the molecular mechanism therein. METHODS: From May 2000 to November 2009, 115 adult HCC recipients were included in the current study. The intragraft microRNA profiles of the grafts greater (Group 1) and less than 60% (Group 2) of standard liver weight (SLW) were characterized by Low Density Array (LDA) analysis. Post-operative circulating EPCs (CD34+CD133+CD45-), MDSCs (CD34+CD13+CD33+) and Tregs (CD4+CD25+FOXP3+) were compared by FACS analysis. Intragraft hepatic stellate cell activation, macrophage infiltration and gene expression of Rac, Pyk2, Egr-1 and VEGF at the early phase after reperfusion were also detected by immunostaining and real-time RT-PCR, respectively. Clinical-pathological data including the incidence of tumor recurrence and metastasis were compared between the two groups. RESULTS: The patients were grouped into Group 1 (>= 60% SLW, n=37) and Group 2 (<60% SLW, n=78). The numbers of patients beyond Milan criteria [15/37(40.5%) vs 29/49(59.2%), p=0.838] or UCSF criteria [9/37(24.3%) vs 19/60(31.7%), p=1] were similar between the two groups. Much more patients in Group 2 developed tumor recurrence and lung metastasis [19/78(24.4%) vs 3/37(8%), p=0.04]. Level of circulating EPCs was significantly higher in Group 2 (Day 3: 0.09% vs 0.002%, p=0.019; Week 4: 0.12% vs 0.033%, p=0.037; Week 8: 0.0585% vs 0.025%, p=0.018; Week 12: 0.055% vs 0.028%, p=0.025). A tendency of larger populations of circulating MDSCs and Tregs was also found in Group 2. Most of the patients with tumor recurrence had hepatic sinusoidal injury at early phase after liver transplantation. Significant activation of hepatic stellate cells was found in Group 2 together with stronger intragraft protein expression of FAK and CAK compared to Group 1. Intragraft mRNA levels of Egr-1, RhoA, FAK and VEGF were also significantly higher in Group 2. microRNA LDA analysis demonstrated that mir-233, mir-141, mir-1308, mir-548 and mir-576 were differentially expressed between the two groups. These mirRNAs were predicted to regulate targeting genes linked to graft injury (MAPK, CCL4 and Egr-1), tumor invasiveness (STAT5, CDC2 and EGFR), angiogenesis (VEGF, FLT4 and ANGPTL5), and macrophage infiltration (MIP2). CONCLUSION: A significantly higher population of postoperative circulating EPCs, which are mobilized by small-for-size graft injury, may lead to a higher incidence of tumor recurrence and metastasis after LDLT. The distinct intragraft miRNA expression profile linked to acute-phase injury and angiogenesis may play a role in the mobilization of circulating EPCs, MDSCs, and Tregs.postprintThe 23rd International Congress of The Transplantation Society (TTS 2010), Vancouver, Canada, 15-19 August 2010. In Transplantation, 2010, v. 90 no. 2S, p. 268, abstract no. 51

On the relative expressiveness of higher-order session processes

By integrating constructs from the λ-calculus and the π-calculus, in higher-order process calculi exchanged values may contain processes. This paper studies the relative expressiveness of HOπ, the higher-order π-calculus in which communications are governed by session types. Our main discovery is that HO, a subcalculus of HOπ which lacks name-passing and recursion, can serve as a new core calculus for session-typed higher-order concurrency. By exploring a new bisimulation for HO, we show that HO can encode HOπ fully abstractly (up to typed contextual equivalence) more precisely and efficiently than the first-order session π-calculus (π). Overall, under session types, HOπ, HO, and π are equally expressive; however, HOπ and HO are more tightly related than HOπ and π

CHIMERA: a wide-field, multi-colour, high-speed photometer at the prime focus of the Hale telescope

The Caltech HIgh-speed Multi-colour camERA (CHIMERA) is a new instrument that has been developed for use at the prime focus of the Hale 200-inch telescope. Simultaneous optical imaging in two bands is enabled by a dichroic beam splitter centred at 567 nm, with Sloan u′ and g′ bands available on the blue arm and Sloan r′, i′ and z_s bands available on the red arm. Additional narrow-band filters will also become available as required. An electron multiplying CCD (EMCCD) detector is employed for both optical channels, each capable of simultaneously delivering sub-electron effective read noise under multiplication gain and frame rates of up to 26 fps full frame (several 1000 fps windowed), over a fully corrected 5 × 5 arcmin field of view. CHIMERA was primarily developed to enable the characterization of the size distribution of sub-km Kuiper Belt Objects via stellar occultation, a science case that motivates the frame-rate, the simultaneous multi-colour imaging and the wide field of view of the instrument. In addition, it also has unique capability in the detection of faint near-Earth asteroids and will be used for the monitoring of short-duration transient and periodic sources, particularly those discovered by the intermediate Palomar Transient Factory (iPTF), and the upcoming Zwicky Transient Facility (ZTF)

Z-Selective Cross-Metathesis and Homodimerization of 3E-1,3-Dienes: Reaction Optimization, Computational Analysis, and Synthetic Applications

Olefin metathesis reactions with 3E-1,3-dienes using Z-selective cyclometalated ruthenium benzylidene catalysts are described. In particular, a procedure for employing 3E-1,3-dienes in Z-selective homodimerization and cross-metathesis with terminal alkenes is detailed. The reaction takes advantage of the pronounced chemoselectivity of a recently reported ruthenium-based catalyst containing a cyclometalated NHC ligand for terminal alkenes in the presence of internal E-alkenes. A wide array of commonly encountered functional groups can be tolerated, and only a small excess (1.5 equiv) of the diene coupling partner is required to achieve high yields of the desired internal E,Z-diene cross-metathesis product. Computational studies have been performed to elucidate the reaction mechanism. The computations are consistent with a diene-first pathway. The reaction can be used to quickly assemble structurally complex targets. The power of this cross-metathesis reaction is demonstrated by the concise syntheses of two insect pheromones