98 research outputs found
Measuring helical FCG voltage with an electric field antenna
A method of measuring the voltage produced by a helical explosive flux compression generator using a remote electric field antenna is described in detail. The diagnostic has been successfully implemented on several experiments. Measured data from the diagnostic compare favorably with voltages predicted using the code CAGEN, validating our predictive modeling tools. The measured data is important to understanding generator performance, and is measured with a low-risk, minimally intrusive approach
OURCOAST, A European initiative to support exchange of experiences and best practices in coastal management
OURCOAST is a three-year initiative commissioned by the General Directorate (DG)
Environment of the European Commission to support and ensure the exchange of
experiences and best practices in coastal management. This initiative was made
possible thanks to the European Parliament that voted a dedicated resource for
this purpose into the EU budget in 2008.
The European Commission has intensively worked on developing and promoting
Integrated Coastal Zone Management (ICZM) principles. More recently, an
evaluation on ICZM in Europe concluded that although there is still great
willingness of Authorities at national, regional and locals levels to implement
ICZM, there is still a number of fundamental obstacles that need to be overcome.
Some of these constraints are reflected in the lack of proper means for exchange
of experiences and access to outstanding studies and best practices being
produced in Coastal Member States, at different authority levels.
The overall goal of OURCOAST is to create an information base and groundwork that
will further support and promote the implementation of ICZM in coastal areas by
the establishment of long-lasting information mechanisms that will promote the
sharing of experiences and practices and the accomplishments of the project. The
project will produce numerous studies of public interest, such as, a comparative
analysis of ICZM and marine planning experiences, a state-of-the-art report on
EU policies and legislation for ICZM and marine planning. Guidance for future
integrated and marine planning projects, and policy recommendations will be
formulated for future development of ICZM in Europe. The final results will be
presented at an international stakeholders conference in Autumn 2011.
The OURCOAST initiative aims to establish a multi-lingual database of Europe-wide
ICZM practices in the form of case studies that will be freely accessible
through the EUROPA European Commission official web-site to the broad coastal
and marine communities and to provide practical guidance to all those who are
seeking sustainable solutions to their coastal management practices. Following
these challenges, this paper aims to provide more insight and details about the
progress activities and various components of the OURCOAST initiative, which is
being implemented by a consortium led by ARCADIS and it's subcontractor the
Coastal & Marine Union (EUCC). The implementation has started in
January 2009 and will end in December 2011. The data collection, website
development as well as the analysis are currently being carried out
Radiatively inefficient MHD accretion-ejection structures
We present magnetohydrodynamic simulations of a resistive accretion disk
continuously launching transmagnetosonic, collimated jets. We time-evolve the
full set of magnetohydrodynamic equations, but neglect radiative losses in the
energetics (radiatively inefficient). Our calculations demonstrate that a jet
is self-consistently produced by the interaction of an accretion disk with an
open, initially bent large-scale magnetic field. A constant fraction of heated
disk material is launched in the inner equipartition disk regions, leading to
the formation of a hot corona and a bright collimated, super-fastmagnetosonic
jet. We illustrate the complete dynamics of the ``hot'' near steady-state
outflow (where thermal pressure magnetic pressure) by showing force
balance, energy budget and current circuits. The evolution to this near
stationary state is analyzed in terms of the temporal variation of energy
fluxes controlling the energetics of the accretion disk. We find that unlike
advection-dominated accretion flow, the energy released by accretion is mainly
sent into the jet rather than transformed into disk enthalpy. These magnetized,
radiatively inefficient accretion-ejection structures can account for
under-luminous thin disks supporting bright fast collimated jets as seen in
many systems displaying jets (for instance M87).Comment: Astrophysical Journal (in press). Figures are missing due to file
size restrictions. To have the complete paper just click on
http://www-laog.obs.ujf-grenoble.fr/~fcasse/MS56638.pd
Mariprofundus ferrooxydans PV-1 the First Genome of a Marine Fe(II) Oxidizing Zetaproteobacterium
© The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 6 (2011): e25386, doi:10.1371/journal.pone.0025386.Mariprofundus ferrooxydans PV-1 has provided the first genome of the recently discovered Zetaproteobacteria subdivision. Genome analysis reveals a complete TCA cycle, the ability to fix CO2, carbon-storage proteins and a sugar phosphotransferase system (PTS). The latter could facilitate the transport of carbohydrates across the cell membrane and possibly aid in stalk formation, a matrix composed of exopolymers and/or exopolysaccharides, which is used to store oxidized iron minerals outside the cell. Two-component signal transduction system genes, including histidine kinases, GGDEF domain genes, and response regulators containing CheY-like receivers, are abundant and widely distributed across the genome. Most of these are located in close proximity to genes required for cell division, phosphate uptake and transport, exopolymer and heavy metal secretion, flagellar biosynthesis and pilus assembly suggesting that these functions are highly regulated. Similar to many other motile, microaerophilic bacteria, genes encoding aerotaxis as well as antioxidant functionality (e.g., superoxide dismutases and peroxidases) are predicted to sense and respond to oxygen gradients, as would be required to maintain cellular redox balance in the specialized habitat where M. ferrooxydans resides. Comparative genomics with other Fe(II) oxidizing bacteria residing in freshwater and marine environments revealed similar content, synteny, and amino acid similarity of coding sequences potentially involved in Fe(II) oxidation, signal transduction and response regulation, oxygen sensation and detoxification, and heavy metal resistance. This study has provided novel insights into the molecular nature of Zetaproteobacteria.Funding has been provided by the NSF Microbial Observatories Program (KJE, DE), NSF’s Science and Technology Program, by the Gordon and Betty
Moore Foundation (KJE), the College of Letters, Arts, and Sciences at the University of Southern California (KJE), and by the NASA Astrobiology Institute (KJE, DE).
Advanced Light Source analyses at the Lawrence Berkeley National Lab are supported by the Office of Science, Basic Energy Sciences, Division of Materials Science
of the United States Department of Energy (DE-AC02-05CH11231)
Novel computational methods for increasing PCR primer design effectiveness in directed sequencing
<p>Abstract</p> <p>Background</p> <p>Polymerase chain reaction (PCR) is used in directed sequencing for the discovery of novel polymorphisms. As the first step in PCR directed sequencing, effective PCR primer design is crucial for obtaining high-quality sequence data for target regions. Since current computational primer design tools are not fully tuned with stable underlying laboratory protocols, researchers may still be forced to iteratively optimize protocols for failed amplifications after the primers have been ordered. Furthermore, potentially identifiable factors which contribute to PCR failures have yet to be elucidated. This inefficient approach to primer design is further intensified in a high-throughput laboratory, where hundreds of genes may be targeted in one experiment.</p> <p>Results</p> <p>We have developed a fully integrated computational PCR primer design pipeline that plays a key role in our high-throughput directed sequencing pipeline. Investigators may specify target regions defined through a rich set of descriptors, such as Ensembl accessions and arbitrary genomic coordinates. Primer pairs are then selected computationally to produce a minimal amplicon set capable of tiling across the specified target regions. As part of the tiling process, primer pairs are computationally screened to meet the criteria for success with one of two PCR amplification protocols. In the process of improving our sequencing success rate, which currently exceeds 95% for exons, we have discovered novel and accurate computational methods capable of identifying primers that may lead to PCR failures. We reveal the laboratory protocols and their associated, empirically determined computational parameters, as well as describe the novel computational methods which may benefit others in future primer design research.</p> <p>Conclusion</p> <p>The high-throughput PCR primer design pipeline has been very successful in providing the basis for high-quality directed sequencing results and for minimizing costs associated with labor and reprocessing. The modular architecture of the primer design software has made it possible to readily integrate additional primer critique tests based on iterative feedback from the laboratory. As a result, the primer design software, coupled with the laboratory protocols, serves as a powerful tool for low and high-throughput primer design to enable successful directed sequencing.</p
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
Explosive pulsed power experimental capability at LLNL
Abstract not provide
The effect of LRRK2 loss-of-function variants in humans
Analysis of large genomic datasets, including gnomAD, reveals that partial LRRK2 loss of function is not strongly associated with diseases, serving as an example of how human genetics can be leveraged for target validation in drug discovery. Human genetic variants predicted to cause loss-of-function of protein-coding genes (pLoF variants) provide natural in vivo models of human gene inactivation and can be valuable indicators of gene function and the potential toxicity of therapeutic inhibitors targeting these genes(1,2). Gain-of-kinase-function variants in LRRK2 are known to significantly increase the risk of Parkinson's disease(3,4), suggesting that inhibition of LRRK2 kinase activity is a promising therapeutic strategy. While preclinical studies in model organisms have raised some on-target toxicity concerns(5-8), the biological consequences of LRRK2 inhibition have not been well characterized in humans. Here, we systematically analyze pLoF variants in LRRK2 observed across 141,456 individuals sequenced in the Genome Aggregation Database (gnomAD)(9), 49,960 exome-sequenced individuals from the UK Biobank and over 4 million participants in the 23andMe genotyped dataset. After stringent variant curation, we identify 1,455 individuals with high-confidence pLoF variants in LRRK2. Experimental validation of three variants, combined with previous work(10), confirmed reduced protein levels in 82.5% of our cohort. We show that heterozygous pLoF variants in LRRK2 reduce LRRK2 protein levels but that these are not strongly associated with any specific phenotype or disease state. Our results demonstrate the value of large-scale genomic databases and phenotyping of human loss-of-function carriers for target validation in drug discovery.Peer reviewe
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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