408 research outputs found
Magnetic bearings for free-piston Stirling engines
The feasibility and efficacy of applying magnetic bearings to free-piston Stirling-cycle power conversion machinery currently being developed for long-term space missions are assessed. The study was performed for a 50-kWe Reference Stirling Space Power Converter (RSSPC) which currently uses hydrostatic gas bearings to support the reciprocating displacer and power piston assemblies. Active magnetic bearings of the attractive electromagnetic type are feasible for the RSSPC power piston. Magnetic support of the displacer assembly would require unacceptable changes to the design of the current RSSPC. However, magnetic suspension of both displacer and power piston is feasible for a relative-displacer version of the RSSPC. Magnetic suspension of the RSSPC power piston can potentially increase overall efficiency by 0.5 to 1 percent (0.1 to 0.3 efficiency points). Magnetic bearings will also overcome several operational concerns associated with hydrostatic gas bearing systems. These advantages, however, are accompanied by a 5 percent increase in specific mass of the RSSPC
Design and development of a resonant piston compressor for hermetically sealed platforms
Resonant piston compressor for recirculation system of hermetically sealed platfor
Research and development of high performance axial-flow turbomachinery. Volume 2 - Design of gas bearings
Design and dynamic simulator testing of gas bearing rotor support for high performance axial flow turbomachiner
Improved annotation of 3' untranslated regions and complex loci by combination of strand-specific direct RNA sequencing, RNA-seq and ESTs
The reference annotations made for a genome sequence provide the framework
for all subsequent analyses of the genome. Correct annotation is particularly
important when interpreting the results of RNA-seq experiments where short
sequence reads are mapped against the genome and assigned to genes according to
the annotation. Inconsistencies in annotations between the reference and the
experimental system can lead to incorrect interpretation of the effect on RNA
expression of an experimental treatment or mutation in the system under study.
Until recently, the genome-wide annotation of 3-prime untranslated regions
received less attention than coding regions and the delineation of intron/exon
boundaries. In this paper, data produced for samples in Human, Chicken and A.
thaliana by the novel single-molecule, strand-specific, Direct RNA Sequencing
technology from Helicos Biosciences which locates 3-prime polyadenylation sites
to within +/- 2 nt, were combined with archival EST and RNA-Seq data. Nine
examples are illustrated where this combination of data allowed: (1) gene and
3-prime UTR re-annotation (including extension of one 3-prime UTR by 5.9 kb);
(2) disentangling of gene expression in complex regions; (3) clearer
interpretation of small RNA expression and (4) identification of novel genes.
While the specific examples displayed here may become obsolete as genome
sequences and their annotations are refined, the principles laid out in this
paper will be of general use both to those annotating genomes and those seeking
to interpret existing publically available annotations in the context of their
own experimental dataComment: 44 pages, 9 figure
The secreted triose phosphate isomerase of Brugia malayi is required to sustain microfilaria production in vivo
Human lymphatic filariasis is a major tropical disease transmitted through mosquito vectors which take up microfilarial larvae from the blood of infected subjects. Microfilariae are produced by long-lived adult parasites, which also release a suite of excretory-secretory products that have recently been subject to in-depth proteomic analysis. Surprisingly, the most abundant secreted protein of adult Brugia malayi is triose phosphate isomerase (TPI), a glycolytic enzyme usually associated with the cytosol. We now show that while TPI is a prominent target of the antibody response to infection, there is little antibody-mediated inhibition of catalytic activity by polyclonal sera. We generated a panel of twenty-three anti-TPI monoclonal antibodies and found only two were able to block TPI enzymatic activity. Immunisation of jirds with B. malayi TPI, or mice with the homologous protein from the rodent filaria Litomosoides sigmodontis, failed to induce neutralising antibodies or protective immunity. In contrast, passive transfer of neutralising monoclonal antibody to mice prior to implantation with adult B. malayi resulted in 60–70% reductions in microfilarial levels in vivo and both oocyte and microfilarial production by individual adult females. The loss of fecundity was accompanied by reduced IFNγ expression by CD4+ T cells and a higher proportion of macrophages at the site of infection. Thus, enzymatically active TPI plays an important role in the transmission cycle of B. malayi filarial parasites and is identified as a potential target for immunological and pharmacological intervention against filarial infections
Dilemmas of Development and The Reconstruction of Fashion
Sustainable development by its nature appears elusive. It seems the more we try to capture and pin it down the more it moves away from us leading us into murkier waters and all manner of contradictions. No more is this felt than in the fashion industry where we are presented with a number of oppositions. The fashion cycle renders styles obsolete before they have worn out generating waste and over-consumptive practices. But it can also bring into the fore practices that have resonance to sustainable development in terms of their location, orientation and consideration for the environment. As studies emerge considering the detrimental environmental impacts of the manufacture and consumption of new clothes, second-hand clothes have become a focus for research endeavours considering how they can be reincorporated into the fashion system and have resonance to an ever ‘fashion’ hungry consumer. This chapter discusses methods for the processing of second-hand clothes into fashionable items and, by drawing on the wealth of ‘waste’ materials through reselling, restyling and remanufacturing, argues that ways of re-appropriating them into a more environmentally focused fashion industry is possible and necessary. It sets out as it hypothesis that the global fashion system has value in its transformative powers but that damaging and exploitative forces are still preventing it from being a force for good. This is due to the nature of the items being produced, the way they are manufactured and how they are ultimately consumed and disposed of
An approach to describing and analysing bulk biological annotation quality: a case study using UniProtKB
Motivation: Annotations are a key feature of many biological databases, used
to convey our knowledge of a sequence to the reader. Ideally, annotations are
curated manually, however manual curation is costly, time consuming and
requires expert knowledge and training. Given these issues and the exponential
increase of data, many databases implement automated annotation pipelines in an
attempt to avoid un-annotated entries. Both manual and automated annotations
vary in quality between databases and annotators, making assessment of
annotation reliability problematic for users. The community lacks a generic
measure for determining annotation quality and correctness, which we look at
addressing within this article. Specifically we investigate word reuse within
bulk textual annotations and relate this to Zipf's Principle of Least Effort.
We use UniProt Knowledge Base (UniProtKB) as a case study to demonstrate this
approach since it allows us to compare annotation change, both over time and
between automated and manually curated annotations.
Results: By applying power-law distributions to word reuse in annotation, we
show clear trends in UniProtKB over time, which are consistent with existing
studies of quality on free text English. Further, we show a clear distinction
between manual and automated analysis and investigate cohorts of protein
records as they mature. These results suggest that this approach holds distinct
promise as a mechanism for judging annotation quality.
Availability: Source code is available at the authors website:
http://homepages.cs.ncl.ac.uk/m.j.bell1/annotation.
Contact: [email protected]: Paper accepted at The European Conference on Computational Biology
2012 (ECCB'12). Subsequently will be published in a special issue of the
journal Bioinformatics. Paper consists of 8 pages, made up of 5 figure
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