669 research outputs found
AGS and other tissue culture cells can unknowingly be persistently infected with PIV5; A virus that blocks interferon signalling by degrading STAT1
AbstractWhilst screening various cell lines for their ability to respond to interferon (IFN), we noted that in comparison to other tissue culture cells AGS tumour cells, which are widely used in biomedical research, had very low levels of STAT1. Subsequent analysis showed that the reason for this is that AGS cells are persistently infected with parainfluenza virus type 5 (PIV5; formally known as SV5), a virus that blocks the interferon (IFN) response by targeting STAT1 for proteasome-mediated degradation. Virus protein expression in AGS is altered in comparison to the normal pattern of virus protein synthesis observed in acutely infected cells, suggesting that the AGS virus is defective. We discuss the relevance of these results in terms of the need to screen cell lines for persistent virus infections that can alter cellular functions
Polymer impregnated concrete and polymer concrete overlays
The feasibility of impregnating bridge decks with methylmethacrylate for protection against freeze-thaw deteriorization and corrosion of the reinforcing steel is reported. Parameters such as monomer system, monomer loading, drying temperature and time, curing temperature and time, soak time and equipment were investigated and dicussed. A nondestructive method for the determination of the polymer depth in a polymer impregnated concrete was investigated and reported. The three methods that are presently used to place polymer concrete overlay on bridge decks were tested and compared with each other.Final ReportN
Generation of thiocillin ring size variants by prepeptide gene replacement and in vivo processing by Bacillus cereus
The thiocillins from Bacillus cereus ATCC 14579 are natural products from the broader class of thiazolyl peptides. Their biosynthesis proceeds via extensive post-translational modification of a ribosomally encoded precursor peptide. This post-translational tailoring involves a key step formal cycloaddition between two distal serine residues. In the wild-type structure, this cycloaddition forms a major macrocycle circumscribed by 26-atoms (shortest path). Results presented herein demonstrate the promiscuity of this last step by means of a set of "competition" experiments. Cyclization proceeds in many cases to provide altered ring sizes, giving access to several variant rings sizes that have not previously been observed in nature
Percolation on two- and three-dimensional lattices
In this work we apply a highly efficient Monte Carlo algorithm recently
proposed by Newman and Ziff to treat percolation problems. The site and bond
percolation are studied on a number of lattices in two and three dimensions.
Quite good results for the wrapping probabilities, correlation length critical
exponent and critical concentration are obtained for the square, simple cubic,
HCP and hexagonal lattices by using relatively small systems. We also confirm
the universal aspect of the wrapping probabilities regarding site and bond
dilution.Comment: 15 pages, 6 figures, 3 table
Soft Openings: The psycho-technological expertise of third sector curriculum reform
Since the late 1990s the "third sector" has become active in generating new curriculum programmes in England. Based on tracing third sector participation in public education during the New Labour years, the article explores a documentary archive of third sector curriculum texts and argues that the programmes, strategies and techniques of the third sector have sought to pursue a new form of governmentality. The type of governmentality pursued by the third sector takes form as a "soft" style of curriculum reform derived from assembling together cybernetic and psychological forms of expertise, interactionist and constructivist pedagogies, and an emerging "psycho-technology" of subjectivity. The third sector fabricates reform proposals for a curriculum of the future in which governance is done by cross-sectoral networking, epistemological categories are blurred, and student subjectivities are made up to be malleable, soft-skilled and psychologically self-shaping. The article examines how third sector texts have assembled this new psycho-technological expertise of curriculum reform through both cybernetic and psychological styles of thinking
The application of a novel fluidised photo reactor under UV-Visible and natural solar irradiation in the photocatalytic generation of hydrogen.
With advancements in the development of visible light responsive catalysts for H2 production frequently being reported, photocatalytic water splitting has become an attractive method as a potential 'solar fuel generator'. The development of novel photo reactors which can enhance the potential of such catalyst, however, is rarely reported. This is particularly important as many reactor configurations are mass transport limited, which in turn limits the efficiency of more effective photocatalysts in larger scale applications. This paper describes the performance of a novel fluidised photo reactor for the production of H2 over two catalysts under UV-Visible light and natural solar illumination. Catalysts Pt-C3N4 and NaTaO3·La were dispersed in the reactor and the rate of H2 was determined by GC-TCD analysis of the gas headspace. The unit was an annular reactor constructed from stainless steel 316 and quartz glass with a propeller located in the base to control fluidisation of powder catalysts. Reactor properties such as propeller rotational speed were found to enhance the photo activity of the system through the elimination of mass transport limitations and increasing light penetration. The optimum conditions for H2 evolution were found to be a propeller rotational speed of 1035rpm and 144W of UV-Visible irradiation, which produced a rate of 89μmol h-1 g-1 over Pt-C3N4. Solar irradiation was provided by the George Ellery Hale Solar Telescope, located at the California Institute of Technology
Frame Theory for Signal Processing in Psychoacoustics
This review chapter aims to strengthen the link between frame theory and
signal processing tasks in psychoacoustics. On the one side, the basic concepts
of frame theory are presented and some proofs are provided to explain those
concepts in some detail. The goal is to reveal to hearing scientists how this
mathematical theory could be relevant for their research. In particular, we
focus on frame theory in a filter bank approach, which is probably the most
relevant view-point for audio signal processing. On the other side, basic
psychoacoustic concepts are presented to stimulate mathematicians to apply
their knowledge in this field
Magnetic Field Amplification in Galaxy Clusters and its Simulation
We review the present theoretical and numerical understanding of magnetic
field amplification in cosmic large-scale structure, on length scales of galaxy
clusters and beyond. Structure formation drives compression and turbulence,
which amplify tiny magnetic seed fields to the microGauss values that are
observed in the intracluster medium. This process is intimately connected to
the properties of turbulence and the microphysics of the intra-cluster medium.
Additional roles are played by merger induced shocks that sweep through the
intra-cluster medium and motions induced by sloshing cool cores. The accurate
simulation of magnetic field amplification in clusters still poses a serious
challenge for simulations of cosmological structure formation. We review the
current literature on cosmological simulations that include magnetic fields and
outline theoretical as well as numerical challenges.Comment: 60 pages, 19 Figure
Creation and impact of containment units with high-risk zones during the coronavirus disease 2019 (COVID-19) pandemic
Background: The rapid spread of coronavirus disease 2019 (COVID-19) required swift preparation to protect healthcare personnel (HCP) and patients, especially considering shortages of personal protective equipment (PPE). Due to the lack of a pre-existing biocontainment unit, we needed to develop a novel approach to placing patients in isolation cohorts while working with the pre-existing physical space. Objectives: To prevent disease transmission to non–COVID-19 patients and HCP caring for COVID-19 patients, to optimize PPE usage, and to provide a comfortable and safe working environment. Methods: An interdisciplinary workgroup developed a combination of approaches to convert existing spaces into COVID-19 containment units with high-risk zones (HRZs). We developed standard workflow and visual management in conjunction with updated staff training and workflows. The infection prevention team created PPE standard practices for ease of use, conservation, and staff safety. Results: The interventions resulted in 1 possible case of patient-to-HCP transmission and zero cases of patient-to-patient transmission. PPE usage decreased with the HRZ model while maintaining a safe environment of care. Staff on the COVID-19 units were extremely satisfied with PPE availability (76.7%) and efforts to protect them from COVID-19 (72.7%). Moreover, 54.8% of HCP working in the COVID-19 unit agreed that PPE monitors played an essential role in staff safety. Conclusions: The HRZ model of containment unit is an effective method to prevent the spread of COVID-19 with several benefits. It is easily implemented and scaled to accommodate census changes. Our experience suggests that other institutions do not need to modify existing physical structures to create similarly protective spaces
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
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