191 research outputs found

    Characterisation of a pucBA deletion mutant from Rhodopseudomonas palustris lacking all but the pucBAd genes

    Get PDF
    Rhodopseudomonas palustris is a species of purple photosynthetic bacteria that has a multigene family of puc genes that encode the alpha and beta apoproteins, which form the LH2 complexes. A genetic dissection strategy has been adopted in order to try and understand which spectroscopic form of LH2 these different genes produce. This paper presents a characterisation of one of the deletion mutants generated in this program, the pucBAd only mutant. This mutant produces an unusual spectroscopic form of LH2 that only has a single large NIR absorption band at 800 nm. Spectroscopic and pigment analyses on this complex suggest that it has basically a similar overall structure as that of the wild-type HL LH2 complex. The mutant has the unique phenotype where the mutant LH2 complex is only produced when cells are grown at LL. At HL the mutant only produces the LH1-RC core complex

    CSI 2264: Characterizing Accretion-Burst Dominated Light Curves for Young Stars in NGC 2264

    Full text link
    Based on more than four weeks of continuous high cadence photometric monitoring of several hundred members of the young cluster NGC 2264 with two space telescopes, NASA's Spitzer and the CNES CoRoT (Convection, Rotation, and planetary Transits), we provide high quality, multi-wavelength light curves for young stellar objects (YSOs) whose optical variability is dominated by short duration flux bursts, which we infer are due to enhanced mass accretion rates. These light curves show many brief -- several hour to one day -- brightenings at optical and near-infrared (IR) wavelengths with amplitudes generally in the range 5-50% of the quiescent value. Typically, a dozen or more of these bursts occur in a thirty day period. We demonstrate that stars exhibiting this type of variability have large ultraviolet (UV) excesses and dominate the portion of the u-g vs. g-r color-color diagram with the largest UV excesses. These stars also have large Halpha equivalent widths, and either centrally peaked, lumpy Halpha emission profiles or profiles with blue-shifted absorption dips associated with disk or stellar winds. Light curves of this type have been predicted for stars whose accretion is dominated by Rayleigh-Taylor instabilities at the boundary between their magnetosphere and inner circumstellar disk, or where magneto-rotational instabilities modulate the accretion rate from the inner disk. Amongst the stars with the largest UV excesses or largest Halpha equivalent widths, light curves with this type of variability greatly outnumber light curves with relatively smooth sinusoidal variations associated with long-lived hot spots. We provide quantitative statistics for the average duration and strength of the accretion bursts and for the fraction of the accretion luminosity associated with these bursts.Comment: Accepted for publication in AJ. 39 pages; 6 tables; 25 figures, many of which are highly degraded to meet size limits. Please download the regular resolution version at http://web.ipac.caltech.edu/staff/amc/staufferetal2014.pd

    Preferences on Governance Models for Mental Health Data: Qualitative Study With Young People

    Get PDF
    BACKGROUND: Improving access to mental health data to accelerate research and improve mental health outcomes is a potentially achievable goal given the substantial data that can now be collected from mobile devices. Smartphones can provide a useful mechanism for collecting mental health data from young people, especially as their use is relatively ubiquitous in high-resource settings such as the United Kingdom and they have a high capacity to collect active and passive data. This raises the interesting opportunity to establish a large bank of mental health data from young people that could be accessed by researchers worldwide, but it is important to clarify how to ensure that this is done in an appropriate manner aligned with the values of young people. OBJECTIVE: In this study, we discussed the preferences of young people in the United Kingdom regarding the governance, sharing, and use of their mental health data with the establishment of a global data bank in mind. We aimed to determine whether young people want and feel safe to share their mental health data; if so, with whom; and their preferences in doing so. METHODS: Young people (N=46) were provided with 2 modules of educational material about data governance models and background in scientific research. We then conducted 2-hour web-based group sessions using a deliberative democracy methodology to reach a consensus where possible. Findings were analyzed using the framework method. RESULTS: Young people were generally enthusiastic about contributing data to mental health research. They believed that broader availability of mental health data could be used to discover what improves or worsens mental health and develop new services to support young people. However, this enthusiasm came with many concerns and caveats, including distributed control of access to ensure appropriate use, distributed power, and data management that included diverse representation and sufficient ethical training for applicants and data managers. CONCLUSIONS: Although it is feasible to use smartphones to collect mental health data from young people in the United Kingdom, it is essential to carefully consider the parameters of such a data bank. Addressing and embedding young people's preferences, including the need for robust procedures regarding how their data are managed, stored, and accessed, will set a solid foundation for establishing any global data bank

    The E3 Ubiquitin Ligase TRIM9 Is a Filopodia Off Switch Required for Netrin-Dependent Axon Guidance

    Get PDF
    Neuronal growth cone filopodia contain guidance receptors and contribute to axon guidance; however, the mechanism by which the guidance cue netrin increases filopodia density is unknown. Here, we demonstrate that TRIM9, an E3 ubiquitin ligase that localizes to filopodia tips and binds the netrin receptor DCC, interacts with and ubiquitinates the barbed-end polymerase VASP to modulate filopodial stability during netrin-dependent axon guidance. Studies with murine Trim9(+/+) and Trim9(-/-) cortical neurons, along with a non-ubiquitinatable VASP mutant, demonstrate that TRIM9-mediated ubiquitination of VASP reduces VASP filopodial tip localization, VASP dynamics at tips, and filopodial stability. Upon netrin treatment, VASP is deubiquitinated, which promotes VASP tip localization and filopodial stability. Trim9 deletion induces axon guidance defects in vitro and in vivo, whereas a gradient of deubiquitinase inhibition promotes axon turning in vitro. We conclude that a gradient of TRIM9-mediated ubiquitination of VASP creates a filopodial stability gradient during axon turning

    Tumor innate immunity primed by specific interferon-stimulated endogenous retroviruses.

    Get PDF
    Mesenchymal tumor subpopulations secrete pro-tumorigenic cytokines and promote treatment resistance1-4. This phenomenon has been implicated in chemorefractory small cell lung cancer and resistance to targeted therapies5-8, but remains incompletely defined. Here, we identify a subclass of endogenous retroviruses (ERVs) that engages innate immune signaling in these cells. Stimulated 3 prime antisense retroviral coding sequences (SPARCS) are oriented inversely in 3' untranslated regions of specific genes enriched for regulation by STAT1 and EZH2. Derepression of these loci results in double-stranded RNA generation following IFN-Îł exposure due to bi-directional transcription from the STAT1-activated gene promoter and the 5' long terminal repeat of the antisense ERV. Engagement of MAVS and STING activates downstream TBK1, IRF3, and STAT1 signaling, sustaining a positive feedback loop. SPARCS induction in human tumors is tightly associated with major histocompatibility complex class 1 expression, mesenchymal markers, and downregulation of chromatin modifying enzymes, including EZH2. Analysis of cell lines with high inducible SPARCS expression reveals strong association with an AXL/MET-positive mesenchymal cell state. While SPARCS-high tumors are immune infiltrated, they also exhibit multiple features of an immune-suppressed microenviroment. Together, these data unveil a subclass of ERVs whose derepression triggers pathologic innate immune signaling in cancer, with important implications for cancer immunotherapy

    Exile Vol. XL No. 2

    Get PDF
    38th Year Title Page by Carrie Horner \u2797 i Epigraph by Ezra Pound ii Table of Contents iii-iv Remembering Sundays by Allison Lemieux \u2795 1 Untitled by James Oliver \u2794 2 \u2778 Beige Chevy Malibu by Craig J. McDonough \u2794 3-4 Brushtown Road by Lelei Jennings \u2795 5 In Memoriam: River Phoenix, 1970-93 by Kirstin Rogers \u2794 6 Untitled by Kira Pollack \u2794 7 Checkmate by Kevin Nix \u2794 8 Anywhere in Ohio by Jen Hanysh \u2795 9 Untitled by Nicky Taylor \u2794 10 Under Your Influence by Katherine Anne Campo \u2794 11 Tulips by Tricia B. Swearingen \u2794 12 Untitled by Keith Chapman \u2795 12 December Storm by Erin Lott \u2796 13-19 On Meeting Phil Levine After a Reading at Denison University April 6, 1993 by Christopher Harnish \u2794 20 The 422 Bypass by Joel Husenits \u2795 21 Untitled by Ken Tyburski \u2794 22 Shakespeare\u27s Foreskin by Carey Christie \u2795 23 The Thaw by Chris Iven \u2794 24 The Rockbridge County Fair by Morgan Roper \u2794 25 Let it Drop Through by Carey Christie \u2795 26-27 Aladdin\u27s by Paul Rinkes \u2794 28-29 Untitled by Aileen Jones \u2794 30 The Tango by Hope Layne Morgan \u2794 31 Icarus by Carey Christine \u2795 32-33 fad by Jeremy Aufrance \u2795 34 Untitled by James Oliver \u2794 35 Desert Villanelle by Christopher Harnish \u2794 36 The Skull by Nicky Taylor \u2794 37 Rodeo Bar by Carl Jeffrey Boon \u2796 38 I, Mordred by Carey Christie \u2795 39-43 Between Centuries by Leslie Dana Wells \u2794 44-45 Untitled by Carrie Horner \u2797 45 Untitled by Alex Emmons \u2796 46 Coleridge\u27s Curse by Allison Lemieux \u2795 47 Untitled by Jenny Baker \u2794 48 five by Jeremy Aufrance \u2795 49 Untitled by James Oliver \u2794 50 Lobster Boy by Kirstin Rogers \u2794 51 Fire on the Mountain by Christopher Harnish \u2794 52-53 Yosemite by Morgan Roper \u2794 54 Untitled by Carrie Horner \u2797 54 Untitled by Ken Tyburski \u2794 55 Sleepless Nights Fades to Credits by Allison Lemieux \u2794 56 Dancing Days by Julie McDonald \u2794 57 Immobile by Adrienne Fair \u2796 58-59 Untitled by Kira Pollack \u2794 60 Dorm Fire by Lisa Marie Antonille \u2795 Untitled by Carrie Horner \u2797 61 The Book by Matt Wanat \u2795 62-63 Distance by Carl Jeffrey Boon \u2796 64 Untitled by Jenny Baker \u2794 65 Cover by Ken Tyburski \u2794 Editorial decision is shared equally among the Editorial Board. -6
    • …
    corecore