Factorization of Standard Model cross sections at ultra high energy

The factorization theorem for organizing multiple electroweak boson emissions at future colliders with energy far above the electroweak scale is formulated. Taking the inclusive muon-pair production in electron-positron collisions as an example, we argue that the summation over isospins is demanded for constructing the universal distributions of leptons and gauge bosons in an electron. These parton distributions are shown to have the same infrared structure in the phases of broken and unbroken electroweak symmetry, an observation consistent with the Goldstone Equivalence Theorem. The electroweak factorization of processes involving protons is sketched, with an emphasis on the subtlety of the scalar distributions.Comment: 5 pages, 3 figure

Drosophila Bestrophin-1 Chloride Current Is Dually Regulated by Calcium and Cell Volume

Mutations in the human bestrophin-1 (hBest1) gene are responsible for Best vitelliform macular dystrophy, however the mechanisms leading to retinal degeneration have not yet been determined because the function of the bestrophin protein is not fully understood. Bestrophins have been proposed to comprise a new family of Cl− channels that are activated by Ca2+. While the regulation of bestrophin currents has focused on intracellular Ca2+, little is known about other pathways/mechanisms that may also regulate bestrophin currents. Here we show that Cl− currents in Drosophila S2 cells, that we have previously shown are mediated by bestrophins, are dually regulated by Ca2+ and cell volume. The bestrophin Cl− currents were activated in a dose-dependent manner by osmotic pressure differences between the internal and external solutions. The increase in the current was accompanied by cell swelling. The volume-regulated Cl− current was abolished by treating cells with each of four different RNAi constructs that reduced dBest1 expression. The volume-regulated current was rescued by transfecting with dBest1. Furthermore, cells not expressing dBest1 were severely depressed in their ability to regulate their cell volume. Volume regulation and Ca2+ regulation can occur independently of one another: the volume-regulated current was activated in the complete absence of Ca2+ and the Ca2+-activated current was activated independently of alterations in cell volume. These two pathways of bestrophin channel activation can interact; intracellular Ca2+ potentiates the magnitude of the current activated by changes in cell volume. We conclude that in addition to being regulated by intracellular Ca2+, Drosophila bestrophins are also novel members of the volume-regulated anion channel (VRAC) family that are necessary for cell volume homeostasis

Effects of detraining on functional fitness and lymphocyte subsets in postmenopausal females

Introduction: Aging leads to declines of functional fitness and regular exercise has been recognized to be beneficial for keeping health and preventing degenerative diseases in older adults. Limited evidences connect the relationships among detraining, functional fitness, immunosenescence, and vascular integrity in aged individuals. Thus, the aims of this study was to inspect: How training and detraining influence functional fitness, mobilization of circulating leukocytes and lymphocyte subsets? Method: Twenty-two female volunteers aged 50 to 65 years were recruited as participants in this study. Participants were assigned into training group (TG, n=13) and control group (CG, n=9). The participants in TG were asked to attend exercise program, including aerobic exercise at 70% HRR for 60 min twice per week and resistance training at 60-70% 1RM, 3 sets and 9 exercises for 60 min per week for 16 weeks and subsequently avoid exercise for 6 weeks to investigate detraining effects. CG were asked to stay in their regular lifestyles. A six-items measurement of functional fitness and resting (at fasting status) venous blood samples were collected at before training program (Pre-training), 8th week of training (Mid-training), after training program (Post-training), and 6th week of detraining 6 weeks (Detraining). Blood cell counts (WBC, RBC, HCT, LYM) were measured using an automated cell counter and lymphocyte subsets (CD4, CD8, CD19, CD56) were analyzed by flow cytometry. Data were analyzed by descriptive statistic, mixed two-factors (time × group) measures ANOVA or ACOVA and the significance was set at pResult: Functional fitness of TG was not significantly improved following the training program although it was significantly better than CG in Pre-training. Blood cell counts were not changed and all in normal range. A significant difference in CD19 counts were observed between TG and CG (71.23±32.05 vs. 116.45±67.95 103/mL) in Post-training. CD19 counts in TG were increased at Detraining compared with Mid-training and Post-training (138.08±50.22 vs. 74.92±31.20, 71.23±32.05 103/mL). No alterations in quantity and percentage of CD4, CD8, and CD56 were observed in this study. Conclusion: Findings of this study suggest that both a 16-week moderate exercise program and a 6-week detraining did not significantly change the functional fitness and lymphocyte subsets in postmenopausal females

Controlled Heterogeneous Nucleation and Growth of Germanium Quantum Dots on Nanopatterned Silicon Dioxide and Silicon Nitride Substrates

Controlled heterogeneous nucleation and growth of Ge quantum dots (QDs) are demonstrated on SiO_2/Si_3N_4 substrates by means of a novel fabrication process of thermally oxidizing nanopatterned SiGe layers. The otherwise random self-assembly process for QDs is shown to be strongly influenced by the nanopatterning in determining both the location and size of the QDs. Ostwald ripening processes are observed under further annealing at the oxidation temperature. Both nanopattern oxidation and Ostwald ripening offer additional mechanisms for lithography for controlling the size and placement of the QDs

Numerical ranges of cyclic shift matrices

We study the numerical range of an $n\times n$ cyclic shift matrix, which can be viewed as the adjacency matrix of a directed cycle with $n$ weighted arcs. In particular, we consider the change in the numerical range if the weights are rearranged or perturbed. In addition to obtaining some general results on the problem, a permutation of the given weights is identified such that the corresponding matrix yields the largest numerical range (in terms of set inclusion), for $n \le 6$. We conjecture that the maximizing pattern extends to general $n\times n$ cylic shift matrices. For $n \le 5$, we also determine permutations such that the corresponding cyclic shift matrix yields the smallest numerical range.Comment: 24 page

5-ALA mediated photodynamic therapy induces autophagic cell death via AMP-activated protein kinase

Photodynamic therapy (PDT) has been developed as an anticancer treatment, which is based on the tumor-specific accumulation of a photosensitizer that induces cell death after irradiation of light with a specific wavelength. Depending on the subcellular localization of the photosensitizer, PDT could trigger various signal transduction cascades and induce cell death such as apoptosis, autophagy, and necrosis. In this study, we report that both AMP-activated protein kinase (AMPK) and mitogen-activated protein kinase (MAPK) signaling cascades are activated following 5-aminolevulinic acid (ALA)-mediated PDT in both PC12 and CL1-0 cells. Although the activities of caspase-9 and -3 are elevated, the caspase inhibitor zVAD-fmk did not protect cells against ALA-PDT-induced cell death. Instead, autophagic cell death was found in PC12 and CL1-0 cells treated with ALA-PDT. Most importantly, we report here for the first time that it is the activation of AMPK, but not MAPKs that plays a crucial role in mediating autophagic cell death induced by ALA-PDT. This novel observation indicates that the AMPK pathway play an important role in ALA-PDT-induced autophagy

Single Cl− Channels Activated by Ca2+ in Drosophila S2 Cells Are Mediated By Bestrophins

Mutations in human bestrophin-1 (VMD2) are genetically linked to several forms of retinal degeneration but the underlying mechanisms are unknown. Bestrophin-1 (hBest1) has been proposed to be a Cl− channel involved in ion and fluid transport by the retinal pigment epithelium (RPE). To date, however, bestrophin currents have only been described in overexpression systems and not in any native cells. To test whether bestrophins function as Ca2+-activated Cl− (CaC) channels physiologically, we used interfering RNA (RNAi) in the Drosophila S2 cell line. S2 cells express four bestrophins (dbest1–4) and have an endogenous CaC current. The CaC current is abolished by several RNAi constructs to dbest1 and dbest2, but not dbest3 or dbest4. The endogenous CaC current was mimicked by expression of dbest1 in HEK cells, and the rectification and relative permeability of the current were altered by replacing F81 with cysteine. Single channel analysis of the S2 bestrophin currents revealed an ∼2-pS single channel with fast gating kinetics and linear current–voltage relationship. A similar channel was observed in CHO cells transfected with dbest1, but no such channel was seen in S2 cells treated with RNAi to dbest1. This provides definitive evidence that bestrophins are components of native CaC channels at the plasma membrane

Applying metabolic models for control in order to enhance algal growth and lipid production

A number of metabolic models have been developed in different algae species in the past five years. In this study, a metabolic model of C. vulgaris was applied for controlling algal growth and lipid production. This method optimized nutrient supply by characterizing algal metabolic pathways under different conditions. The approach was validated for autotrophic growth under nitrogen replete condition, in which nitrate requirement was lowered while retaining robust algal growth. Furthermore, this approach was also applied for nitrogen limited environments. Previous studies have found C. vulgaris can accumulate high lipid content in biomass, which can be hydrotreated to biodiesel, while decreasing algal growth under nitrogen limitation [1]. Our method optimized the nitrate supply to sustain algal growth while still producing fatty acids efficiently under nitrogen limited conditions. Compared with C. vulgaris cultures with complete nitrogen withdrawal, fatty acid methyl esters (FAME) increased substantially. This metabolic model-based approach will have applicability for optimizing nutrient inputs and biomanufacturing across a wide spectrum of organisms ranging from prokaryotes to eukaryotes used to produce a variety of biotechnology products in coming decades. References [1] M.T. Guarnieri, A. Nag, S.L. Smolinski, A. Darzins, M. Seibert, P.T. Pienkos, Examination of triacylglycerol biosynthetic pathways via de novo transcriptomic and proteomic analyses in an unsequenced microalga, PLoS One, 6 (2011) e25851