1,242 research outputs found

    The Meeting of Two Police Ideas

    Get PDF

    You May Have to Do it Again, Rocky! An Experimental Analysis of Bargaining with Risky Joint Profits

    Get PDF
    We present an experimental study of a risky sequential bargaining to model negotiations in risky joint ventures that proceed through multiple stages.Our example is the production of a movie that may give rise to a sequel, so actors and producers negitiate sequentially.We compare the predictions of alternative theoretical approaches to understanding such a game.The game theoretic solution predicts (assuming risk neutrality) that actors are willing to accept wages below their outside option for first films in order to capture the gains from winning lucrative sequel contracts.This prediction is strongly rejected by the data.The data are better explained by either equity theory (equal splits) or by a game theoretic model where actors have uncertain risk aversion.The parameters of the game are calibrated to match data on 99 movies for 1989 available from a case study.

    The agrin gene codes for a family of basal lamina proteins that differ in function and distribution

    Get PDF
    We isolated two cDNAs that encode isoforms of agrin, the basal lamina protein that mediates the motor neuron-induced aggregation of acetylcholine receptors on muscle fibers at the neuromuscular junction. Both proteins are the result of alternative splicing of the product of the agrin gene, but, unlike agrin, they are inactive in standard acetylcholine receptor aggregation assays. They lack one (agrin-related protein 1) or two (agrin-related protein 2) regions in agrin that are required for its activity. Expression studies provide evidence that both proteins are present in the nervous system and muscle and that, in muscle, myofibers and Schwann cells synthesize the agrin-related proteins while the axon terminals of motor neurons are the sole source of agrin

    The Impact of 18 Ancestral and Horizontally-Acquired Regulatory Proteins upon the Transcriptome and sRNA Landscape of Salmonella enterica serovar Typhimurium

    Get PDF
    Article Authors Metrics Comments Media Coverage Abstract Author Summary Introduction Results and Discussion Materials and Methods Supporting Information Acknowledgments Author Contributions References Reader Comments (0) Media Coverage (0) Figures Abstract We know a great deal about the genes used by the model pathogen Salmonella enterica serovar Typhimurium to cause disease, but less about global gene regulation. New tools for studying transcripts at the single nucleotide level now offer an unparalleled opportunity to understand the bacterial transcriptome, and expression of the small RNAs (sRNA) and coding genes responsible for the establishment of infection. Here, we define the transcriptomes of 18 mutants lacking virulence-related global regulatory systems that modulate the expression of the SPI1 and SPI2 Type 3 secretion systems of S. Typhimurium strain 4/74. Using infection-relevant growth conditions, we identified a total of 1257 coding genes that are controlled by one or more regulatory system, including a sub-class of genes that reflect a new level of cross-talk between SPI1 and SPI2. We directly compared the roles played by the major transcriptional regulators in the expression of sRNAs, and discovered that the RpoS (σ38) sigma factor modulates the expression of 23% of sRNAs, many more than other regulatory systems. The impact of the RNA chaperone Hfq upon the steady state levels of 280 sRNA transcripts is described, and we found 13 sRNAs that are co-regulated with SPI1 and SPI2 virulence genes. We report the first example of an sRNA, STnc1480, that is subject to silencing by H-NS and subsequent counter-silencing by PhoP and SlyA. The data for these 18 regulatory systems is now available to the bacterial research community in a user-friendly online resource, SalComRegulon

    Radio-planetary from tie from Phobos-2 VLBI data

    Get PDF
    In an ongoing effort to improve the knowledge of the relative orientation (the 'frame tie') of the planetary ephemeris reference frame used in deep navigation and a second reference frame that is defined by the coordinates of a set of extragalactic radio sources, VLBI observations of the Soviet Phobos-2 spacecraft and nearby (in angle) radio sources were obtained at two epochs in 1989, shortly after the spacecraft entered orbit about Mars. The frame tie is an important systematic error source affecting both interplanetary navigation and the process of improving the theory of the Earth's orientation. The data from a single Phobos-2 VLBI session measure one component of the direction vector from Earth to Mars in the frame of the extragalactic radio sources (the 'radio frame'). The radio frame has been shown to be stable and internally consistent with an accuracy of 5 nrad. The planetary ephemeris reference frame has an internal consistency of approximately 15 nrad. The planetary and radio source reference frames were aligned prior to 1989 and measurements of occulations of the radio source 3C273 by the Moon. The Phobos-2 VLBI measurements provide improvement in the accuracy of two of the three angles describing a general rotation between the planetary and radio reference frames. A complete set of measurements is not available because data acquisition was terminated prematurely by loss of spacecraft. The analysis of the two Phobos-2 VLBI data sets indicates that, in the directions of the two rotation components determined by these data, the JPL planetary ephemeris DE200 is aligned with the radio frame as adopted by the International Earth Rotation Service within an accuracy of 20-40 nrad, depending on direction. The limiting errors in the solutions for these offsets are spacecraft trajectory (20 nrad), instrumental biases (19 nrad), and dependence of quasar coordinates on observing frequency (24 nrad)

    Vertex functions for d-wave mesons in the light-front approach

    Full text link
    While the light-front quark model (LFQM) is employed to calculate hadronic transition matrix elements, the vertex functions must be pre-determined. In this work we derive the vertex functions for all d-wave states in this model. Especially, since both of 3D1^3D_1 and 3S1^3S_1 are 11^{--} mesons, the Lorentz structures of their vertex functions are the same. Thus when one needs to study the processes where 3D1^3D_1 is involved, all the corresponding formulas for 3S1^3S_1 states can be directly applied, only the coefficient of the vertex function should be replaced by that for 3D1^3D_1. The results would be useful for studying the newly observed resonances which are supposed to be d-wave mesons and furthermore the possible 2S-1D mixing in ψ\psi' with the LFQM.Comment: 12 pages, 2 figures, some typos corrected and more discussions added. Accepted by EPJ

    RUNX3 Regulates Intercellular Adhesion Molecule 3 (ICAM-3) Expression during Macrophage Differentiation and Monocyte Extravasation

    Get PDF
    The adhesion molecule ICAM-3 belongs to the immunoglobulin gene superfamily and functions as a ligand for the β2 integrins LFA-1, Mac-1 and αdβ2. The expression of ICAM-3 is restricted to cells of the hematopoietic lineage. We present evidences that the ICAM-3 gene promoter exhibits a leukocyte-specific activity, as its activity is significantly higher in ICAM-3+ hematopoietic cell lines. The activity of the ICAM-3 gene promoter is dependent on the occupancy of RUNX cognate sequences both in vitro and in vivo, and whose integrity is required for RUNX responsiveness and for the cooperative actions of RUNX with transcription factors of the Ets and C/EBP families. Protein analysis revealed that ICAM-3 levels diminish upon monocyte-derived macrophage differentiation, monocyte transendothelial migration and dendritic cell maturation, changes that correlate with an increase in RUNX3. Importantly, disruption of RUNX-binding sites led to enhanced promoter activity, and small interfering RNA-mediated reduction of RUNX3 expression resulted in increased ICAM-3 mRNA levels. Altogether these results indicate that the ICAM-3 gene promoter is negatively regulated by RUNX transcription factors, which contribute to the leukocyte-restricted and the regulated expression of ICAM-3 during monocyte-to-macrophage differentiation and monocyte extravasation

    The role of PET/CT in Cogan’s syndrome

    Get PDF
    We report on the case of a 60-year-old woman with complaints of fatigue, coughing, anorexia, atypical chest pain, recurrent fever, and also ear pain and hearing loss. A test for anti-neutrophil cytoplasmic antibody (ANCA) was myeloperoxidase positive with p-ANCA specificity. Laboratory acute phase parameters were increased. A 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography/computed tomography investigation showed pathological uptake in the aorta ascendens, with no other involvement of the large vessels. After therapy with methylprednisolon intravenously and later prednisolon orally with methothrexate, her general condition and hearing loss improved both subjectively and objectively. “Atypical” Cogan’s syndrome was diagnosed on the basis of sensorineural deafness with improvement on steroids and large-vessel vasculitis of the aortic arch

    Polarised Quark Distributions in the Nucleon from Semi-Inclusive Spin Asymmetries

    Get PDF
    We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 0.0030.0031 GeV2^2. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at Q2Q^2=10 GeV2^2. The polarised uu valence quark distribution, Δuv(x)\Delta u_v(x), is positive and the polarisation increases with xx. The polarised dd valence quark distribution, Δdv(x)\Delta d_v(x), is negative and the non-strange sea distribution, Δqˉ(x)\Delta \bar q(x), is consistent with zero over the measured range of xx. We find for the first moments 01Δuv(x)dx=0.77±0.10±0.08\int_0^1 \Delta u_v(x) dx = 0.77 \pm 0.10 \pm 0.08, 01Δdv(x)dx=0.52±0.14±0.09\int_0^1 \Delta d_v(x) dx = -0.52 \pm 0.14 \pm 0.09 and 01Δqˉ(x)dx=0.01±0.04±0.03\int_0^1 \Delta \bar q(x) dx= 0.01 \pm 0.04 \pm 0.03, where we assumed Δuˉ(x)=Δdˉ(x)\Delta \bar u(x) = \Delta \bar d(x). We also determine for the first time the second moments of the valence distributions 01xΔqv(x)dx\int_0^1 x \Delta q_v(x) dx.Comment: 17 page
    corecore