1,945 research outputs found
Molecular Insights into the Role of Serum Amyloid-P Component in the Stabilzation of Fibrillar Beta-2 Microglobulin
V344 Lyrae: A Touchstone SU UMa Cataclysmic Variable in the Kepler Field
We report on the analysis of the Kepler short-cadence (SC) light curve of
V344 Lyr obtained during 2009 June 20 through 2010 Mar 19 (Q2--Q4). The system
is an SU UMa star showing dwarf nova outbursts and superoutbursts, and promises
to be a touchstone for CV studies for the foreseeable future. The system
displays both positive and negative superhumps with periods of 2.20 and
2.06-hr, respectively, and we identify an orbital period of 2.11-hr. The
positive superhumps have a maximum amplitude of ~0.25-mag, the negative
superhumps a maximum amplitude of ~0.8 mag, and the orbital period at
quiescence has an amplitude of ~0.025 mag. The quality of the Kepler data is
such that we can test vigorously the models for accretion disk dynamics that
have been emerging in the past several years. The SC data for V344 Lyr are
consistent with the model that two physical sources yield positive superhumps:
early in the superoutburst, the superhump signal is generated by viscous
dissipation within the periodically flexing disk, but late in the
superoutburst, the signal is generated as the accretion stream bright spot
sweeps around the rim of the non-axisymmetric disk. The disk superhumps are
roughly anti-phased with the stream/late superhumps. The V344 Lyr data also
reveal negative superhumps arising from accretion onto a tilted disk precessing
in the retrograde direction, and suggest that negative superhumps may appear
during the decline of DN outbursts. The period of negative superhumps has a
positive dP/dt in between outbursts.Comment: ApJ, In Press (20 pages, 27 figures) A version with full-resolution
figures is available at http://www.astro.fit.edu/wood/WoodV344.pd
Sonification of Kepler Field SU UMa Cataclysmic Variable Stars V344 Lyr and V1504 Cyg
Sonification is the conversion of quantitative data into sound. In this work we explain the methods used in the sonification of light curves provided by the Kepler instrument from Q2 through Q6 for the cataclysmic variable systems V344 Lyr and V1504 Cyg . Both systems are SU UMa stars showing dwarf nova outbursts and superoutbursts as well as positive and negative superhumps. Focused sonifications were done from average pulse shapes of each superhump, and separate sonifications of the full, residual light curves were done for both stars. The audio of these data reflected distinct patterns within the evolutions of supercycles and superhumps that matched pervious observations and proved to be effective aids in data analysis
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Air Pollution, housing and respiratory tract Infections in Children: NatIonal birth Cohort study (PICNIC) - study protocol
INTRODUCTION: Respiratory tract infections (RTIs) are the most common reason for hospital admission among children <5 years in the UK. The relative contribution of ambient air pollution exposure and adverse housing conditions to RTI admissions in young children is unclear and has not been assessed in a UK context. METHODS AND ANALYSIS: The aim of the PICNIC study (Air Pollution, housing and respiratory tract Infections in Children: NatIonal birth Cohort Study) is to quantify the extent to which in-utero, infant and childhood exposures to ambient air pollution and adverse housing conditions are associated with risk of RTI admissions in children <5 years old. We will use national administrative data birth cohorts, including data from all children born in England in 2005-2014 and in Scotland in 1997-2020, created via linkage between civil registration, maternity and hospital admission data sets. We will further enhance these cohorts via linkage to census data on housing conditions and socioeconomic position and small area-level data on ambient air pollution and building characteristics. We will use time-to-event analyses to examine the association between air pollution, housing characteristics and the risk of RTI admissions in children, calculate population attributable fractions for ambient air pollution and housing characteristics, and use causal mediation analyses to explore the mechanisms through which housing and air pollution influence the risk of infant RTI admission. ETHICS, EXPECTED IMPACT AND DISSEMINATION: To date, we have obtained approval from six ethics and information governance committees in England and two in Scotland. Our results will inform parents, national and local governments, the National Health Service and voluntary sector organisations of the relative contribution of adverse housing conditions and air pollution to RTI admissions in young children. We will publish our results in open-access journals and present our results to the public via parent groups and social media and on the PICNIC website. Code and metadata will be published on GitHub
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In crystallo-screening for discovery of human norovirus 3C-like protease inhibitors.
Outbreaks of human epidemic nonbacterial gastroenteritis are mainly caused by noroviruses. Viral replication requires a 3C-like cysteine protease (3CLpro) which processes the 200Â kDa viral polyprotein into six functional proteins. The 3CLpro has attracted much interest due to its potential as a target for antiviral drugs. A system for growing high-quality crystals of native Southampton norovirus 3CLpro (SV3CP) has been established, allowing the ligand-free crystal structure to be determined to 1.3Â Ã… in a tetrameric state. This also allowed crystal-based fragment screening to be performed with various compound libraries, ultimately to guide drug discovery for SV3CP. A total of 19 fragments were found to bind to the protease out of the 844 which were screened. Two of the hits were located at the active site of SV3CP and showed good inhibitory activity in kinetic assays. Another 5 were found at the enzyme's putative RNA-binding site and a further 11 were located in the symmetric central cavity of the tetramer
The Grizzly, February 5, 1988
Cavorting Cop Caught • Lewis Disclaims Labels at Forum • Rock\u27N America • Patterns Campaign Nears Completion • Hockey Held as Hokey • Contra-versial Censorship Irks Student • History Department Interviews a New Way • Concert Features Christian Music • Summer Study in France a Fun-do • Notes: R.A. Rap Session Announced; Presidency Probers Convene; ALF Re-runs Rewarding; Child Safety Course Offered • Men\u27s Hoopsters Suffer Temporary Setback • Track Team Making Great Strides • Record Books Rewritten • U.C. Matters: Wrestling Tough and Confident • Men \u27Mers Holding Their Ownhttps://digitalcommons.ursinus.edu/grizzlynews/1203/thumbnail.jp
The X-ray structure of L-threonine dehydrogenase from the common hospital pathogen Clostridium difficile.
In many prokaryotes, the first step of threonine metabolism is catalysed by the enzyme threonine dehydrogenase (TDH), which uses NAD+ to oxidize its substrate to 2-amino-3-ketobutyrate. The absence of a functional TDH gene in humans suggests that inhibitors of this enzyme may have therapeutic potential against pathogens which are reliant on this enzyme. Here, TDH from Clostridium difficile has been cloned and overexpressed, and the X-ray structure of the apoenzyme form has been determined at 2.6 Å resolution
Crystallization, X-ray diffraction and preliminary structure analysis of Mycobacterium tuberculosis
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