30,493 research outputs found

    Neutrino Physics and Nuclear Axial Two-Body Interactions

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    We consider the counter-term describing isoscalar axial two-body currents in the nucleon-nucleon interaction, L1A, in the effective field theory approach. We determine this quantity using the solar neutrino data. We investigate the variation of L1A when different sets of data are used.Comment: 8 pages with 4 figures. To be published in the Proceedings of the Conference "Blueprints For The Nucleus: From First Principles to Collective Motion" held at Feza Gursey Institute, Istanbul, Turkey; May 17 -22, 200

    Writing in your own voice: An intervention that reduces plagiarism and common writing problems in students' scientific writing.

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    In many of our courses, particularly laboratory courses, students are expected to engage in scientific writing. Despite various efforts by other courses and library resources, as instructors we are often faced with the frustration of student plagiarism and related writing problems. Here, we describe a simple Writing in Your Own Voice intervention designed to help students become more aware of different types of plagiarism and writing problems, avoid those problems, and practice writing in their own voice. In this article, we will introduce the types of plagiarism and writing problems commonly encountered in our molecular biology laboratory course, the intervention, and the results of our study. From the evaluation of 365 student reports, we found the intervention resulted in nearly 50% fewer instances of plagiarism and common writing problems. We also observed significantly fewer instances of severe plagiarism (e.g. several sentences copied from an external source). In addition, we find that the effects last for several weeks after the students complete the intervention assignment. This assignment is particularly easy to implement and can be a very useful tool for teaching students how to write in their own voices. © 2019 International Union of Biochemistry and Molecular Biology, 47(5):589-598, 2019

    The Expanded Very Large Array

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    In almost 30 years of operation, the Very Large Array (VLA) has proved to be a remarkably flexible and productive radio telescope. However, the basic capabilities of the VLA have changed little since it was designed. A major expansion utilizing modern technology is currently underway to improve the capabilities of the VLA by at least an order of magnitude in both sensitivity and in frequency coverage. The primary elements of the Expanded Very Large Array (EVLA) project include new or upgraded receivers for continuous frequency coverage from 1 to 50 GHz, new local oscillator, intermediate frequency, and wide bandwidth data transmission systems to carry signals with 16 GHz total bandwidth from each antenna, and a new digital correlator with the capability to process this bandwidth with an unprecedented number of frequency channels for an imaging array. Also included are a new monitor and control system and new software that will provide telescope ease of use. Scheduled for completion in 2012, the EVLA will provide the world research community with a flexible, powerful, general-purpose telescope to address current and future astronomical issues.Comment: Added journal reference: published in Proceedings of the IEEE, Special Issue on Advances in Radio Astronomy, August 2009, vol. 97, No. 8, 1448-1462 Six figures, one tabl

    Novel insights into the expression of CGB1 & 2 genes by epithelial cancer cell lines secreting ectopic free hCGβ

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    BACKGROUND Ectopic secretion of human chorionic gonadotrophin free beta (hCGβ) by epithelial cancer is associated with aggressive tumors which more readily metastasize, possibly by acting as an autocrine anti-apoptotic agent. hCGβ is encoded by six homologous CGB genes, with poorly-understood variable transcriptionally active expression profiles; CGB1 and CGB2 have always been considered pseudogenes. However, transcripts from CGB1 and -2 can be detected in placental, testicular and pituitary tissues. The expression and function of these genes in cancer is less well-known. MATERIALS AND METHODS Expression profiles of CGB genes in epithelial cancer cells by quantitative polymerase chain reaction (qPCR) were explored, along with the consequence of specific siRNA silencing of CGB1 and 2. Immunohistochemical and immunoassay techniques were used to detect the translation and secretion of hCGβ in these cells. RESULTS CGB1 and -2 gene transcripts were only detected in cells which secreted hCGβ. siRNA-mediated silencing of CGB1 and -2 transcripts significantly reduced secreted protein in concordance with a reduction in cell survival to a greater degree than that of other CGB genes. CONCLUSION CGB genes 1 and 2, previously considered as pseudogenes, are notably expressed by epithelial cancer cell lines. The transcription of these genes, but not other CGB genes, correlates with a functionally expressed protein and propensity for cancer growth

    VLA Observations of Single Pulses from the Galactic Center Magnetar

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    We present the results of a 7-12 GHz phased-array study of the Galactic center magnetar J1745-2900 with the Karl G. Jansky Very Large Array (VLA). Using data from two 6.5 hour observations from September 2014, we find that the average profile is comprised of several distinct components at these epochs and is stable over \simday timescales and \simGHz frequencies. Comparison with additional phased VLA data at 8.7 GHz shows significant profile changes on longer timescales. The average profile at 7-12 GHz is dominated by the jitter of relatively narrow pulses. The pulses in each of the four main profile components seen in September 2014 are uncorrelated in phase and amplitude, though there is a small but significant correlation in the occurrence of pulses in two of the profile components. Using the brightest pulses, we measure the dispersion and scattering parameters of J1745-2900. A joint fit of 38 pulses gives a 10 GHz pulse broadening time of τsc,10=0.09±0.03 ms\tau_{\rm sc, 10} = 0.09 \pm 0.03~\rm ms and a dispersion measure of DM=17601.3+2.4 pc cm3{\rm DM} = 1760^{+2.4}_{-1.3}~{\rm pc~cm}^{-3}. Both of these results are consistent with previous measurements, which suggests that the scattering and dispersion measure of J1745-2900 may be stable on timescales of several years.Comment: 20 pages, 10 figures, published in Ap

    Travelling and sticky affects: : Exploring teens and sexualized cyberbullying through a Butlerian-Deleuzian- Guattarian lens

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    In this paper we combine the thinking of Deleuze and Guattari (1984, 1987) with Judith Butler’s (1990, 1993, 2004, 2009) work to follow the rhizomatic becomings of young people’s affective relations in a range of on- and off-line school spaces. In particular we explore how events that may be designated as sexual cyberbullying are constituted and how they are mediated by technology (such as texting or in/through social networking sites). Drawing on findings from two different studies looking at teens’ uses of and experiences with social networking sites, Arto in Denmark, and Bebo in the UK, we use this approach to think about how affects flow, are distributed, and become fixed in assemblages. We map how affects are manoeuvred and potentially disrupted by young people, suggesting that in the incidences discussed affects travel as well as stick in points of fixation. We argue that we need to grasp both affective flow and fixity in order to gain knowledge of how subjectification of the gendered/classed/racialised/sexualised body emerges. A Butlerian-Deleuzian-Guattarian frame helps us to map some of these affective complexities that shape sexualized cyberbully events; and to recognize technologically mediated lines of flight when subjectifications are at least temporarily disrupted and new terms of recognition and intelligibility staked out. Keywords

    Electromagnetic Moments of the Baryon Decuplet

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    We compute the leading contributions to the magnetic dipole and electric quadrupole moments of the baryon decuplet in chiral perturbation theory. The measured value for the magnetic moment of the Ω\Omega^- is used to determine the local counterterm for the magnetic moments. We compare the chiral perturbation theory predictions for the magnetic moments of the decuplet with those of the baryon octet and find reasonable agreement with the predictions of the large--NcN_c limit of QCD. The leading contribution to the quadrupole moment of the Δ\Delta and other members of the decuplet comes from one--loop graphs. The pionic contribution is shown to be proportional to IzI_z (and so will not contribute to the quadrupole moment of I=0I=0 nuclei), while the contribution from kaons has both isovector and isoscalar components. The chiral logarithmic enhancement of both pion and kaon loops has a coefficient that vanishes in the SU(6)SU(6) limit. The third allowed moment, the magnetic octupole, is shown to be dominated by a local counterterm with corrections arising at two loops. We briefly mention the strange counterparts of these moments.Comment: Uses harvmac.tex, 15 pages with 3 PostScript figures packed using uufiles. UCSD/PTH 93-22, QUSTH-93-05, Duke-TH-93-5

    Realfast: Real-Time, Commensal Fast Transient Surveys with the Very Large Array

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    Radio interferometers have the ability to precisely localize and better characterize the properties of sources. This ability is having a powerful impact on the study of fast radio transients, where a few milliseconds of data is enough to pinpoint a source at cosmological distances. However, recording interferometric data at millisecond cadence produces a terabyte-per-hour data stream that strains networks, computing systems, and archives. This challenge mirrors that of other domains of science, where the science scope is limited by the computational architecture as much as the physical processes at play. Here, we present a solution to this problem in the context of radio transients: realfast, a commensal, fast transient search system at the Jansky Very Large Array. Realfast uses a novel architecture to distribute fast-sampled interferometric data to a 32-node, 64-GPU cluster for real-time imaging and transient detection. By detecting transients in situ, we can trigger the recording of data for those rare, brief instants when the event occurs and reduce the recorded data volume by a factor of 1000. This makes it possible to commensally search a data stream that would otherwise be impossible to record. This system will search for millisecond transients in more than 1000 hours of data per year, potentially localizing several Fast Radio Bursts, pulsars, and other sources of impulsive radio emission. We describe the science scope for realfast, the system design, expected outcomes, and ways real-time analysis can help in other fields of astrophysics.Comment: Accepted to ApJS Special Issue on Data; 11 pages, 4 figure
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