178 research outputs found

    Deep convolutional neural networks for Bearings failure predictionand temperature correlation

    Get PDF
    Rolling elements bearings (REBs) is one of the most sensitive components and the common failure unit in mechanical equipment. Bearings failure prognostics, which aims to achieve an effective way to handle the increasing requirements for higher reliability and in the same time reduce unnecessary costs, has been an area of extensive research. The accurate prediction of bearings Remaining Useful Life (RUL) is indispensable for safe and lifetime-optimized operations. To monitor this vital component and planning repair work, a new intelligent method based on Wavelet Packet Decomposition (WPD) and deep learning networks is proposed in this paper. Firstly, features extraction from WPD used as input data. Secondly, these selected features are fed into deep Convolutional Neural Networks (CNNs) to construct the Health Indicator (HI). This study focuses on analysing the relationships such as correlations between the HI and temperature. We develop a solution for the Connectiomics contest dataset of bearings under different operating conditions and severity of defects. The performance of the proposed method is verified by four bearing data sets collected from experimental setup called “PRONOSTIA”. The results show that the health indicator obtains fairly high monotonicity and correlation values and it is beneficial to bearing life prediction. In addition, it is experimentally demonstrated that the proposed method is able to achieve better performance than a traditional neural network based method

    Facilitating new forms of discourse for learning and teaching: harnessing the power of Web 2.0 practices

    Get PDF
    When asked what they would find most helpful to enable them to use technologies more in their teaching, most teachers say "give me examples, in my subject area" and "point me to relevant people I can discuss these issues with". Web 2.0 technologies - with their emphasis on sharing, networking and user production - seem to offer a potential solution. However uptake and use of web 2.0 sites such as blogs, social networking and wikis by teachers for sharing and discussing practice has being marginal so far. This paper focuses on work we are undertaking as part of the OU Learning Design Initiative (http://ouldi.open.ac.uk) and the Hewlett-funded Olnet initiative (http://olnet.org). A key focus of our work is the development of tools, methods and approaches to support the design of innovative learning activities and Open Educational Resources (OER). In this paper I want to focus on one strand of our work; namely how to leverage technologies to promote better sharing and discussing of learning and teaching ideas and designs

    Behavioural cloning of teachers for automatic homework selection

    Get PDF
    © Springer Nature Switzerland AG 2019. We describe a machine-learning system for supporting teachers through the selection of homework assignments. Our system uses behavioural cloning of teacher activity to generate personalised homework assignments for students. Classroom use is then supported through additional mechanisms to combine these predictions into group assignments. We train and evaluate our system against 50,065 homework assignments collected over two years by the Isaac Physics platform. We use baseline policies incorporating expert curriculum knowledge for evaluation and find that our technique improves on the strongest baseline policy by 18.5% in Year 1 and by 13.3% in Year 2.Cambridge Assessmen

    Draft genome sequence of marine alphaproteobacterial strain HIMB11, the first cultivated representative of a unique lineage within the Roseobacter clade possessing an unusually small genome

    Get PDF
    © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Standards in Genomic Sciences 9 (2014): 632-645, doi:10.4056/sigs.4998989.Strain HIMB11 is a planktonic marine bacterium isolated from coastal seawater in Kaneohe Bay, Oahu, Hawaii belonging to the ubiquitous and versatile Roseobacter clade of the alphaproteobacterial family Rhodobacteraceae. Here we describe the preliminary characteristics of strain HIMB11, including annotation of the draft genome sequence and comparative genomic analysis with other members of the Roseobacter lineage. The 3,098,747 bp draft genome is arranged in 34 contigs and contains 3,183 protein-coding genes and 54 RNA genes. Phylogenomic and 16S rRNA gene analyses indicate that HIMB11 represents a unique sublineage within the Roseobacter clade. Comparison with other publicly available genome sequences from members of the Roseobacter lineage reveals that strain HIMB11 has the genomic potential to utilize a wide variety of energy sources (e.g. organic matter, reduced inorganic sulfur, light, carbon monoxide), while possessing a reduced number of substrate transporters.We gratefully acknowledge the support of the Gordon and Betty Moore Foundation, which funded the sequencing of this genome. Annotation was performed as part of the 2011 C-MORE Summer Course in Microbial Oceanography (http://cmore.soest.hawaii.edu/summercourse/2011/index.htm), with support by the Agouron Institute, the Gordon and Betty Moore Foundation, the University of Hawaii and Manoa School of Ocean and Earth Science and Technology (SOEST), and the Center for Microbial Oceanography: Research and Education (C-MORE), a National Science Foundation-funded Science and Technology Center (award No. EF0424599)

    Apolipoprotein D synthesis progressively increases in frontal cortex during human lifespan

    Get PDF
    Apolipoprotein D (apo D) is a lipocalin present in the nervous system that may be related to processes of reinnervation, regeneration and neuronal cell protection. In the other way, apo D expression has been correlated, in some brain regions, with normal aging and neurodegenerative diseases. To elucidate the regional and cellular expression of apo D in normal human brain during aging, we performed a detailed and extensive study in samples of post-mortem human cerebral cortices. To achieve this study, slot blot techniques, for protein and mRNA, as well as immunohistochemistry and hybridohistochemistry methods were used. A positive correlation for apo D expression with aging was found; furthermore, mRNA levels, as well as the protein ones, were higher in the white than in the grey matter. Immunohistochemistry and non-isotopic HIS showed that apo D is synthesized in both neurons and glial cells. Apo D expression is notorious in oligodendrocytes but with aging the number of neurons that synthesize apo D is increased. Our results indicate that apo D could play a fundamental role in central nervous system aging and in the reduction of products derivated from lipid peroxidation. The increment in the expression of apo D with aging can be included in a global mechanism of cellular protection to prevent the deleterious effects caused by aging

    The Mammalian Disaggregase Machinery: Hsp110 Synergizes with Hsp70 and Hsp40 to Catalyze Protein Disaggregation and Reactivation in a Cell-Free System

    Get PDF
    Bacteria, fungi, protozoa, chromista and plants all harbor homologues of Hsp104, a AAA+ ATPase that collaborates with Hsp70 and Hsp40 to promote protein disaggregation and reactivation. Curiously, however, metazoa do not possess an Hsp104 homologue. Thus, whether animal cells renature large protein aggregates has long remained unclear. Here, it is established that mammalian cytosol prepared from different sources possesses a potent, ATP-dependent protein disaggregase and reactivation activity, which can be accelerated and stimulated by Hsp104. This activity did not require the AAA+ ATPase, p97. Rather, mammalian Hsp110 (Apg-2), Hsp70 (Hsc70 or Hsp70) and Hsp40 (Hdj1) were necessary and sufficient to slowly dissolve large disordered aggregates and recover natively folded protein. This slow disaggregase activity was conserved to yeast Hsp110 (Sse1), Hsp70 (Ssa1) and Hsp40 (Sis1 or Ydj1). Hsp110 must engage substrate, engage Hsp70, promote nucleotide exchange on Hsp70, and hydrolyze ATP to promote disaggregation of disordered aggregates. Similarly, Hsp70 must engage substrate and Hsp110, and hydrolyze ATP for protein disaggregation. Hsp40 must harbor a functional J domain to promote protein disaggregation, but the J domain alone is insufficient. Optimal disaggregase activity is achieved when the Hsp40 can stimulate the ATPase activity of Hsp110 and Hsp70. Finally, Hsp110, Hsp70 and Hsp40 fail to rapidly remodel amyloid forms of the yeast prion protein, Sup35, or the Parkinson's disease protein, alpha-synuclein. However, Hsp110, Hsp70 and Hsp40 enhanced the activity of Hsp104 against these amyloid substrates. Taken together, these findings suggest that Hsp110 fulfils a subset of Hsp104 activities in mammals. Moreover, they suggest that Hsp104 can collaborate with the mammalian disaggregase machinery to rapidly remodel amyloid conformers

    Protein Folding Activity of the Ribosome is involved in Yeast Prion Propagation.

    Get PDF
    6AP and GA are potent inhibitors of yeast and mammalian prions and also specific inhibitors of PFAR, the protein-folding activity borne by domain V of the large rRNA of the large subunit of the ribosome. We therefore explored the link between PFAR and yeast prion [PSI(+)] using both PFAR-enriched mutants and site-directed methylation. We demonstrate that PFAR is involved in propagation and de novo formation of [PSI(+)]. PFAR and the yeast heat-shock protein Hsp104 partially compensate each other for [PSI(+)] propagation. Our data also provide insight into new functions for the ribosome in basal thermotolerance and heat-shocked protein refolding. PFAR is thus an evolutionarily conserved cell component implicated in the prion life cycle, and we propose that it could be a potential therapeutic target for human protein misfolding diseases

    Protease-Resistant Prions Selectively Decrease Shadoo Protein

    Get PDF
    The central event in prion diseases is the conformational conversion of the cellular prion protein (PrPC) into PrPSc, a partially protease-resistant and infectious conformer. However, the mechanism by which PrPSc causes neuronal dysfunction remains poorly understood. Levels of Shadoo (Sho), a protein that resembles the flexibly disordered N-terminal domain of PrPC, were found to be reduced in the brains of mice infected with the RML strain of prions [1], implying that Sho levels may reflect the presence of PrPSc in the brain. To test this hypothesis, we examined levels of Sho during prion infection using a variety of experimental systems. Sho protein levels were decreased in the brains of mice, hamsters, voles, and sheep infected with different natural and experimental prion strains. Furthermore, Sho levels were decreased in the brains of prion-infected, transgenic mice overexpressing Sho and in infected neuroblastoma cells. Time-course experiments revealed that Sho levels were inversely proportional to levels of protease-resistant PrPSc. Membrane anchoring and the N-terminal domain of PrP both influenced the inverse relationship between Sho and PrPSc. Although increased Sho levels had no discernible effect on prion replication in mice, we conclude that Sho is the first non-PrP marker specific for prion disease. Additional studies using this paradigm may provide insight into the cellular pathways and systems subverted by PrPSc during prion disease
    • 

    corecore