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Sample records for machinery protein slab

  1. Mitochondrial Machineries for Protein Import and Assembly.

    Science.gov (United States)

    Wiedemann, Nils; Pfanner, Nikolaus

    2017-03-15

    Mitochondria are essential organelles with numerous functions in cellular metabolism and homeostasis. Most of the >1,000 different mitochondrial proteins are synthesized as precursors in the cytosol and are imported into mitochondria by five transport pathways. The protein import machineries of the mitochondrial membranes and aqueous compartments reveal a remarkable variability of mechanisms for protein recognition, translocation, and sorting. The protein translocases do not operate as separate entities but are connected to each other and to machineries with functions in energetics, membrane organization, and quality control. Here, we discuss the versatility and dynamic organization of the mitochondrial protein import machineries. Elucidating the molecular mechanisms of mitochondrial protein translocation is crucial for understanding the integration of protein translocases into a large network that controls organelle biogenesis, function, and dynamics. Expected final online publication date for the Annual Review of Biochemistry Volume 86 is June 20, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  2. Dynamic organization of the mitochondrial protein import machinery.

    Science.gov (United States)

    Straub, Sebastian P; Stiller, Sebastian B; Wiedemann, Nils; Pfanner, Nikolaus

    2016-11-01

    Mitochondria contain elaborate machineries for the import of precursor proteins from the cytosol. The translocase of the outer mitochondrial membrane (TOM) performs the initial import of precursor proteins and transfers the precursors to downstream translocases, including the presequence translocase and the carrier translocase of the inner membrane, the mitochondrial import and assembly machinery of the intermembrane space, and the sorting and assembly machinery of the outer membrane. Although the protein translocases can function as separate entities in vitro, recent studies revealed a close and dynamic cooperation of the protein import machineries to facilitate efficient transfer of precursor proteins in vivo. In addition, protein translocases were found to transiently interact with distinct machineries that function in the respiratory chain or in the maintenance of mitochondrial membrane architecture. Mitochondrial protein import is embedded in a regulatory network that ensures protein biogenesis, membrane dynamics, bioenergetic activity and quality control.

  3. Machinery

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ China Council for the Promotion of International Trade, Machin-ery Sub-Council (referred to as CCPIT MSC) & China Chamber of International Commerce, Machinery Chamber of Commerce was founded in 1988 as one of the first group of industrial trade promotion agencies approved by the governing authorities of China.

  4. Therapeutic interventions to disrupt the protein synthetic machinery in melanoma.

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    Kardos, Gregory R; Robertson, Gavin P

    2015-09-01

    Control of the protein synthetic machinery is deregulated in many cancers, including melanoma, to increase the protein production. Tumor suppressors and oncogenes play key roles in protein synthesis from the transcription of rRNA and ribosome biogenesis to mRNA translation initiation and protein synthesis. Major signaling pathways are altered in melanoma to modulate the protein synthetic machinery, thereby promoting tumor development. However, despite the importance of this process in melanoma development, involvement of the protein synthetic machinery in this cancer type is an underdeveloped area of study. Here, we review the coupling of melanoma development to deregulation of the protein synthetic machinery. We examine existing knowledge regarding RNA polymerase I inhibition and mRNA translation focusing on their inhibition for therapeutic applications in melanoma. Furthermore, the contribution of amino acid biosynthesis and involvement of ribosomal proteins are also reviewed as future therapeutic strategies to target deregulated protein production in melanoma.

  5. Giardia mitosomal protein import machinery differentially recognizes mitochondrial targeting signals.

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    Nyindodo-Ogari, Lilian; Schwartzbach, Steven D; Estraño, Carlos E

    2014-01-01

    Giardia lamblia mitosomes are believed to be vestigial mitochondria which lack a genome. Similar to higher eukaryotes, mitosomal proteins possess either N-terminal or internal mitosomal targeting sequences. To date, some components of the higher eukaryote archetypal mitochondrial protein import apparatus have been identified and characterized in Giardia mitosomes; therefore, it is expected that mitochondrial signals will be recognized by the mitosomal protein import system. To further determine the level of conservation of the Giardia mitosome protein import apparatus, we expressed mitochondrial proteins from higher eukaryotes in Giardia. These recombinant proteins include Tom20 and Tom22; two components of the mitochondrial protein import machinery. Our results indicate that N-terminal mitochondrial targeting sequence is recognized by the mitosomal protein import machinery; however, interestingly the internal mitochondrial targeting sequences of higher eukaryotes are not recognized by the mitosome. Our results indicate that Giardia mitosome protein transport machinery shows differential recognition of higher eukaryotic mitochondria transfer signals, suggesting a divergence of the transport system in G. lamblia. Therefore, our data support the hypothesis that the protein import machinery in Giardia lamblia mitosome is an incomplete vestigial derivative of mitochondria components.

  6. Interaction of anesthetics with neurotransmitter release machinery proteins.

    Science.gov (United States)

    Xie, Zheng; McMillan, Kyle; Pike, Carolyn M; Cahill, Anne L; Herring, Bruce E; Wang, Qiang; Fox, Aaron P

    2013-02-01

    General anesthetics produce anesthesia by depressing central nervous system activity. Activation of inhibitory GABA(A) receptors plays a central role in the action of many clinically relevant general anesthetics. Even so, there is growing evidence that anesthetics can act at a presynaptic locus to inhibit neurotransmitter release. Our own data identified the neurotransmitter release machinery as a target for anesthetic action. In the present study, we sought to examine the site of anesthetic action more closely. Exocytosis was stimulated by directly elevating the intracellular Ca(2+) concentration at neurotransmitter release sites, thereby bypassing anesthetic effects on channels and receptors, allowing anesthetic effects on the neurotransmitter release machinery to be examined in isolation. Three different PC12 cell lines, which had the expression of different release machinery proteins stably suppressed by RNA interference, were used in these studies. Interestingly, there was still significant neurotransmitter release when these knockdown PC12 cells were stimulated. We have previously shown that etomidate, isoflurane, and propofol all inhibited the neurotransmitter release machinery in wild-type PC12 cells. In the present study, we show that knocking down synaptotagmin I completely prevented etomidate from inhibiting neurotransmitter release. Synaptotagmin I knockdown also diminished the inhibition produced by propofol and isoflurane, but the magnitude of the effect was not as large. Knockdown of SNAP-25 and SNAP-23 expression also changed the ability of these three anesthetics to inhibit neurotransmitter release. Our results suggest that general anesthetics inhibit the neurotransmitter release machinery by interacting with multiple SNARE and SNARE-associated proteins.

  7. The oxidative protein folding machinery in plant cells.

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    Aller, Isabel; Meyer, Andreas J

    2013-08-01

    Formation of intra-molecular disulfides and concomitant oxidative protein folding is essential for stability and catalytic function of many soluble and membrane-bound proteins in the endomembrane system, the mitochondrial inter-membrane space and the thylakoid lumen. Disulfide generation from free cysteines in nascent polypeptide chains is generally a catalysed process for which distinct pathways exist in all compartments. A high degree of similarities between highly diverse eukaryotic and bacterial systems for generation of protein disulfides indicates functional conservation of key processes throughout evolution. However, while many aspects about molecular function of enzymatic systems promoting disulfide formation have been demonstrated for bacterial and non-plant eukaryotic organisms, it is now clear that the plant machinery for oxidative protein folding displays distinct details, suggesting that the different pathways have been adapted to plant-specific requirements in terms of compartmentation, molecular function and regulation. Here, we aim to evaluate biological diversity by comparing the plant systems for oxidative protein folding to the respective systems from non-plant eukaryotes.

  8. Genome-scale modeling of the protein secretory machinery in yeast.

    Science.gov (United States)

    Feizi, Amir; Österlund, Tobias; Petranovic, Dina; Bordel, Sergio; Nielsen, Jens

    2013-01-01

    The protein secretory machinery in Eukarya is involved in post-translational modification (PTMs) and sorting of the secretory and many transmembrane proteins. While the secretory machinery has been well-studied using classic reductionist approaches, a holistic view of its complex nature is lacking. Here, we present the first genome-scale model for the yeast secretory machinery which captures the knowledge generated through more than 50 years of research. The model is based on the concept of a Protein Specific Information Matrix (PSIM: characterized by seven PTMs features). An algorithm was developed which mimics secretory machinery and assigns each secretory protein to a particular secretory class that determines the set of PTMs and transport steps specific to each protein. Protein abundances were integrated with the model in order to gain system level estimation of the metabolic demands associated with the processing of each specific protein as well as a quantitative estimation of the activity of each component of the secretory machinery.

  9. Genome-scale modeling of the protein secretory machinery in yeast

    DEFF Research Database (Denmark)

    Feizi, Amir; Österlund, Tobias; Petranovic, Dina;

    2013-01-01

    The protein secretory machinery in Eukarya is involved in post-translational modification (PTMs) and sorting of the secretory and many transmembrane proteins. While the secretory machinery has been well-studied using classic reductionist approaches, a holistic view of its complex nature is lackin...

  10. Protein-protein interaction network and subcellular localization of the Arabidopsis thaliana ESCRT machinery

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    Lynn eRichardson

    2011-06-01

    Full Text Available The Endosomal Sorting Complex Required for Transport (ESCRT consists of several multi-protein subcomplexes which assemble sequentially at the endosomal surface and function in multivesicular body (MVB biogenesis. While ESCRT has been relatively well characterized in yeasts and mammals, comparably little is known about ESCRT in plants. Here we explored the yeast two-hybrid protein interaction network and subcellular localization of the Arabidopsis thaliana ESCRT machinery. We show that Arabidopsis ESCRT interactome possess a number of protein-protein interactions that are either conserved in yeasts and mammals or distinct to plants. We show also that most of the Arabidopsis ESCRT proteins examined at least partially localize to MVBs in plant cells when ectopically expressed on their own or co-expressed with other interacting ESCRT proteins, and some also induce abnormal MVB phenotypes, consistent with their proposed functional roles in MVB biogenesis. Overall, our results help define the plant ESCRT machinery by highlighting both conserved and unique features when compared to ESCRT in other evolutionarily diverse organisms, providing a foundation for further exploration of ESCRT in plants.

  11. Characteristics and concepts of dynamic hub proteins in DNA processing machinery from studies of RPA.

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    Sugitani, Norie; Chazin, Walter J

    2015-03-01

    DNA replication, damage response and repair require the coordinated action of multi-domain proteins operating within dynamic multi-protein machines that act upon the DNA substrate. These modular proteins contain flexible linkers of various lengths, which enable changes in the spatial distribution of the globular domains (architecture) that harbor their essential biochemical functions. This mobile architecture is uniquely suited to follow the evolving substrate landscape present over the course of the specific process performed by the multi-protein machinery. A fundamental advance in understanding of protein machinery is the realization of the pervasive role of dynamics. Not only is the machine undergoing dynamic transformations, but the proteins themselves are flexible and constantly adapting to the progression through the steps of the overall process. Within this dynamic context the activity of the constituent proteins must be coordinated, a role typically played by hub proteins. A number of important characteristics of modular proteins and concepts about the operation of dynamic machinery have been discerned. These provide the underlying basis for the action of the machinery that reads DNA, and responds to and repairs DNA damage. Here, we introduce a number of key characteristics and concepts, including the modularity of the proteins, linkage of weak binding sites, direct competition between sites, and allostery, using the well recognized hub protein replication protein A (RPA).

  12. Protein import into plant mitochondria: signals, machinery, processing, and regulation.

    Science.gov (United States)

    Murcha, Monika W; Kmiec, Beata; Kubiszewski-Jakubiak, Szymon; Teixeira, Pedro F; Glaser, Elzbieta; Whelan, James

    2014-12-01

    The majority of more than 1000 proteins present in mitochondria are imported from nuclear-encoded, cytosolically synthesized precursor proteins. This impressive feat of transport and sorting is achieved by the combined action of targeting signals on mitochondrial proteins and the mitochondrial protein import apparatus. The mitochondrial protein import apparatus is composed of a number of multi-subunit protein complexes that recognize, translocate, and assemble mitochondrial proteins into functional complexes. While the core subunits involved in mitochondrial protein import are well conserved across wide phylogenetic gaps, the accessory subunits of these complexes differ in identity and/or function when plants are compared with Saccharomyces cerevisiae (yeast), the model system for mitochondrial protein import. These differences include distinct protein import receptors in plants, different mechanistic operation of the intermembrane protein import system, the location and activity of peptidases, the function of inner-membrane translocases in linking the outer and inner membrane, and the association/regulation of mitochondrial protein import complexes with components of the respiratory chain. Additionally, plant mitochondria share proteins with plastids, i.e. dual-targeted proteins. Also, the developmental and cell-specific nature of mitochondrial biogenesis is an aspect not observed in single-celled systems that is readily apparent in studies in plants. This means that plants provide a valuable model system to study the various regulatory processes associated with protein import and mitochondrial biogenesis.

  13. The peroxisomal protein import machinery displays a preference for monomeric substrates.

    Science.gov (United States)

    Freitas, Marta O; Francisco, Tânia; Rodrigues, Tony A; Lismont, Celien; Domingues, Pedro; Pinto, Manuel P; Grou, Cláudia P; Fransen, Marc; Azevedo, Jorge E

    2015-04-01

    Peroxisomal matrix proteins are synthesized on cytosolic ribosomes and transported by the shuttling receptor PEX5 to the peroxisomal membrane docking/translocation machinery, where they are translocated into the organelle matrix. Under certain experimental conditions this protein import machinery has the remarkable capacity to accept already oligomerized proteins, a property that has heavily influenced current models on the mechanism of peroxisomal protein import. However, whether or not oligomeric proteins are really the best and most frequent clients of this machinery remain unclear. In this work, we present three lines of evidence suggesting that the peroxisomal import machinery displays a preference for monomeric proteins. First, in agreement with previous findings on catalase, we show that PEX5 binds newly synthesized (monomeric) acyl-CoA oxidase 1 (ACOX1) and urate oxidase (UOX), potently inhibiting their oligomerization. Second, in vitro import experiments suggest that monomeric ACOX1 and UOX are better peroxisomal import substrates than the corresponding oligomeric forms. Finally, we provide data strongly suggesting that although ACOX1 lacking a peroxisomal targeting signal can be imported into peroxisomes when co-expressed with ACOX1 containing its targeting signal, this import pathway is inefficient.

  14. Protein Machineries Involved in the Attachment of Heme to Cytochrome c: Protein Structures and Molecular Mechanisms

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    Carlo Travaglini-Allocatelli

    2013-01-01

    Full Text Available Cytochromes c (Cyt c are ubiquitous heme-containing proteins, mainly involved in electron transfer processes, whose structure and functions have been and still are intensely studied. Surprisingly, our understanding of the molecular mechanism whereby the heme group is covalently attached to the apoprotein (apoCyt in the cell is still largely unknown. This posttranslational process, known as Cyt c biogenesis or Cyt c maturation, ensures the stereospecific formation of the thioether bonds between the heme vinyl groups and the cysteine thiols of the apoCyt heme binding motif. To accomplish this task, prokaryotic and eukaryotic cells have evolved distinctive protein machineries composed of different proteins. In this review, the structural and functional properties of the main maturation apparatuses found in gram-negative and gram-positive bacteria and in the mitochondria of eukaryotic cells will be presented, dissecting the Cyt c maturation process into three functional steps: (i heme translocation and delivery, (ii apoCyt thioreductive pathway, and (iii apoCyt chaperoning and heme ligation. Moreover, current hypotheses and open questions about the molecular mechanisms of each of the three steps will be discussed, with special attention to System I, the maturation apparatus found in gram-negative bacteria.

  15. Multi-state targeting machinery govern the fidelity and efficiency of protein localization.

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    Yang, Mingjun; Pang, Xueqin; Han, Keli

    2014-01-01

    Proper localization of newly synthesized proteins is essential to cellular function. Among different protein localization modes, the signal recognition particle (SRP) and SRP receptor (SR) constitute the conserved targeting machinery in all three life kingdoms and mediate about one third of the protein targeting reactions. Based on experimental and computational studies, a detailed molecular model is proposed to explain how this molecular machinery governs the efficiency and fidelity of protein localizations. In this targeting machinery, two distinct SRP GTPases are contained into the SRP and SR that are responsible to the interactions between SRP and SR. These two GTPases can interact with one another through a series of sequential and discrete interaction states that are the early intermediate formation, stable complex association, and GTPase activation. In contrast to canonical GTPases, a floppy and open conformation adopted in free SRP GTPases can facilitate efficient GTP/GDP exchange without the aid of any external factors. As the apo-form free SRP GTPases can adopt the conformational states of GDP- or GTP-bound form, the binding of GTP/GDP follows a mechanism of conformational selection. In the first step of complex formation, the two SRP GTPases can rapidly assemble into an unstable early intermediate by selecting and stabilizing one another's primed states from the equilibrium conformational ensemble. Subsequently, extensive inter- and intra-domain changes rearrange the early complex into a tight and closed state of stable complex through induced fit mechanism. Upon stable complex association, further tune of several important interaction networks activates the SRP GTPase for GTP hydrolysis. These different conformational states are coupled to corresponding protein targeting events, in which the complex formation deliveries the translating ribosome to the target membrane and the GTPase activation couples to the cargo release from SRP-SR machinery to the

  16. The pupylation machinery is involved in iron homeostasis by targeting the iron storage protein ferritin.

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    Küberl, Andreas; Polen, Tino; Bott, Michael

    2016-04-26

    The balance of sufficient iron supply and avoidance of iron toxicity by iron homeostasis is a prerequisite for cellular metabolism and growth. Here we provide evidence that, in Actinobacteria, pupylation plays a crucial role in this process. Pupylation is a posttranslational modification in which the prokaryotic ubiquitin-like protein Pup is covalently attached to a lysine residue in target proteins, thus resembling ubiquitination in eukaryotes. Pupylated proteins are recognized and unfolded by a dedicated AAA+ ATPase (Mycobacterium proteasomal AAA+ ATPase; ATPase forming ring-shaped complexes). In Mycobacteria, degradation of pupylated proteins by the proteasome serves as a protection mechanism against several stress conditions. Other bacterial genera capable of pupylation such as Corynebacterium lack a proteasome, and the fate of pupylated proteins is unknown. We discovered that Corynebacterium glutamicum mutants lacking components of the pupylation machinery show a strong growth defect under iron limitation, which was caused by the absence of pupylation and unfolding of the iron storage protein ferritin. Genetic and biochemical data support a model in which the pupylation machinery is responsible for iron release from ferritin independent of degradation.

  17. From DNA to proteins via the ribosome: Structural insights into the workings of the translation machinery

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    Agirrezabala Xabier

    2010-04-01

    Full Text Available Abstract Understanding protein synthesis in bacteria and humans is important for understanding the origin of many human diseases and devising treatments for them. Over the past decade, the field of structural biology has made significant advances in the visualisation of the molecular machinery involved in protein synthesis. It is now possible to discern, at least in outline, the way that interlocking ribosomal components and factors adapt their conformations throughout this process. The determination of structures in various functional contexts, along with the application of kinetic and fluorescent resonance energy transfer approaches to the problem, has given researchers the frame of reference for what remains as the greatest challenge: the complete dynamic portrait of protein synthesis in the cell.

  18. A new structural framework for integrating replication protein A into DNA processing machinery

    Energy Technology Data Exchange (ETDEWEB)

    Brosey, Chris; Yan, Chunli; Tsutakawa, Susan; Heller, William; Rambo, Robert; Tainer, John; Ivanov, Ivaylo; Chazin, Walter

    2013-01-17

    By coupling the protection and organization of single-stranded DNA (ssDNA) with recruitment and alignment of DNA processing factors, replication protein A (RPA) lies at the heart of dynamic multi-protein DNA processing machinery. Nevertheless, how RPA coordinates biochemical functions of its eight domains remains unknown. We examined the structural biochemistry of RPA's DNA-binding activity, combining small-angle X-ray and neutron scattering with all-atom molecular dynamics simulations to investigate the architecture of RPA's DNA-binding core. The scattering data reveal compaction promoted by DNA binding; DNA-free RPA exists in an ensemble of states with inter-domain mobility and becomes progressively more condensed and less dynamic on binding ssDNA. Our results contrast with previous models proposing RPA initially binds ssDNA in a condensed state and becomes more extended as it fully engages the substrate. Moreover, the consensus view that RPA engages ssDNA in initial, intermediate and final stages conflicts with our data revealing that RPA undergoes two (not three) transitions as it binds ssDNA with no evidence for a discrete intermediate state. These results form a framework for understanding how RPA integrates the ssDNA substrate into DNA processing machinery, provides substrate access to its binding partners and promotes the progression and selection of DNA processing pathways.

  19. A new structural framework for integrating replication protein A into DNA processing machinery

    Energy Technology Data Exchange (ETDEWEB)

    Brosey, Chris A [Vanderbilt University; Yan, Chunli [Georgia State University, Atlanta; Tsutakawa, Susan E [Lawrence Berkeley National Laboratory (LBNL); Heller, William T [ORNL; Rambo, Robert P [Lawrence Berkeley National Laboratory (LBNL); Tainer, John A [Lawrence Berkeley National Laboratory, The Scripps Research Institite and The Skaggs Institute; Ivanov, Ivaylo [Georgia State University, Atlanta; Chazin, Walter J [Vanderbilt University

    2013-01-01

    By coupling the protection and organization of ssDNA with the recruitment and alignment of DNA processing factors, Replication Protein A (RPA) lies at the heart of dynamic multi-protein DNA processing machinery. Nevertheless, how RPA manages to coordinate the biochemical functions of its eight domains remains unknown. We examined the structural biochemistry of RPA s DNA binding activity, combining small-angle x-ray and neutron scattering with all-atom molecular dynamics simulations to investigate the architecture of RPA s DNA-binding core. It has been long held that RPA engages ssDNA in three stages, but our data reveal that RPA undergoes two rather than three transitions as it binds ssDNA. In contrast to previous models, RPA is more compact when fully engaged on 20-30 nucleotides of ssDNA than when DNA-free, and there is no evidence for significant population of a highly compacted structure in the initial 8-10 nucleotide binding mode. These results provide a new framework for understanding the integration of ssDNA into DNA processing machinery and how binding partners may manipulate RPA architecture to gain access to the substrate.

  20. Arabidopsis mRNA polyadenylation machinery: comprehensive analysis of protein-protein interactions and gene expression profiling

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    Mo Min

    2008-05-01

    Full Text Available Abstract Background The polyadenylation of mRNA is one of the critical processing steps during expression of almost all eukaryotic genes. It is tightly integrated with transcription, particularly its termination, as well as other RNA processing events, i.e. capping and splicing. The poly(A tail protects the mRNA from unregulated degradation, and it is required for nuclear export and translation initiation. In recent years, it has been demonstrated that the polyadenylation process is also involved in the regulation of gene expression. The polyadenylation process requires two components, the cis-elements on the mRNA and a group of protein factors that recognize the cis-elements and produce the poly(A tail. Here we report a comprehensive pairwise protein-protein interaction mapping and gene expression profiling of the mRNA polyadenylation protein machinery in Arabidopsis. Results By protein sequence homology search using human and yeast polyadenylation factors, we identified 28 proteins that may be components of Arabidopsis polyadenylation machinery. To elucidate the protein network and their functions, we first tested their protein-protein interaction profiles. Out of 320 pair-wise protein-protein interaction assays done using the yeast two-hybrid system, 56 (~17% showed positive interactions. 15 of these interactions were further tested, and all were confirmed by co-immunoprecipitation and/or in vitro co-purification. These interactions organize into three distinct hubs involving the Arabidopsis polyadenylation factors. These hubs are centered around AtCPSF100, AtCLPS, and AtFIPS. The first two are similar to complexes seen in mammals, while the third one stands out as unique to plants. When comparing the gene expression profiles extracted from publicly available microarray datasets, some of the polyadenylation related genes showed tissue-specific expression, suggestive of potential different polyadenylation complex configurations. Conclusion An

  1. Leptin stimulates protein synthesis-activating translation machinery in human trophoblastic cells.

    Science.gov (United States)

    Pérez-Pérez, Antonio; Maymó, Julieta; Gambino, Yésica; Dueñas, José L; Goberna, Raimundo; Varone, Cecilia; Sánchez-Margalet, Víctor

    2009-11-01

    Leptin was originally considered as an adipocyte-derived signaling molecule for the central control of metabolism. However, pleiotropic effects of leptin have been identified in reproduction and pregnancy, particularly in placenta, where it may work as an autocrine hormone, mediating angiogenesis, growth, and immunomodulation. Leptin receptor (LEPR, also known as Ob-R) shows sequence homology to members of the class I cytokine receptor (gp130) superfamily. In fact, leptin may function as a proinflammatory cytokine. We have previously found that leptin is a trophic and mitogenic factor for trophoblastic cells. In order to further investigate the mechanism by which leptin stimulates cell growth in JEG-3 cells and trophoblastic cells, we studied the phosphorylation state of different proteins of the initiation stage of translation and the total protein synthesis by [(3)H]leucine incorporation in JEG-3 cells. We have found that leptin dose-dependently stimulates the phosphorylation and activation of the translation initiation factor EIF4E as well as the phosphorylation of the EIF4E binding protein EIF4EBP1 (PHAS-I), which releases EIF4E to form active complexes. Moreover, leptin dose-dependently stimulates protein synthesis, and this effect can be partially prevented by blocking mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 kinase (PIK3) pathways. In conclusion, leptin stimulates protein synthesis, at least in part activating the translation machinery, via the activation of MAPK and PIK3 pathways.

  2. Telomere binding protein TRB1 is associated with promoters of translation machinery genes in vivo.

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    Schrumpfová, Petra Procházková; Vychodilová, Ivona; Hapala, Jan; Schořová, Šárka; Dvořáček, Vojtěch; Fajkus, Jiří

    2016-01-01

    Recently we characterised TRB1, a protein from a single-myb-histone family, as a structural and functional component of telomeres in Arabidopsis thaliana. TRB proteins, besides their ability to bind specifically to telomeric DNA using their N-terminally positioned myb-like domain of the same type as in human shelterin proteins TRF1 or TRF2, also possess a histone-like domain which is involved in protein-protein interactions e.g., with POT1b. Here we set out to investigate the genome-wide localization pattern of TRB1 to reveal its preferential sites of binding to chromatin in vivo and its potential functional roles in the genome-wide context. Our results demonstrate that TRB1 is preferentially associated with promoter regions of genes involved in ribosome biogenesis, in addition to its roles at telomeres. This preference coincides with the frequent occurrence of telobox motifs in the upstream regions of genes in this category, but it is not restricted to the presence of a telobox. We conclude that TRB1 shows a specific genome-wide distribution pattern which suggests its role in regulation of genes involved in biogenesis of the translational machinery, in addition to its preferential telomeric localization.

  3. Defects in Protein Folding Machinery Affect Cell Wall Integrity and Reduce Ethanol Tolerance in S. cerevisiae.

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    Narayanan, Aswathy; Pullepu, Dileep; Reddy, Praveen Kumar; Uddin, Wasim; Kabir, M Anaul

    2016-07-01

    The chaperonin complex CCT/TRiC (chaperonin containing TCP-1/TCP-1 ring complex) participates in the folding of many crucial proteins including actin and tubulin in eukaryotes. Mutations in genes encoding its subunits can affect protein folding and in turn, the physiology of the organism. Stress response in Saccharomyces cerevisiae is important in fermentation reactions and operates through overexpression and underexpression of genes, thus altering the protein profile. Defective protein folding machinery can disturb this process. In this study, the response of cct mutants to stress conditions in general and ethanol in specific was investigated. CCT1 mutants showed decreased resistance to different conditions tested including osmotic stress, metal ions, surfactants, reducing and oxidising agents. Cct1-3 mutant with the mutation in the conserved ATP-binding region showed irreversible defects than other mutants. These mutants were found to have inherent cell wall defects and showed decreased ethanol tolerance. This study reveals that cell wall defects and ethanol sensitivity are linked. Genetic and proteomic analyses showed that the yeast genes RPS6A (ribosomal protein), SCL1 (proteasomal subunit) and TDH3 (glyceraldehyde-3-phosphate dehydrogenase) on overexpression, improved the growth of cct1-3 mutant on ethanol. We propose the breakdown of common stress response pathways caused by mutations in CCT complex and the resulting scarcity of functional stress-responsive proteins, affecting the cell's defence against different stress agents in cct mutants. Defective cytoskeleton and perturbed cell wall integrity reduce the ethanol tolerance in the mutants which are rescued by the extragenic suppressors.

  4. The exocyst affects protein synthesis by acting on the translocation machinery of the endoplasmic reticulum.

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    Lipschutz, Joshua H; Lingappa, Vishwanath R; Mostov, Keith E

    2003-06-01

    RNA. Although the exact mechanism remains to be elucidated, the exocyst/Sec61beta interaction represents an important link between the cellular membrane trafficking and protein synthetic machinery.

  5. Desired alteration of protein affinities: competitive selection of protein variants using yeast signal transduction machinery.

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    Misato Kaishima

    Full Text Available Molecules that can control protein-protein interactions (PPIs have recently drawn attention as new drug pipeline compounds. Here, we report a technique to screen desirable affinity-altered (affinity-enhanced and affinity-attenuated protein variants. We previously constructed a screening system based on a target protein fused to a mutated G-protein γ subunit (Gγcyto lacking membrane localization ability. This ability, required for signal transmission, is restored by recruiting Gγcyto into the membrane only when the target protein interacts with an artificially membrane-anchored candidate protein, thereby allowing interacting partners (Gγ recruitment system to be searched and identified. In the present study, the Gγ recruitment system was altered by integrating the cytosolic expression of a third protein as a competitor to set a desirable affinity threshold. This enabled the reliable selection of both affinity-enhanced and affinity-attenuated protein variants. The presented approach may facilitate the development of therapeutic proteins that allow the control of PPIs.

  6. Recognition of signal peptide by protein translocation machinery in middle silk gland of silkworm Bombyx mori

    Institute of Scientific and Technical Information of China (English)

    Xiuyang Guo; Yi Zhang; Xue Zhang; Shengpeng Wang; Changde Lu

    2008-01-01

    To investigate the functions of signal peptide in protein secretion in the middle silk gland of silkworm Bombyx mori,a series of recombinant Autographa californica multiple nucleopolyhedroviruses containing enhanced green fluorescent protein (egfp) gene,led by sericin-1 promoter and mutated signal peptide coding sequences,were constructed by region-deletions or single amino acid residue deletions.The recombinant Autographa californica multiple nucleopolyhedroviruses were injected into the hemocoele of newly ecdysed fifth-instar silkworm larvae.The expression and secretion of EGFP in the middle silk gland were examined by fluorescence microscopy and Western blot analysis.Results showed that even with a large part (up to 14 amino acid residues) of the ser-1 signal peptide deleted,the expressed EGFP could still be secreted into the cavity of the silk gland.Western blot analysis showed that shortening of the signal peptide from the C-terminal suppressed the maturation of pro-EGFP to EGFP.When 8 amino acid residues were deleted from the C-terminal of the signal peptide (mutant 13 aa),the secretion of EGFP was incomplete,implicating the importance of proper coupling of the h-region and c-region.The deletion of amino acid residue(s) in the h-region did not affect the secretion of EGFP,indicating that the recognition of signal peptide by translocation machinery was mainly by a structural domain,but not by special amino acid residue(s).Furthermore,the deletion of Arg2 or replacement with Asp in the n-region of the signal peptide did not influence secretion of EGFP,suggesting that a positive charge is not crucial.

  7. Folding machineries displayed on a cation-exchanger for the concerted refolding of cysteine- or proline-rich proteins

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    Lee Dae-Hee

    2009-03-01

    Full Text Available Abstract Background Escherichia coli has been most widely used for the production of valuable recombinant proteins. However, over-production of heterologous proteins in E. coli frequently leads to their misfolding and aggregation yielding inclusion bodies. Previous attempts to refold the inclusion bodies into bioactive forms usually result in poor recovery and account for the major cost in industrial production of desired proteins from recombinant E. coli. Here, we describe the successful use of the immobilized folding machineries for in vitro refolding with the examples of high yield refolding of a ribonuclease A (RNase A and cyclohexanone monooxygenase (CHMO. Results We have generated refolding-facilitating media immobilized with three folding machineries, mini-chaperone (a monomeric apical domain consisting of residues 191–345 of GroEL and two foldases (DsbA and human peptidyl-prolyl cis-trans isomerase by mimicking oxidative refolding chromatography. For efficient and simple purification and immobilization simultaneously, folding machineries were fused with the positively-charged consecutive 10-arginine tag at their C-terminal. The immobilized folding machineries were fully functional when assayed in a batch mode. When the refolding-facilitating matrices were applied to the refolding of denatured and reduced RNase A and CHMO, both of which contain many cysteine and proline residues, RNase A and CHMO were recovered in 73% and 53% yield of soluble protein with full enzyme activity, respectively. Conclusion The refolding-facilitating media presented here could be a cost-efficient platform and should be applicable to refold a wide range of E. coli inclusion bodies in high yield with biological function.

  8. Characterization of YmgF, a 72-residue inner membrane protein that associates with the Escherichia coli cell division machinery.

    Science.gov (United States)

    Karimova, Gouzel; Robichon, Carine; Ladant, Daniel

    2009-01-01

    Formation of the Escherichia coli division septum is catalyzed by a number of essential proteins (named Fts) that assemble into a ring-like structure at the future division site. Many of these Fts proteins are intrinsic transmembrane proteins whose functions are largely unknown. In the present study, we attempted to identify a novel putative component(s) of the E. coli cell division machinery by searching for proteins that could interact with known Fts proteins. To do that, we used a bacterial two-hybrid system based on interaction-mediated reconstitution of a cyclic AMP (cAMP) signaling cascade to perform a library screening in order to find putative partners of E. coli cell division protein FtsL. Here we report the characterization of YmgF, a 72-residue integral membrane protein of unknown function that was found to associate with many E. coli cell division proteins and to localize to the E. coli division septum in an FtsZ-, FtsA-, FtsQ-, and FtsN-dependent manner. Although YmgF was previously shown to be not essential for cell viability, we found that when overexpressed, YmgF was able to overcome the thermosensitive phenotype of the ftsQ1(Ts) mutation and restore its viability under low-osmolarity conditions. Our results suggest that YmgF might be a novel component of the E. coli cell division machinery.

  9. Interactions of ataxin-3 with its molecular partners in the protein machinery that sorts protein aggregates to the aggresome.

    Science.gov (United States)

    Bonanomi, Marcella; Mazzucchelli, Serena; D'Urzo, Annalisa; Nardini, Marco; Konarev, Petr V; Invernizzi, Gaetano; Svergun, Dmitri I; Vanoni, Marco; Regonesi, Maria Elena; Tortora, Paolo

    2014-06-01

    Ataxin-3 (AT3) is the protein that triggers the inherited neurodegenerative disorder spinocerebellar ataxia type 3 when its polyglutamine (polyQ) stretch close to the C-terminus exceeds a critical length. AT3 consists of the N-terminal globular Josephin domain (JD) and the C-terminal disordered one. It cleaves isopeptide bonds between ubiquitin monomers, an event involved in protein quality control mechanisms. AT3 has been implicated in the pathway that sorts aggregated protein to aggresomes via microtubules, in which dynein and histone deacetylase 6 (HDAC6) also seem to be involved. By taking advantage of small angle X-ray scattering (SAXS) and surface plasmon resonance (SPR), we have investigated the interaction of AT3 with tubulin and HDAC6. Based on SAXS results, the AT3 oligomer, consisting of 6-7 subunits, tightly binds to the tubulin hexameric oligomer in a "parallel" fashion. By SPR analysis we have demonstrated that AT3 binds to tubulin dimer with a 50nM affinity. Binding fits with a Langmuir 1:1 model and involves a single binding interface. Nevertheless, the interaction surface consists of three distinct, discontinuous tubulin-binding regions (TBR), one located in the JD, and the two others in the disordered domain, upstream and downstream of the polyQ stretch. In the absence of any of the three TBRs, the affinity is drastically reduced. By SPR we have also provided the first evidence of direct binding of AT3 to HDAC6, with affinity in the range 0.1-1μM. These results shed light on the interactions among the components of the transport machinery that sorts aggregate protein to the aggresome, and pave the way to in vivo studies aimed at further clarifying their roles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. The role of mitochondria and the CIA machinery in the maturation of cytosolic and nuclear iron-sulfur proteins.

    Science.gov (United States)

    Lill, Roland; Dutkiewicz, Rafal; Freibert, Sven A; Heidenreich, Torsten; Mascarenhas, Judita; Netz, Daili J; Paul, Viktoria D; Pierik, Antonio J; Richter, Nadine; Stümpfig, Martin; Srinivasan, Vasundara; Stehling, Oliver; Mühlenhoff, Ulrich

    2015-01-01

    Mitochondria have been derived from alpha-bacterial endosymbionts during the evolution of eukaryotes. Numerous bacterial functions have been maintained inside the organelles including fatty acid degradation, citric acid cycle, oxidative phosphorylation, and the synthesis of heme or lipoic acid cofactors. Additionally, mitochondria have inherited the bacterial iron-sulfur cluster assembly (ISC) machinery. Many of the ISC components are essential for cell viability because they generate a still unknown, sulfur-containing compound for the assembly of cytosolic and nuclear Fe/S proteins that perform important functions in, e.g., protein translation, DNA synthesis and repair, and chromosome segregation. The sulfur-containing compound is exported by the mitochondrial ABC transporter Atm1 (human ABCB7) and utilized by components of the cytosolic iron-sulfur protein assembly (CIA) machinery. An appealing minimal model for the striking compartmentation of eukaryotic Fe/S protein biogenesis is provided by organisms that contain mitosomes instead of mitochondria. Mitosomes have been derived from mitochondria by reductive evolution, during which they have lost virtually all classical mitochondrial tasks. Nevertheless, mitosomes harbor all core ISC components which presumably have been maintained for assisting the maturation of cytosolic-nuclear Fe/S proteins. The current review is centered around the Atm1 export process. We present an overview on the mitochondrial requirements for the export reaction, summarize recent insights into the 3D structure and potential mechanism of Atm1, and explain how the CIA machinery uses the mitochondrial export product for the assembly of cytosolic and nuclear Fe/S proteins.

  11. Evolutionary aspects of plastid proteins involved in transcription: the transcription of a tiny genome is mediated by a complicated machinery.

    Science.gov (United States)

    Yagi, Yusuke; Shiina, Takashi

    2012-01-01

    Chloroplasts in land plants have a small genome consisting of only 100 genes encoding partial sets of proteins for photosynthesis, transcription and translation. Although it has been thought that chloroplast transcription is mediated by a basically cyanobacterium-derived system, due to the endosymbiotic origin of plastids, recent studies suggest the existence of a hybrid transcription machinery containing non-bacterial proteins that have been newly acquired during plant evolution. Here, we highlight chloroplast-specific non-bacterial transcription mechanisms by which land plant chloroplasts have gained novel functions.

  12. Dynamic Changes in Local Protein Synthetic Machinery in Regenerating Central Nervous System Axons after Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Rahul Sachdeva

    2016-01-01

    Full Text Available Intra-axonal localization of mRNAs and protein synthesis machinery (PSM endows neurons with the capacity to generate proteins locally, allowing precise spatiotemporal regulation of the axonal response to extracellular stimuli. A number of studies suggest that this local translation is a promising target to enhance the regenerative capacity of damaged axons. Using a model of central nervous system (CNS axons regenerating into intraspinal peripheral nerve grafts (PNGs we established that adult regenerating CNS axons contain several different mRNAs and protein synthetic machinery (PSM components in vivo. After lower thoracic level spinal cord transection, ascending sensory axons regenerate into intraspinal PNGs but axon growth is stalled when they reach the distal end of the PNG (3 versus 7 weeks after grafting, resp.. By immunofluorescence with optical sectioning of axons by confocal microscopy, the total and phosphorylated forms of PSMs are significantly lower in stalled compared with actively regenerating axons. Reinjury of these stalled axons increased axonal localization of the PSM proteins, indicative of possible priming for a subcellular response to axotomy. These results suggest that axons downregulate protein synthetic capacity as they cease growing, yet they retain the ability to upregulate PSM after a second injury.

  13. Folding outer membrane proteins independently of the β-barrel assembly machinery: an assembly pathway for multimeric complexes?

    Science.gov (United States)

    Huysmans, Gerard H M

    2016-06-15

    Since the discovery of the essential role of the β-barrel assembly machinery (BAM) for the membrane insertion of outer membrane proteins (OMPs) that are unrelated in sequence, members of this universally conserved family dominate discussions on OMP assembly in bacteria, mitochondria and chloroplasts. However, several multimeric bacterial OMPs assemble independently of the catalyzing BAM-component BamA. Recent progress on this alternative pathway is reviewed here, and a model for BAM-independent assembly for multimeric OMPs is proposed in which monomer delivery to the membrane and stable prepore formation are key steps towards productive membrane insertion.

  14. Applications of cell-free protein synthesis in synthetic biology: Interfacing bio-machinery with synthetic environments.

    Science.gov (United States)

    Lee, Kyung-Ho; Kim, Dong-Myung

    2013-11-01

    Synthetic biology is built on the synthesis, engineering, and assembly of biological parts. Proteins are the first components considered for the construction of systems with designed biological functions because proteins carry out most of the biological functions and chemical reactions inside cells. Protein synthesis is considered to comprise the most basic levels of the hierarchical structure of synthetic biology. Cell-free protein synthesis has emerged as a powerful technology that can potentially transform the concept of bioprocesses. With the ability to harness the synthetic power of biology without many of the constraints of cell-based systems, cell-free protein synthesis enables the rapid creation of protein molecules from diverse sources of genetic information. Cell-free protein synthesis is virtually free from the intrinsic constraints of cell-based methods and offers greater flexibility in system design and manipulability of biological synthetic machinery. Among its potential applications, cell-free protein synthesis can be combined with various man-made devices for rapid functional analysis of genomic sequences. This review covers recent efforts to integrate cell-free protein synthesis with various reaction devices and analytical platforms. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A New Membrane Protein Sbg1 Links the Contractile Ring Apparatus and Septum Synthesis Machinery in Fission Yeast

    Science.gov (United States)

    Sethi, Kriti; Palani, Saravanan; Cortés, Juan C. G.; Sato, Mamiko; Sevugan, Mayalagu; Ramos, Mariona; Vijaykumar, Shruthi; Osumi, Masako; Naqvi, Naweed I.; Ribas, Juan Carlos; Balasubramanian, Mohan

    2016-01-01

    Cytokinesis in many organisms requires a plasma membrane anchored actomyosin ring, whose contraction facilitates cell division. In yeast and fungi, actomyosin ring constriction is also coordinated with division septum assembly. How the actomyosin ring interacts with the plasma membrane and the plasma membrane-localized septum synthesizing machinery remains poorly understood. In Schizosaccharomyces pombe, an attractive model organism to study cytokinesis, the β-1,3-glucan synthase Cps1p / Bgs1p, an integral membrane protein, localizes to the plasma membrane overlying the actomyosin ring and is required for primary septum synthesis. Through a high-dosage suppressor screen we identified an essential gene, sbg1+ (suppressor of beta glucan synthase 1), which suppressed the colony formation defect of Bgs1-defective cps1-191 mutant at higher temperatures. Sbg1p, an integral membrane protein, localizes to the cell ends and to the division site. Sbg1p and Bgs1p physically interact and are dependent on each other to localize to the division site. Loss of Sbg1p results in an unstable actomyosin ring that unravels and slides, leading to an inability to deposit a single contiguous division septum and an important reduction of the β-1,3-glucan proportion in the cell wall, coincident with that observed in the cps1-191 mutant. Sbg1p shows genetic and / or physical interaction with Rga7p, Imp2p, Cdc15p, and Pxl1p, proteins known to be required for actomyosin ring integrity and efficient septum synthesis. This study establishes Sbg1p as a key member of a group of proteins that link the plasma membrane, the actomyosin ring, and the division septum assembly machinery in fission yeast. PMID:27749909

  16. Slab Leaf Bowls

    Science.gov (United States)

    Suitor, Cheryl

    2012-01-01

    In science class, fourth graders investigate the structure of plants and leaves from trees and how the process of photosynthesis turns sunlight into sugar proteins. In this article, the author fuses art and science for a creative and successful clay slab project in her elementary art classroom. (Contains 1 online resource.)

  17. Slab Leaf Bowls

    Science.gov (United States)

    Suitor, Cheryl

    2012-01-01

    In science class, fourth graders investigate the structure of plants and leaves from trees and how the process of photosynthesis turns sunlight into sugar proteins. In this article, the author fuses art and science for a creative and successful clay slab project in her elementary art classroom. (Contains 1 online resource.)

  18. `The HSP70 chaperone machinery : J proteins as drivers of functional specificity

    NARCIS (Netherlands)

    Kampinga, Harm H.; Craig, Elizabeth A.

    Heat shock 70 kDa proteins (HSP70s) are ubiquitous molecular chaperones that function in a myriad of biological processes, modulating polypeptide folding, degradation and translocation across membranes, and protein-protein interactions. This multitude of roles is not easily reconciled with the

  19. Routing of Hansenula polymorpha alcohol oxidase : An alternative peroxisomal protein-sorting machinery

    NARCIS (Netherlands)

    Gunkel, Katja; Dijk, Ralf van; Veenhuis, Marten; Klei, Ida J. van der

    Import of Hansenula polymorpha alcohol oxidase (AO) into peroxisomes is dependent on the PTS1 receptor, HpPex5p. The PTS1 of AO (-LARF) is sufficient to direct reporter proteins to peroxisomes. To study AO sorting in more detail, strains producing mutant AO proteins were constructed. AO containing a

  20. Crystal structure of a marine glycoside hydrolase family 99 related protein lacking catalytic machinery.

    Science.gov (United States)

    Robb, Craig S; Mystkowska, Agata Anna; Hehemann, Jan-Hendrik

    2017-09-08

    Algal polysaccharides of diverse structures are one of the most abundant carbon resources for heterotrophic, marine bacteria with coevolved digestive enzymes. A putative sulfo-mannan polysaccharide utilization locus, which is conserved in marine Flavobacteriia, contains an unusual GH99-like protein that lacks the conserved catalytic residues of glycoside hydrolase family 99. Using X-ray crystallography, we structurally characterized this protein from the marine Flavobacterium Ochrovirga pacifica to help elucidate its molecular function. The structure reveals the absence of potential catalytic residues for polysaccharide hydrolysis, which, together with additional structural features, suggests this protein may be non-catalytic and involved in carbohydrate binding. This article is protected by copyright. All rights reserved. © 2017 The Protein Society.

  1. Protein biogenesis machinery is a driver of replicative aging in yeast

    Science.gov (United States)

    Janssens, Georges E; Meinema, Anne C; González, Javier; Wolters, Justina C; Schmidt, Alexander; Guryev, Victor; Bischoff, Rainer; Wit, Ernst C; Veenhoff, Liesbeth M; Heinemann, Matthias

    2015-01-01

    An integrated account of the molecular changes occurring during the process of cellular aging is crucial towards understanding the underlying mechanisms. Here, using novel culturing and computational methods as well as latest analytical techniques, we mapped the proteome and transcriptome during the replicative lifespan of budding yeast. With age, we found primarily proteins involved in protein biogenesis to increase relative to their transcript levels. Exploiting the dynamic nature of our data, we reconstructed high-level directional networks, where we found the same protein biogenesis-related genes to have the strongest ability to predict the behavior of other genes in the system. We identified metabolic shifts and the loss of stoichiometry in protein complexes as being consequences of aging. We propose a model whereby the uncoupling of protein levels of biogenesis-related genes from their transcript levels is causal for the changes occurring in aging yeast. Our model explains why targeting protein synthesis, or repairing the downstream consequences, can serve as interventions in aging. DOI: http://dx.doi.org/10.7554/eLife.08527.001 PMID:26422514

  2. Species-specificity of the BamA component of the bacterial outer membrane protein-assembly machinery.

    Directory of Open Access Journals (Sweden)

    Elena B Volokhina

    Full Text Available The BamA protein is the key component of the Bam complex, the assembly machinery for outer membrane proteins (OMP in gram-negative bacteria. We previously demonstrated that BamA recognizes its OMP substrates in a species-specific manner in vitro. In this work, we further studied species specificity in vivo by testing the functioning of BamA homologs of the proteobacteria Neisseria meningitidis, Neisseria gonorrhoeae, Bordetella pertussis, Burkholderia mallei, and Escherichia coli in E. coli and in N. meningitidis. We found that no BamA functioned in another species than the authentic one, except for N. gonorrhoeae BamA, which fully complemented a N. meningitidis bamA mutant. E. coli BamA was not assembled into the N. meningitidis outer membrane. In contrast, the N. meningitidis BamA protein was assembled into the outer membrane of E. coli to a significant extent and also associated with BamD, an essential accessory lipoprotein of the Bam complex.Various chimeras comprising swapped N-terminal periplasmic and C-terminal membrane-embedded domains of N. meningitidis and E. coli BamA proteins were also not functional in either host, although some of them were inserted in the OM suggesting that the two domains of BamA need to be compatible in order to function. Furthermore, conformational analysis of chimeric proteins provided evidence for a 16-stranded β-barrel conformation of the membrane-embedded domain of BamA.

  3. High light induced changes in organization, protein profile and function of photosynthetic machinery in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Nama, Srilatha; Madireddi, Sai Kiran; Devadasu, Elsin Raju; Subramanyam, Rajagopal

    2015-11-01

    The green alga Chlamydomonas (C.) reinhardtii is used as a model organism to understand the efficiency of photosynthesis along with the organization and protein profile of photosynthetic apparatus under various intensities of high light exposure for 1h. Chlorophyll (Chl) a fluorescence induction, OJIPSMT transient was decreased with increase in light intensity indicating the reduction in photochemical efficiency. Further, circular dichroism studies of isolated thylakoids from high light exposed cells showed considerable change in the pigment-pigment interactions and pigment-proteins interactions. Furthermore, the organization of supercomplexes from thylakoids is studied, in which, one of the hetero-trimer of light harvesting complex (LHC) II is affected significantly in comparison to other complexes of LHC's monomers. Also, other supercomplexes, photosystem (PS)II reaction center dimer and PSI complexes are reduced. Additionally, immunoblot analysis of thylakoid proteins revealed that PSII core proteins D1 and D2 were significantly decreased during high light treatment. Similarly, the PSI core proteins PsaC, PsaD and PsaG were drastically changed. Further, the LHC antenna proteins of PSI and PSII were differentially affected. From our results it is clear that LHCs are damaged significantly, consequently the excitation energy is not efficiently transferred to the reaction center. Thus, the photochemical energy transfer from PSII to PSI is reduced. The inference of the study deciphers the structural and functional changes driven by light may therefore provide plants/alga to regulate the light harvesting capacity in excess light conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Evaluation of the effects of Streptococcus mutans chaperones and protein secretion machinery components on cell surface protein biogenesis, competence, and mutacin production.

    Science.gov (United States)

    Crowley, P J; Brady, L J

    2016-02-01

    The respective contributions of components of the protein translocation/maturation machinery to cell surface biogenesis in Streptococcus mutans are not fully understood. Here we used a genetic approach to characterize the effects of deletion of genes encoding the ribosome-associated chaperone RopA (Trigger Factor), the surface-localized foldase PrsA, and the membrane-localized chaperone insertases YidC1 and YidC2, both singly and in combination, on bacterial growth, chain length, self-aggregation, cell surface hydrophobicity, autolysis, and antigenicity of surface proteins P1 (AgI/II, PAc), WapA, GbpC, and GtfD. The single and double deletion mutants, as well as additional mutant strains lacking components of the signal recognition particle pathway, were also evaluated for their effects on mutacin production and genetic competence.

  5. The α-proteobacteria Wolbachia pipientis protein disulfide machinery has a regulatory mechanism absent in γ-proteobacteria.

    Directory of Open Access Journals (Sweden)

    Patricia M Walden

    Full Text Available The α-proteobacterium Wolbachia pipientis infects more than 65% of insect species worldwide and manipulates the host reproductive machinery to enable its own survival. It can live in mutualistic relationships with hosts that cause human disease, including mosquitoes that carry the Dengue virus. Like many other bacteria, Wolbachia contains disulfide bond forming (Dsb proteins that introduce disulfide bonds into secreted effector proteins. The genome of the Wolbachia strain wMel encodes two DsbA-like proteins sharing just 21% sequence identity to each other, α-DsbA1 and α-DsbA2, and an integral membrane protein, α-DsbB. α-DsbA1 and α-DsbA2 both have a Cys-X-X-Cys active site that, by analogy with Escherichia coli DsbA, would need to be oxidized to the disulfide form to serve as a disulfide bond donor toward substrate proteins. Here we show that the integral membrane protein α-DsbB oxidizes α-DsbA1, but not α-DsbA2. The interaction between α-DsbA1 and α-DsbB is very specific, involving four essential cysteines located in the two periplasmic loops of α-DsbB. In the electron flow cascade, oxidation of α-DsbA1 by α-DsbB is initiated by an oxidizing quinone cofactor that interacts with the cysteine pair in the first periplasmic loop. Oxidizing power is transferred to the second cysteine pair, which directly interacts with α-DsbA1. This reaction is inhibited by a non-catalytic disulfide present in α-DsbA1, conserved in other α-proteobacterial DsbAs but not in γ-proteobacterial DsbAs. This is the first characterization of the integral membrane protein α-DsbB from Wolbachia and reveals that the non-catalytic cysteines of α-DsbA1 regulate the redox relay system in cooperation with α-DsbB.

  6. The DUF582 Proteins of Chlamydia trachomatis Bind to Components of the ESCRT Machinery, Which Is Dispensable for Bacterial Growth In vitro

    Science.gov (United States)

    Vromman, François; Perrinet, Stéphanie; Gehre, Lena; Subtil, Agathe

    2016-01-01

    Chlamydiae are Gram negative bacteria that develop exclusively inside eukaryotic host cells, within a membrane-bounded compartment. Members of the family Chlamydiaceae, such as Chlamydia trachomatis, are pathogenic species infecting vertebrates. They have a very reduced genome and exploit the capacities of their host for their own development, mainly through the secretion of proteins tailored to interfere with eukaryotic processes, called effector proteins. All Chlamydiaceae possess genes coding for four to five effectors that share a domain of unknown function (DUF582). Here we show that four of these effectors, which represent the conserved set in all Chlamydiaceae, accumulate in the infectious form of C. trachomatis, and are therefore likely involved in an early step of the developmental cycle. The fifth member of the family, CT621, is specific to C. trachomatis, and is secreted during the growth phase. Using a two-hybrid screen in yeast we identified an interaction between the host protein Hrs and the DUF582, which we confirmed by co-immunoprecipitations in co-transfected mammalian cells. Furthermore, we provide biochemical evidence that a second domain of one of the DUF582 proteins, CT619, binds the host protein Tsg101. Hrs and Tsg101 are both implicated in a well conserved machinery of the eukaryotic cell called the ESCRT machinery, which is involved in several cellular processes requiring membrane constriction. Using RNA interference targeting proteins implicated at different stages of ESCRT-driven processes, or inhibition by expression of a dominant negative mutant of VPS4, we demonstrated that this machinery was dispensable for bacterial entry, multiplication and differentiation into infectious progeny, and for uptake of glycogen into the parasitophorous vacuole. In light of these observations we discuss how the DUF582 proteins might target the ESCRT machinery during infection. PMID:27774439

  7. Splicing Machinery Facilitates Post-Transcriptional Regulation by FBFs and Other RNA-Binding Proteins in Caenorhabditis elegans Germline.

    Science.gov (United States)

    Novak, Preston; Wang, Xiaobo; Ellenbecker, Mary; Feilzer, Sara; Voronina, Ekaterina

    2015-08-11

    Genetic interaction screens are an important approach for understanding complex regulatory networks governing development. We used a genetic interaction screen to identify cofactors of FBF-1 and FBF-2, RNA-binding proteins that regulate germline stem cell proliferation in Caenorhabditis elegans. We found that components of splicing machinery contribute to FBF activity as splicing factor knockdowns enhance sterility of fbf-1 and fbf-2 single mutants. This sterility phenocopied multiple aspects of loss of fbf function, suggesting that splicing factors contribute to stem cell maintenance. However, previous reports indicate that splicing factors instead promote the opposite cell fate, namely, differentiation. We explain this discrepancy by proposing that splicing factors facilitate overall RNA regulation in the germline. Indeed, we find that loss of splicing factors produces synthetic phenotypes with a mutation in another RNA regulator, FOG-1, but not with a mutation in a gene unrelated to posttranscriptional regulation (dhc-1). We conclude that inefficient pre-mRNA splicing may interfere with multiple posttranscriptional regulatory events, which has to be considered when interpreting results of genetic interaction screens.

  8. The machinery at endoplasmic reticulum-plasma membrane contact sites contributes to spatial regulation of multiple Legionella effector proteins.

    Directory of Open Access Journals (Sweden)

    Andree Hubber

    2014-07-01

    Full Text Available The Dot/Icm system of the intracellular pathogen Legionella pneumophila has the capacity to deliver over 270 effector proteins into host cells during infection. Important questions remain as to spatial and temporal mechanisms used to regulate such a large array of virulence determinants after they have been delivered into host cells. Here we investigated several L. pneumophila effector proteins that contain a conserved phosphatidylinositol-4-phosphate (PI4P-binding domain first described in the effector DrrA (SidM. This PI4P binding domain was essential for the localization of effectors to the early L. pneumophila-containing vacuole (LCV, and DrrA-mediated recruitment of Rab1 to the LCV required PI4P-binding activity. It was found that the host cell machinery that regulates sites of contact between the plasma membrane (PM and the endoplasmic reticulum (ER modulates PI4P dynamics on the LCV to control localization of these effectors. Specifically, phosphatidylinositol-4-kinase IIIα (PI4KIIIα was important for generating a PI4P signature that enabled L. pneumophila effectors to localize to the PM-derived vacuole, and the ER-associated phosphatase Sac1 was involved in metabolizing the PI4P on the vacuole to promote the dissociation of effectors. A defect in L. pneumophila replication in macrophages deficient in PI4KIIIα was observed, highlighting that a PM-derived PI4P signature is critical for biogenesis of a vacuole that supports intracellular multiplication of L. pneumophila. These data indicate that PI4P metabolism by enzymes controlling PM-ER contact sites regulate the association of L. pneumophila effectors to coordinate early stages of vacuole biogenesis.

  9. Alba-domain proteins of Trypanosoma brucei are cytoplasmic RNA-binding proteins that interact with the translation machinery.

    Directory of Open Access Journals (Sweden)

    Jan Mani

    Full Text Available Trypanosoma brucei and related pathogens transcribe most genes as polycistronic arrays that are subsequently processed into monocistronic mRNAs. Expression is frequently regulated post-transcriptionally by cis-acting elements in the untranslated regions (UTRs. GPEET and EP procyclins are the major surface proteins of procyclic (insect midgut forms of T. brucei. Three regulatory elements common to the 3' UTRs of both mRNAs regulate mRNA turnover and translation. The glycerol-responsive element (GRE is unique to the GPEET 3' UTR and regulates its expression independently from EP. A synthetic RNA encompassing the GRE showed robust sequence-specific interactions with cytoplasmic proteins in electromobility shift assays. This, combined with column chromatography, led to the identification of 3 Alba-domain proteins. RNAi against Alba3 caused a growth phenotype and reduced the levels of Alba1 and Alba2 proteins, indicative of interactions between family members. Tandem-affinity purification and co-immunoprecipitation verified these interactions and also identified Alba4 in sub-stoichiometric amounts. Alba proteins are cytoplasmic and are recruited to starvation granules together with poly(A RNA. Concomitant depletion of all four Alba proteins by RNAi specifically reduced translation of a reporter transcript flanked by the GPEET 3' UTR. Pulldown of tagged Alba proteins confirmed interactions with poly(A binding proteins, ribosomal protein P0 and, in the case of Alba3, the cap-binding protein eIF4E4. In addition, Alba2 and Alba3 partially cosediment with polyribosomes in sucrose gradients. Alba-domain proteins seem to have exhibited great functional plasticity in the course of evolution. First identified as DNA-binding proteins in Archaea, then in association with nuclear RNase MRP/P in yeast and mammalian cells, they were recently described as components of a translationally silent complex containing stage-regulated mRNAs in Plasmodium. Our results are

  10. Structural Bioinformatics and Protein Docking Analysis of the Molecular Chaperone-Kinase Interactions: Towards Allosteric Inhibition of Protein Kinases by Targeting the Hsp90-Cdc37 Chaperone Machinery

    Directory of Open Access Journals (Sweden)

    Gennady Verkhivker

    2013-11-01

    Full Text Available A fundamental role of the Hsp90-Cdc37 chaperone system in mediating maturation of protein kinase clients and supporting kinase functional activity is essential for the integrity and viability of signaling pathways involved in cell cycle control and organism development. Despite significant advances in understanding structure and function of molecular chaperones, the molecular mechanisms and guiding principles of kinase recruitment to the chaperone system are lacking quantitative characterization. Structural and thermodynamic characterization of Hsp90-Cdc37 binding with protein kinase clients by modern experimental techniques is highly challenging, owing to a transient nature of chaperone-mediated interactions. In this work, we used experimentally-guided protein docking to probe the allosteric nature of the Hsp90-Cdc37 binding with the cyclin-dependent kinase 4 (Cdk4 kinase clients. The results of docking simulations suggest that the kinase recognition and recruitment to the chaperone system may be primarily determined by Cdc37 targeting of the N-terminal kinase lobe. The interactions of Hsp90 with the C-terminal kinase lobe may provide additional “molecular brakes” that can lock (or unlock kinase from the system during client loading (release stages. The results of this study support a central role of the Cdc37 chaperone in recognition and recruitment of the kinase clients. Structural analysis may have useful implications in developing strategies for allosteric inhibition of protein kinases by targeting the Hsp90-Cdc37 chaperone machinery.

  11. The Yeast Aac2 Protein Exists in Physical Association with the Cytochrome bc1-COX Supercomplex and the TIM23 Machinery

    OpenAIRE

    Dienhart, Mary K.; Stuart, Rosemary A.

    2008-01-01

    The ADP/ATP carrier (AAC) proteins play a central role in cellular metabolism as they facilitate the exchange of ADP and ATP across the mitochondrial inner membrane. We present evidence here that in yeast (Saccharomyces cerevisiae) mitochondria the abundant Aac2 isoform exists in physical association with the cytochrome c reductase (cytochrome bc1)-cytochrome c oxidase (COX) supercomplex and its associated TIM23 machinery. Using a His-tagged Aac2 derivative and affinity purification studies, ...

  12. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte;

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  13. Fusion Machinery

    DEFF Research Database (Denmark)

    Sørensen, Jakob Balslev; Milosevic, Ira

    2015-01-01

    the vesicular SNARE VAMP2/synaptobrevin-2 and the target (plasma membrane) SNAREs SNAP25 and syntaxin-1 results in fusion and release of neurotransmitter, synchronized to the electrical activity of the cell by calcium influx and binding to synaptotagmin. Formation of the SNARE complex is tightly regulated...... and appears to start with syntaxin-1 bound to an SM (Sec1/Munc18-like) protein. Proteins of the Munc13-family are responsible for opening up syntaxin and allowing sequential binding of SNAP-25 and VAMP2/synaptobrevin-2. N- to C-terminal “zippering” of the SNARE domains leads to membrane fusion...

  14. Hepatitis C Virus Proteins Interact with the Endosomal Sorting Complex Required for Transport (ESCRT Machinery via Ubiquitination To Facilitate Viral Envelopment

    Directory of Open Access Journals (Sweden)

    Rina Barouch-Bentov

    2016-11-01

    Full Text Available Enveloped viruses commonly utilize late-domain motifs, sometimes cooperatively with ubiquitin, to hijack the endosomal sorting complex required for transport (ESCRT machinery for budding at the plasma membrane. However, the mechanisms underlying budding of viruses lacking defined late-domain motifs and budding into intracellular compartments are poorly characterized. Here, we map a network of hepatitis C virus (HCV protein interactions with the ESCRT machinery using a mammalian-cell-based protein interaction screen and reveal nine novel interactions. We identify HRS (hepatocyte growth factor-regulated tyrosine kinase substrate, an ESCRT-0 complex component, as an important entry point for HCV into the ESCRT pathway and validate its interactions with the HCV nonstructural (NS proteins NS2 and NS5A in HCV-infected cells. Infectivity assays indicate that HRS is an important factor for efficient HCV assembly. Specifically, by integrating capsid oligomerization assays, biophysical analysis of intracellular viral particles by continuous gradient centrifugations, proteolytic digestion protection, and RNase digestion protection assays, we show that HCV co-opts HRS to mediate a late assembly step, namely, envelopment. In the absence of defined late-domain motifs, K63-linked polyubiquitinated lysine residues in the HCV NS2 protein bind the HRS ubiquitin-interacting motif to facilitate assembly. Finally, ESCRT-III and VPS/VTA1 components are also recruited by HCV proteins to mediate assembly. These data uncover involvement of ESCRT proteins in intracellular budding of a virus lacking defined late-domain motifs and a novel mechanism by which HCV gains entry into the ESCRT network, with potential implications for other viruses.

  15. Membrane manipulations by the ESCRT machinery.

    Science.gov (United States)

    Odorizzi, Greg

    2015-01-01

    The endosomal sorting complexes required for transport (ESCRTs) collectively comprise a machinery that was first known for its function in the degradation of transmembrane proteins in the endocytic pathway of eukaryotic cells. Since their discovery, however, ESCRTs have been recognized as playing important roles at the plasma membrane, which appears to be the original site of function for the ESCRT machinery. This article reviews some of the major research findings that have shaped our current understanding of how the ESCRT machinery controls membrane dynamics and considers new roles for the ESCRT machinery that might be driven by these mechanisms.

  16. Nuclear export of human hepatitis B virus core protein and pregenomic RNA depends on the cellular NXF1-p15 machinery.

    Science.gov (United States)

    Yang, Ching-Chun; Huang, Er-Yi; Li, Hung-Cheng; Su, Pei-Yi; Shih, Chiaho

    2014-01-01

    Hepatitis B virus (HBV) core protein (HBc) can shuttle between nucleus and cytoplasm. Cytoplasm-predominant HBc is clinically associated with severe liver inflammation. Previously, we found that HBc arginine-rich domain (ARD) can associate with a host factor NXF1 (TAP) by coimmunoprecipitation. It is well known that NXF1-p15 heterodimer can serve as a major export receptor of nuclear mRNA as a ribonucleoprotein complex (RNP). In the NXF1-p15 pathway, TREX (transcription/export) complex plays an important role in coupling nuclear pre-mRNA processing with mRNA export in mammalian cells. Here, we tested the hypothesis whether HBc and HBV specific RNA can be exported via the TREX and NXF1-p15 mediated pathway. We demonstrated here that HBc can physically and specifically associate with TREX components, and the NXF1-p15 export receptor by coimmunoprecipitation. Accumulation of HBc protein in the nucleus can be induced by the interference with TREX and NXF1-p15 mediated RNA export machinery. HBV transcripts encodes a non-spliced 3.5 kb pregenomic RNA (pgRNA) which can serve as a template for reverse transcription. Cytoplasmic HBV pgRNA appeared to be reduced by siRNA treatment specific for the NXF1-p15 complex by quantitative RT-qPCR and Northern blot analyses. This result suggests that the pgRNA was also exported via the NXF1-p15 machinery. We entertain the hypothesis that HBc protein can be exported as an RNP cargo via the mRNA export pathway by hijacking the TREX and NXF1-p15 complex. In our current and previous studies, HBc is not required for pgRNA accumulation in the cytoplasm. Furthermore, HBc ARD can mediate nuclear export of a chimeric protein containing HBc ARD in a pgRNA-independent manner. Taken together, it suggests that while both pgRNA and HBc protein exports are dependent on NXF1-p15, they are using the same export machinery in a manner independent of each other.

  17. Proteome changes in tomato fruits prior to visible symptoms of chilling injury are linked to defensive mechanisms, uncoupling of photosynthetic processes and protein degradation machinery.

    Science.gov (United States)

    Sanchez-Bel, Paloma; Egea, Isabel; Sanchez-Ballesta, María Teresa; Sevillano, Laura; Del Carmen Bolarin, Maria; Flores, Francisco B

    2012-02-01

    A comparative proteomic analysis between tomato fruits stored at chilling and non-chilling temperatures was carried out just before the appearance of visible symptoms of chilling injury. At this stage of the stress period it was possible to discriminate between proteins involved in symptoms and proteins implicated in response. To investigate the changes in the tomato fruit proteome under this specific stressful condition, two-dimensional differential in-gel electrophoresis coupled with spot identification by mass spectrometry was applied. This proteomic approach allowed the identification of differentially expressed proteins which are involved in two main biological functions: (i) defensive mechanisms represented by small heat shock and late embryogenesis proteins; and (ii) reaction to the uncoupling of photosynthetic processes and the protein degradation machinery. One of the first changes observed in chilled fruits is the down-regulation of ATP synthase, 26S proteasome subunit RPN11 and aspartic proteinase, whereas the first responses in order to deal with the stress are mainly multifunctional proteins involved not only in metabolism but also in stress regulation such as glyceraldehyde phosphate dehydrogenase, 2-oxoglutarate dehydrogenase and invertase. In addition, our data seem to indicate a possible candidate to be used as a protein marker for further studies on cold stress: aldose-1-epimerase, which seems to have an important role in low temperature tolerance.

  18. The β-barrel assembly machinery (BAM) is required for the assembly of a primitive S-layer protein in the ancient outer membrane of Thermus thermophilus.

    Science.gov (United States)

    Acosta, Federico; Ferreras, Eloy; Berenguer, José

    2012-11-01

    The ancient bacterial lineage Thermus spp has a primitive form of outer membrane attached to the cell wall through SlpA, a protein that shows intermediate properties between S-layer proteins and outer membrane (OM) porins. In E. coli and related Proteobacteria, porins are secreted through the BAM (β-barrel assembly machinery) pathway, whose main component is BamA. A homologue to this protein is encoded in all the Thermus spp so far sequenced, so we wondered if this pathway could be responsible for SlpA secretion in this ancient bacterial model. To analyse this hypothesis, we attempted to get mutants on this BamA(th) of T. thermophilus HB27. Knockout and deletion mutants lacking the last 10 amino acids were not viable, whereas its depletion by means of a BamA antisense RNA lead defective attachment to the cell wall of its OM-like envelope. Such defects were related to defective folding of the SlpA protein that was more sensitive to proteases than in a wild-type strain. A similar phenotype was found in mutants lacking the terminal Phe of SlpA. Further protein-protein interaction assays confirmed the existence of specific binding between SlpA and BamA(th). Taking together, these data suggest that SlpA is secreted through a BAM-like pathway in this ancestral bacterial lineage, supporting an ancient origin of this pathway before the evolution of the Proteobacteria.

  19. Bacillus subtilis actin-like protein MreB influences the positioning of the replication machinery and requires membrane proteins MreC/D and other actin-like proteins for proper localization

    Directory of Open Access Journals (Sweden)

    Defeu Soufo Hervé Joël

    2005-03-01

    Full Text Available Abstract Background Bacterial actin-like proteins have been shown to perform essential functions in several aspects of cellular physiology. They affect cell growth, cell shape, chromosome segregation and polar localization of proteins, and localize as helical filaments underneath the cell membrane. Bacillus subtilis MreB and Mbl have been shown to perform dynamic motor like movements within cells, extending along helical tracks in a time scale of few seconds. Results In this work, we show that Bacillus subtilis MreB has a dual role, both in the formation of rod cell shape, and in chromosome segregation, however, its function in cell shape is distinct from that of MreC. Additionally, MreB is important for the localization of the replication machinery to the cell centre, which becomes aberrant soon after depletion of MreB. 3D image reconstructions suggest that frequently, MreB filaments consist of several discontinuous helical filaments with varying length. The localization of MreB was abnormal in cells with decondensed chromosomes, as well as during depletion of Mbl, MreBH and of the MreC/MreD proteins, which we show localize to the cell membrane. Thus, proper positioning of MreB filaments depends on and is affected by a variety of factors in the cell. Conclusion Our data provide genetic and cytological links between MreB and the membrane, as well as with other actin like proteins, and further supports the connection of MreB with the chromosome. The functional dependence on MreB of the localization of the replication machinery suggests that the replisome is not anchored at the cell centre, but is positioned in a dynamic manner.

  20. The β-lactam resistance protein Blr, a small membrane polypeptide, is a component of the Escherichia coli cell division machinery.

    Science.gov (United States)

    Karimova, Gouzel; Davi, Marilyne; Ladant, Daniel

    2012-10-01

    In Escherichia coli, cell division is performed by a multimolecular machinery called the divisome, made of 10 essential proteins and more than 20 accessory proteins. Through a bacterial two-hybrid library screen, we identified the E. coli β-lactam resistance protein Blr, a short membrane polypeptide of 41 residues, as an interacting partner of the essential cell division protein FtsL. In addition to FtsL, Blr was found to associate with several other divisomal proteins, including FtsI, FtsK, FtsN, FtsQ, FtsW, and YmgF. Using fluorescently tagged Blr, we showed that this peptide localizes to the division septum and that its colocalization requires the presence of the late division protein FtsN. Although Blr is not essential, previous studies have shown that the inactivation of the blr gene increased the sensitivity of bacteria to β-lactam antibiotics or their resistance to cell envelope stress. Here, we found that Blr, when overproduced, restores the viability of E. coli ftsQ1(Ts) cells, carrying a thermosensitive allele of the ftsQ gene, during growth under low-osmotic-strength conditions (e.g., in synthetic media or in Luria-Bertani broth without NaCl). In contrast, the inactivation of blr increases the osmosensitivity of ftsQ1(Ts) cells, and blr ftsQ1 double mutants exhibit filamentous growth in LB broth even at a moderate salt concentration (0.5% NaCl) compared to parental ftsQ1(Ts) cells. Altogether, our results suggest that the small membrane polypeptide Blr is a novel component of the E. coli cell division apparatus involved in the stabilization of the divisome under certain stress conditions.

  1. Improving machinery reliability

    CERN Document Server

    Bloch, Heinz P

    1998-01-01

    This totally revised, updated and expanded edition provides proven techniques and procedures that extend machinery life, reduce maintenance costs, and achieve optimum machinery reliability. This essential text clearly describes the reliability improvement and failure avoidance steps practiced by best-of-class process plants in the U.S. and Europe.

  2. Streptococcus mutans extracellular DNA is upregulated during growth in biofilms, actively released via membrane vesicles, and influenced by components of the protein secretion machinery.

    Science.gov (United States)

    Liao, Sumei; Klein, Marlise I; Heim, Kyle P; Fan, Yuwei; Bitoun, Jacob P; Ahn, San-Joon; Burne, Robert A; Koo, Hyun; Brady, L Jeannine; Wen, Zezhang T

    2014-07-01

    Streptococcus mutans, a major etiological agent of human dental caries, lives primarily on the tooth surface in biofilms. Limited information is available concerning the extracellular DNA (eDNA) as a scaffolding matrix in S. mutans biofilms. This study demonstrates that S. mutans produces eDNA by multiple avenues, including lysis-independent membrane vesicles. Unlike eDNAs from cell lysis that were abundant and mainly concentrated around broken cells or cell debris with floating open ends, eDNAs produced via the lysis-independent pathway appeared scattered but in a structured network under scanning electron microscopy. Compared to eDNA production of planktonic cultures, eDNA production in 5- and 24-h biofilms was increased by >3- and >1.6-fold, respectively. The addition of DNase I to growth medium significantly reduced biofilm formation. In an in vitro adherence assay, added chromosomal DNA alone had a limited effect on S. mutans adherence to saliva-coated hydroxylapatite beads, but in conjunction with glucans synthesized using purified glucosyltransferase B, the adherence was significantly enhanced. Deletion of sortase A, the transpeptidase that covalently couples multiple surface-associated proteins to the cell wall peptidoglycan, significantly reduced eDNA in both planktonic and biofilm cultures. Sortase A deficiency did not have a significant effect on membrane vesicle production; however, the protein profile of the mutant membrane vesicles was significantly altered, including reduction of adhesin P1 and glucan-binding proteins B and C. Relative to the wild type, deficiency of protein secretion and membrane protein insertion machinery components, including Ffh, YidC1, and YidC2, also caused significant reductions in eDNA.

  3. Dynamin-like protein 1 at the Golgi complex: a novel component of the sorting/targeting machinery en route to the plasma membrane.

    Science.gov (United States)

    Bonekamp, Nina A; Vormund, Kerstin; Jacob, Ralf; Schrader, Michael

    2010-12-10

    The final step in the liberation of secretory vesicles from the trans-Golgi network (TGN) involves the mechanical action of the large GTPase dynamin as well as conserved dynamin-independent fission mechanisms, e.g. mediated by Brefeldin A-dependent ADP-ribosylated substrate (BARS). Another member of the dynamin family is the mammalian dynamin-like protein 1 (DLP1/Drp1) that is known to constrict and tubulate membranes, and to divide mitochondria and peroxisomes. Here, we examined a potential role for DLP1 at the Golgi complex. DLP1 localized to the Golgi complex in some but not all cell lines tested, thus explaining controversial reports on its cellular distribution. After silencing of DLP1, an accumulation of the apical reporter protein YFP-GL-GPI, but not the basolateral reporter VSVG-SP-GFP at the Golgi complex was observed. A reduction in the transport of YFP-GL-GPI to the plasma membrane was confirmed by surface immunoprecipitation and TGN-exit assays. In contrast, YFP-GL-GPI trafficking was not disturbed in cells silenced for BARS, which is involved in basolateral sorting and trafficking of VSVG-SP-GFP in COS-7 cells. Our data indicate a new role for DLP1 at the Golgi complex and thus a role for DLP1 as a novel component of the apical sorting machinery at the TGN is discussed.

  4. Dynamin-like protein 1 at the Golgi complex: A novel component of the sorting/targeting machinery en route to the plasma membrane

    Energy Technology Data Exchange (ETDEWEB)

    Bonekamp, Nina A. [Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal); Vormund, Kerstin; Jacob, Ralf [Department of Cell Biology and Cell Pathology, University of Marburg, Robert-Koch-Str. 6, 35037 Marburg (Germany); Schrader, Michael, E-mail: mschrader@ua.pt [Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)

    2010-12-10

    The final step in the liberation of secretory vesicles from the trans-Golgi network (TGN) involves the mechanical action of the large GTPase dynamin as well as conserved dynamin-independent fission mechanisms, e.g. mediated by Brefeldin A-dependent ADP-ribosylated substrate (BARS). Another member of the dynamin family is the mammalian dynamin-like protein 1 (DLP1/Drp1) that is known to constrict and tubulate membranes, and to divide mitochondria and peroxisomes. Here, we examined a potential role for DLP1 at the Golgi complex. DLP1 localized to the Golgi complex in some but not all cell lines tested, thus explaining controversial reports on its cellular distribution. After silencing of DLP1, an accumulation of the apical reporter protein YFP-GL-GPI, but not the basolateral reporter VSVG-SP-GFP at the Golgi complex was observed. A reduction in the transport of YFP-GL-GPI to the plasma membrane was confirmed by surface immunoprecipitation and TGN-exit assays. In contrast, YFP-GL-GPI trafficking was not disturbed in cells silenced for BARS, which is involved in basolateral sorting and trafficking of VSVG-SP-GFP in COS-7 cells. Our data indicate a new role for DLP1 at the Golgi complex and thus a role for DLP1 as a novel component of the apical sorting machinery at the TGN is discussed.

  5. TP0326, a Treponema pallidum β-barrel assembly machinery A (BamA) orthologue and rare outer membrane protein.

    Science.gov (United States)

    Desrosiers, Daniel C; Anand, Arvind; Luthra, Amit; Dunham-Ems, Star M; LeDoyt, Morgan; Cummings, Michael A D; Eshghi, Azad; Cameron, Caroline E; Cruz, Adriana R; Salazar, Juan C; Caimano, Melissa J; Radolf, Justin D

    2011-06-01

    Definitive identification of Treponema pallidum rare outer membrane proteins (OMPs) has long eluded researchers. TP0326, the sole protein in T. pallidum with sequence homology to a Gram-negative OMP, belongs to the BamA family of proteins essential for OM biogenesis. Structural modelling predicted that five polypeptide transport-associated (POTRA) domains comprise the N-terminus of TP0326, while the C-terminus forms an 18-stranded amphipathic β-barrel. Circular dichroism, heat modifiability by SDS-PAGE, Triton X-114 phase partitioning and liposome incorporation supported these topological predictions and confirmed that the β-barrel is responsible for the native protein's amphiphilicity. Expression analyses revealed that native TP0326 is expressed at low abundance, while a protease-surface accessibility assay confirmed surface exposure. Size-exclusion chromatography and blue native polyacrylamide gel electrophoresis revealed a modular Bam complex in T. pallidum larger than that of Escherichia coli. Non-orthologous ancillary factors and self-association of TP0326 via its β-barrel may both contribute to the Bam complex. T. pallidum-infected rabbits mount a vigorous antibody response to both POTRA and β-barrel portions of TP0326, whereas humans with secondary syphilis respond predominantly to POTRA. The syphilis spirochaete appears to have devised a stratagem for harnessing the Bam pathway while satisfying its need to limit surface antigenicity.

  6. Differential localization of LTA synthesis proteins and their interaction with the cell division machinery in Staphylococcus aureus.

    Science.gov (United States)

    Reichmann, Nathalie T; Piçarra Cassona, Carolina; Monteiro, João M; Bottomley, Amy L; Corrigan, Rebecca M; Foster, Simon J; Pinho, Mariana G; Gründling, Angelika

    2014-04-01

    Lipoteichoic acid (LTA) is an important cell wall component of Gram-positive bacteria. In Staphylococcus aureus it consists of a polyglycerolphosphate-chain that is retained within the membrane via a glycolipid. Using an immunofluorescence approach, we show here that the LTA polymer is not surface exposed in S. aureus, as it can only be detected after digestion of the peptidoglycan layer. S. aureus mutants lacking LTA are enlarged and show aberrant positioning of septa, suggesting a link between LTA synthesis and the cell division process. Using a bacterial two-hybrid approach, we show that the three key LTA synthesis proteins, YpfP and LtaA, involved in glycolipid production, and LtaS, required for LTA backbone synthesis, interact with one another. All three proteins also interacted with numerous cell division and peptidoglycan synthesis proteins, suggesting the formation of a multi-enzyme complex and providing further evidence for the co-ordination of these processes. When assessed by fluorescence microscopy, YpfP and LtaA fluorescent protein fusions localized to the membrane while the LtaS enzyme accumulated at the cell division site. These data support a model whereby LTA backbone synthesis proceeds in S. aureus at the division site in co-ordination with cell division, while glycolipid synthesis takes place throughout the membrane. © 2014 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

  7. Dehydroepiandrosterone and the relationship with aging and memory: a possible link with protein kinase C functional machinery.

    Science.gov (United States)

    Racchi, M; Govoni, S; Solerte, S B; Galli, C L; Corsini, E

    2001-11-01

    A progressive decline of cognitive and memory functions, compared to the average young-life performance, characterizes brain aging. The changes in performance may depend upon altered activity of neurotransmitters acting on attention and memory trace formation (acetylcholine, catecholamines, glutamate, for example) or the failure of the transduction mechanisms linked to receptor activation. One of the fundamental cellular changes associated with brain aging is the alteration of mechanisms involving the activity of the calcium-phospholipid-dependent protein kinase C (PKC). A crucial event for the activation of protein kinase C is its translocation from the cytosol to different intracellular sites and recent studies have demonstrated the key role played by several anchoring proteins in this mechanism. The defective activation of PKC-dependent pathways during aging is due to a defective mechanism of translocation of the kinase because of reduced levels of the major anchoring protein RACK-1 (receptor for activated C kinase). Pharmacological strategies aimed at the correction of age-associated memory deficits have been mostly focused on neurotransmitters using direct or indirect agonists. More recently, attention has been paid to the memory enhancing properties of some steroid hormones, namely 'neurosteroids'. Among these the activities of dehydroepiandrosterone (DHEA), pregnenolone (PREG) and their sulfates, have been extensively studied. These neuroactive steroids, can regulate neuronal function through their concurrent influence on transmitter-gated ion channels and gene expression. We addressed the possibility that DHEA, among other neurosteroids, could modulate directly the age-associated impairment of PKC signal transduction and provide experimental evidence that DHEA can revert the alteration of RACK-1 anchoring protein expression.

  8. The molecular cell death machinery in the simple cnidarian Hydra includes an expanded caspase family and pro- and anti-apoptotic Bcl-2 proteins.

    Science.gov (United States)

    Lasi, Margherita; Pauly, Barbara; Schmidt, Nikola; Cikala, Mihai; Stiening, Beate; Käsbauer, Tina; Zenner, Gerhardt; Popp, Tanja; Wagner, Anita; Knapp, Regina T; Huber, Andreas H; Grunert, Michaela; Söding, Johannes; David, Charles N; Böttger, Angelika

    2010-07-01

    The fresh water polyp Hydra belongs to the phylum Cnidaria, which diverged from the metazoan lineage before the appearance of bilaterians. In order to understand the evolution of apoptosis in metazoans, we have begun to elucidate the molecular cell death machinery in this model organism. Based on ESTs and the whole Hydra genome assembly, we have identified 15 caspases. We show that one is activated during apoptosis, four have characteristics of initiator caspases with N-terminal DED, CARD or DD domain and two undergo autoprocessing in vitro. In addition, we describe seven Bcl-2-like and two Bak-like proteins. For most of the Bcl-2 family proteins, we have observed mitochondrial localization. When expressed in mammalian cells, HyBak-like 1 and 2 strongly induced apoptosis. Six of the Bcl-2 family members inhibited apoptosis induced by camptothecin in mammalian cells with HyBcl-2-like 4 showing an especially strong protective effect. This protein also interacted with HyBak-like 1 in a yeast two-hybrid assay. Mutation of the conserved leucine in its BH3 domain abolished both the interaction with HyBak-like 1 and the anti-apoptotic effect. Moreover, we describe novel Hydra BH-3-only proteins. One of these interacted with Bcl-2-like 4 and induced apoptosis in mammalian cells. Our data indicate that the evolution of a complex network for cell death regulation arose at the earliest and simplest level of multicellular organization, where it exhibited a substantially higher level of complexity than in the protostome model organisms Caenorhabditis and Drosophila.

  9. β-Boswellic acid, a bioactive substance used in food supplements, inhibits protein synthesis by targeting the ribosomal machinery.

    Science.gov (United States)

    Casapullo, A; Cassiano, C; Capolupo, A; Del Gaudio, F; Esposito, R; Tosco, A; Riccio, R; Monti, M C

    2016-09-01

    The Boswellia gum resin extracts have been used in traditional medicines because of their remarkable anti-inflammatory properties. Nowadays, these extracts are on the market as food supplements. β-Boswellic acid (βBA) is one of the main pentacyclic triterpene components, among the family of BAs, of the Boswellia gum resins. BAs have been broadly studied and are well known for their wide anti-inflammatory and potential anticancer properties. In this paper, a mass spectrometry-based chemoproteomic approach has been applied to characterize the whole βBA interacting profile. Among the large numbers of proteins fished out, proteasome, 14-3-3 and some ribosomal proteins were considered the most interesting targets strictly connected to the modulation of the cancer progression. In particular, because of their recent assessment as innovative chemotherapeutic targets, the ribosomal proteins were considered the most attractive βBA partners, and the biological role of their interaction with the natural compound has been evaluated. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Identification of a protein–protein interaction between KCNE1 and the activation gate machinery of KCNQ1

    Science.gov (United States)

    Lvov, Anatoli; Gage, Steven D.; Berrios, Virla M.

    2010-01-01

    KCNQ1 channels assemble with KCNE1 transmembrane (TM) peptides to form voltage-gated K+ channel complexes with slow activation gate opening. The cytoplasmic C-terminal domain that abuts the KCNE1 TM segment has been implicated in regulating KCNQ1 gating, yet its interaction with KCNQ1 has not been described. Here, we identified a protein–protein interaction between the KCNE1 C-terminal domain and the KCNQ1 S6 activation gate and S4–S5 linker. Using cysteine cross-linking, we biochemically screened over 300 cysteine pairs in the KCNQ1–KCNE1 complex and identified three residues in KCNQ1 (H363C, P369C, and I257C) that formed disulfide bonds with cysteine residues in the KCNE1 C-terminal domain. Statistical analysis of cross-link efficiency showed that H363C preferentially reacted with KCNE1 residues H73C, S74C, and D76C, whereas P369C showed preference for only D76C. Electrophysiological investigation of the mutant K+ channel complexes revealed that the KCNQ1 residue, H363C, formed cross-links not only with KCNE1 subunits, but also with neighboring KCNQ1 subunits in the complex. Cross-link formation involving the H363C residue was state dependent, primarily occurring when the KCNQ1–KCNE1 complex was closed. Based on these biochemical and electrophysiological data, we generated a closed-state model of the KCNQ1–KCNE1 cytoplasmic region where these protein–protein interactions are poised to slow activation gate opening. PMID:20479109

  11. Premature Activation of the Paramyxovirus Fusion Protein before Target Cell Attachment with Corruption of the Viral Fusion Machinery*

    Science.gov (United States)

    Farzan, Shohreh F.; Palermo, Laura M.; Yokoyama, Christine C.; Orefice, Gianmarco; Fornabaio, Micaela; Sarkar, Aurijit; Kellogg, Glen E.; Greengard, Olga; Porotto, Matteo; Moscona, Anne

    2011-01-01

    Paramyxoviruses, including the childhood pathogen human parainfluenza virus type 3, enter host cells by fusion of the viral and target cell membranes. This fusion results from the concerted action of its two envelope glycoproteins, the hemagglutinin-neuraminidase (HN) and the fusion protein (F). The receptor-bound HN triggers F to undergo conformational changes that render it competent to mediate fusion of the viral and cellular membranes. We proposed that, if the fusion process could be activated prematurely before the virion reaches the target host cell, infection could be prevented. We identified a small molecule that inhibits paramyxovirus entry into target cells and prevents infection. We show here that this compound works by an interaction with HN that results in F-activation prior to receptor binding. The fusion process is thereby prematurely activated, preventing fusion of the viral membrane with target cells and precluding viral entry. This first evidence that activation of a paramyxovirus F can be specifically induced before the virus contacts its target cell suggests a new strategy with broad implications for the design of antiviral agents. PMID:21799008

  12. The conserved Bud20 zinc finger protein is a new component of the ribosomal 60S subunit export machinery.

    Science.gov (United States)

    Bassler, Jochen; Klein, Isabella; Schmidt, Claudia; Kallas, Martina; Thomson, Emma; Wagner, Maria Anna; Bradatsch, Bettina; Rechberger, Gerald; Strohmaier, Heimo; Hurt, Ed; Bergler, Helmut

    2012-12-01

    The nuclear export of the preribosomal 60S (pre-60S) subunit is coordinated with late steps in ribosome assembly. Here, we show that Bud20, a conserved C(2)H(2)-type zinc finger protein, is an unrecognized shuttling factor required for the efficient export of pre-60S subunits. Bud20 associates with late pre-60S particles in the nucleoplasm and accompanies them into the cytoplasm, where it is released through the action of the Drg1 AAA-ATPase. Cytoplasmic Bud20 is then reimported via a Kap123-dependent pathway. The deletion of Bud20 induces a strong pre-60S export defect and causes synthetic lethality when combined with mutant alleles of known pre-60S subunit export factors. The function of Bud20 in ribosome export depends on a short conserved N-terminal sequence, as we observed that mutations or the deletion of this motif impaired 60S subunit export and generated the genetic link to other pre-60S export factors. We suggest that the shuttling Bud20 is recruited to the nascent 60S subunit via its central zinc finger rRNA binding domain to facilitate the subsequent nuclear export of the preribosome employing its N-terminal extension.

  13. The plastid-dividing machinery: formation, constriction and fission.

    Science.gov (United States)

    Yoshida, Yamato; Miyagishima, Shin-ya; Kuroiwa, Haruko; Kuroiwa, Tsuneyoshi

    2012-12-01

    Plastids divide by constriction of the plastid-dividing (PD) machinery, which encircles the division site. The PD machinery consists of the stromal inner machinery which includes the inner PD and filamenting temperature-sensitive mutant Z (FtsZ) rings and the cytosolic outer machinery which includes the outer PD and dynamin rings. The major constituent of the PD machinery is the outer PD ring, which consists of a bundle of polyglucan filaments. In addition, recent proteomic studies suggest that the PD machinery contains additional proteins that have not been characterized. The PD machinery forms from the inside to the outside of the plastid. The constriction seems to occur by sliding of the polyglucan filaments of the outer PD ring, aided by dynamin. The final fission of the plastid is probably promoted by the 'pinchase' activity of dynamin.

  14. Genomic reduction and evolution of novel genetic membranes and protein-targeting machinery in eukaryote-eukaryote chimaeras (meta-algae).

    Science.gov (United States)

    Cavalier-Smith, T

    2003-01-29

    non-coding DNA, i.e. most DNA in the biosphere, and dramatic examples of genomic reduction. I briefly argue that chloroplast replacement in dinoflagellates, which happened at least twice, may have been evolutionarily easier than secondary symbiogenesis because parts of the chromalveolate protein-targeting machinery could have helped enslave the foreign plastids.

  15. A SEL1L mutation links a canine progressive early-onset cerebellar ataxia to the endoplasmic reticulum-associated protein degradation (ERAD machinery.

    Directory of Open Access Journals (Sweden)

    Kaisa Kyöstilä

    Full Text Available Inherited ataxias are characterized by degeneration of the cerebellar structures, which results in progressive motor incoordination. Hereditary ataxias occur in many species, including humans and dogs. Several mutations have been found in humans, but the genetic background has remained elusive in dogs. The Finnish Hound suffers from an early-onset progressive cerebellar ataxia. We have performed clinical, pathological, and genetic studies to describe the disease phenotype and to identify its genetic cause. Neurological examinations on ten affected dogs revealed rapidly progressing generalized cerebellar ataxia, tremors, and failure to thrive. Clinical signs were present by the age of 3 months, and cerebellar shrinkage was detectable through MRI. Pathological and histological examinations indicated cerebellum-restricted neurodegeneration. Marked loss of Purkinje cells was detected in the cerebellar cortex with secondary changes in other cortical layers. A genome-wide association study in a cohort of 31 dogs mapped the ataxia gene to a 1.5 Mb locus on canine chromosome 8 (p(raw = 1.1x10(-7, p(genome = 7.5x10(-4. Sequencing of a functional candidate gene, sel-1 suppressor of lin-12-like (SEL1L, revealed a homozygous missense mutation, c.1972T>C; p.Ser658Pro, in a highly conserved protein domain. The mutation segregated fully in the recessive pedigree, and a 10% carrier frequency was indicated in a population cohort. SEL1L is a component of the endoplasmic reticulum (ER-associated protein degradation (ERAD machinery and has not been previously associated to inherited ataxias. Dysfunctional protein degradation is known to cause ER stress, and we found a significant increase in expression of nine ER stress responsive genes in the cerebellar cortex of affected dogs, supporting the pathogenicity of the mutation. Our study describes the first early-onset neurodegenerative ataxia mutation in dogs, establishes an ERAD-mediated neurodegenerative

  16. Cavitation in Hydraulic Machinery

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, M.

    1996-11-01

    The main purpose of this doctoral thesis on cavitation in hydraulic machinery is to change focus towards the coupling of non-stationary flow phenomena and cavitation. It is argued that, in addition to turbulence, superimposed sound pressure fluctuations can have a major impact on cavitation and lead to particularly severe erosion. For the design of hydraulic devices this finding may indicate how to further limit the cavitation problems. Chapter 1 reviews cavitation in general in the context of hydraulic machinery, emphasizing the initial cavitation event and the role of the water quality. Chapter 2 discusses the existence of pressure fluctuations for situations common in such machinery. Chapter 3 on cavitation dynamics presents an algorithm for calculating the nucleation of a cavity cluster. Chapter 4 describes the equipment used in this work. 53 refs., 55 figs.,10 tabs.

  17. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P...

  18. A repeat sequence domain of the ring-exported protein-1 of Plasmodium falciparum controls export machinery architecture and virulence protein trafficking.

    Science.gov (United States)

    McHugh, Emma; Batinovic, Steven; Hanssen, Eric; McMillan, Paul J; Kenny, Shannon; Griffin, Michael D W; Crawford, Simon; Trenholme, Katharine R; Gardiner, Donald L; Dixon, Matthew W A; Tilley, Leann

    2015-12-01

    The malaria parasite Plasmodium falciparum dramatically remodels its host red blood cell to enhance its own survival, using a secretory membrane system that it establishes outside its own cell. Cisternal organelles, called Maurer's clefts, act as a staging point for the forward trafficking of virulence proteins to the red blood cell (RBC) membrane. The Ring-EXported Protein-1 (REX1) is a Maurer's cleft resident protein. We show that inducible knockdown of REX1 causes stacking of Maurer's cleft cisternae without disrupting the organization of the knob-associated histidine-rich protein at the RBC membrane. Genetic dissection of the REX1 sequence shows that loss of a repeat sequence domain results in the formation of giant Maurer's cleft stacks. The stacked Maurer's clefts are decorated with tether-like structures and retain the ability to dock onto the RBC membrane skeleton. The REX1 mutant parasites show deficient export of the major virulence protein, PfEMP1, to the red blood cell surface and markedly reduced binding to the endothelial cell receptor, CD36. REX1 is predicted to form a largely α-helical structure, with a repetitive charge pattern in the repeat sequence domain, providing potential insights into the role of REX1 in Maurer's cleft sculpting.

  19. Stepwise evolution of the Sec machinery in Proteobacteria

    NARCIS (Netherlands)

    van der Sluis, EO; Driessen, AJM; Sluis, Eli O. van der

    2006-01-01

    The Sec machinery facilitates the translocation of proteins across and into biological membranes. In several of the Proteobacteria, this machinery contains accessory features that are not present in any other bacterial division. The genomic distribution of these features in the context of bacterial

  20. Evolution and diversification of the basal transcription machinery.

    Science.gov (United States)

    Duttke, Sascha H C

    2015-03-01

    Transcription initiation was once thought to be regulated primarily by sequence-specific transcription factors with the basal transcription machinery being largely invariant. Gradually it became apparent that the basal transcription machinery greatly diversified during evolution and new studies now demonstrate that diversification of the TATA-binding protein (TBP) family yielded specialized and largely independent transcription systems.

  1. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  2. The eIF4E-Binding Protein 4E-T Is a Component of the mRNA Decay Machinery that Bridges the 5′ and 3′ Termini of Target mRNAs

    Directory of Open Access Journals (Sweden)

    Tamiko Nishimura

    2015-06-01

    Full Text Available Eukaryotic mRNA degradation often initiates with the recruitment of the CCR4-NOT deadenylase complex and decay factors to the mRNA 3′ terminus. How the 3′-proximal decay machinery interacts with the 5′-terminal cap structure in order to engender mRNA decapping and 5′–3′ degradation is unclear. Human 4E-T is an eIF4E-binding protein that has been reported to promote mRNA decay, albeit via an unknown mechanism. Here, we show that 4E-T is a component of the mRNA decay machinery and interacts with factors including DDX6, LSM14, and the LSM1-7-PAT1 complex. We also provide evidence that 4E-T associates with, and enhances the decay of, mRNAs targeted by the CCR4-NOT deadenylase complex, including microRNA targets. Importantly, we demonstrate that 4E-T must interact with eIF4E to engender mRNA decay. Taken together, our data support a model where 4E-T promotes mRNA turnover by physically linking the 3′-terminal mRNA decay machinery to the 5′ cap via its interaction with eIF4E.

  3. The RNA polymerase I transcription machinery.

    Science.gov (United States)

    Russell, Jackie; Zomerdijk, Joost C B M

    2006-01-01

    The rRNAs constitute the catalytic and structural components of the ribosome, the protein synthesis machinery of cells. The level of rRNA synthesis, mediated by Pol I (RNA polymerase I), therefore has a major impact on the life and destiny of a cell. In order to elucidate how cells achieve the stringent control of Pol I transcription, matching the supply of rRNA to demand under different cellular growth conditions, it is essential to understand the components and mechanics of the Pol I transcription machinery. In this review, we discuss: (i) the molecular composition and functions of the Pol I enzyme complex and the two main Pol I transcription factors, SL1 (selectivity factor 1) and UBF (upstream binding factor); (ii) the interplay between these factors during pre-initiation complex formation at the rDNA promoter in mammalian cells; and (iii) the cellular control of the Pol I transcription machinery.

  4. IOP1 protein is an external component of the human cytosolic iron-sulfur cluster assembly (CIA) machinery and functions in the MMS19 protein-dependent CIA pathway.

    Science.gov (United States)

    Seki, Mineaki; Takeda, Yukiko; Iwai, Kazuhiro; Tanaka, Kiyoji

    2013-06-07

    The emerging link between iron metabolism and genome integrity is increasingly clear. Recent studies have revealed that MMS19 and cytosolic iron-sulfur cluster assembly (CIA) factors form a complex and have central roles in CIA pathway. However, the composition of the CIA complex, particularly the involvement of the Fe-S protein IOP1, is still unclear. The roles of each component are also largely unknown. Here, we show that MMS19, MIP18, and CIAO1 form a tight "core" complex and that IOP1 is an "external" component of this complex. Although IOP1 and the core complex form a complex both in vivo and in vitro, IOP1 behaves differently in vivo. A deficiency in any core component leads to down-regulation of all of the components. In contrast, IOP1 knockdown does not affect the level of any core component. In MMS19-overproducing cells, other core components are also up-regulated, but the protein level of IOP1 remains unchanged. IOP1 behaves like a target protein in the CIA reaction, like other Fe-S helicases, and the core complex may participate in the maturation process of IOP1. Alternatively, the core complex may catch and hold IOP1 when it becomes mature to prevent its degradation. In any case, IOP1 functions in the MMS19-dependent CIA pathway. We also reveal that MMS19 interacts with target proteins. MIP18 has a role to bridge MMS19 and CIAO1. CIAO1 also binds IOP1. Based on our in vivo and in vitro data, new models of the CIA machinery are proposed.

  5. Matrix analysis of electrical machinery

    CERN Document Server

    Hancock, N N

    2013-01-01

    Matrix Analysis of Electrical Machinery, Second Edition is a 14-chapter edition that covers the systematic analysis of electrical machinery performance. This edition discusses the principles of various mathematical operations and their application to electrical machinery performance calculations. The introductory chapters deal with the matrix representation of algebraic equations and their application to static electrical networks. The following chapters describe the fundamentals of different transformers and rotating machines and present torque analysis in terms of the currents based on the p

  6. Pumping machinery theory and practice

    CERN Document Server

    Badr, Hassan M

    2014-01-01

    Pumping Machinery Theory and Practice comprehensively covers the theoretical foundation and applications of pumping machinery. Key features: Covers characteristics of centrifugal pumps, axial flow pumps and displacement pumpsConsiders pumping machinery performance and operational-type problemsCovers advanced topics in pumping machinery including multiphase flow principles, and two and three-phase flow pumping systemsCovers different methods of flow rate control and relevance to machine efficiency and energy consumptionCovers different methods of flow rate control and relevance to machine effi

  7. Topological Susceptibility from Slabs

    CERN Document Server

    Bietenholz, Wolfgang; Gerber, Urs

    2015-01-01

    In quantum field theories with topological sectors, a non-perturbative quantity of interest is the topological susceptibility chi_t. In principle it seems straightforward to measure chi_t by means of Monte Carlo simulations. However, for local update algorithms and fine lattice spacings, this tends to be difficult, since the Monte Carlo history rarely changes the topological sector. Here we test a method to measure chi_t even if data from only one sector are available. It is based on the topological charges in sub-volumes, which we denote as slabs. Assuming a Gaussian distribution of these charges, this method enables the evaluation of chi_t, as we demonstrate with numerical results for non-linear sigma-models.

  8. The exportomer: the peroxisomal receptor export machinery.

    Science.gov (United States)

    Platta, Harald W; Hagen, Stefanie; Erdmann, Ralf

    2013-04-01

    Peroxisomes constitute a dynamic compartment of almost all eukaryotic cells. Depending on environmental changes and cellular demands peroxisomes can acquire diverse metabolic roles. The compartmentalization of peroxisomal matrix enzymes is a prerequisite to carry out their physiologic function. The matrix proteins are synthesized on free ribosomes in the cytosol and are ferried to the peroxisomal membrane by specific soluble receptors. Subsequent to cargo release into the peroxisomal matrix, the receptors are exported back to the cytosol to facilitate further rounds of matrix protein import. This dislocation step is accomplished by a remarkable machinery, which comprises enzymes required for the ubiquitination as well as the ATP-dependent extraction of the receptor from the membrane. Interestingly, receptor ubiquitination and dislocation are the only known energy-dependent steps in the peroxisomal matrix protein import process. The current view is that the export machinery of the receptors might function as molecular motor not only in the dislocation of the receptors but also in the import step of peroxisomal matrix protein by coupling ATP-dependent removal of the peroxisomal import receptor with cargo translocation into the organelle. In this review we will focus on the architecture and function of the peroxisomal receptor export machinery, the peroxisomal exportomer.

  9. Reconstruction of Metabolic Pathways, Protein Expression, and Homeostasis Machineries across Maize Bundle Sheath and Mesophyll Chloroplasts: Large-Scale Quantitative Proteomics Using the First Maize Genome Assembly1[W][OA

    Science.gov (United States)

    Friso, Giulia; Majeran, Wojciech; Huang, Mingshu; Sun, Qi; van Wijk, Klaas J.

    2010-01-01

    Chloroplasts in differentiated bundle sheath (BS) and mesophyll (M) cells of maize (Zea mays) leaves are specialized to accommodate C4 photosynthesis. This study provides a reconstruction of how metabolic pathways, protein expression, and homeostasis functions are quantitatively distributed across BS and M chloroplasts. This yielded new insights into cellular specialization. The experimental analysis was based on high-accuracy mass spectrometry, protein quantification by spectral counting, and the first maize genome assembly. A bioinformatics workflow was developed to deal with gene models, protein families, and gene duplications related to the polyploidy of maize; this avoided overidentification of proteins and resulted in more accurate protein quantification. A total of 1,105 proteins were assigned as potential chloroplast proteins, annotated for function, and quantified. Nearly complete coverage of primary carbon, starch, and tetrapyrole metabolism, as well as excellent coverage for fatty acid synthesis, isoprenoid, sulfur, nitrogen, and amino acid metabolism, was obtained. This showed, for example, quantitative and qualitative cell type-specific specialization in starch biosynthesis, arginine synthesis, nitrogen assimilation, and initial steps in sulfur assimilation. An extensive overview of BS and M chloroplast protein expression and homeostasis machineries (more than 200 proteins) demonstrated qualitative and quantitative differences between M and BS chloroplasts and BS-enhanced levels of the specialized chaperones ClpB3 and HSP90 that suggest active remodeling of the BS proteome. The reconstructed pathways are presented as detailed flow diagrams including annotation, relative protein abundance, and cell-specific expression pattern. Protein annotation and identification data, and projection of matched peptides on the protein models, are available online through the Plant Proteome Database. PMID:20089766

  10. Skill Sheets for Agricultural Machinery.

    Science.gov (United States)

    Iowa State Univ. of Science and Technology, Ames. Dept. of Agricultural Education.

    This set of 21 skill sheets for agricultural machinery was developed for use in high school and vocational school agricultural mechanics programs. Each sheet covers a single operational procedure for a piece of agricultural machinery, and includes: (1) a diagram, (2) a step-by-step operational procedure, (3) abilities or understandings taught, (4)…

  11. New Packaging for Amplifier Slabs

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thorsness, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Suratwala, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Steele, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rogowski, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-18

    The following memo provides a discussion and detailed procedure for a new finished amplifier slab shipping and storage container. The new package is designed to maintain an environment of <5% RH to minimize weathering.

  12. Optimization of reinforced concrete slabs

    Science.gov (United States)

    Ferritto, J. M.

    1979-01-01

    Reinforced concrete cells composed of concrete slabs and used to limit the effects of accidental explosions during hazardous explosives operations are analyzed. An automated design procedure which considers the dynamic nonlinear behavior of the reinforced concrete of arbitrary geometrical and structural configuration subjected to dynamic pressure loading is discussed. The optimum design of the slab is examined using an interior penalty function. The optimization procedure is presented and the results are discussed and compared with finite element analysis.

  13. Optimization of reinforced concrete slabs

    Science.gov (United States)

    Ferritto, J. M.

    1979-01-01

    Reinforced concrete cells composed of concrete slabs and used to limit the effects of accidental explosions during hazardous explosives operations are analyzed. An automated design procedure which considers the dynamic nonlinear behavior of the reinforced concrete of arbitrary geometrical and structural configuration subjected to dynamic pressure loading is discussed. The optimum design of the slab is examined using an interior penalty function. The optimization procedure is presented and the results are discussed and compared with finite element analysis.

  14. Stochastic noise in splicing machinery.

    Science.gov (United States)

    Melamud, Eugene; Moult, John

    2009-08-01

    The number of known alternative human isoforms has been increasing steadily with the amount of available transcription data. To date, over 100 000 isoforms have been detected in EST libraries, and at least 75% of human genes have at least one alternative isoform. In this paper, we propose that most alternative splicing events are the result of noise in the splicing process. We show that the number of isoforms and their abundance can be predicted by a simple stochastic noise model that takes into account two factors: the number of introns in a gene and the expression level of a gene. The results strongly support the hypothesis that most alternative splicing is a consequence of stochastic noise in the splicing machinery, and has no functional significance. The results are also consistent with error rates tuned to ensure that an adequate level of functional product is produced and to reduce the toxic effect of accumulation of misfolding proteins. Based on simulation of sampling of virtual cDNA libraries, we estimate that error rates range from 1 to 10% depending on the number of introns and the expression level of a gene.

  15. Rheological evolution of subducting slabs

    Science.gov (United States)

    Hirth, G.

    2016-12-01

    The mechanical behavior of subducting lithosphere depends on both the rheological evolution of the slab and how the slab is modified prior to subduction. Geophysical data demonstrate that the combination of thermal evolution and deformation lead to alteration of the slab at both mid-ocean ridges and the outer rise of subduction zones. In addition, the locations of earthquakes in these locations are generally consistent with both extrapolation of laboratory data that constrain the depth to the brittle-plastic transition, and deformation mechanisms inferred from microstructural analysis of mantle rocks recovered from the oceanic lithosphere. However, the frictional properties of both mantle aggregates and their alteration products suggest that linking the location of lithospheric earthquakes to regions that become hydrothermally altered is not straightforward. Furthermore, the inferred link between the location of intermediate-depth seismicity and the conditions of dehydration reactions is challenged by laboratory studies on dehydration embrittlement. In this presentation, I will introduce these apparent discrepancies; provide some possible resolutions for them based on scaling of laboratory data and discuss the implications for how an integrated understanding of slab rheology informs our understanding of the mechanical and geochemical evolution of the slab.

  16. 46 CFR 169.241 - Machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Machinery. 169.241 Section 169.241 Shipping COAST GUARD... Certification Inspections § 169.241 Machinery. (a) At each inspection for certification and periodic inspection.... Mechanisms are operationally tested and visually examined. (3) Auxiliary machinery. All machinery...

  17. Evolution of the chloroplast division machinery

    Institute of Scientific and Technical Information of China (English)

    Hongbo GAO; Fuli GAO

    2011-01-01

    Chloroplasts are photosynthetic organelles derived from endosymbiotic cyanobacteria during evolution.Dramatic changes occurred during the process of the formation and evolution of chloroplasts,including the large-scale gene transfer from chloroplast to nucleus.However,there are still many essential characters remaining.For the chloroplast division machinery,FtsZ proteins,Ftn2,SulA and part of the division site positioning system- MinD and MinE are still conserved.New or at least partially new proteins,such as FtsZ family proteins FtsZl and ARC3,ARC6H,ARC5,PDV1,PDV2 and MCD1,were introduced for the division of chloroplasts during evolution.Some bacterial cell division proteins,such as FtsA,MreB,Ftn6,FtsW and Ftsl,probably lost their function or were gradually lost.Thus,the chloroplast division machinery is a dynamically evolving structure with both conservation and innovation.

  18. The RNA polymerase I transcription machinery

    OpenAIRE

    Russell, Jackie; Zomerdijk, Joost C. B. M.

    2006-01-01

    The rRNAs constitute the catalytic and structural components of the ribosome, the protein synthesis machinery of cells. The level of rRNA synthesis, mediated by Pol I (RNA polymerase I), therefore has a major impact on the life and destiny of a cell. In order to elucidate how cells achieve the stringent control of Pol I transcription, matching the supply of rRNA to demand under different cellular growth conditions, it is essential to understand the components and mechanics of the Pol I transc...

  19. How mantle slabs drive plate tectonics.

    Science.gov (United States)

    Conrad, Clinton P; Lithgow-Bertelloni, Carolina

    2002-10-04

    The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction.

  20. ARC Code TI: SLAB Spatial Audio Renderer

    Data.gov (United States)

    National Aeronautics and Space Administration — SLAB is a software-based, real-time virtual acoustic environment rendering system being developed as a tool for the study of spatial hearing. SLAB is designed to...

  1. The uptake machinery of clostridial actin ADP-ribosylating toxins--a cell delivery system for fusion proteins and polypeptide drugs.

    Science.gov (United States)

    Barth, Holger; Blöcker, Dagmar; Aktories, Klaus

    2002-12-01

    Several bacterial protein toxins, including Clostridium botulinum C2 toxin, Clostridum perfringens iota toxin, Clostridium difficile ADP-ribosyltransferase, and the Bacillus-produced vegetative insecticidal proteins, target the cytoskeleton by ADP-ribosylation of actin. All these toxins are binary in structure and consist of an enzyme component, possessing ADP-ribosyltransferase activity and a separated binding and translocation component, which is involved in the delivery of the enzyme component into the cell. The toxins are not only important virulence factors but also cell biological tools to study the function of the actin cytoskeleton. Moreover, the binary toxins turned out to be effective transporter systems for the delivery of specific fusion toxins (e.g., Rho-ADP-ribosylating C3 exoenzyme) into cells. The present review describes the biological functions of the toxins, focuses on recent studies on the uptake and delivery mechanism and discusses the usage as a drug delivery system.

  2. 酿酒酵母线粒体蛋白转运系统在立克次体中的同源分析%The homology analysis of Saccharomyces cerevisiae mitochondrial protein import machinery in Rickettsia prowazekii

    Institute of Scientific and Technical Information of China (English)

    刘震; 李校; 赵培虎; 桂俊鸿; 张义正

    2011-01-01

    进化分析表明,与线粒体亲缘关系最近的原核生物是立克次体(Rickettsia prowazekii).搜索酿酒酵母(Saccharom ycescerevisia)线粒体蛋白转运系统的35个亚基在立克次体中的同源蛋白质,仅发现了5个同源蛋白,且它们只属于转运系统在线粒体外膜和基质上的模块,没有发现转运系统在膜间隙和内膜模块的同源蛋白.对大肠杆菌(Escherichia coli K-12 MG1655)的分析也有类似的结果.因此线粒体蛋白转运系统应该不是直接起源于内共生的原核生物.%ConA from 0 μg/mL to 100 μg/mL was added into Tca8113 cells, and MTT, cellular mor phology observation, LDH assay, flow cytometry detection and caspase assay were performed. MTT was applied to detect the inhibitory ratio of Tca8113 cells, and-morphologic changes, LDH, flow cytom etry detection were applied to detect apoptosis. In addition, caspase assy was also applied to observe whether caspase was involved in ConA-induced apoptosis in Tca8113 cells. After 24 h incubation with 25 μg/mL ConA, the inhibitory rate reached nearly 50%. Typical morphologic changes like membrane blebbing, chromatin condensation and nuclei fragmentation were confirmed. LDH assay and flow cytom etry detection showed that with the progressively increasing the concentration of ConA, more and more apoptotic cells appeared. And, caspase assay demonstrated that ConA could induce apoptosis in Tca8113 Phylogenetic analyses identified that Rickettsia prowazekii is the closest relatives of modern mitochondria. The homology analysis results from the 35 subunits of mitochondrial protein import mechanism of Saccharomyces cerevisiae, with thoce of Rickettsia prowazekii, suggest that only 5 sub units of the machinery have orthologous sequences from Rickettsia prowazekii. These 5 subunits are lo cated in the outer membrane and the matrix of mitochondria, while no subunit located in the inner mem brane and intermembrane space. Analysis of the Escherichia coli K

  3. Translational machinery of the chaetognath Spadella cephaloptera: a transcriptomic approach to the analysis of cytosolic ribosomal protein genes and their expression

    Directory of Open Access Journals (Sweden)

    Casanova Jean-Paul

    2007-08-01

    Full Text Available Abstract Background Chaetognaths, or arrow worms, are small marine, bilaterally symmetrical metazoans. The objective of this study was to analyse ribosomal protein (RP coding sequences from a published collection of expressed sequence tags (ESTs from a chaetognath (Spadella cephaloptera and to use them in phylogenetic studies. Results This analysis has allowed us to determine the complete primary structures of 23 out of 32 RPs from the small ribosomal subunit (SSU and 32 out of 47 RPs from the large ribosomal subunit (LSU. Ten proteins are partially determined and 14 proteins are missing. Phylogenetic analyses of concatenated RPs from six animals (chaetognath, echinoderm, mammalian, insect, mollusc and sponge and one fungal taxa do not resolve the chaetognath phylogenetic position, although each mega-sequence comprises approximately 5,000 amino acid residues. This is probably due to the extremely biased base composition and to the high evolutionary rates in chaetognaths. However, the analysis of chaetognath RP genes revealed three unique features in the animal Kingdom. First, whereas generally in animals one RP appeared to have a single type of mRNA, two or more genes are generally transcribed for one RP type in chaetognath. Second, cDNAs with complete 5'-ends encoding a given protein sequence can be divided in two sub-groups according to a short region in their 5'-ends: two novel and highly conserved elements have been identified (5'-TAATTGAGTAGTTT-3' and 5'-TATTAAGTACTAC-3' which could correspond to different transcription factor binding sites on paralog RP genes. And, third, the overall number of deduced paralogous RPs is very high compared to those published for other animals. Conclusion These results suggest that in chaetognaths the deleterious effects of the presence of paralogous RPs, such as apoptosis or cancer are avoided, and also that in each protein family, some of the members could have tissue-specific and extra-ribosomal functions

  4. SecF stabilizes SecD and SecY, components of the protein translocation machinery of the Escherichia coli cytoplasmic membrane.

    OpenAIRE

    Sagara, K; Matsuyama, S.; Mizushima, S

    1994-01-01

    The effect of the overproduction of SecF encoded by the tac-secF gene on a plasmid on the synthesis of other Sec proteins was studied in Escherichia coli. SecF overproduction resulted in the simultaneous overproduction of SecD encoded by the tac-secD gene on a plasmid. Deletion of the orf6 gene, located downstream of the secF gene, had no effect on SecD overproduction. A pulse-chase experiment revealed that the overproduction was due to stabilization of SecD with SecF. SecF overproduction als...

  5. Textile Machinery: Imports Rebound Again

    Institute of Scientific and Technical Information of China (English)

    Zheng Yan

    2007-01-01

    @@ In the year of 2006, the general situation of China's textile machinery equipment imports had shown a clear sign of revival from the downward trend of two years ago, with a total annual import of 4.1 billion USD, an increase of 19.05% against the same period of 2005.

  6. Tractor & Machinery Safety. 1984 Revision.

    Science.gov (United States)

    Montana State Office of Public Instruction, Helena. Dept. of Vocational Education Services.

    This curriculum guide is intended for use in teaching an instructional unit in tractor and machinery safety that is geared toward college freshmen. Addressed in the individual lessons of the unit are the following topics: understanding the importance of safe and efficient tractor operation, understanding the characteristics of tractors, preparing…

  7. Transient Temperature Analysis of Slab in Erdemir

    Institute of Scientific and Technical Information of China (English)

    (U)nal Camdali; Murat Tunc; Sedat Sisbot

    2008-01-01

    A transient thermal model was developed for slab furnaces in Eregli Iron and Steel Worlds (Erdemir) in Turkey and the model was solved using the FlexPDE computer program. This program uses the finite element method. Program codes were written to solve the temperature distribution of slabs that are put into furnace at 25℃ and removed at about 1 250℃. To obtain the optimum slab exit temperature variation, the necessary air temperature inside the furnace was calculated to be 1 390℃. The slab temperature versus time and the temperature variation inside the slab were depicted.

  8. Method for Bubbledeck Concrete Slab with Gaps

    Directory of Open Access Journals (Sweden)

    Sergiu Călin

    2009-01-01

    Full Text Available The composite slabs are made of BubbleDeck type slab elements with spherical gaps, poured in place on transversal and longitudinal directions. By introducing the gaps leads to a 30...50\\% lighter slab which reduces the loads on the columns, walls and foundations, and of course of the entire building. BubbleDeck slab elements are plates with ribs on two directions made of reinforced concrete or precast concrete with spherical shaped bubbles. These slab elements have a bottom and an upper concrete part connected with vertical ribs that go around the gaps.

  9. Metaproteomics Identifies the Protein Machinery Involved in Metal and Radionuclide Reduction in Subsurface Microbiomes and Elucidates Mechanisms and U(VI) Reduction Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Pfiffner, Susan M. [Univ. of Tennessee, Knoxville, TN (United States); Löffler, Frank [Univ. of Tennessee, Knoxville, TN (United States); Ritalahti, Kirsti [Univ. of Tennessee, Knoxville, TN (United States); Sayler, Gary [Univ. of Tennessee, Knoxville, TN (United States); Layton, Alice [Univ. of Tennessee, Knoxville, TN (United States); Hettich, Robert [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-31

    analyses, and gene expression studies to support the metaproteomics characterizations. Growth experiments of target microorganisms (Anaeromyxobacter, Shewanella, Geobacter) revealed tremendous respiratory versatility, as evidenced by the ability to utilize a range of electron donors (e.g. acetate, hydrogen, pyruvate, lactate, succinate, formate) and electron acceptors (e.g. nitrate, fumarate, halogenated phenols, ferric iron, nitrous oxide, etc.). In particular, the dissimilatory metabolic reduction of metals, including radionuclides, by target microorganisms spurred interest for in situ bioremediation of contaminated soils and sediments. Distinct c-type cytochrome expression patterns were observed in target microorganisms grown with the different electron acceptors. For each target microorganism, the core proteome covered almost all metabolic pathways represented by their corresponding pan-proteomes. Unique proteins were detected for each target microorganism, and their expression and possible functionalities were linked to specific growth conditions through proteomics measurements. Optimization of the proteomic tools included in-depth comprehensive metagenomic and metaproteomic analyses on a limited number of samples. The optimized metaproteomic analyses were then applied to Oak Ridge IFRC field samples from the slow-release substrate biostimulation. Metaproteomic analysis and pathway mapping results demonstrated the distinct effects of metal and non-metal growth conditions on the proteome expression. With these metaproteomic tools, we identified which previously hypothetical metabolic pathways were active during the analyzed time points of the slow release substrate biostimulation. Thus, we demonstrated the utility of these tools for site assessment, efficient implementation of bioremediation and long-term monitoring. This research of detailed protein analysis linked with metal reduction activity did (1) show that c-type cytochrome isoforms, previously associated with

  10. Metaproteomics Identifies the Protein Machinery Involved in Metal and Radionuclide Reduction in Subsurface Microbiomes and Elucidates Mechanisms and U(VI) Reduction Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Pfiffner, Susan M. [Univ. of Tennessee, Knoxville, TN (United States); Löffler, Frank [Univ. of Tennessee, Knoxville, TN (United States); Ritalahti, Kirsti [Univ. of Tennessee, Knoxville, TN (United States); Sayler, Gary [Univ. of Tennessee, Knoxville, TN (United States); Layton, Alice [Univ. of Tennessee, Knoxville, TN (United States); Hettich, Robert [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-31

    analyses, and gene expression studies to support the metaproteomics characterizations. Growth experiments of target microorganisms (Anaeromyxobacter, Shewanella, Geobacter) revealed tremendous respiratory versatility, as evidenced by the ability to utilize a range of electron donors (e.g. acetate, hydrogen, pyruvate, lactate, succinate, formate) and electron acceptors (e.g. nitrate, fumarate, halogenated phenols, ferric iron, nitrous oxide, etc.). In particular, the dissimilatory metabolic reduction of metals, including radionuclides, by target microorganisms spurred interest for in situ bioremediation of contaminated soils and sediments. Distinct c-type cytochrome expression patterns were observed in target microorganisms grown with the different electron acceptors. For each target microorganism, the core proteome covered almost all metabolic pathways represented by their corresponding pan-proteomes. Unique proteins were detected for each target microorganism, and their expression and possible functionalities were linked to specific growth conditions through proteomics measurements. Optimization of the proteomic tools included in-depth comprehensive metagenomic and metaproteomic analyses on a limited number of samples. The optimized metaproteomic analyses were then applied to Oak Ridge IFRC field samples from the slow-release substrate biostimulation. Metaproteomic analysis and pathway mapping results demonstrated the distinct effects of metal and non-metal growth conditions on the proteome expression. With these metaproteomic tools, we identified which previously hypothetical metabolic pathways were active during the analyzed time points of the slow release substrate biostimulation. Thus, we demonstrated the utility of these tools for site assessment, efficient implementation of bioremediation and long-term monitoring. This research of detailed protein analysis linked with metal reduction activity did (1) show that c-type cytochrome isoforms, previously associated with

  11. Energy Savings Thanks to French Textile Machinery

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ The French Textile Machinery Manufacturers' Association (UCMTF) has presented, during a seminar it organized for textile professionals and students, the spectacular energy savings achieved thanks to state of the art machinery.

  12. Italian Textile Machinery Seminar in Bangladesh

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Association of Italian Textile Machinery Manufacturers (ACIMIT) and the Italian Trade Commission will hold a technological seminar on "Italian textile machinery: the way to improve Bangladesh textile competitiveness"

  13. The SNARE machinery in mast cell secretion

    Directory of Open Access Journals (Sweden)

    Axel eLorentz

    2012-06-01

    Full Text Available Mast cells are known as inflammatory cells which exert their functions in allergic and anaphylactic reactions by secretion of numerous inflammatory mediators. During an allergic response, the high-affinity IgE receptor, FcεRI, becomes cross-linked by receptor-bound IgE and antigen resulting in immediate release of pre-synthesized mediators – stored in granules – as well as in de novo synthesis of various mediators like cytokines and chemokines. Soluble N-ethylmaleimide-Sensitive Factor (NSF Attachment Protein (SNAP Receptors (SNARE proteins were found to play a central role in regulating membrane fusion events during exocytosis. In addition, several accessory regulators like Munc13, Munc18, Rab GTPases, SCAMPs, complexins or synaptotagmins were found to be involved in membrane fusion. In this review we summarize our current knowledge about the SNARE machinery and its mechanism of action in mast cell secretion.

  14. 30 CFR 56.14204 - Machinery lubrication.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery lubrication. 56.14204 Section 56.14204 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Equipment Safety Practices and Operational Procedures § 56.14204 Machinery lubrication. Machinery...

  15. 30 CFR 57.14204 - Machinery lubrication.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery lubrication. 57.14204 Section 57.14204 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Equipment Safety Practices and Operational Procedures § 57.14204 Machinery lubrication. Machinery...

  16. 46 CFR 176.804 - Machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Machinery. 176.804 Section 176.804 Shipping COAST GUARD... CERTIFICATION Material Inspections § 176.804 Machinery. At each initial and subsequent inspection for... ready for inspections of machinery, fuel, and piping systems, including the following: (a) Operation...

  17. 46 CFR 130.450 - Machinery alarms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms....

  18. MicroRNA Machinery Genes as Novel Biomarkers for Cancer.

    Science.gov (United States)

    Huang, Jing-Tao; Wang, Jin; Srivastava, Vibhuti; Sen, Subrata; Liu, Song-Mei

    2014-01-01

    MicroRNAs (miRNAs) directly and indirectly affect tumorigenesis. To be able to perform their myriad roles, miRNA machinery genes, such as Drosha, DGCR8, Dicer1, XPO5, TRBP, and AGO2, must generate precise miRNAs. These genes have specific expression patterns, protein-binding partners, and biochemical capabilities in different cancers. Our preliminary analysis of data from The Cancer Genome Atlas consortium on multiple types of cancer revealed significant alterations in these miRNA machinery genes. Here, we review their biological structures and functions with an eye toward understanding how they could serve as cancer biomarkers.

  19. MACHINERY

    African Journals Online (AJOL)

    Data were collected using a portable data acquisition system: SKF Microlog. Data were collected' ... Modelling (HMM) ofvibrational signals. ... trifugal pump designed for a pressure increase of. 6.6 bars at ..... These frequency amplitudes are located at the vertical. axial and .... distribution centre the residual chlorine concen-.

  20. Metallurgical quality of CSP thin slabs

    Institute of Scientific and Technical Information of China (English)

    Deguang Zhou; Jie Fu; Yonglin Kang; Zhongbing Wang; Jing Li; Zhongbo Xu

    2004-01-01

    The casting structure, chemical composition segregation, dendrite arm space, inclusiona and during the CSP (compact strip production) rolling process were investigated. The results show that the CSP thin slab has a feature of uniform fme grains, more columnar crystals, less central porosity and segregation etc. There is no great difference in macrostructure between the CSP thin slab and conventional slab; however, the fine dendrite structure of the CSP slab is more uniform. Moreover, the central porosity and segregation are obviously improved after the first pass; and the dendrite is bent along the rolling direction rather than broken into pieces.Small inclusions with the diameter less than 10 μm in the CSP slab are dominantly consisted of aluminates formed by A1 deoxidation and Ca treatment and not floating out of the melt. The large size inclusions found in the continuous casting slab are very few.

  1. Higher order modes in photonic crystal slabs.

    Science.gov (United States)

    Gansch, Roman; Kalchmair, Stefan; Detz, Hermann; Andrews, Aaron M; Klang, Pavel; Schrenk, Werner; Strasser, Gottfried

    2011-08-15

    We present a detailed investigation of higher order modes in photonic crystal slabs. In such structures the resonances exhibit a blue-shift compared to an ideal two-dimensional photonic crystal, which depends on the order of the slab mode and the polarization. By fabricating a series of photonic crystal slab photo detecting devices, with varying ratios of slab thickness to photonic crystal lattice constant, we are able to distinguish between 0th and 1st order slab modes as well as the polarization from the shift of resonances in the photocurrent spectra. This method complements the photonic band structure mapping technique for characterization of photonic crystal slabs. © 2011 Optical Society of America

  2. Strategies for Improving Enterprise Standardization Management of Tropical Crop Machinery

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ There are two categories of tropical crop machinery. One comprises operation machinery that is used for planting, managing and harvesting tropical crops, while the other comprises process machinery for processing tropical crops. Tropical crop machinery is distinguished from other agricultural machinery by the special crops that such machinery cultivates and processes.

  3. Ribosome evolution: Emergence of peptide synthesis machinery

    Indian Academy of Sciences (India)

    Koji Tamura

    2011-12-01

    Proteins, the main players in current biological systems, are produced on ribosomes by sequential amide bond (peptide bond) formations between amino-acid-bearing tRNAs. The ribosome is an exquisite super-complex of RNA-proteins, containing more than 50 proteins and at least 3 kinds of RNAs. The combination of a variety of side chains of amino acids (typically 20 kinds with some exceptions) confers proteins with extraordinary structure and functions. The origin of peptide bond formation and the ribosome is crucial to the understanding of life itself. In this article, a possible evolutionary pathway to peptide bond formation machinery (proto-ribosome) will be discussed, with a special focus on the RNA minihelix (primordial form of modern tRNA) as a starting molecule. Combining the present data with recent experimental data, we can infer that the peptidyl transferase center (PTC) evolved from a primitive system in the RNA world comprising tRNA-like molecules formed by duplication of minihelix-like small RNA.

  4. A slab expression in the Gibraltar arc?

    Science.gov (United States)

    Nijholt, Nicolai; Govers, Rob; Wortel, Rinus

    2017-04-01

    The present-day geodynamic setting of the Gibraltar arc region results from several Myrs of subduction rollback in the overall (oblique) convergence of Africa and Iberia. As for most rollback settings in a convergence zone, the interaction of these two components is complex and distinctly non-stationary. Gibraltar slab rollback is considered to have stalled, or at least diminished largely in magnitude, since the late Miocene/early Pliocene, suggesting that the effect of the slab on present-day surface motions is negligible. However, GPS measurements indicate that the Gibraltar arc region has an anomalous motion with respect to both Iberia and Africa, i.e., the Gibraltar arc region does not move as part of the rigid Iberian, or the rigid African plate. A key question is whether this surface motion is an expression of the Gibraltar slab. Seismic activity in the Gibraltar region is diffuse and considerable in magnitude, making it a region of high seismic risk. Unlike the North African margin to the east, where thrust earthquakes dominate the focal mechanism tables, a complex pattern is observed with thrust, normal and strike-slip earthquakes in a region stretching between the northern Moroccan Atlas across the Gibraltar arc and Alboran Sea (with the Trans-Alboran Shear Zone) to the Betics of southern Spain. Even though no large mega-thrust earthquakes have been observed in recent history, slab rollback may not have completely ceased. However, since no activity has been observed in the accretionary wedge, probably since the Pliocene, it is likely that the subduction interface is locked. In this study, we perform a series of numerical models in which we combine the relative plate convergence, variable magnitude of friction on fault segments, regional variations in gravitational potential energy and slab pull of the Gibraltar slab. We seek to reproduce the GPS velocities and slip sense on regional faults and thereby determine whether the Gibraltar slab has an effect on

  5. Developing Process of Tropical Crop Machinery Standardization

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ General Situation Tropical crop machinery is a new special mechanical profession, which began to develop from 1950s to 1960s in China. Because the weather, soil and farm crops varieties in tropical region are greatly different from those in the other regions, most of the traditional farm machinery can't be directly used in tropical region or on the tropical crops. Tropical crop machinery needs a special design and manufacture. So some professional research institutes and education units were set up and some enterprises were built at that time, and the profession of tropical crop machinery was formed.

  6. Slab stagnation and detachment under northeast China

    Science.gov (United States)

    Honda, Satoru

    2016-03-01

    Results of tomography models around the Japanese Islands show the existence of a gap between the horizontally lying (stagnant) slab extending under northeastern China and the fast seismic velocity anomaly in the lower mantle. A simple conversion from the fast velocity anomaly to the low-temperature anomaly shows a similar feature. This feature appears to be inconsistent with the results of numerical simulations on the interaction between the slab and phase transitions with temperature-dependent viscosity. Such numerical models predict a continuous slab throughout the mantle. I extend previous analyses of the tomography model and model calculations to infer the origins of the gap beneath northeastern China. Results of numerical simulations that take the geologic history of the subduction zone into account suggest two possible origins for the gap: (1) the opening of the Japan Sea led to a breaking off of the otherwise continuous subducting slab, or (2) the western edge of the stagnant slab is the previous subducted ridge, which was the plate boundary between the extinct Izanagi and the Pacific plates. Origin (2) suggesting the present horizontally lying slab has accumulated since the ridge subduction, is preferable for explaining the present length of the horizontally lying slab in the upper mantle. Numerical models of origin (1) predict a stagnant slab in the upper mantle that is too short, and a narrow or non-existent gap. Preferred models require rather stronger flow resistance of the 660-km phase change than expected from current estimates of the phase transition property. Future detailed estimates of the amount of the subducted Izanagi plate and the present stagnant slab would be useful to constrain models. A systematic along-arc variation of the slab morphology from the northeast Japan to Kurile arcs is also recognized, and its understanding may constrain the 3D mantle flow there.

  7. Turbulence in the cylindrical slab

    Energy Technology Data Exchange (ETDEWEB)

    Gentle, K. W.; Rowan, W. L.; Williams, C. B.; Brookman, M. W. [Institute of Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

    2014-09-15

    The cylindrical slab was the first and simplest model of intrinsically unstable microturbulence. The Helimak is an experimental realization of this model. Although finite, it is sufficiently large to escape boundary effects, with dimensionless parameters similar to those of a tokamak edge or scrape off layer. The essential drive is interchange-like, a pressure gradient with unfavorable magnetic curvature, leading to a non-linearly saturated state of large-amplitude turbulence, Δn{sub rms}/n ∼ 0.5. The nonlinear processes governing this saturation are unique, unlike any of those posited for the much weaker turbulence typical of confined plasma, e.g., in a tokamak. Neither linear stability theory, quasi-linear theory, zonal flows, nor flow shear stabilization is consistent with the observations. The mechanisms determining the non-linearly saturated state constitute an important challenge to our understanding of strongly nonlinear systems.

  8. Spatiotemporal Regulation of Nuclear Transport Machinery and Microtubule Organization

    Directory of Open Access Journals (Sweden)

    Naoyuki Okada

    2015-08-01

    Full Text Available Spindle microtubules capture and segregate chromosomes and, therefore, their assembly is an essential event in mitosis. To carry out their mission, many key players for microtubule formation need to be strictly orchestrated. Particularly, proteins that assemble the spindle need to be translocated at appropriate sites during mitosis. A small GTPase (hydrolase enzyme of guanosine triphosphate, Ran, controls this translocation. Ran plays many roles in many cellular events: nucleocytoplasmic shuttling through the nuclear envelope, assembly of the mitotic spindle, and reorganization of the nuclear envelope at the mitotic exit. Although these events are seemingly distinct, recent studies demonstrate that the mechanisms underlying these phenomena are substantially the same as explained by molecular interplay of the master regulator Ran, the transport factor importin, and its cargo proteins. Our review focuses on how the transport machinery regulates mitotic progression of cells. We summarize translocation mechanisms governed by Ran and its regulatory proteins, and particularly focus on Ran-GTP targets in fission yeast that promote spindle formation. We also discuss the coordination of the spatial and temporal regulation of proteins from the viewpoint of transport machinery. We propose that the transport machinery is an essential key that couples the spatial and temporal events in cells.

  9. Oils degradation in agricultural machinery

    Directory of Open Access Journals (Sweden)

    Vojtěch Kumbár

    2013-01-01

    Full Text Available Evaluating of oils condition in agricultural machinery is very important. With monitoring and evaluating we can prevent technical and economic losses. In this paper there were monitored the liquid lubricants taken from mobile thresher New Holland CX 860. Chemical and viscosity degradation of the lubricants were evaluated. Temperature dependence dynamic viscosity was observed in the range of temperature from −10 °C to 80 °C (for all oils. Considerable temperature dependence dynamic viscosity was found and demonstrated in case of all samples, which is in accordance with theoretical assumptions and literature data. Mathematical models were developed and tested. Temperature dependence dynamic viscosity was modeled using a polynomial 6th degree. The proposed models can be used for prediction of flow behavior of oils.

  10. Cretaceous Arctic magmatism: Slab vs. plume? Or slab and plume?

    Science.gov (United States)

    Gottlieb, E. S.; Miller, E. L.; Andronikov, A. V.; Brumley, K.; Mayer, L. A.; Mukasa, S. B.

    2010-12-01

    Tectonic models for the Cretaceous paleogeographic evolution of the Arctic Ocean and its adjacent landmasses propose that rifting in the Amerasia Basin (AB) began in Jura-Cretaceous time, accompanied by the development of the High Arctic Large Igneous Province (HALIP). During the same timespan, deformation and slab-related magmatism, followed by intra-arc rifting, took place along the Pacific side of what was to become the Arctic Ocean. A compilation and comparison of the ages, characteristics and space-time variation of circum-Arctic magmatism allows for a better understanding of the role of Pacific margin versus Arctic-Atlantic plate tectonics and the role of plume-related magmatism in the origin of the Arctic Ocean. In Jura-Cretaceous time, an arc built upon older terranes overthrust the Arctic continental margins of North America and Eurasia, shedding debris into foreland basins in the Brooks Range, Alaska, across Chukotka, Russia, to the Lena Delta and New Siberian Islands region of the Russian Arctic. These syn-tectonic sediments have some common sources (e.g., ~250-300 Ma magmatic rocks) as determined by U-Pb detrital zircon geochronology. They are as young as Valanginian-Berriasian (~136 Ma, Gradstein et al., 2004) and place a lower limit on the age of formation of the AB. Subsequent intrusions of granitoid plutons, inferred to be ultimately slab-retreat related, form a belt along the far eastern Russian Arctic continental margin onto Seward Peninsula and have yielded a continuous succession of zircon U-Pb ages from ~137-95 Ma (n=28) and a younger suite ~91-82 Ma (n=16). All plutons dated were intruded in an extensional tectonic setting based on their relations to wall-rock deformation. Regional distribution of ages shows a southward migration of the locus of magmatism during Cretaceous time. Basaltic lavas as old as 130 Ma and as young as 80 Ma (40Ar/39Ar)) erupted across the Canadian Arctic Islands, Svalbard and Franz Josef Land and are associated with

  11. Sausage oscillations of coronal plasma slabs

    Science.gov (United States)

    Hornsey, C.; Nakariakov, V. M.; Fludra, A.

    2014-07-01

    Context. Sausage oscillations are observed in plasma non-uniformities of the solar corona as axisymmetric perturbations of the non-uniformity. Often, these non-uniformities can be modelled as field-aligned slabs of the density enhancement. Aims: We perform parametric studies of sausage oscillations of plasma slabs, aiming to determine the dependence of the oscillation period on its parameters, and the onset of leaky and trapped regimes of the oscillations. Methods: Slabs with smooth transverse profiles of the density of a zero-beta plasma are perturbed by an impulsive localised perturbation of the sausage symmetry. In particular, the slab can contain an infinitely thin current sheet in its centre. The initial value problem is then solved numerically. The numerical results are subject to spectral analysis. The results are compared with analytical solutions for a slab with a step-function profile and also with sausage oscillations of a plasma cylinder. Results: We established that sausage oscillations in slabs generally have the same properties as in plasma cylinders. In the trapped regime, the sausage oscillation period increases with the increase in the longitudinal wavelength. In the leaky regime, the dependence of the period on the wavelength experiences saturation, and the period becomes independent of the wavelength in the long-wavelength limit. In the leaky regime the period is always longer than in the trapped regime. The sausage oscillation period in a slab is always longer than in a cylinder with the same transverse profile. In slabs with steeper transverse profiles, sausage oscillations have longer periods. The leaky regime occurs at shorter wavelengths in slabs with smoother profiles.

  12. The Olympic of Textile Machinery closed

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The five days 2012 China International Textile Machinery Exhibition ITMA Asia Exhibition, which attracted much attention from the industry, was closed at the Shanghai New International Expo Center on June 16, more than 1300 textile enterprises from nearly 30 countries around the world gathered on the exhibition, the world’s latest textile machinery technologies, crafts and equipments were also presented one by one.

  13. 46 CFR 115.804 - Machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery. 115.804 Section 115.804 Shipping COAST GUARD....804 Machinery. At each initial and subsequent inspection for certification of a vessel, the owner or managing operator shall be prepared to conduct tests and have the vessel ready for inspections of...

  14. China Textile Machinery Expresses Self-Surpassing

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    It’s difficult to imagine that any sector of the textile industry has benefited more from innovations in the past 10 years than textile machinery. Advanced textile machinery has brought new life to the production segment of the business and fulfills the essential preconditions for economically efficient textile production.

  15. 46 CFR 58.01-40 - Machinery, angles of inclination.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery, angles of inclination. 58.01-40 Section 58.01... AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-40 Machinery, angles of inclination. (a) Propulsion machinery and all auxiliary machinery essential to the propulsion and safety of the vessel must...

  16. 46 CFR 58.01-45 - Machinery space, ventilation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery space, ventilation. 58.01-45 Section 58.01-45... MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-45 Machinery space, ventilation. Each machinery space must be ventilated to ensure that, when machinery or boilers are operating at full power in...

  17. Radiation pressure of active dispersive chiral slabs.

    Science.gov (United States)

    Wang, Maoyan; Li, Hailong; Gao, Dongliang; Gao, Lei; Xu, Jun; Qiu, Cheng-Wei

    2015-06-29

    We report a mechanism to obtain optical pulling or pushing forces exerted on the active dispersive chiral media. Electromagnetic wave equations for the pure chiral media using constitutive relations containing dispersive Drude models are numerically solved by means of Auxiliary Differential Equation Finite Difference Time Domain (ADE-FDTD) method. This method allows us to access the time averaged Lorentz force densities exerted on the magnetoelectric coupling chiral slabs via the derivation of bound electric and magnetic charge densities, as well as bound electric and magnetic current densities. Due to the continuously coupled cross-polarized electromagnetic waves, we find that the pressure gradient force is engendered on the active chiral slabs under a plane wave incidence. By changing the material parameters of the slabs, the total radiation pressure exerted on a single slab can be directed either along the propagation direction or in the opposite direction. This finding provides a promising avenue for detecting the chirality of materials by optical forces.

  18. Crust rheology, slab detachment and topography

    Science.gov (United States)

    Duretz, T.; Gerya, T. V.

    2012-04-01

    The collision between continents following the closure of an ocean can lead to the subduction of continental crust. The introduction of buoyant crust within subduction zones triggers the development of extensional stresses in slabs which eventually result in their detachment. The dynamic consequences of slab detachment affects the development of topography, the exhumation of high-pressure rocks and the geodynamic evolution of collision zones. We employ two-dimensional thermo-mechanical modelling in order to study the importance of crustal rheology on the evolution of spontaneous subduction-collision systems and the occurrence of slab detachment. The modelling results indicate that varying the rheological structure of the crust can results in a broad range of collisional evolutions involving slab detachment, delamination (associated to slab rollback), or the combination of both mechanisms. By enhancing mechanical coupling at the Moho, a strong crust leads to the deep subduction of the crust (180 km). These collisions are subjected to slab detachment and subsequent coherent exhumation of the crust accommodated by eduction (inversion of subduction sense) and thrusting. In these conditions, slab detachment promotes the development of a high (> 4.5 km) and narrow (delamination of the lithosphere, preventing slab detachment to occur. Further shortening leads to buckling and thickening of the crust resulting in the development of topographic bulging on the lower plate. Collisions involving rheologically layered crust are characterised by a decoupling level at mid-crustal depths. These initial condition favours the delamination of the upper crust as well as the deep subduction of the lower crust. These collisions are thus successively affected by delamination and slab detachment and both processes contribute to the exhumation of the subducted crust. A wide (> 200 km) topographic plateau develops as the results of the buoyant extrusion of the upper crust onto the foreland

  19. Moisture redistribution in screeded concrete slabs

    OpenAIRE

    Åhs, Magnus

    2007-01-01

    The principal objective for this licentiate thesis is to develop a methodology and evaluation model in order to make the future relative humidity in a screeded concrete slab predictable. Residual moisture in screeded concrete slabs may redistribute to the top screed surface under semi-permeable flooring, thus elevating the relative humidity, RH, and possibly exceed the critical humidity level. Passing the critical humidity level may result in material damages on the flooring and adhesive. ...

  20. Estimation of the Reliability of Plastic Slabs

    DEFF Research Database (Denmark)

    Pirzada, G. B. : Ph.D.

    and the concrete but in this thesis these material properties are modelled by stochastic variables. The probabilistic analysis performed in this thesis is mainly based on work by Thoft-Christensen & Baker (9) and Thoft-Christensen & Murotsu (10). Since considerable information about these basic materials used...... in reinforced concrete slabs and the loading is available it is highly probable that other aspects of slab failure, i.e. the punching shear failure and buckling failure, can be included in the probabilistic approach....

  1. Mantle wedge serpentinization effects on slab dips

    Directory of Open Access Journals (Sweden)

    Eh Tan

    2017-01-01

    Full Text Available The mechanical coupling between a subducting slab and the overlying mantle wedge is an important factor in controlling the subduction dip angle and the flow in mantel wedge. This paper investigates the role of the amount of mantle serpentinization on the subduction zone evolution. With numerical thermos-mechanical models with elasto-visco-plastic rheology, we vary the thickness and depth extent of mantle serpentinization in the mantle wedge to control the degree of coupling between the slab and mantle wedge. A thin serpentinized mantle layer is required for stable subduction. For models with stable subduction, we find that the slab dip is affected by the down-dip extent and the mantle serpentinization thickness. A critical down-dip extent exists in mantle serpentinization, determined by the thickness of the overriding lithosphere. If the down-dip extent does not exceed the critical depth, the slab is partially coupled to the overriding lithosphere and has a constant dip angle regardless of the mantle serpentinization thickness. However, if the down-dip extent exceeds the critical depth, the slab and the base of the overriding lithosphere would be separated and decoupled by a thick layer of serpentinized peridotite. This allows further slab bending and results in steeper slab dip. Increasing mantle serpentinization thickness will also result in larger slab dip. We also find that with weak mantle wedge, there is no material flowing from the asthenosphere into the serpentinized mantle wedge. All of these results indicate that serpentinization is an important ingredient when studying the subduction dynamics in the mantle wedge.

  2. Photocatalytic, highly hydrophilic porcelain stoneware slabs

    Science.gov (United States)

    Raimondo, M.; Guarini, G.; Zanelli, C.; Marani, F.; Fossa, L.; Dondi, M.

    2011-10-01

    Photocatalytic, highly hydrophilic industrial porcelain stoneware large slabs were realized by deposition of nanostructured TiO2 coatings. Different surface finishing and experimental conditions were considered in order to assess the industrial feasibility. Photocatalytic and wetting behaviour of functionalized slabs mainly depends on surface phase composition in terms of anatase/rutile ratio, this involving - as a key issue - the deposition of TiO2 on industrially sintered products with an additional annealing step to strengthen coatings' performances and durability.

  3. Architecture of the Yeast Mitochondrial Iron-Sulfur Cluster Assembly Machinery: THE SUB-COMPLEX FORMED BY THE IRON DONOR, Yfh1 PROTEIN, AND THE SCAFFOLD, Isu1 PROTEIN.

    Science.gov (United States)

    Ranatunga, Wasantha; Gakh, Oleksandr; Galeano, Belinda K; Smith, Douglas Y; Söderberg, Christopher A G; Al-Karadaghi, Salam; Thompson, James R; Isaya, Grazia

    2016-05-06

    The biosynthesis of Fe-S clusters is a vital process involving the delivery of elemental iron and sulfur to scaffold proteins via molecular interactions that are still poorly defined. We reconstituted a stable, functional complex consisting of the iron donor, Yfh1 (yeast frataxin homologue 1), and the Fe-S cluster scaffold, Isu1, with 1:1 stoichiometry, [Yfh1]24·[Isu1]24 Using negative staining transmission EM and single particle analysis, we obtained a three-dimensional reconstruction of this complex at a resolution of ∼17 Å. In addition, via chemical cross-linking, limited proteolysis, and mass spectrometry, we identified protein-protein interaction surfaces within the complex. The data together reveal that [Yfh1]24·[Isu1]24 is a roughly cubic macromolecule consisting of one symmetric Isu1 trimer binding on top of one symmetric Yfh1 trimer at each of its eight vertices. Furthermore, molecular modeling suggests that two subunits of the cysteine desulfurase, Nfs1, may bind symmetrically on top of two adjacent Isu1 trimers in a manner that creates two putative [2Fe-2S] cluster assembly centers. In each center, conserved amino acids known to be involved in sulfur and iron donation by Nfs1 and Yfh1, respectively, are in close proximity to the Fe-S cluster-coordinating residues of Isu1. We suggest that this architecture is suitable to ensure concerted and protected transfer of potentially toxic iron and sulfur atoms to Isu1 during Fe-S cluster assembly.

  4. Assembly of the bacterial type III secretion machinery.

    Science.gov (United States)

    Diepold, Andreas; Wagner, Samuel

    2014-07-01

    Many bacteria that live in contact with eukaryotic hosts, whether as symbionts or as pathogens, have evolved mechanisms that manipulate host cell behaviour to their benefit. One such mechanism, the type III secretion system, is employed by Gram-negative bacterial species to inject effector proteins into host cells. This function is reflected by the overall shape of the machinery, which resembles a molecular syringe. Despite the simplicity of the concept, the type III secretion system is one of the most complex known bacterial nanomachines, incorporating one to more than hundred copies of up to twenty different proteins into a multi-MDa transmembrane complex. The structural core of the system is the so-called needle complex that spans the bacterial cell envelope as a tripartite ring system and culminates in a needle protruding from the bacterial cell surface. Substrate targeting and translocation are accomplished by an export machinery consisting of various inner membrane embedded and cytoplasmic components. The formation of such a multimembrane-spanning machinery is an intricate task that requires precise orchestration. This review gives an overview of recent findings on the assembly of type III secretion machines, discusses quality control and recycling of the system and proposes an integrated assembly model.

  5. Viral interactions with components of the splicing machinery.

    Science.gov (United States)

    Meyer, F

    2016-01-01

    Eukaryotic genes are often interrupted by stretches of sequence with no protein coding potential or obvious function. After transcription, these interrupting sequences must be removed to give rise to the mature messenger RNA. This fundamental process is called RNA splicing and is achieved by complicated machinery made of protein and RNA that assembles around the RNA to be edited. Viruses also use RNA splicing to maximize their coding potential and economize on genetic space, and use clever strategies to manipulate the splicing machinery to their advantage. This article gives an overview of the splicing process and provides examples of viral strategies that make use of various components of the splicing system to promote their replicative cycle. Representative virus families have been selected to illustrate the interaction with various regulatory proteins and ribonucleoproteins. The unifying theme is fine regulation through protein-protein and protein-RNA interactions with the spliceosome components and associated factors to promote or prevent spliceosome assembly on given splice sites, in addition to a strong influence from cis-regulatory sequences on viral transcripts. Because there is an intimate coupling of splicing with the processes that direct mRNA biogenesis, a description of how these viruses couple the regulation of splicing with the retention or stability of mRNAs is also included. It seems that a unique balance of suppression and activation of splicing and nuclear export works optimally for each family of viruses.

  6. The retinoic acid machinery in invertebrates: ancestral elements and vertebrate innovations.

    Science.gov (United States)

    Albalat, Ricard

    2009-12-10

    Recent discoveries have changed our view of the evolutionary history of retinoic acid (RA) machinery. It is no longer considered a vertebrate or chordate invention but rather a common genetic toolkit of diverse lineages of metazoans. In particular, the basic machinery of RA-metabolizing enzymes, retinoid-binding proteins and RA-binding nuclear receptors has been identified in protostome and deuterostome lineages. Moreover, the retinoid content and the effects of RA treatment have been described in a number of invertebrates, although the physiological role of RA signaling outside vertebrates is still not fully understood. This review summarizes the evidence gathered over many years on the invertebrate RA system, highlighting the ancient origin of the RA genetic machinery and a basic role in neuronal differentiation. Comparison of invertebrate and vertebrate RA toolkits suggests some innovations in the RA machinery of vertebrates that might have contributed to improving the physiological control of retinoid homeostasis, compensating for vitamin A fluctuations in this lineage. Analysis of the RA machinery in invertebrates also reveals independent losses of RA components during evolution, which might be related to changes in embryonic developmental modes and the absence of the temporal collinearity of hox clusters. Additional studies analyzing the biochemical and functional characteristics of the invertebrate RA genetic machinery are warranted to lend experimental support to the hypotheses sketched in this review. These hypotheses open, however, new perspectives toward understanding how the RA genetic machinery evolved to suit the physiological and developmental requirements of metazoans.

  7. Textile Machinery:Imports Rebound Again

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In the year of 2006,the general situation of China’s textile machinery equipment imports had shown a clear sign of revival from the downward trend of two years ago,with a total annual import of 4.1 billion USD,an increase of 19.05% against the same period of 2005. Continuingly,the year of 2007 has witnessed a sustainable growth trend of textile machinery equipment imports in the first quarter and the trend definitely will be maintained through the whole year.According to statistics released from China Customs,the imports of textile machinery reached 1.098 billion USD in the first three months of 2007, up by 35.26% year-on-year. Then,why China’s textile machinery imports warm up again after two years’ cool down?

  8. A comprehensive overview of hybrid construction machinery

    Directory of Open Access Journals (Sweden)

    Jixin Wang

    2016-03-01

    Full Text Available With the increasing attention of energy saving and emission reduction technology, the recent application of hybrid powertrain technology affects the development of construction machinery industry. This article reviews these publications and provides comprehensive references. This article reviews the state-of-art for the hybrid wheel loader and excavator, which focuses on powertrain configuration, energy storage devices, and energy management strategies. The basis of classification and characteristic of each powertrain configuration are described. Advantages and disadvantages of batteries, supercapacitors, hydraulic accumulators, and flywheel used in hybrid construction machinery are summarized. The existing energy management strategies for hybrid construction machinery are also elaborated. The technological challenges and developing trends in the near future for hybrid construction machinery are discussed.

  9. Energy Savings Thanks to French Textile Machinery

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The French Textile Machinery Manufacturers’ Association (UCMTF) has presented,during a seminar it organized for textile professionals and students,the spectacular energy savings achieved thanks to state of the art

  10. Effects of change in slab geometry on the mantle flow and slab fabric in Southern Peru

    Science.gov (United States)

    Knezevic Antonijevic, Sanja; Wagner, Lara S.; Beck, Susan L.; Long, Maureen D.; Zandt, George; Tavera, Hernando

    2016-10-01

    The effects of complex slab geometries on the surrounding mantle flow field are still poorly understood. Here we combine shear wave velocity structure with Rayleigh wave phase anisotropy to examine these effects in southern Peru, where the slab changes its geometry from steep to flat. To the south, where the slab subducts steeply, we find trench-parallel anisotropy beneath the active volcanic arc that we attribute to the mantle wedge and/or upper portions of the subducting plate. Farther north, beneath the easternmost corner of the flat slab, we observe a pronounced low-velocity anomaly. This anomaly is caused either by the presence of volatiles and/or flux melting that could result from southward directed, volatile-rich subslab mantle flow or by increased temperature and/or decompression melting due to small-scale vertical flow. We also find evidence for mantle flow through the tear north of the subducting Nazca Ridge. Finally, we observe anisotropy patterns associated with the fast velocity anomalies that reveal along strike variations in the slab's internal deformation. The change in slab geometry from steep to flat contorts the subducting plate south of the Nazca Ridge causing an alteration of the slab petrofabric. In contrast, the torn slab to the north still preserves the primary (fossilized) petrofabric first established shortly after plate formation.

  11. Textile Machinery Import and Export in 2011

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Along with the rebounded international market, in the year of 2011, the foreign trade of textile machinery industry preserved a stable development: the import amount saw a slightly decrease, while the total import and export value kept an increasing trend. According to the Customs, the export and import of textile machinery totalized 2.245 billion USD and 5.364 billion USD, increasing by 27.81% and 24.70%, respectively, comparing with the same period of time in 2010.

  12. Glycosylphosphatidylinositol Anchor Modification Machinery Deficiency Is Responsible for the Formation of Pro-Prion Protein (PrP) in BxPC-3 Protein and Increases Cancer Cell Motility.

    Science.gov (United States)

    Yang, Liheng; Gao, Zhenxing; Hu, Lipeng; Wu, Guiru; Yang, Xiaowen; Zhang, Lihua; Zhu, Ying; Wong, Boon-Seng; Xin, Wei; Sy, Man-Sun; Li, Chaoyang

    2016-02-19

    The normal cellular prion protein (PrP) is a glycosylphosphatidylinositol (GPI)-anchored cell surface glycoprotein. However, in pancreatic ductal adenocarcinoma cell lines, such as BxPC-3, PrP exists as a pro-PrP retaining its glycosylphosphatidylinositol (GPI) peptide signaling sequence. Here, we report the identification of another pancreatic ductal adenocarcinoma cell line, AsPC-1, which expresses a mature GPI-anchored PrP. Comparison of the 24 genes involved in the GPI anchor modification pathway between AsPC-1 and BxPC-3 revealed 15 of the 24 genes, including PGAP1 and PIG-F, were down-regulated in the latter cells. We also identified six missense mutations in DPM2, PIG-C, PIG-N, and PIG-P alongside eight silent mutations. When BxPC-3 cells were fused with Chinese hamster ovary (CHO) cells, which lack endogenous PrP, pro-PrP was successfully converted into mature GPI-anchored PrP. Expression of the individual gene, such as PGAP1, PIG-F, or PIG-C, into BxPC-3 cells does not result in phosphoinositide-specific phospholipase C sensitivity of PrP. However, when PIG-F but not PIG-P is expressed in PGAP1-expressing BxPC-3 cells, PrP on the surface of the cells becomes phosphoinositide-specific phospholipase C-sensitive. Thus, low expression of PIG-F and PGAP1 is the major factor contributing to the accumulation of pro-PrP. More importantly, BxPC-3 cells expressing GPI-anchored PrP migrate much slower than BxPC-3 cells bearing pro-PrP. In addition, GPI-anchored PrP-bearing AsPC-1 cells also migrate slower than pro-PrP bearing BxPC-3 cells, although both cells express filamin A. "Knocking out" PRNP in BxPC-3 cell drastically reduces its migration. Collectively, these results show that multiple gene irregularity in BxPC-3 cells is responsible for the formation of pro-PrP, and binding of pro-PrP to filamin A contributes to enhanced tumor cell motility.

  13. Magnetohydrodynamic Waves in an Asymmetric Magnetic Slab

    Science.gov (United States)

    Allcock, Matthew; Erdélyi, Robert

    2017-02-01

    Analytical models of solar atmospheric magnetic structures have been crucial for our understanding of magnetohydrodynamic (MHD) wave behaviour and in the development of the field of solar magneto-seismology. Here, an analytical approach is used to derive the dispersion relation for MHD waves in a magnetic slab of homogeneous plasma enclosed on its two sides by non-magnetic, semi-infinite plasma with different densities and temperatures. This generalises the classic magnetic slab model, which is symmetric about the slab. The dispersion relation, unlike that governing a symmetric slab, cannot be decoupled into the well-known sausage and kink modes, i.e. the modes have mixed properties. The eigenmodes of an asymmetric magnetic slab are better labelled as quasi-sausage and quasi-kink modes. Given that the solar atmosphere is highly inhomogeneous, this has implications for MHD mode identification in a range of solar structures. A parametric analysis of how the mode properties (in particular the phase speed, eigenfrequencies, and amplitudes) vary in terms of the introduced asymmetry is conducted. In particular, avoided crossings occur between quasi-sausage and quasi-kink surface modes, allowing modes to adopt different properties for different parameters in the external region.

  14. Accidents due to falls from roof slabs

    Directory of Open Access Journals (Sweden)

    Bruno Alves Rudelli

    Full Text Available CONTEXT AND OBJECTIVE Falls from the roof slabs of houses are accidents of high potential severity that occur in large Brazilian cities and often affect children and adolescents. The aims of this study were to characterize the factors that predispose towards this type of fall involving children and adolescents, quantify the severity of associated lesions and suggest preventive measures. DESIGN AND SETTING Descriptive observational prospective longitudinal study in two hospitals in the metropolitan region of São Paulo. METHODS Data were collected from 29 cases of falls from roof slabs involving children and adolescents between October 2008 and October 2009. RESULTS Cases involving males were more prevalent, accounting for 84%. The predominant age group was schoolchildren (7 to 12 years old; 44%. Leisure activities were most frequently being practiced on the roof slab at the time of the fall (86%, and flying a kite was the most prevalent game (37.9%. In 72% of the cases, the children were unaccompanied by an adult responsible for them. Severe conditions such as multiple trauma and traumatic brain injuries resulted from 79% of the accidents. CONCLUSION Falls from roof slabs are accidents of high potential severity, and preventive measures aimed towards informing parents and guardians about the dangers and risk factors associated with this type of accident are needed, along with physical protective measures, such as low walls around the slab and gates with locks to restrict free access to these places.

  15. Accidents due to falls from roof slabs.

    Science.gov (United States)

    Rudelli, Bruno Alves; Silva, Marcelo Valerio Alabarce da; Akkari, Miguel; Santili, Claudio

    2013-01-01

    CONTEXT AND OBJECTIVE Falls from the roof slabs of houses are accidents of high potential severity that occur in large Brazilian cities and often affect children and adolescents. The aims of this study were to characterize the factors that predispose towards this type of fall involving children and adolescents, quantify the severity of associated lesions and suggest preventive measures. DESIGN AND SETTING Descriptive observational prospective longitudinal study in two hospitals in the metropolitan region of São Paulo. METHODS Data were collected from 29 cases of falls from roof slabs involving children and adolescents between October 2008 and October 2009. RESULTS Cases involving males were more prevalent, accounting for 84%. The predominant age group was schoolchildren (7 to 12 years old; 44%). Leisure activities were most frequently being practiced on the roof slab at the time of the fall (86%), and flying a kite was the most prevalent game (37.9%). In 72% of the cases, the children were unaccompanied by an adult responsible for them. Severe conditions such as multiple trauma and traumatic brain injuries resulted from 79% of the accidents. CONCLUSION Falls from roof slabs are accidents of high potential severity, and preventive measures aimed towards informing parents and guardians about the dangers and risk factors associated with this type of accident are needed, along with physical protective measures, such as low walls around the slab and gates with locks to restrict free access to these places.

  16. Mediator is an intrinsic component of the basal RNA polymerase II machinery in vivo.

    Science.gov (United States)

    Lacombe, Thierry; Poh, Siew Lay; Barbey, Régine; Kuras, Laurent

    2013-11-01

    Mediator is a prominent multisubunit coactivator that functions as a bridge between gene-specific activators and the basal RNA polymerase (Pol) II initiation machinery. Here, we study the poorly documented role of Mediator in basal, or activator-independent, transcription in vivo. We show that Mediator is still present at the promoter when the Pol II machinery is recruited in the absence of an activator, in this case through a direct fusion between a basal transcription factor and a heterologous DNA binding protein bound to the promoter. Moreover, transcription resulting from activator-independent recruitment of the Pol II machinery is impaired by inactivation of the essential Mediator subunit Med17 due to the loss of Pol II from the promoter. Our results strongly support that Mediator is an integral component of the minimal machinery essential in vivo for stable Pol II association with the promoter.

  17. siRNA machinery in whitefly (Bemisia tabaci).

    Science.gov (United States)

    Upadhyay, Santosh Kumar; Dixit, Sameer; Sharma, Shailesh; Singh, Harpal; Kumar, Jitesh; Verma, Praveen C; Chandrashekar, K

    2013-01-01

    RNA interference has been emerged as an utmost tool for the control of sap sucking insect pests. Systemic response is necessary to control them in field condition. Whitefly is observed to be more prone to siRNA in recent studies, however the siRNA machinery and mechanism is not well established. To identify the core siRNA machinery, we curated transcriptome data of whitefly from NCBI database. Partial mRNA sequences encoding Dicer2, R2D2, Argonaute2 and Sid1 were identified by tblastn search of homologous sequences from Aphis glycines and Tribolium castaneum. Complete encoding sequences were obtained by RACE, protein sequences derived by Expasy translate tool and confirmed by blastp analysis. Conserved domain search and Prosite-Scan showed similar domain architecture as reported in homologs from related insects. We found helicase, PAZ, RNaseIIIa, RNaseIIIb and double-stranded RNA-binding fold (DSRBF) in Dicer2; DsRBD in R2D2; and PAZ and PIWI domains in Argonaute2. Eleven transmembrane domains were detected in Sid1. Sequence homology and phylogenetic analysis revealed that RNAi machinery of whitefly is close to Aphids. Real-time PCR analysis showed similar expression of these genes in different developmental stages as reported in A. glycines and T. castaneum. Further, the expression level of above genes was quite similar to the housekeeping gene actin. Availability of core siRNA machinery including the Sid1 and their universal expression in reasonable quantity indicated significant response of whitefly towards siRNA. Present report opens the way for controlling whitefly, one of the most destructive crop insect pest.

  18. 46 CFR 58.20-15 - Installation of refrigerating machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Installation of refrigerating machinery. 58.20-15... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of refrigerating machinery. (a) Where refrigerating machines are installed in which anhydrous ammonia is used as...

  19. 46 CFR 169.625 - Compartments containing diesel machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Compartments containing diesel machinery. 169.625... SCHOOL VESSELS Machinery and Electrical Ventilation § 169.625 Compartments containing diesel machinery. (a) Spaces containing machinery must be fitted with adequate dripproof ventilators, trunks,...

  20. 46 CFR 174.195 - Bulkheads in machinery spaces.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Bulkheads in machinery spaces. 174.195 Section 174.195... in machinery spaces. (a) The bulkhead in each machinery space of each OSV must be watertight to the bulkhead deck. (b) Each penetration of, and each opening in, a bulkhead in a machinery space must— (1)...

  1. 46 CFR 58.01-35 - Main propulsion auxiliary machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main propulsion auxiliary machinery. 58.01-35 Section 58... AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-35 Main propulsion auxiliary machinery. Auxiliary machinery vital to the main propulsion system must be provided in duplicate unless the...

  2. 46 CFR 58.01-25 - Means of stopping machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Means of stopping machinery. 58.01-25 Section 58.01-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-25 Means of stopping machinery. Machinery...

  3. 46 CFR 42.15-35 - Machinery space openings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery space openings. 42.15-35 Section 42.15-35... BY SEA Conditions of Assignment of Freeboard § 42.15-35 Machinery space openings. (a) Machinery space..., funnel, or machinery space ventilators in an exposed position on the freeboard or superstructure...

  4. 46 CFR 45.149 - Machinery space openings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery space openings. 45.149 Section 45.149 Shipping... Assignment § 45.149 Machinery space openings. (a) Machinery space openings in position 1 or 2 must be framed... funnel or machinery space ventilator that must be kept open for the essential operations of the ship...

  5. Slab tears and intermediate-depth seismicity

    Science.gov (United States)

    Meighan, Hallie E.; Ten Brink, Uri; Pulliam, Jay

    2013-01-01

    Active tectonic regions where plate boundaries transition from subduction to strike slip can take several forms, such as triple junctions, acute, and obtuse corners. Well-documented slab tears that are associated with high rates of intermediate-depth seismicity are considered here: Gibraltar arc, the southern and northern ends of the Lesser Antilles arc, and the northern end of Tonga trench. Seismicity at each of these locations occurs, at times, in the form of swarms or clusters, and various authors have proposed that each marks an active locus of tear propagation. The swarms and clusters start at the top of the slab below the asthenospheric wedge and extend 30–60 km vertically downward within the slab. We propose that these swarms and clusters are generated by fluid-related embrittlement of mantle rocks. Focal mechanisms of these swarms generally fit the shear motion that is thought to be associated with the tearing process.

  6. Novel Radon Sub-Slab Suctioning System

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    the zone below the ground-floor construction. For this purpose a new system of prefabricated lightweight elements is introduced. The effectiveness of the system is demonstrated for the case of a ground-floor reinforced concrete slab situated on top of a rigid insulation layer (consisting of a thermal......A new principle for radon protection is currently presented which makes use of a system of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground-floor slab. The function of this system is based on the principles of pressure reduction within...... a grid of horizontal air ducts with low pressure which are able to remove air and radon from the ground. Results showed the system to be effective in preventing radon infiltrating from the ground through the ground-floor slab, avoiding high concentrations of radon being accumulated inside houses...

  7. Photon transport in thin disordered slabs

    Indian Academy of Sciences (India)

    Venkatesh Gopal; S Anantha Ramakrishna; A K Sood; N Kumar

    2001-06-01

    We examine using Monte Carlo simulations, photon transport in optically `thin’ slabs whose thickness is only a few times the transport mean free path *, with particles of different scattering anisotropies. The confined geometry causes an auto-selection of only photons with looping paths to remain within the slab. The results of the Monte Carlo simulations are borne out by our analytical treatment that incorporates directional persistence by the use of the Ornstein–Uhlenbeck process, which interpolates between the short time ballistic and long time diffusive regimes.

  8. ADJUSTMENT, MAINTENANCE, AND REPAIR OF CROP HARVESTING MACHINERY. AGRICULTURAL MACHINERY--SERVICE OCCUPATIONS, MODULE NUMBER 11.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    ONE OF A SERIES DESIGNED FOR HELPING TEACHERS PREPARE POSTSECONDARY-LEVEL STUDENTS FOR AGRICULTURAL MACHINERY SERVICE OCCUPATIONS AS PARTS MEN, MECHANICS, MECHANIC'S HELPERS, AND SERVICE SUPERVISORS, THIS GUIDE AIMS TO DEVELOP STUDENT COMPETENCY IN ADJUSTING, REPAIRING, AND MAINTAINING CROP HARVESTING MACHINERY. SUGGESTIONS FOR INTRODUCTION OF THE…

  9. The eukaryotic gene transcription machinery.

    Science.gov (United States)

    Kornberg, R D

    2001-08-01

    Seven purified proteins may be combined to reconstitute regulated, promoter-dependent RNA polymerase II transcription: five general transcription factors, Mediator, and RNA polymerase II. The entire system has been conserved across species from yeast to humans. The structure of RNA polymerase II, consisting of 10 polypeptides with a mass of about 500 kDa, has been determined at atomic resolution. On the basis of this structure, that of an actively transcribing RNA polymerase II complex has been determined as well.

  10. Mantle circulation and the lateral migration of subducted slabs

    Science.gov (United States)

    Garfunkel, Z.; Anderson, C. A.; Schubert, G.

    1986-01-01

    The geometry of transverse migration of subducted lithospheric slabs is examined, and the way in which this influences the flow in the mantle is studied. The migration of subducted slabs generally appears to be retrograde (at rates of 10-25 mm/yr), so that the descent of material is actually steeper than the slab dip. Retrograde slab migration is probably caused by the tendence of negatively buoyant slabs to sink in the surrounding mantle. The properties of the flow driven by such retrograde slab migration are explored in simple two-dimensional models. The results are used as a guide to infer the contribution of retrograde slab motion to the more complex mantle flow and to examine some consequences of the additional component of mantle flow. It is shown that slab migration is an important factor that causes mantle flow to be geometrically complex and time dependent.

  11. Lifetime Reliability Assessment of Concrete Slab Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    A procedure for lifetime assesment of the reliability of short concrete slab bridges is presented in the paper. Corrosion of the reinforcement is the deterioration mechanism used for estimating the reliability profiles for such bridges. The importance of using sensitivity measures is stressed. Fi...

  12. Retrofitting of RC Slabs Against Explosive Loads

    Institute of Scientific and Technical Information of China (English)

    WU Chengqing; OEHLERS Deric John; XIA Shaohua

    2006-01-01

    With the increase of terrorist bomb attacks on buildings,there is a need to develop advanced retrofitting techniques to strengthen structures against blast loads.Currently,several guidelines including an Australian version for retrofitting reinforced concrete (RC) structures are available for the design of retrofitting systems against seismic and monotonic loads using steel or fibre reinforced polymer (FRP) plates that can be either adhesively bonded to the surface or near surface mounted to the concrete cover.However,none of these guidelines provide advice suitable for retrofitting structures subjected to blast loads.In this paper,numerical models are used to simulate the performance of retrofitted RC slabs subjected to blast loads.Airblast pressure distributions on the surface of the slabs estimated in a previous study are used as input in the analysis.A material damage model developedpreviously for concrete and an elastoplastic model for steel bars are employed in this research for modelling reinforced concrete behaviour due to explosive loads.The material models and blast loading are coded into a finite element computer program LS-DYNA3D to do the analysis.With the numerical model,parametric studies are conducted to investigate RC slabs retrofitted by either externally bonded or near-surface mounted plates or GFRP sheets subjected to blast loads.Discussion is made on the effectiveness of the retrofitting system for RC slabs against blast loads.

  13. Numerical Evaluations of Functionally Graded RC Slabs

    Directory of Open Access Journals (Sweden)

    M. Mastali

    2014-01-01

    Full Text Available Nowadays, using fibrous materials is used widely in strengthening applications such as cross-section enlargement and using functionally graded reinforced concrete. Functionally graded reinforced concrete is used as multireinforced concrete layers that can be reinforced by different fiber types. The objective of this research was to address the structural benefits of functionally graded concrete materials by performing analytical simulations. In order to achieve this purpose, in the first stage of this study, three functionally graded reinforced concretes by steel and polypropylene (PP were experimentally tested under flexural loading. Inverse analysis was applied to obtain the used material properties of reinforced concrete by FEMIX software. After obtaining the material properties, to assess the performance of proposed slabs, some other cases were proposed and numerically evaluated under flexural and shear loading. The results showed that increasing steel fiber in reinforced entire cross section led to achieve better shear and flexural performance while the best performance of reinforced functionally graded slabs was achieved for slab at 1% fiber content. In the second stage, nineteen reinforced functionally graded RC slabs with steel bars were simulated and assessed and some other cases were considered which were not experimentally tested.

  14. Longitudinal shear resistance of composite slabs

    NARCIS (Netherlands)

    Schuurman, R.G.; Stark, J.W.B.

    1996-01-01

    Verification methods for longitudinal shear. currently in use, are empirical. This applies for both the m-k method as the Partial Shear Connection method. Parameters and mechanisms determining the behaviour of the shear connection in composite slabs are not directly considered in these methods. A

  15. Plastic design of continuous composite slabs

    NARCIS (Netherlands)

    Stark, J.W.B.; Brekelmans, J.W.P.M.

    1996-01-01

    Most current regulations for continuous composite slabs contain rules that limit the application of plastic analysis in the design process. In this paper, results of numerical studies for positive and negative bending and experimental results for negative bending are presented. From these

  16. Benchmark Experiment for Beryllium Slab Samples

    Institute of Scientific and Technical Information of China (English)

    NIE; Yang-bo; BAO; Jie; HAN; Rui; RUAN; Xi-chao; REN; Jie; HUANG; Han-xiong; ZHOU; Zu-ying

    2015-01-01

    In order to validate the evaluated nuclear data on beryllium,a benchmark experiment has been performed at China Institution of Atomic Energy(CIAE).Neutron leakage spectra from pure beryllium slab samples(10cm×10cm×11cm)were measured at 61°and 121°using timeof-

  17. All-polymer photonic crystal slab sensor

    DEFF Research Database (Denmark)

    Hermannsson, Pétur Gordon; Sørensen, Kristian Tølbøl; Vannahme, Christoph;

    2015-01-01

    An all-polymer photonic crystal slab sensor is presented, and shown to exhibit narrow resonant reflection with a FWHM of less than 1 nm and a sensitivity of 31 nm/RIU when sensing media with refractive indices around that of water. This results in a detection limit of 4.5x10-6 RIU when measured...

  18. Effects of Edge Restraint on Slab Behavior

    Science.gov (United States)

    1986-02-01

    manufactured limestone sand fine aggregate. Two batches were prepared, one for each of the different thickness slab groups. A total of thirty-eight 4...Building Code Require- ments" 1983; Detroit, Mich. 4. T. Takehira, A. T. Derecho , and M. Iqbal; "Design Criteria for De- flection Capacity of

  19. Cost analysis of reinforced concrete slabs and columns

    OpenAIRE

    Spuś, Piotr

    2013-01-01

    The construction industry is increasingly looking for solutions that are both simple and effective and that provide cost savings, speed and flexibility of execution. Two-way slabs are a form of construction unique to reinforced concrete comparing with the other major structural materials. It is an efficient, economical, and widely used structural system. The present dissertation aims to analyze and compare costs between four types of slabs: waffle slab with recuperate molds, flat slabs wit...

  20. Abrupt tectonics and rapid slab detachment with grain damage

    OpenAIRE

    2015-01-01

    Subduction zones are delineated by Earth’s ocean trenches, and are where tectonic plates sink into the mantle as cold heavy slabs, which in turn drive plate motion. But slabs can detach from their surface plates, thus altering tectonic driving forces. Slab detachment can occur if thick crust from continents or oceanic plateaux is swept by plate motion into the subduction zone, thus plugging it up. Detachment is also accelerated because mineral grains in the slab become smaller during deformat...

  1. Reinforcement of the concrete base slab of the ATLAS cavern

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Photo 02: UX15 cavern, preparation for concreting of base slab first lift. Photo 05: UX15 cavern, placing of reinforcement for base slab first lift. Photo 07: UX15 cavern, preparation for concreting of base slab first lift. Photo 09: UX15 cavern, placing of reinforcement for base slab first lift. Photo 10: UX15 cavern, view into PX14 shaft above. Photo 12: UX15 cavern, temporary access platform of RB16 tunnel. Photo 15: UJ17 chamber, invert excavation.

  2. Machinery condition monitoring principles and practices

    CERN Document Server

    Mohanty, Amiya Ranjan

    2015-01-01

    Find the Fault in the MachinesDrawing on the author's more than two decades of experience with machinery condition monitoring and consulting for industries in India and abroad, Machinery Condition Monitoring: Principles and Practices introduces the practicing engineer to the techniques used to effectively detect and diagnose faults in machines. Providing the working principle behind the instruments, the important elements of machines as well as the technique to understand their conditions, this text presents every available method of machine fault detection occurring in machines in general, an

  3. The Thermodynamic Machinery of Life

    CERN Document Server

    Kurzynski, Michal

    2006-01-01

    Living organisms are open thermodynamic systems whose functional structure has developed and been kinetically frozen during the historical process of biological evolution. A thermodynamics of both nonequilibrium and complex systems is needed for their description. In this book, the foundations of such a thermodynamics are presented. Biological processes at the cellular level are considered as coupled chemical reactions and transport processes across internal and the cytoplasmic membrane. All these processes are catalyzed by specific enzymes hence the kinetics of enzymatic catalysis and its control are described here in detail. The coupling of several processes through a common enzyme is considered in the context of free energy or signal transduction. Special attention is paid to evidence for a rich stochastic internal dynamics of native proteins and its possible role in the control of enzyme activity and in the action of biological molecular machines.

  4. Mantle Response to a Slab Gap and Three-dimensional Slab Interaction in Central America

    Science.gov (United States)

    Jadamec, M. A.; Fischer, K. M.

    2013-12-01

    Seismically constrained global slab geometries suggest the Middle America-South American subduction system contains a gap on the order of 500 km separating the east-dipping Cocos and Nazca slabs at depth (Gudmundsson and Sambridge, 1998; Syracuse and Abers, 2006; Hayes et al., 2012). The location of the gap correlates with tectonic features impinging on the Pacific side of the Middle America trench, in particular the incoming young buoyant oceanic lithosphere and oceanic ridges associated with the Galapagos hotspot and Cocos-Nazca spreading center (Protti et al., 1994; Mann et al., 2007; Muller et al., 2008). Moreover, geochemical studies focusing on the arc chemistry in the Central American volcanic front argue for a slab window of some kind in this region (Johnston and Thorkelson, 1997; Abratis and Worner, 2001; Hoernle et al., 2008). We use high-resolution, three-dimensional (3D) geodynamic modeling of the Middle America-South American subduction system to investigate the role of the incoming young oceanic lithosphere and a gap between the Cocos and Nazca slabs in controlling mantle flow velocity and geochemical signatures beneath Central America. The geodynamic models are geographically referenced with the geometry and thermal structure for the overriding and subducting plates based on geological and geophysical observables and constructed with the multi-plate subduction generator code, SlabGenerator (Jadamec and Billen, 2010; Jadamec et al., 2012; Jadamec and Billen, 2012). The viscous flow simulations are solved using the mantle convection finite-element code, CitcomCU (Zhong, 2006), modified by Jadamec and Billen (2010) to take into account the experimentally derived flow law for olivine and allow for variable 3D plate interface geometries and magnitudes of inter-plate coupling. The 3D numerical models indicate the gap between the Cocos and Nazca slabs serves as a conduit for Pacific-Cocos mantle to pass into the Caribbean, with toroidal flow around the

  5. Italian Textile Machinery Industry Focuses on Sustainability

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    As for fashion industry,Italian brands always play as one of the leaders influencing the global trends.This time,in Shanghai,the Italian textile machinery manufacturers highlight the latest proposals on sustainability and eco-friendly technology.

  6. Italian Textite Machinery Industry Focuses on Sustainability

    Institute of Scientific and Technical Information of China (English)

    Wang Ting

    2010-01-01

    @@ At the ITMA Asia+CITME 2010,which was held on June 22at the Shanghai New International Expo Centre in Shanghai,Italian textile machinery manufacturers represented one of the largest foreign delegations: 115exhibitors occupying a total surface area of about 4,000 sq.meters.

  7. Active Vibration Dampers For Rotating Machinery

    Science.gov (United States)

    Kascack, Albert F.; Ropchock, John J.; Lakatos, Tomas F.; Montague, Gerald T.; Palazzolo, Alan; Lin, Reng Rong

    1994-01-01

    Active dampers developed to suppress vibrations in rotating machinery. Essentially feedback control systems and reciprocating piezoelectric actuators. Similar active damper containing different actuators described in LEW-14488. Concept also applicable to suppression of vibrations in stationary structures subject to winds and earthquakes. Active damper offers adjustable suppression of vibrations. Small and lightweight and responds faster to transients.

  8. CCPIT Machinery Exhibition Succeeded in Kuala Lumpur

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

      From August 18 to 20, 2005, China Council for the Promotion of International Trade(CCPIT) held China Machinery and Electronics Trade Exhibition, CME 2005 in Kuala Lumpur, the capital of Malaysia on behalf of China, a good job has been done.……

  9. CCPIT Machinery Exhibition Succeeded in Kuala Lumpur

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ From August 18 to 20, 2005, China Council for the Promotion of International Trade(CCPIT) held China Machinery and Electronics Trade Exhibition, CME 2005 in Kuala Lumpur, the capital of Malaysia on behalf of China, a good job has been done.

  10. Brownian machinery in physics and biology

    OpenAIRE

    Hänggi, Peter

    2001-01-01

    Brownian machinery in physics and biology. - In: Noise in physical systems and 1/f fluctuations : proceedings of the 16th internat. conference, Gainesville, Fl., 22-25 Oct. 2001 / Ed.: Gijs Bosman. - New Jersey u.a. : World Scientific, 2001. - S. 397-399

  11. Computational design of hydrogen fluid machinery

    Energy Technology Data Exchange (ETDEWEB)

    Kaupert, K.A. [Ebara Cryodynamics Div., Sparks, NV (United States)

    2001-06-01

    This paper presented computational design methods for liquid hydrogen fluid machinery for which the aerospace industry holds a particular interest. The main design points are reliability, efficiency and predictability. The methods described here were based on experience gained in the liquefied natural gas sector. The main design validation tools presented in this paper were computational fluid dynamics, computational rotordynamics, and computational stress analysis. Recent advances have made it possible to incorporate the influence of unsteady phenomena. These new design techniques make it possible to increase the reliability, efficiency and predictability of fluid machinery. A design example for an Ebara Cryodynamics multi-stage impeller/diffuser-return vane combination operating in liquefied natural gas was presented. The fluid machinery characteristics were compared for liquid hydrogen and liquefied natural gas to demonstrate the technical feasibility of industrial liquid hydrogen fluid machinery. Currently, no significant demand exists for liquid hydrogen turbomachinery except for the rocket engine industry. But the emergence of the hydrogen economy will promote the growth in liquefied natural gas and or liquid hydrogen cryogenic turbomachinery. 11 refs., 3 tabs., 6 figs.

  12. Regulation of host translational machinery by African swine fever virus.

    Directory of Open Access Journals (Sweden)

    Alfredo Castelló

    2009-08-01

    Full Text Available African swine fever virus (ASFV, like other complex DNA viruses, deploys a variety of strategies to evade the host's defence systems, such as inflammatory and immune responses and cell death. Here, we analyse the modifications in the translational machinery induced by ASFV. During ASFV infection, eIF4G and eIF4E are phosphorylated (Ser1108 and Ser209, respectively, whereas 4E-BP1 is hyperphosphorylated at early times post infection and hypophosphorylated after 18 h. Indeed, a potent increase in eIF4F assembly is observed in ASFV-infected cells, which is prevented by rapamycin treatment. Phosphorylation of eIF4E, eIF4GI and 4E-BP1 is important to enhance viral protein production, but is not essential for ASFV infection as observed in rapamycin- or CGP57380-treated cells. Nevertheless, eIF4F components are indispensable for ASFV protein synthesis and virus spread, since eIF4E or eIF4G depletion in COS-7 or Vero cells strongly prevents accumulation of viral proteins and decreases virus titre. In addition, eIF4F is not only activated but also redistributed within the viral factories at early times of infection, while eIF4G and eIF4E are surrounding these areas at late times. In fact, other components of translational machinery such as eIF2alpha, eIF3b, eIF4E, eEF2 and ribosomal P protein are enriched in areas surrounding ASFV factories. Notably, the mitochondrial network is polarized in ASFV-infected cells co-localizing with ribosomes. Thus, translation and ATP synthesis seem to be coupled and compartmentalized at the periphery of viral factories. At later times after ASFV infection, polyadenylated mRNAs disappear from the cytoplasm of Vero cells, except within the viral factories. The distribution of these pools of mRNAs is similar to the localization of viral late mRNAs. Therefore, degradation of cellular polyadenylated mRNAs and recruitment of the translation machinery to viral factories may contribute to the inhibition of host protein synthesis

  13. HEAT TRANSFER ANALYSIS DURING ROLLING OF THIN SLAB IN CSP

    Institute of Scientific and Technical Information of China (English)

    W.F. Wu; Y.H. Feng; X.X. Zhang

    2006-01-01

    A mathematical model has been built to numerically predict the thermal history of thin slab during CSP (compact strip process) rolling. To estimate the temperature distribution in the slab more accurately, the mathematical model combines heat transfer in the slab, in the roll, and at the roll-slab interface during bite. The numerical results agree with on-site running data, which proves the reliability of the mathematical model. The results show that roll chilling has a significant effect on the temperature distribution in the slab.

  14. Rapid detection of biothreat agents based on cellular machinery.

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Todd W.; Gantt, Richard W.

    2004-12-01

    This research addresses rapid and sensitive identification of biological agents in a complex background. We attempted to devise a method by which the specificity of the cellular transcriptional machinery could be used to detect and identify bacterial bio-terror agents in a background of other organisms. Bacterial cells contain RNA polymerases and transcription factors that transcribe genes into mRNA for translation into proteins. RNA polymerases in conjunction with transcription factors recognize regulatory elements (promoters) upstream of the gene. These promoters are, in many cases, recognized by the polymerase and transcription factor combinations of one species only. We have engineered a plasmid, for Escherichia coli, containing the virA promoter from the target species Shigella flexneri. This promoter was fused to a reporter gene Green Fluorescent Protein (GFP). In theory the indicator strain (carrying the plasmid) is mixed with the target strain and the two are lysed. The cellular machinery from both cells mixes and the GFP is produced. This report details the results of testing this system.

  15. Thin-slab casting – New possibilities

    Indian Academy of Sciences (India)

    Amit Chatterjee; Sanjay Chandra

    2001-02-01

    Changes in the IT industry are known to proceed at a scorching pace. In sharp contrast, the rate of development in the steel industry is generally slow. Nonetheless, The impact of recent technical developments on the steel industry has been quite significant. The production chain from iron ore to final rolled steel is a long one and the shortening of this length has long been the endeavour of scientists and engineers. The initial development came in the form of speeding up the process of steelmaking by reducing the slow open-hearth process (8 h tap-to-tap time) with the 45 min tap-tp-tap time of the Basic Oxygen Furnace (BOF) process. Significant developments thereafter have been in the process of continuous production of billets and blooms from liquid steel thereby doing away with the large blooming mills needed for rolling ingots. For a fairly long time after the stabilisation of continuous casting. hot rolling involved reheating thick (200-250 mm) slabs and reducing them in a hot-strip mill. The advent of thin-slab casters has made even these large hot-strip mills redundant. The new installtion produce thin slabs (50-70 mm) that are directly rolled into strips without the need of an intermediate furnace for raising the stock temperature; the so-called tunnel furance prior to the rolling stands serving only to equalise stock temperatures. Additionally, what started as a step for reducing investment in hot rolling has, in fact, given new opportunity for direct hot rolling of thickness that were, for long, considered to be feasible only through the cold-rolling route. This article discuss the slow but steady encroachment of hot-rolled sheets into the domain of strip thickness hitherto produced by cold rolling and tries to show how the development of thin-slab casters has allowed this process to be accelerated. A techno-economic analysis of thin-slab casting has been presented along with the benefits that arise when a thin-slab caster is linked to the blast furnace

  16. Alterations in the ribosomal machinery in cancer and hematologic disorders

    Directory of Open Access Journals (Sweden)

    Shenoy Niraj

    2012-06-01

    Full Text Available Abstract Ribosomes are essential components of the protein translation machinery and are composed of more than 80 unique large and small ribosomal proteins. Recent studies show that in addition to their roles in protein translation, ribosomal proteins are also involved in extra-ribosomal functions of DNA repair, apoptosis and cellular homeostasis. Consequently, alterations in the synthesis or functioning of ribosomal proteins can lead to various hematologic disorders. These include congenital anemias such as Diamond Blackfan anemia and Shwachman Diamond syndrome; both of which are associated with mutations in various ribosomal genes. Acquired uniallelic deletion of RPS14 gene has also been shown to lead to the 5q syndrome, a distinct subset of MDS associated with macrocytic anemia. Recent evidence shows that specific ribosomal proteins are overexpressed in liver, colon, prostate and other tumors. Ribosomal protein overexpression can promote tumorigenesis by interactions with the p53 tumor suppressor pathway and also by direct effects on various oncogenes. These data point to a broad role of ribosome protein alterations in hematologic and oncologic diseases.

  17. Evidence of fire resistance of hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes...... is therefore going on in the Netherlands about the fire resistance of hollow-core slabs. In 2014 the producers of hollow-core slabs have published a report of a project called Holcofire containing a collection of 162 fire tests on hollow-core slabs giving for the first time an overview of the fire tests made....... The present paper analyses the evidence now available for assessment of the fire resistance of extruded hollow-core slabs. The 162 fire tests from the Holcofire report are compared against the requirements for testing from the product standard for hollow-core slabs EN1168 and knowledge about the possible...

  18. Radiative transfer model for contaminated rough slabs

    CERN Document Server

    Andrieu, François; Schmidt, Frédéric; Schmitt, Bernard

    2015-01-01

    We present a semi-analytical model to simulate bidirectional reflectance distribution function (BRDF) spectra of a rough slab layer containing impurities. This model has been optimized for fast computation in order to analyze hyperspectral data. We designed it for planetary surfaces ices studies but it could be used for other purposes. It estimates the bidirectional reflectance of a rough slab of material containing inclusions, overlaying an optically thick media (semi-infinite media or stratified media, for instance granular material). The inclusions are supposed to be close to spherical, and of any type of other material than the ice matrix. It can be any type of other ice, mineral or even bubbles, defined by their optical constants. We suppose a low roughness and we consider the geometrical optics conditions. This model is thus applicable for inclusions larger than the considered wavelength. The scattering on the inclusions is assumed to be isotropic. This model has a fast computation implementation and th...

  19. Subduction zone earthquakes and stress in slabs

    Science.gov (United States)

    Vassiliou, M. S.; Hager, B. H.

    1988-01-01

    Simple viscous fluid models of subducting slabs are used to explain observations of the distribution of earthquakes as a function of depth and the orientation of stress axes of deep (greater than 300 km) and intermediate (70-300 km) earthquakes. Results suggest the following features in the distribution of earthquakes with depth: (1) an exponential decrease from shallow depths down to 250 to 300 km, (2) a minimum near 250 to 300 km, and (3) a deep peak below 300 km. Many shallow subducting slabs show only the first characteristic, while deeper extending regions tend to show all three features, with the deep peak varying in position and intensity. These data, combined with the results on the stress orientations of various-depth earthquakes, are consistent with the existence of a barrier of some sort at 670-km depth and a uniform viscosity mantle above this barrier.

  20. Behavior of Partially Restrained Reinforced Concrete Slabs.

    Science.gov (United States)

    1986-09-01

    Takehira, Derecho , and Iqbal [34] followed a similar approach to arrive at recommended design criteria for 1 the Naval Facilities Engineering Command...Datta, T. K., "Ultimate Strength of Reinforced Concrete Slab-Beam Systems: A New Approach," r Indian Concrete Journal, Bombay, India , Vol. 47, 1973, pp...Journal of Solids and Structures, Vol. 1, 1965, pp. 97-111. 34. Takehira, T., Derecho , A.T., and Iqbal, M., "Design Criteria for Deflection Capacity

  1. Electrostatics in Periodic Slab Geometries II

    OpenAIRE

    de Joannis, Jason; Arnold, Axel; Holm, Christian

    2002-01-01

    In a previous paper a method was developed to subtract the interactions due to periodically replicated charges (or other long-range entities) in one spatial dimension. The method constitutes a generalized "electrostatic layer correction" (ELC) which adapts any standard 3D summation method to slab-like conditions. Here the implementation of the layer correction is considered in detail for the standard Ewald (EW3DLC) and the PPPM mesh Ewald (PPPMLC) methods. In particular this method offers a s...

  2. Continental underplating after slab break-off

    Science.gov (United States)

    Magni, V.; Allen, M. B.; van Hunen, J.; Bouilhol, P.

    2017-09-01

    We present three-dimensional numerical models to investigate the dynamics of continental collision, and in particular what happens to the subducted continental lithosphere after oceanic slab break-off. We find that in some scenarios the subducting continental lithosphere underthrusts the overriding plate not immediately after it enters the trench, but after oceanic slab break-off. In this case, the continental plate first subducts with a steep angle and then, after the slab breaks off at depth, it rises back towards the surface and flattens below the overriding plate, forming a thick horizontal layer of continental crust that extends for about 200 km beyond the suture. This type of behaviour depends on the width of the oceanic plate marginal to the collision zone: wide oceanic margins promote continental underplating and marginal back-arc basins; narrow margins do not show such underplating unless a far field force is applied. Our models show that, as the subducted continental lithosphere rises, the mantle wedge progressively migrates away from the suture and the continental crust heats up, reaching temperatures >900 °C. This heating might lead to crustal melting, and resultant magmatism. We observe a sharp peak in the overriding plate rock uplift right after the occurrence of slab break-off. Afterwards, during underplating, the maximum rock uplift is smaller, but the affected area is much wider (up to 350 km). These results can be used to explain the dynamics that led to the present-day crustal configuration of the India-Eurasia collision zone and its consequences for the regional tectonic and magmatic evolution.

  3. Benchmark Experiment for Beryllium Slab Samples

    Institute of Scientific and Technical Information of China (English)

    NIE; Yang-bo; BAO; Jie; HAN; Rui; RUAN; Xi-chao; REN; Jie; HUANG; Han-xiong; ZHOU; Zu-ying

    2013-01-01

    The neutron leakage spectra were measured at 60°from pure beryllium slab samples(10 cm×10 cm×5 cm and 10 cm×10 cm×11 cm)by TOF method.The experimental results were compared with the calculated ones by MCNP5 simulation,using the evaluated data of beryllium from CENDL3.1,

  4. Wave Scattering by Superluminal Spacetime Slab

    CERN Document Server

    Deck-Léger, Zoé-Lise

    2016-01-01

    Spacetime media offers new opportunities for wave manipulation. Here we study superluminal slabs, and show that the amplitudes of the reflected waves are controlled by the velocity of the medium. In addition, the backward wave continuously scans from the specular to the collinear angle. A diagrammatic method is provided for insight into the deflection angles. A fundamental symmetry between sub- and superluminal scattering is derived from this diagrammatic description.

  5. Convection in Slab and Spheroidal Geometries

    Science.gov (United States)

    Porter, David H.; Woodward, Paul R.; Jacobs, Michael L.

    2000-01-01

    Three-dimensional numerical simulations of compressible turbulent thermally driven convection, in both slab and spheroidal geometries, are reviewed and analyzed in terms of velocity spectra and mixing-length theory. The same ideal gas model is used in both geometries, and resulting flows are compared. The piecewise-parabolic method (PPM), with either thermal conductivity or photospheric boundary conditions, is used to solve the fluid equations of motion. Fluid motions in both geometries exhibit a Kolmogorov-like k(sup -5/3) range in their velocity spectra. The longest wavelength modes are energetically dominant in both geometries, typically leading to one convection cell dominating the flow. In spheroidal geometry, a dipolar flow dominates the largest scale convective motions. Downflows are intensely turbulent and up drafts are relatively laminar in both geometries. In slab geometry, correlations between temperature and velocity fluctuations, which lead to the enthalpy flux, are fairly independent of depth. In spheroidal geometry this same correlation increases linearly with radius over the inner 70 percent by radius, in which the local pressure scale heights are a sizable fraction of the radius. The effects from the impenetrable boundary conditions in the slab geometry models are confused with the effects from non-local convection. In spheroidal geometry nonlocal effects, due to coherent plumes, are seen as far as several pressure scale heights from the lower boundary and are clearly distinguishable from boundary effects.

  6. Convection in Slab and Spheroidal Geometries

    Science.gov (United States)

    Porter, David H.; Woodward, Paul R.; Jacobs, Michael L.

    2000-01-01

    Three-dimensional numerical simulations of compressible turbulent thermally driven convection, in both slab and spheroidal geometries, are reviewed and analyzed in terms of velocity spectra and mixing-length theory. The same ideal gas model is used in both geometries, and resulting flows are compared. The piecewise-parabolic method (PPM), with either thermal conductivity or photospheric boundary conditions, is used to solve the fluid equations of motion. Fluid motions in both geometries exhibit a Kolmogorov-like k(sup -5/3) range in their velocity spectra. The longest wavelength modes are energetically dominant in both geometries, typically leading to one convection cell dominating the flow. In spheroidal geometry, a dipolar flow dominates the largest scale convective motions. Downflows are intensely turbulent and up drafts are relatively laminar in both geometries. In slab geometry, correlations between temperature and velocity fluctuations, which lead to the enthalpy flux, are fairly independent of depth. In spheroidal geometry this same correlation increases linearly with radius over the inner 70 percent by radius, in which the local pressure scale heights are a sizable fraction of the radius. The effects from the impenetrable boundary conditions in the slab geometry models are confused with the effects from non-local convection. In spheroidal geometry nonlocal effects, due to coherent plumes, are seen as far as several pressure scale heights from the lower boundary and are clearly distinguishable from boundary effects.

  7. Present Situation of Petroleum Machinery Manufacturers in China

    Institute of Scientific and Technical Information of China (English)

    Li Xilu

    2008-01-01

    Since China joined the WTO, the environment for the development of petroleum machinery industry in the country has changed a lot. As international petroleum machinery manufacturers enter into Chinese market, petroleum machinery manufacturers of the country are facing fierce competition both at home and abroad.

  8. 30 CFR 56.14205 - Machinery, equipment, and tools.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery, equipment, and tools. 56.14205... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Practices and Operational Procedures § 56.14205 Machinery, equipment, and tools....

  9. 46 CFR 58.01-20 - Machinery guards.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery guards. 58.01-20 Section 58.01-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-20 Machinery guards. Gears, couplings, flywheels...

  10. 46 CFR 109.205 - Inspection of boilers and machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Inspection of boilers and machinery. 109.205 Section 109... OPERATIONS Tests, Drills, and Inspections § 109.205 Inspection of boilers and machinery. The chief engineer or engineer in charge, before he assumes charge of the boilers and machinery of a unit shall...

  11. 29 CFR 1915.165 - Ship's deck machinery.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Ship's deck machinery. 1915.165 Section 1915.165 Labor... (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Ship's Machinery and Piping Systems § 1915.165 Ship's deck machinery. (a) Before work is performed on the anchor windlass or any...

  12. 46 CFR 122.208 - Accidents to machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Accidents to machinery. 122.208 Section 122.208 Shipping... Voyage Records § 122.208 Accidents to machinery. The owner, managing operator, or master shall report damage to a boiler, unfired pressure vessel, or machinery that renders further use of the item...

  13. 29 CFR 1915.164 - Ship's propulsion machinery.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Ship's propulsion machinery. 1915.164 Section 1915.164 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Machinery and Piping Systems § 1915.164 Ship's propulsion machinery. (a) Before work is performed on...

  14. 46 CFR 109.419 - Report of unsafe machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Report of unsafe machinery. 109.419 Section 109.419... OPERATIONS Reports, Notifications, and Records Reports and Notifications § 109.419 Report of unsafe machinery. If a boiler, unfired pressure vessel, or other machinery on a unit is unsafe to operate, the...

  15. 30 CFR 57.14205 - Machinery, equipment, and tools.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery, equipment, and tools. 57.14205... NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Practices and Operational Procedures § 57.14205 Machinery, equipment, and...

  16. 46 CFR 252.33 - Hull and machinery insurance.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Hull and machinery insurance. 252.33 Section 252.33... Subsidy Rates § 252.33 Hull and machinery insurance. (a) Subsidy items. The fair and reasonable net premium costs (including stamp taxes) of hull and machinery, increased value, excess general...

  17. 29 CFR 1910.214 - Cooperage machinery. [Reserved

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Cooperage machinery. 1910.214 Section 1910.214 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.214 Cooperage machinery....

  18. 46 CFR 196.30-5 - Accidents to machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Accidents to machinery. 196.30-5 Section 196.30-5... Reports of Accidents, Repairs, and Unsafe Equipment § 196.30-5 Accidents to machinery. (a) In the event of an accident to a boiler, unfired pressure vessel, or machinery tending to render the further use...

  19. 46 CFR 97.30-5 - Accidents to machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Accidents to machinery. 97.30-5 Section 97.30-5 Shipping... Reports of Accidents, Repairs, and Unsafe Equipment § 97.30-5 Accidents to machinery. (a) In the event of an accident to a boiler, unfired pressure vessel, or machinery tending to render the further use...

  20. 46 CFR 185.208 - Accidents to machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Accidents to machinery. 185.208 Section 185.208 Shipping...) OPERATIONS Marine Casualties and Voyage Records § 185.208 Accidents to machinery. The owner, managing operator, or master shall report damage to a boiler, unfired pressure vessel, or machinery that...

  1. 46 CFR 78.33-5 - Accidents to machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Accidents to machinery. 78.33-5 Section 78.33-5 Shipping... Accidents, Repairs, and Unsafe Equipment § 78.33-5 Accidents to machinery. (a) In the event of an accident to a boiler, unfired pressure vessel, or machinery tending to render the further use of the...

  2. 46 CFR 185.352 - Ventilation of gasoline machinery spaces.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation of gasoline machinery spaces. 185.352 Section 185.352 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS... machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space, required...

  3. 46 CFR 130.460 - Placement of machinery alarms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Placement of machinery alarms. 130.460 Section 130.460..., AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.460 Placement of machinery alarms. (a) Visible and audible alarms must be installed at the pilothouse to...

  4. 46 CFR 171.095 - Machinery space bulkhead.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Machinery space bulkhead. 171.095 Section 171.095... PERTAINING TO VESSELS CARRYING PASSENGERS Additional Subdivision Requirements § 171.095 Machinery space... transverse watertight bulkheads to separate the machinery space from the remainder of the vessel....

  5. 46 CFR 111.103-3 - Machinery space ventilation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  6. 33 CFR 157.39 - Machinery space bilges.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Machinery space bilges. 157.39... Vessel Operation § 157.39 Machinery space bilges. (a) A tank vessel may discharge an oily mixture from a machinery space bilge that is combined with an oil cargo residue if the vessel discharges in compliance...

  7. OPTIMAL MAINTENANCE AND REPLACEMENT OF EXTRACTION MACHINERY

    Institute of Scientific and Technical Information of China (English)

    Suresh P.SETHI; Hong-Mo YEH; Rong ZHANG; Andrew K.S.JARDINE

    2008-01-01

    This paper considers a problem of optimal preventive maintenance and replacement schedule ofequipment devoted to extracting resources from known deposits. Typical examples are oil drills, mine shovels, etc. At most one replacement of the existing machinery by a new one is allowed. The problem is formulated as an optimal control problem subject to the state constraint that the remaining deposit at any given time is nonnegative. We show that the optimal preventive maintenance, production rates, and the replacement and salvage times of the existing machinery and the new one, if required, can be obtained by solving sequentially a series of free-end-point optimal control problems. Moreover, an algorithm based on this result is developed and used to solve two illustrative examples.

  8. The Autophagic Machinery in Enterovirus Infection

    Directory of Open Access Journals (Sweden)

    Jeffrey K. F. Lai

    2016-01-01

    Full Text Available The Enterovirus genus of the Picornaviridae family comprises many important human pathogens, including polioviruses, rhinovirus, enterovirus A71, and enterovirus D68. They cause a wide variety of diseases, ranging from mild to severe life-threatening diseases. Currently, no effective vaccine is available against enteroviruses except for poliovirus. Enteroviruses subvert the autophagic machinery to benefit their assembly, maturation, and exit from host. Some enteroviruses spread between cells via a process described as autophagosome-mediated exit without lysis (AWOL. The early and late phases of autophagy are regulated through various lipids and their metabolizing enzymes. Some of these lipids and enzymes are specifically regulated by enteroviruses. In the present review, we summarize the current understanding of the regulation of autophagic machinery by enteroviruses, and provide updates on recent developments in this field.

  9. Viscous Dissipation and Criticality of Subducting Slabs

    Science.gov (United States)

    Riedel, Mike; Karato, Shun; Yuen, Dave

    2016-04-01

    Rheology of subducting lithosphere appears to be complicated. In the shallow part, deformation is largely accomodated by brittle failure, whereas at greater depth, at higher confining pressures, ductile creep is expected to control slab strength. The amount of viscous dissipation ΔQ during subduction at greater depth, as constrained by experimental rock mechanics, can be estimated on the basis of a simple bending moment equation [1,2] 2ɛ˙0(z) ∫ +h/2 2 M (z) = h ṡ -h/2 4μ(y,z)y dy , (1) for a complex multi-phase rheology in the mantle transition zone, including the effects of a metastable phase transition as well as the pressure, temperature, grain-size and stress dependency of the relevant creep mechanisms; μ is here the effective viscosity and ɛ˙0(z) is a (reference) strain rate. Numerical analysis shows that the maximum bending moment, Mcrit, that can be sustained by a slab is of the order of 1019 Nm per m according to Mcrit˜=σp ∗h2/4, where σp is the Peierl's stress limit of slab materials and h is the slab thickness. Near Mcrit, the amount of viscous dissipation grows strongly as a consequence of a lattice instability of mantle minerals (dislocation glide in olivine), suggesting that thermo-mechanical instabilities become prone to occur at places where a critical shear-heating rate is exceeded, see figure. This implies that the lithosphere behaves in such cases like a perfectly plastic solid [3]. Recently available detailed data related to deep seismicity [4,5] seems to provide support to our conclusion. It shows, e.g., that thermal shear instabilities, and not transformational faulting, is likely the dominating mechanism for deep-focus earthquakes at the bottom of the transition zone, in accordance with this suggested "deep criticality" model. These new findings are therefore briefly outlined and possible implications are discussed. References [1] Riedel, M. R., Karato, S., Yuen, D. A. Criticality of Subducting Slabs. University of Minnesota

  10. Machinery prognostics and prognosis oriented maintenance management

    CERN Document Server

    Yan, Jihong

    2014-01-01

    This book gives a complete presentatin of the basic essentials of machinery prognostics and prognosis oriented maintenance management, and takes a look at the cutting-edge discipline of intelligent failure prognosis technologies for condition-based maintenance.  Latest research results and application methods are introduced for signal processing, reliability moelling, deterioration evaluation, residual life prediction and maintenance-optimization as well as applications of these methods.

  11. Property Analysis of the Agricultural Machinery Lubricants

    Directory of Open Access Journals (Sweden)

    Tone Ploj

    2000-03-01

    Full Text Available We need to produce enough healthy and cheap food as well as to preserve the ecologic equilibrium. This can be achived by using modern machinery and up- to-date knowledge and technology. Agricultural machinery, in which 40-60% of all funds are invested, is poorly maintained and underused. The main causes for this are poor knowledge and extensive farm land fragmentation. The fact that over 140,000 tractors in Slovenia are on average 9.6 years old, i.e. that more than 80% of overall agricultural machinery is obsolete, should be a matter of serious concern. In the paper we follow tribological conditions in particular tractor assemblies. In the first part of the paper we have treated the required conditions of tractor manufacturers in Europe and primarily in Slovenia, what has served us in the final phase of the research for elaboration of the model. In this way we have got data about the presence of particular tractor types. We have separately elaborated the necessary specifications of engine lubricants, transmission, gears, hydraulics and wet breaks. We have carried out chemical and mechanical analyses of all accessible lubricants in agricultural mechanisation. The results of the new oils were coordinated with the required specifications of tractor manufacturers and so we have got such a model, that certainly meet all lubricating requirements of our tractors.

  12. Regulation of alternative splicing by the core spliceosomal machinery

    Science.gov (United States)

    Saltzman, Arneet L.; Pan, Qun; Blencowe, Benjamin J.

    2011-01-01

    Alternative splicing (AS) plays a major role in the generation of proteomic diversity and in gene regulation. However, the role of the basal splicing machinery in regulating AS remains poorly understood. Here we show that the core snRNP (small nuclear ribonucleoprotein) protein SmB/B′ self-regulates its expression by promoting the inclusion of a highly conserved alternative exon in its own pre-mRNA that targets the spliced transcript for nonsense-mediated mRNA decay (NMD). Depletion of SmB/B′ in human cells results in reduced levels of snRNPs and a striking reduction in the inclusion levels of hundreds of additional alternative exons, with comparatively few effects on constitutive exon splicing levels. The affected alternative exons are enriched in genes encoding RNA processing and other RNA-binding factors, and a subset of these exons also regulate gene expression by activating NMD. Our results thus demonstrate a role for the core spliceosomal machinery in controlling an exon network that appears to modulate the levels of many RNA processing factors. PMID:21325135

  13. Tectonic controls on earthquake size distribution and seismicity rate: slab buoyancy and slab bending

    Science.gov (United States)

    Nishikawa, T.; Ide, S.

    2014-12-01

    There are clear variations in maximum earthquake magnitude among Earth's subduction zones. These variations have been studied extensively and attributed to differences in tectonic properties in subduction zones, such as relative plate velocity and subducting plate age [Ruff and Kanamori, 1980]. In addition to maximum earthquake magnitude, the seismicity of medium to large earthquakes also differs among subduction zones, such as the b-value (i.e., the slope of the earthquake size distribution) and the frequency of seismic events. However, the casual relationship between the seismicity of medium to large earthquakes and subduction zone tectonics has been unclear. Here we divide Earth's subduction zones into over 100 study regions following Ide [2013] and estimate b-values and the background seismicity rate—the frequency of seismic events excluding aftershocks—for subduction zones worldwide using the maximum likelihood method [Utsu, 1965; Aki, 1965] and the epidemic type aftershock sequence (ETAS) model [Ogata, 1988]. We demonstrate that the b-value varies as a function of subducting plate age and trench depth, and that the background seismicity rate is related to the degree of slab bending at the trench. Large earthquakes tend to occur relatively frequently (lower b-values) in shallower subduction zones with younger slabs, and more earthquakes occur in subduction zones with deeper trench and steeper dip angle. These results suggest that slab buoyancy, which depends on subducting plate age, controls the earthquake size distribution, and that intra-slab faults due to slab bending, which increase with the steepness of the slab dip angle, have influence on the frequency of seismic events, because they produce heterogeneity in plate coupling and efficiently inject fluid to elevate pore fluid pressure on the plate interface. This study reveals tectonic factors that control earthquake size distribution and seismicity rate, and these relationships between seismicity and

  14. Emergence and modular evolution of a novel motility machinery in bacteria.

    Directory of Open Access Journals (Sweden)

    Jennifer Luciano

    2011-09-01

    Full Text Available Bacteria glide across solid surfaces by mechanisms that have remained largely mysterious despite decades of research. In the deltaproteobacterium Myxococcus xanthus, this locomotion allows the formation stress-resistant fruiting bodies where sporulation takes place. However, despite the large number of genes identified as important for gliding, no specific machinery has been identified so far, hampering in-depth investigations. Based on the premise that components of the gliding machinery must have co-evolved and encode both envelope-spanning proteins and a molecular motor, we re-annotated known gliding motility genes and examined their taxonomic distribution, genomic localization, and phylogeny. We successfully delineated three functionally related genetic clusters, which we proved experimentally carry genes encoding the basal gliding machinery in M. xanthus, using genetic and localization techniques. For the first time, this study identifies structural gliding motility genes in the Myxobacteria and opens new perspectives to study the motility mechanism. Furthermore, phylogenomics provide insight into how this machinery emerged from an ancestral conserved core of genes of unknown function that evolved to gliding by the recruitment of functional modules in Myxococcales. Surprisingly, this motility machinery appears to be highly related to a sporulation system, underscoring unsuspected common mechanisms in these apparently distinct morphogenic phenomena.

  15. Emergence and modular evolution of a novel motility machinery in bacteria.

    Science.gov (United States)

    Luciano, Jennifer; Agrebi, Rym; Le Gall, Anne Valérie; Wartel, Morgane; Fiegna, Francesca; Ducret, Adrien; Brochier-Armanet, Céline; Mignot, Tâm

    2011-09-01

    Bacteria glide across solid surfaces by mechanisms that have remained largely mysterious despite decades of research. In the deltaproteobacterium Myxococcus xanthus, this locomotion allows the formation stress-resistant fruiting bodies where sporulation takes place. However, despite the large number of genes identified as important for gliding, no specific machinery has been identified so far, hampering in-depth investigations. Based on the premise that components of the gliding machinery must have co-evolved and encode both envelope-spanning proteins and a molecular motor, we re-annotated known gliding motility genes and examined their taxonomic distribution, genomic localization, and phylogeny. We successfully delineated three functionally related genetic clusters, which we proved experimentally carry genes encoding the basal gliding machinery in M. xanthus, using genetic and localization techniques. For the first time, this study identifies structural gliding motility genes in the Myxobacteria and opens new perspectives to study the motility mechanism. Furthermore, phylogenomics provide insight into how this machinery emerged from an ancestral conserved core of genes of unknown function that evolved to gliding by the recruitment of functional modules in Myxococcales. Surprisingly, this motility machinery appears to be highly related to a sporulation system, underscoring unsuspected common mechanisms in these apparently distinct morphogenic phenomena.

  16. A SNARE-like superfamily protein SbSLSP from the halophyte Salicornia brachiata confers salt and drought tolerance by maintaining membrane stability, K+/Na+ ratio, and antioxidant machinery

    Directory of Open Access Journals (Sweden)

    Dinkar eSingh

    2016-06-01

    Full Text Available About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP, (Salicornia brachiata SNARE-like superfamily protein showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterised proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localisation studies indicated that the SbSLSP protein is mainly localised in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na+ ion and reactive oxygen species (ROS. Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signalling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

  17. A SNARE-Like Superfamily Protein SbSLSP from the Halophyte Salicornia brachiata Confers Salt and Drought Tolerance by Maintaining Membrane Stability, K(+)/Na(+) Ratio, and Antioxidant Machinery.

    Science.gov (United States)

    Singh, Dinkar; Yadav, Narendra Singh; Tiwari, Vivekanand; Agarwal, Pradeep K; Jha, Bhavanath

    2016-01-01

    About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP (Salicornia brachiata SNARE-like superfamily protein), showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterized proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis, and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localization studies indicated that the SbSLSP protein is mainly localized in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na(+) ion and reactive oxygen species (ROS). Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability, and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signaling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil.

  18. A SNARE-Like Superfamily Protein SbSLSP from the Halophyte Salicornia brachiata Confers Salt and Drought Tolerance by Maintaining Membrane Stability, K+/Na+ Ratio, and Antioxidant Machinery

    Science.gov (United States)

    Singh, Dinkar; Yadav, Narendra Singh; Tiwari, Vivekanand; Agarwal, Pradeep K.; Jha, Bhavanath

    2016-01-01

    About 1000 salt-responsive ESTs were identified from an extreme halophyte Salicornia brachiata. Among these, a novel salt-inducible gene SbSLSP (Salicornia brachiata SNARE-like superfamily protein), showed up-regulation upon salinity and dehydration stress. The presence of cis-regulatory motifs related to abiotic stress in the putative promoter region supports our finding that SbSLSP gene is inducible by abiotic stress. The SbSLSP protein showed a high sequence identity to hypothetical/uncharacterized proteins from Beta vulgaris, Spinacia oleracea, Eucalyptus grandis, and Prunus persica and with SNARE-like superfamily proteins from Zostera marina and Arabidopsis thaliana. Bioinformatics analysis predicted a clathrin adaptor complex small-chain domain and N-myristoylation site in the SbSLSP protein. Subcellular localization studies indicated that the SbSLSP protein is mainly localized in the plasma membrane. Using transgenic tobacco lines, we establish that overexpression of SbSLSP resulted in elevated tolerance to salt and drought stress. The improved tolerance was confirmed by alterations in a range of physiological parameters, including high germination and survival rate, higher leaf chlorophyll contents, and reduced accumulation of Na+ ion and reactive oxygen species (ROS). Furthermore, overexpressing lines also showed lower water loss, higher cell membrane stability, and increased accumulation of proline and ROS-scavenging enzymes. Overexpression of SbSLSP also enhanced the transcript levels of ROS-scavenging and signaling enzyme genes. This study is the first investigation of the function of the SbSLSP gene as a novel determinant of salinity/drought tolerance. The results suggest that SbSLSP could be a potential candidate to increase salinity and drought tolerance in crop plants for sustainable agriculture in semi-arid saline soil. PMID:27313584

  19. Responses of chromosome segregation machinery to mechanical perturbations.

    Science.gov (United States)

    Itabashi, Takeshi; Takagi, Jun; Suzuki, Kazuya; Ishiwata, Shin'ichi

    2013-01-01

    For genome stability, the proper segregation of chromosomes is required. The exquisite process of chromosome segregation has charmed a lot of cell- and molecular biologists into watching what happens inside a mitotic cell and how each molecule contributes to this process for the accomplishment of accurate cell division1. The process to partition the duplicated genome to the daughter cells in each cell division is mediated by a self-organized structure called the mitotic spindle. It is well known that the mitotic spindle is a multi-component macromolecular machine composed of microtubules, molecular motors (kinesins, cytoplasmic dynein), and other regulatory molecules (microtubule-associated proteins, kinases, etc.). In recent years, most of the protein components of the mitotic spindle have been identified and the functions of these proteins have been characterized using molecular perturbations2,3. Thus, the mechanisms for spindle assembly and chromosome segregation are being revealed rapidly. However, the chromosome segregation machinery is poorly understood from the mechanical point of view, such as how the mitotic spindle within a cell responds to a variety of mechanical forces, originating from cell-cell interactions or environmental fluctuations. Recent advances in the controlled mechanical perturbation have indicated that the mitotic spindle possesses a structural pliability, size adaptability to the applied external forces, and a strong self-organizing ability. Mechanical perturbations revealed also the mechanochemical regulation of chromosome segregation machinery, which responds to the applied forces. Here, we discuss the current progress in the biophysical research on the architectural and functional dynamics of the mitotic spindle.

  20. A STUDY ON THE WHEELSET/SLAB TRACK VERTICAL INTERACTION

    Directory of Open Access Journals (Sweden)

    Traian MAZILU

    2012-05-01

    Full Text Available This paper deals with the interaction between a moving wheelset and a slab track due to the short-pitch corrugated rail. The wheelset is modeled using a free-free Timoshenko beam with attached rigid bodies as the axle boxes, wheels and brake discs. The slab track model consists of elastically supported double Euler-Bernoulli beams. In fact, both wheelset and slab track are symmetric structures and the issue of the wheelset/slab track interaction is reduced to the wheel/rail interaction. The nonlinear equations of motion describing the wheelset/slab track interaction due to the short-pitch corrugated rail are solved using the time-domain Green’s functions method and the convolution theorem. The wheelset/slab track interaction due to the short-pitch corrugated rail exhibits a critical velocity when the vibration reaches the maximum level

  1. Localization of P42 and F(1)-ATPase α-subunit homolog of the gliding machinery in Mycoplasma mobile revealed by newly developed gene manipulation and fluorescent protein tagging.

    Science.gov (United States)

    Tulum, Isil; Yabe, Masaru; Uenoyama, Atsuko; Miyata, Makoto

    2014-05-01

    Mycoplasma mobile has a unique mechanism that enables it to glide on solid surfaces faster than any other gliding mycoplasma. To elucidate the gliding mechanism, we developed a transformation system for M. mobile based on a transposon derived from Tn4001. Modification of the electroporation conditions, outgrowth time, and colony formation from the standard method for Mycoplasma species enabled successful transformation. A fluorescent-protein tagging technique was developed using the enhanced yellow fluorescent protein (EYFP) and applied to two proteins that have been suggested to be involved in the gliding mechanism: P42 (MMOB1050), which is transcribed as continuous mRNA with other proteins essential for gliding, and a homolog of the F1-ATPase α-subunit (MMOB1660). Analysis of the amino acid sequence of P42 by PSI-BLAST suggested that P42 evolved from a common ancestor with FtsZ, the bacterial tubulin homologue. The roles of P42 and the F(1)-ATPase subunit homolog are discussed as part of our proposed gliding mechanism.

  2. Localization of P42 and F1-ATPase α-Subunit Homolog of the Gliding Machinery in Mycoplasma mobile Revealed by Newly Developed Gene Manipulation and Fluorescent Protein Tagging

    Science.gov (United States)

    Tulum, Isil; Yabe, Masaru; Uenoyama, Atsuko

    2014-01-01

    Mycoplasma mobile has a unique mechanism that enables it to glide on solid surfaces faster than any other gliding mycoplasma. To elucidate the gliding mechanism, we developed a transformation system for M. mobile based on a transposon derived from Tn4001. Modification of the electroporation conditions, outgrowth time, and colony formation from the standard method for Mycoplasma species enabled successful transformation. A fluorescent-protein tagging technique was developed using the enhanced yellow fluorescent protein (EYFP) and applied to two proteins that have been suggested to be involved in the gliding mechanism: P42 (MMOB1050), which is transcribed as continuous mRNA with other proteins essential for gliding, and a homolog of the F1-ATPase α-subunit (MMOB1660). Analysis of the amino acid sequence of P42 by PSI-BLAST suggested that P42 evolved from a common ancestor with FtsZ, the bacterial tubulin homologue. The roles of P42 and the F1-ATPase subunit homolog are discussed as part of our proposed gliding mechanism. PMID:24509320

  3. Structure, Function and Regulation of the Hsp90 Machinery

    Directory of Open Access Journals (Sweden)

    Jing Li

    2013-06-01

    Full Text Available Heat shock protein 90 (Hsp90 is an ATP-dependent molecular chaperone which is essential in eukaryotes. It is required for the activation and stabilization of a wide variety of client proteins and many of them are involved in important cellular pathways. Since Hsp90 affects numerous physiological processes such as signal transduction, intracellular transport, and protein degradation, it became an interesting target for cancer therapy. Structurally, Hsp90 is a flexible dimeric protein composed of three different domains which adopt structurally distinct conformations. ATP binding triggers directionality in these conformational changes and leads to a more compact state. To achieve its function, Hsp90 works together with a large group of cofactors, termed co-chaperones. Co-chaperones form defined binary or ternary complexes with Hsp90, which facilitate the maturation of client proteins. In addition, posttranslational modifications of Hsp90, such as phosphorylation and acetylation, provide another level of regulation. They influence the conformational cycle, co-chaperone interaction, and inter-domain communications. In this review, we discuss the recent progress made in understanding the Hsp90 machinery.

  4. Identification of an iron acquisition machinery in Flavobacterium columnare.

    Science.gov (United States)

    Guan, Lingyu; Santander, Javier; Mellata, Melha; Zhang, Yuangxing; Curtiss, Roy

    2013-10-11

    Flavobacterium columnare, a fastidious Gram-negative pathogen and the causative agent of columnaris disease, is one of the most harmful pathogens in the freshwater fish-farming industry. Nevertheless the virulence mechanisms of F. columnare are not well understood. Bacterial iron uptake from the host during infection is an important mechanism of virulence. Here we identified and analyzed part of the iron uptake machinery of F. columnare. Under iron-limited conditions during in vitro growth, synthesis of an outer membrane protein of ~86 kDa was upregulated. This protein was identified as a TonB-dependent ferrichrome-iron receptor precursor (FhuA). Synthesis of siderophores in F. columnare was corroborated by chrome azurol S assays. A putative ferric uptake regulator (Fur) protein was also identified in the F. columnare genome. Structural analysis of the F. columnare Fur protein revealed that it was similar to Fur proteins involved in iron uptake regulation of other bacteria. Furthermore, Salmonella enterica serovar Typhimurium (S. Typhimurium) Δfur mutants were partially complemented by the F. columnare fur gene. We conclude that a siderophore-mediated iron uptake system exists in F. columnare, and fur from F. columnare could partially complement S. Typhimurium Δfur mutant.

  5. Hybrid slab-microchannel gel electrophoresis system

    Science.gov (United States)

    Balch, Joseph W.; Carrano, Anthony V.; Davidson, James C.; Koo, Jackson C.

    1998-01-01

    A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.

  6. Photonic crystal slab quantum well infrared photodetector

    Science.gov (United States)

    Kalchmair, S.; Detz, H.; Cole, G. D.; Andrews, A. M.; Klang, P.; Nobile, M.; Gansch, R.; Ostermaier, C.; Schrenk, W.; Strasser, G.

    2011-01-01

    In this letter we present a quantum well infrared photodetector (QWIP), which is fabricated as a photonic crystal slab (PCS). With the PCS it is possible to enhance the absorption efficiency by increasing photon lifetime in the detector active region. To understand the optical properties of the device we simulate the PCS photonic band structure, which differs significantly from a real two-dimensional photonic crystal. By fabricating a PCS-QWIP with 100x less quantum well doping, compared to a standard QWIP, we are able to see strong absorption enhancement and sharp resonance peaks up to temperatures of 170 K.

  7. Photonic crystal slab quantum cascade detector

    Energy Technology Data Exchange (ETDEWEB)

    Reininger, Peter, E-mail: peter.reininger@tuwien.ac.at; Schwarz, Benedikt; Harrer, Andreas; Zederbauer, Tobias; Detz, Hermann; Maxwell Andrews, Aaron; Gansch, Roman; Schrenk, Werner; Strasser, Gottfried [Institute for Solid State Electronics and Center for Micro- and Nanostructures, Vienna University of Technology, Floragasse 7, Vienna 1040 (Austria)

    2013-12-09

    In this Letter, we demonstrate the design, fabrication, and characterization of a photonic crystal slab quantum cascade detector (PCS-QCD). By employing a specifically designed resonant cavity, the performance of the photodetector is improved in three distinct ways. The PCS makes the QCD sensitive to surface normal incident light. It resonantly enhances the photon lifetime inside the active zone, thus increasing the photocurrent significantly. And, the construction form of the device inherently decreases the noise. Finally, we compare the characteristics of the PCS-QCD to a PCS - quantum well infrared photodetector and outline the advantages for certain fields of applications.

  8. Automated inspection of hot steel slabs

    Science.gov (United States)

    Martin, Ronald J.

    1985-01-01

    The disclosure relates to a real time digital image enhancement system for performing the image enhancement segmentation processing required for a real time automated system for detecting and classifying surface imperfections in hot steel slabs. The system provides for simultaneous execution of edge detection processing and intensity threshold processing in parallel on the same image data produced by a sensor device such as a scanning camera. The results of each process are utilized to validate the results of the other process and a resulting image is generated that contains only corresponding segmentation that is produced by both processes.

  9. Damage Function Rating Procedure for Flat Slab Basement Shelters.

    Science.gov (United States)

    1982-12-01

    with solid heads at the columns . These types of slabs are 33 I r~ Omm- D6U0St - m . -I ig. "-.TyiaaFalSasontucin 34 -4 called ribbed, or " waffle ", slabs ...and for design purposes are considered flat slabs with the solid heads at the columns performing the same function as the drop panels. Waffle flat...she:.ers, an upgrading method must be developed and verified by test for these critical stress areas adjacent to the column supports. Waffle Slabs

  10. CFRP strengthened openings in two-way concrete slabs

    DEFF Research Database (Denmark)

    Enochsson, O.; Lundqvist, J.; Täljsten, Björn

    2006-01-01

    Rehabilitation and strengthening of concrete structures with externally bonded fibre reinforced polymers (FRPs) has been a viable technique for at least a decade. An interesting and useful application is strengthening of slabs or walls where openings are introduced. In these situations, FRP sheets....... In this paper, laboratory tests on I I slabs with openings, loaded with a distributed load are presented together with analytical and numerical evaluations. Six slabs with openings have been strengthened with carbon fibre reinforced polymers (CFRPs) sheets. These slabs are compared with traditionally steel...

  11. Gain of double-slab Cherenkov free-electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Li, D. [Institute for laser Technology, suita, Osaka 565-0871 (Japan)], E-mail: dazhi_li@hotmail.com; Huo, G. [Petroleum development center, Shengli Oilfield, SINOPEC, Dongying 257001 (China); Imasak, K. [Institute for laser Technology, suita, Osaka 565-0871 (Japan); Asakawa, M. [Department of pure and applied physics, Faculty of Engineering Science, Kansai University, Osaka 564-8680 (Japan)

    2009-07-21

    A formula is derived for the small-signal gain of a double-slab Cherenkov free-electron laser. The simplified model is composed of a rectangular wave-guide partially filled with two lined parallel dielectric slabs and a sheet electron beam. The theory describes the electron beam as a plasma dielectric moving between the two dielectric slabs. With the help of hydrodynamic approximation, we derived the dispersion equation and the formula of small-signal gain. Through numerical computing, we studied an ongoing experiment of double-slab Cherenkov free-electron laser, and worked out the synchronous frequency and single-pass gain.

  12. Evidence of fire resistance of hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes) are predo......Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes...

  13. A STUDY ON THE WHEELSET/SLAB TRACK VERTICAL INTERACTION

    OpenAIRE

    2012-01-01

    This paper deals with the interaction between a moving wheelset and a slab track due to the short-pitch corrugated rail. The wheelset is modeled using a free-free Timoshenko beam with attached rigid bodies as the axle boxes, wheels and brake discs. The slab track model consists of elastically supported double Euler-Bernoulli beams. In fact, both wheelset and slab track are symmetric structures and the issue of the wheelset/slab track interaction is reduced to the wheel/rail interaction. The n...

  14. Control of exceptional points in photonic crystal slabs

    DEFF Research Database (Denmark)

    Kaminski, Piotr Marek; Taghizadeh, Alireza; Breinbjerg, Olav

    2017-01-01

    Various ways of controlling the extent of the ring of exceptional points in photonic crystal slabs are investigated. The extent of the ring in photonic crystal slabs is found to vary with the thickness of the slab. This enables recovery of Dirac cones in open, non-Hermitian systems......, such as a photonic crystal slab. In this case, all three bands exhibit a bound state in the continuum in close proximity of the Γ point. These results may lead to new designs of small photonic-crystal-based lasers exhibiting high-quality factors....

  15. 46 CFR 30.10-42 - Machinery space-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Machinery space-TB/ALL. 30.10-42 Section 30.10-42...-42 Machinery space—TB/ALL. The term machinery space means any space that contains machinery and related equipment including Category A machinery spaces, propelling machinery, boilers, oil fuel...

  16. 3D super-resolution microscopy of bacterial division machinery

    Science.gov (United States)

    Vedyaykin, A. D.; Sabantsev, A. V.; Vishnyakov, I. E.; Morozova, N. E.; Polinovskaya, V. S.; Khodorkovskii, M. A.

    2016-08-01

    Super-resolution microscopy is a promising tool for the field of microbiology, as bacteria sizes are comparable to the resolution limit of light microscopy. Bacterial division machinery and FtsZ protein in particular attract much attention of scientists who use different super-resolution microscopy techniques, but most of the available data on FtsZ structures was obtained using two-dimensional (2D) super-resolution microscopy. Using 3D single-molecule localization microscopy (SMLM, namely dSTORM) to visualize FtsZ, we demonstrate that this approach allows more accurate interpretation of super-resolution images and provides new opportunities for the study of complex structures like bacterial divisome.

  17. C4 photosynthetic machinery: insights from maize chloroplast proteomics

    Directory of Open Access Journals (Sweden)

    Qi eZhao

    2013-04-01

    Full Text Available C4 plants exhibit much higher CO2 assimilation rates than C3 plants. The specialized differentiation of mesophyll cell (M and bundle sheath cell (BS type chloroplasts is unique to C4 plants and improves photosynthesis efficiency. Maize (Zea mays is an important crop and model with C4 photosynthetic machinery. Current high-throughput quantitative proteomics approaches (e.g., 2DE, iTRAQ, and shotgun proteomics have been employed to investigate maize chloroplast structure and function. These proteomic studies have provided valuable information on C4 chloroplast protein components, photosynthesis, and other metabolic mechanisms underlying chloroplast biogenesis, stromal and membrane differentiation, as well as response to salinity, high/low temperature, and light stress. This review presents an overview of proteomics advances in maize chloroplast biology.

  18. An allosteric photoredox catalyst inspired by photosynthetic machinery.

    Science.gov (United States)

    Lifschitz, Alejo M; Young, Ryan M; Mendez-Arroyo, Jose; Stern, Charlotte L; McGuirk, C Michael; Wasielewski, Michael R; Mirkin, Chad A

    2015-03-30

    Biological photosynthetic machinery allosterically regulate light harvesting via conformational and electronic changes at the antenna protein complexes as a response to specific chemical inputs. Fundamental limitations in current approaches to regulating inorganic light-harvesting mimics prevent their use in catalysis. Here we show that a light-harvesting antenna/reaction centre mimic can be regulated by utilizing a coordination framework incorporating antenna hemilabile ligands and assembled via a high-yielding, modular approach. As in nature, allosteric regulation is afforded by coupling the conformational changes to the disruptions in the electrochemical landscape of the framework upon recognition of specific coordinating analytes. The hemilabile ligands enable switching using remarkably mild and redox-inactive inputs, allowing one to regulate the photoredox catalytic activity of the photosynthetic mimic reversibly and in situ. Thus, we demonstrate that bioinspired regulatory mechanisms can be applied to inorganic light-harvesting arrays displaying switchable catalytic properties and with potential uses in solar energy conversion and photonic devices.

  19. The iron-sulfur cluster assembly machineries in plants: current knowledge and open questions

    Directory of Open Access Journals (Sweden)

    Jérémy eCouturier

    2013-07-01

    Full Text Available Many metabolic pathways and cellular processes occurring in most sub-cellular compartments depend on the functioning of iron-sulfur (Fe-S proteins, whose cofactors are assembled through dedicated protein machineries. Recent advances have been made in the knowledge of the functions of individual components through a combination of genetic, biochemical and structural approaches, primarily in prokaryotes and non-plant eukaryotes. Whereas most of the components of these machineries are conserved between kingdoms, their complexity is likely increased in plants owing to the presence of additional assembly proteins and to the existence of expanded families for several assembly proteins. This review focuses on the new actors discovered in the past few years, such as glutaredoxin, BOLA and NEET proteins as well as MIP18, MMS19, TAH18, DRE2 for the cytosolic machinery, which are integrated into a model for the plant Fe-S cluster biogenesis systems. It also discusses a few issues currently subjected to an intense debate such as the role of the mitochondrial frataxin and of glutaredoxins, the functional separation between scaffold, carrier and iron-delivery proteins and the crosstalk existing between different organelles.

  20. Analysis of electric machinery and drive systems

    CERN Document Server

    Krause, Paul C; Sudhoff, Scott D; Pekarek, Steven

    2013-01-01

    Introducing a new edition of the popular reference on machine analysis Now in a fully revised and expanded edition, this widely used reference on machine analysis boasts many changes designed to address the varied needs of engineers in the electric machinery, electric drives, and electric power industries. The authors draw on their own extensive research efforts, bringing all topics up to date and outlining a variety of new approaches they have developed over the past decade. Focusing on reference frame theory that has been at the core of this work since the first edition, th

  1. Radiative transfer model for contaminated rough slabs.

    Science.gov (United States)

    Andrieu, François; Douté, Sylvain; Schmidt, Frédéric; Schmitt, Bernard

    2015-11-01

    We present a semi-analytical model to simulate the bidirectional reflectance distribution function (BRDF) of a rough slab layer containing impurities. This model has been optimized for fast computation in order to analyze massive hyperspectral data by a Bayesian approach. We designed it for planetary surface ice studies but it could be used for other purposes. It estimates the bidirectional reflectance of a rough slab of material containing inclusions, overlaying an optically thick media (semi-infinite media or stratified media, for instance granular material). The inclusions are assumed to be close to spherical and constituted of any type of material other than the ice matrix. It can be any other type of ice, mineral, or even bubbles defined by their optical constants. We assume a low roughness and we consider the geometrical optics conditions. This model is thus applicable for inclusions larger than the considered wavelength. The scattering on the inclusions is assumed to be isotropic. This model has a fast computation implementation and thus is suitable for high-resolution hyperspectral data analysis.

  2. Single-membrane-bounded peroxisome division revealed by isolation of dynamin-based machinery.

    Science.gov (United States)

    Imoto, Yuuta; Kuroiwa, Haruko; Yoshida, Yamato; Ohnuma, Mio; Fujiwara, Takayuki; Yoshida, Masaki; Nishida, Keiji; Yagisawa, Fumi; Hirooka, Shunsuke; Miyagishima, Shin-ya; Misumi, Osami; Kawano, Shigeyuki; Kuroiwa, Tsuneyoshi

    2013-06-01

    Peroxisomes (microbodies) are ubiquitous single-membrane-bounded organelles and fulfill essential roles in the cellular metabolism. They are found in virtually all eukaryotic cells and basically multiply by division. However, the mechanochemical machinery involved in peroxisome division remains elusive. Here, we first identified the peroxisome-dividing (POD) machinery. We isolated the POD machinery from Cyanidioschyzon merolae, a unicellular red alga containing a single peroxisome. Peroxisomal division in C. merolae can be highly synchronized by light/dark cycles and the microtubule-disrupting agent oryzalin. By proteomic analysis based on the complete genome sequence of C. merolae, we identified a dynamin-related protein 3 (DRP3) ortholog, CmDnm1 (Dnm1), that predominantly accumulated with catalase in the dividing-peroxisome fraction. Immunofluorescence microscopy demonstrated that Dnm1 formed a ring at the division site of the peroxisome. The outlines of the isolated dynamin rings were dimly observed by phase-contrast microscopy and clearly stained for Dnm1. Electron microscopy revealed that the POD machinery was formed at the cytoplasmic side of the equator. Immunoelectron microscopy showed that the POD machinery consisted of an outer dynamin-based ring and an inner filamentous ring. Down-regulation of Dnm1 impaired peroxisomal division. Surprisingly, the same Dnm1 serially controlled peroxisomal division after mitochondrial division. Because genetic deficiencies of Dnm1 orthologs in multiperoxisomal organisms inhibited both mitochondrial and peroxisomal proliferation, it is thought that peroxisomal division by contraction of a dynamin-based machinery is universal among eukaryotes. These findings are useful for understanding the fundamental systems in eukaryotic cells.

  3. Rotating Machinery Predictive Maintenance Through Expert System

    Directory of Open Access Journals (Sweden)

    M. Sarath Kumar

    2000-01-01

    Full Text Available Modern rotating machines such as turbomachines, either produce or absorb huge amount of power. Some of the common applications are: steam turbine-generator and gas turbine-compressor-generator trains produce power and machines, such as pumps, centrifugal compressors, motors, generators, machine tool spindles, etc., are being used in industrial applications. Condition-based maintenance of rotating machinery is a common practice where the machine's condition is monitored constantly, so that timely maintenance can be done. Since modern machines are complex and the amount of data to be interpreted is huge, we need precise and fast methods in order to arrive at the best recommendations to prevent catastrophic failure and to prolong the life of the equipment. In the present work using vibration characteristics of a rotor-bearing system, the condition of a rotating machinery (electrical rotor is predicted using an off-line expert system. The analysis of the problem is carried out in an Object Oriented Programming (OOP framework using the finite element method. The expert system which is also developed in an OOP paradigm gives the type of the malfunctions, suggestions and recommendations. The system is implemented in C++.

  4. Shear and anchorage behaviour of fire exposed hollow core slabs

    NARCIS (Netherlands)

    Fellinger, J.H.H.; Stark, J.; Walraven, J.C.

    2005-01-01

    The fire resistance of hollow core slabs is currently assessed considering flexural failure only. However, fire tests showed that shear or anchorage failure can also govern the load bearing behaviour. As the shear and anchorage capacity of these slabs rely on the tensile strength of the concrete, th

  5. How to produce flat slabs: insights from numeric modeling

    Science.gov (United States)

    Constantin Manea, Vlad; Perez-Gussinye, Marta; Manea, Marina

    2010-05-01

    Flat slab subduction occurs at ~10% of the active convergent margins and it is assumed that subduction of oceanic aseismic ridges or seamount chains is the main mechanism to produce very low angle subduction slabs. However, recent numeric and analog modeling showed that ridges alone of moderate dimensions subducted perpendicular to the trench are not sufficient to produce flat-slab geometries. Therefore an alternative mechanism able to produce flat-slabs is required. In this paper we present dynamic numeric modeling results of subduction in the vicinity of thick continental lithosphere, as a craton for example. We tailored our modeling setup for the Chilean margins at ~31° and our models are integrated back in time 30 Myr. Modeling results show that a craton thickness of 200 km or more when approaching the trench is capable of blocking the asthenospheric flow in the mantle wedge and increasing considerably the suction force. We were able to produce a flat slab that fits well the flat slab geometry in Chile (based on seismicity) and stress distribution. We conclude that thick cratons located in the vicinity of subduction zones, are capable to produce very low angle slabs, and probable a combination of buoyant ridge subduction with a neighbor thick craton represent a better mechanism to produce flat slabs.

  6. Shear and Anchorage Behaviour of Fire Exposed Hollow Core Slabs

    NARCIS (Netherlands)

    Fellinger, J.H.H.

    2004-01-01

    Hollow core (HC) slabs are made of precast concrete with pretensioned strands. These slabs are popular as floor structures in offices and housing. At ambient conditions, the load bearing capacity can be dominated by four different failure modes, i.e. flexure, anchorage, shear compression and shear t

  7. Ultimate deformation capacity of reinforced concrete slabs underblast load

    NARCIS (Netherlands)

    Doormaal, J.C.A.M. van; Weerheijm, J.

    1996-01-01

    In this paper a test method to determine the deformation capacity and the resistance-deformation curve of blast-loaded slabs is described. This method was developed at TNO-PML. The method has been used to determine the ultimate deformation capacity of some simply supported reinforced concrete slabs

  8. Shear and Anchorage Behaviour of Fire Exposed Hollow Core Slabs

    NARCIS (Netherlands)

    Fellinger, J.H.H.

    2004-01-01

    Hollow core (HC) slabs are made of precast concrete with pretensioned strands. These slabs are popular as floor structures in offices and housing. At ambient conditions, the load bearing capacity can be dominated by four different failure modes, i.e. flexure, anchorage, shear compression and shear

  9. Radon Sub-slab Suctioning System Integrated in Insulating Layer

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    This poster presents a new radon sub-slab suctioning system. This system makes use of a grid of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground floor slab. For this purpose a new system of prefabricated lightweight elements is introduced...

  10. Superluminal pulse reflection from a weakly absorbing dielectric slab

    CERN Document Server

    Wang, L G; Wang, Li-Gang; Zhu, Shi-Yao

    2006-01-01

    Group delay for a reflected light pulse from a weakly absorbing dielectric slab is theoretically investigated, and large negative group delay is found for weak absorption near a resonance of the slab ($Re(kd)=m\\pi$). The group delays for both the reflected and transmitted pulses will be saturated with the increase of the absorption.

  11. Shear capacity of slabs under a combination of loads

    NARCIS (Netherlands)

    Lantsoght, E.O.L.; Van der Veen, C.; Walraven, J.C.

    2013-01-01

    Existing solid slab bridges under a combination of wheel loads and distributed traffic loads sometimes do not fulfil the code requirements for shear. However, reinforced concrete slabs loaded close to the support are subjected to shear stresses which might result in a failure mode of combined punchi

  12. Ultimate deformation capacity of reinforced concrete slabs underblast load

    NARCIS (Netherlands)

    Doormaal, J.C.A.M. van; Weerheijm, J.

    1996-01-01

    In this paper a test method to determine the deformation capacity and the resistance-deformation curve of blast-loaded slabs is described. This method was developed at TNO-PML. The method has been used to determine the ultimate deformation capacity of some simply supported reinforced concrete slabs

  13. Shear and Anchorage Behaviour of Fire Exposed Hollow Core Slabs

    NARCIS (Netherlands)

    Fellinger, J.H.H.

    2004-01-01

    Hollow core (HC) slabs are made of precast concrete with pretensioned strands. These slabs are popular as floor structures in offices and housing. At ambient conditions, the load bearing capacity can be dominated by four different failure modes, i.e. flexure, anchorage, shear compression and shear t

  14. On Early Age Crack Formation in FRC Slabs

    DEFF Research Database (Denmark)

    Olesen, John Forbes; Stang, Henrik

    1997-01-01

    The problem of early age crack formation in FRC slabs due to restrained temperature and shrinkage deformations, is given an analytical treatment. A model taking into account the ageing properties of the tensile softening curve and the continued development in the temperature and shrinkage...... deformations after crack initiation, is presented. Based on this model a design strategy for FRC slabs is outlined....

  15. Influence of weak layer heterogeneity and slab properties on slab tensile failure propensity and avalanche release area

    Directory of Open Access Journals (Sweden)

    J. Gaume

    2014-12-01

    Full Text Available Dry-snow slab avalanches are generally caused by a sequence of fracture processes including failure initiation in a weak snow layer underlying a cohesive slab followed by crack propagation within the weak layer (WL and tensile fracture through the slab. During past decades, theoretical and experimental work has gradually improved our knowledge of the fracture process in snow. However, our limited understanding of crack propagation and fracture arrest propensity prevents the evaluation of avalanche release sizes and thus impedes hazard assessment. To address this issue, slab tensile failure propensity is examined using a mechanically-based statistical model of the slab–WL system based on the finite element method. This model accounts for WL heterogeneity, stress redistribution by elasticity of the slab and the slab possible tensile failure. Two types of avalanche release are distinguished in the simulations: (1 full-slope release if the heterogeneity is not sufficient to stop crack propagation and to trigger a tensile failure within the slab, (2 partial-slope release if fracture arrest and slab tensile failure occurs due to the WL heterogeneity. The probability of these two release types is presented as a function of the characteristics of WL heterogeneity and of the slab. One of the main outcomes is that, for realistic values of the parameters, the tensile failure propensity is mainly influenced by slab properties. Hard and thick snow slabs are more prone to wide-scale crack propagation and thus lead to larger avalanches (full-slope release. In this case, the avalanche size is mainly influenced by topographical and morphological features such as rocks, trees, slope curvature and the spatial variability of the snow depth as it is often claimed in the literature.

  16. On Development of Agricultural Machinery Operating Service in Chongqing

    Institute of Scientific and Technical Information of China (English)

    Chongjing; TAN; Shi; YANG

    2015-01-01

    Development of agricultural machinery operating service in Chongqing takes on rapid increase in number of service organizations,diversified service methods,improvement in service level,and constant service income. However,there are some problems,including unreasonable composition and small scale of service organization,imbalanced development of four service methods,low service level,and low operating income of agricultural machinery households. To accelerate development of agricultural machinery operating service in Chongqing,it is recommended to take following measures: adjusting subsidy for purchase and operation of agricultural machinery; improving fiscal and taxation and financial system; speeding up infrastructure construction,establishing agricultural machinery information network,and improving organizational form and methods of agricultural machinery operating service.

  17. ABOUT ETHICS IN PLANT, MACHINERY AND EQUIPMENT VALUATION DOMAIN

    Directory of Open Access Journals (Sweden)

    Sorin Adrian Achim

    2015-09-01

    Full Text Available In this paper we put in discussion some ethical aspects of plant, machinery and equipment valuation. After a presentation of the general issues of ethics in valuation domain, we analyze the application of the fundamental ethical principles in plant, machinery and equipment valuation domain. To support our conclusions we use some findings of a study that we conducted to identify the particularities of the plant, machinery and equipment valuation activity in Romania.

  18. Electromagnetic Tunneling and Resonances in Pseudochiral Omega Slabs

    Science.gov (United States)

    Razzaz, Faroq; Alkanhal, Majeed A. S.

    2017-01-01

    This paper presents theoretical investigation of the electromagnetic wave tunneling and anomalous transmission around the trapped modes in a pseudochiral omega slab. The dispersion relation, the conditions of the trapped modes, and the evanescent wave coupling and tunneling in two different reciprocal pseudochiral omega slab structures are derived. The Berreman’s matrix method is applied to obtain the transmission coefficients across the pseudochiral omega slab. When the structure is perturbed, a resonance phenomenon is detected around the trapped modes. This resonance results in transmission anomalies (total transmission and total reflection) and dramatic field amplifications around the trapped modes. The number of the discrete trapped modes and then the resonance frequencies are prescribed by the parameters of the pseudochiral omega slab such as the value of the omega parameter and its orientation and the slab thickness. PMID:28165058

  19. Numerical Study of FRP Reinforced Concrete Slabs at Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Masoud Adelzadeh

    2014-02-01

    Full Text Available One-way glass fibre reinforced polymer (GFRP reinforced concrete slabs at elevated temperatures are investigated through numerical modeling. Serviceability and strength requirements of ACI-440.1R are considered for the design of the slabs. Diagrams to determine fire endurance of slabs by employing “strength domain” failure criterion are presented. Comparisons between the existing “temperature domain” method with the more representative “strength domain” method show that the “temperature domain” method is conservative. Additionally, a method to increase the fire endurance of slabs by placing FRP reinforcement in two layers is investigated numerically. The amount of fire endurance gained by placing FRP in two layers increases as the thickness of slab increases.

  20. Punching strength of reinforced concrete flat slabs without shear reinforcement

    Directory of Open Access Journals (Sweden)

    P. V. P. Sacramento

    Full Text Available Punching strength is a critical point in the design of flat slabs and due to the lack of a theoretical method capable of explaining this phenomenon, empirical formulations presented by codes of practice are still the most used method to check the bearing capacity of slab-column connections. This paper discusses relevant aspects of the development of flat slabs, the factors that influence the punching resistance of slabs without shear reinforcement and makes comparisons between the experimental results organized in a database with 74 slabs carefully selected with theoretical results using the recommendations of ACI 318, EUROCODE 2 and NBR 6118 and also through the Critical Shear Crack Theory, presented by Muttoni (2008 and incorporated the new fib Model Code (2010.

  1. Electromagnetic Tunneling and Resonances in Pseudochiral Omega Slabs.

    Science.gov (United States)

    Razzaz, Faroq; Alkanhal, Majeed A S

    2017-02-06

    This paper presents theoretical investigation of the electromagnetic wave tunneling and anomalous transmission around the trapped modes in a pseudochiral omega slab. The dispersion relation, the conditions of the trapped modes, and the evanescent wave coupling and tunneling in two different reciprocal pseudochiral omega slab structures are derived. The Berreman's matrix method is applied to obtain the transmission coefficients across the pseudochiral omega slab. When the structure is perturbed, a resonance phenomenon is detected around the trapped modes. This resonance results in transmission anomalies (total transmission and total reflection) and dramatic field amplifications around the trapped modes. The number of the discrete trapped modes and then the resonance frequencies are prescribed by the parameters of the pseudochiral omega slab such as the value of the omega parameter and its orientation and the slab thickness.

  2. Drug release from slabs and the effects of surface roughness.

    Science.gov (United States)

    Kalosakas, George; Martini, Dimitra

    2015-12-30

    We discuss diffusion-controlled drug release from slabs or thin films. Analytical and numerical results are presented for slabs with flat surfaces, having a uniform thickness. Then, considering slabs with rough surfaces, the influence of a non-uniform slab thickness on release kinetics is numerically investigated. The numerical release profiles are obtained using Monte Carlo simulations. Release kinetics is quantified through the stretched exponential (or Weibull) function and the resulting dependence of the two parameters of this function on the thickness of the slab, for flat surfaces, and the amplitude of surface fluctuations (or the degree of thickness variability) in case of roughness. We find that a higher surface roughness leads to a faster drug release. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Characterizing wet slab and glide slab avalanche occurrence along the Going-to-the-Sun Road, Glacier National Park, Montana, USA

    Science.gov (United States)

    Peitzsch, Erich H.; Hendrikx, Jordy; Fagre, Daniel B.; Reardon, Blase

    2010-01-01

    Wet slab and glide slab snow avalanches are dangerous and yet can be particularly difficult to predict. Both wet slab and glide slab avalanches are thought to depend upon free water moving through the snowpack but are driven by different processes. In Glacier National Park, Montana, both types of avalanches can occur in the same year and affect the Going-to-the-Sun Road (GTSR). Both wet slab and glide slab avalanches along the GTSR from 2003-2010 are investigated. Meteorological data from two high-elevation weather stations and one SNOTEL site are used in conjunction with an avalanche database and snowpit profiles. These data were used to characterize years when only glide slab avalanches occurred and those years when both glide slab and wet slab avalanches occurred. Results of 168 glide slab and 57 wet slab avalanches along the GTSR suggest both types of avalanche occurrence depend on sustained warming periods with intense solar radiation (or rain on snow) to produce free water in the snowpack. Differences in temperature and net radiation metrics between wet slab and glide slab avalanches emerge as one moves from one day to seven days prior to avalanche occurrence. On average, a more rapid warming precedes wet slab avalanche occurrence. Glide slab and wet slab avalanches require a similar amount of net radiation. Wet slab avalanches do not occur every year, while glide slab avalanches occur annually. These results aim to enhance understanding of the required meteorological conditions for wet slab and glide slab avalanches and aid in improved wet snow avalanche forecasting.

  4. General Course of Failure Distributions at Complex Machineries

    Directory of Open Access Journals (Sweden)

    Naqib Daneshjo

    2017-02-01

    Full Text Available In the process of maintenance management of machinery and devices there is necessity to keep in the mind "construction technologicity” (ability of construction technology. This term is used in evaluating of machinery construction, their groups and components in terms of production. The aim of management and planning maintenance of machinery is the failure-free operation in the application process. The range of machinery maintenance machines from routine one and inspection to general repairs is important to organize in a way to prevent unplanned idle time and failures or very likely to accidents.

  5. Software sensor for slab reheating furnace

    Institute of Scientific and Technical Information of China (English)

    Zhihua Xiong; Guohong Huang; Huihe Shao

    2005-01-01

    It has long been thought that a reheating furnace, with its inherent measurement difficulties and complex dynamics, posed almost insurmountable problems to engineers in steel plants. A novel software sensor is proposed to make more effective use of those measurements that are already available, which has great importance both to slab quality and energy saving. The proposed method is based on the mixtures of Gaussian processes (GP) with the expectation maximization (EM) algorithm employed for parameter estimation of the mixture of models. The mixture model can alleviate the computational complexity of GP and also accords with the changes of operating condition in practical processes. It is demonstrated by on-line estimation of the furnace gas temperature in 1580 reheating furnace in Baosteel Corporation (Group).

  6. Laser applications in machining slab materials

    Science.gov (United States)

    Zhang, Xiaoping

    1990-10-01

    Since the invention of the laser back in 1960, laser technology has been extensively applied in many fields of science and technology. These has been a history of nearly two decades of using lasers as an energy source in machining materials, such as cutting, welding, ruling and boring, among other operations. With the development of flexible automation in production, the advantages of laser machining have has grown more and more obvious. The combination of laser technology and computer science further promotes the enhancement and upgrading of laser machining and related equipment. At present, many countries are building high quality laser equipment for machining slab materials, such as the Coherent and Spectra Physics corporations in the United States, the Trumpf Corporation in West Germany, the Amada Corporation in Japan, and the Bystronic Corporation in Switzerland, among other companies.

  7. Half-disordered photonic crystal slabs.

    Science.gov (United States)

    Beque, V; Keilman, J; Citrin, D S

    2016-08-10

    Optical transmission spectra of finite-thickness slabs of two-dimensional triangular-lattice photonic crystals of air holes in a dielectric matrix with various concentrations of randomly located vacancies (absent air holes) are studied. We focus on structures in which only one half of the structure-the incidence or transmission side-is disordered. We find vacancy-induced scattering gives rise to a strong difference in the two cases; for light incident on the disordered side, high transmission within the photonic pseudogap at normal incidence is predicted, in strong contrast to the opposite case, where low transmission is predicted throughout the pseudogap, as is observed in the case of an ideal structure with no defects.

  8. Accessorizing the human mitochondrial transcription machinery.

    Science.gov (United States)

    Bestwick, Megan L; Shadel, Gerald S

    2013-06-01

    The human genome comprises large chromosomes in the nucleus and mitochondrial DNA (mtDNA) housed in the dynamic mitochondrial network. Human cells contain up to thousands of copies of the double-stranded, circular mtDNA molecule that encodes essential subunits of the oxidative phosphorylation complexes and the rRNAs and tRNAs needed to translate these in the organelle matrix. Transcription of human mtDNA is directed by a single-subunit RNA polymerase, POLRMT, which requires two primary transcription factors, TFB2M (transcription factor B2, mitochondrial) and TFAM (transcription factor A, mitochondrial), to achieve basal regulation of the system. Here, we review recent advances in understanding the structure and function of the primary human transcription machinery and the other factors that facilitate steps in transcription beyond initiation and provide more intricate control over the system. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. On the mechanochemical machinery underlying chromatin remodeling

    Science.gov (United States)

    Yusufaly, Tahir I.

    This dissertation discuss two recent efforts, via a unique combination of structural bioinformatics and density functional theory, to unravel some of the details concerning how molecular machinery within the eukaryotic cell nucleus controls chromatin architecture. The first, a study of the 5-methylation of cytosine in 5'-CG-3' : 5'-CG-3' base-pair steps, reveals that the methyl groups roughen the local elastic energy landscape of the DNA. This enhances the probability of the canonical B-DNA structure transitioning into the undertwisted A-like and overtwisted C-like forms seen in nucleosomes, or looped segments of DNA bound to histones. The second part focuses on the formation of salt bridges between arginine residues in histones and phosphate groups on the DNA backbone. The arginine residues are ob- served to apply a tunable mechanical load to the backbone, enabling precision-controlled activation of DNA deformations.

  10. Numerical Noise Prediction in Fluid Machinery

    Institute of Scientific and Technical Information of China (English)

    Iris PANTLE; Franco MAGAGNATO; Martin GABI

    2005-01-01

    Numerical methods successively became important in the design and optimization of fluid machinery. However,as noise emission is considered, one can hardly find standardized prediction methods combining flow and acoustical optimization. Several numerical field methods for sound calculations have been developed. Due to the complexity of the considered flow, approaches must be chosen to avoid exhaustive computing. In this contribution the noise of a simple propeller is investigated. The configurations of the calculations comply with an existing experimental setup chosen for evaluation. The used in-house CFD solver SPARC contains an acoustic module based on Ffowcs Williams-Hawkings Acoustic Analogy. From the flow results of the time dependent Large Eddy Simulation the time dependent acoustic sources are extracted and given to the acoustic module where relevant sound pressure levels are calculated. The difficulties, which arise while proceeding from open to closed rotors and from gas to liquid are discussed.

  11. Effect of amyloids on the vesicular machinery: implications for somatic neurotransmission.

    Science.gov (United States)

    Das, Anand Kant; Pandit, Rucha; Maiti, Sudipta

    2015-07-01

    Certain neurodegenerative diseases are thought to be initiated by the aggregation of amyloidogenic proteins. However, the mechanism underlying toxicity remains obscure. Most of the suggested mechanisms are generic in nature and do not directly explain the neuron-type specific lesions observed in many of these diseases. Some recent reports suggest that the toxic aggregates impair the synaptic vesicular machinery. This may lead to an understanding of the neuron-type specificity observed in these diseases. A disruption of the vesicular machinery can also be deleterious for extra-synaptic, especially somatic, neurotransmission (common in serotonergic and dopaminergic systems which are specifically affected in Alzheimer's disease (AD) and Parkinson's disease (PD), respectively), though this relationship has remained unexplored. In this review, we discuss amyloid-induced damage to the neurotransmitter vesicular machinery, with an eye on the possible implications for somatic exocytosis. We argue that the larger size of the system, and the availability of multi-photon microscopy techniques for directly visualizing monoamines, make the somatic exocytosis machinery a more tractable model for understanding the effect of amyloids on all types of vesicular neurotransmission. Indeed, exploring this neglected connection may not just be important, it may be a more fruitful route for understanding AD and PD.

  12. Special characteristics of the transcription and splicing machinery in photoreceptor cells of the mammalian retina.

    Science.gov (United States)

    Derlig, Kristin; Giessl, Andreas; Brandstätter, Johann Helmut; Enz, Ralf; Dahlhaus, Regina

    2015-11-01

    Chromatin organization and the management of transcription and splicing are fundamental to the correct functioning of every cell but, in particular, for highly active cells such as photoreceptors, the sensory neurons of the retina. Rod photoreceptor cells of nocturnal animals have recently been shown to have an inverted chromatin architecture compared with rod photoreceptor cells of diurnal animals. The heterochromatin is concentrated in the center of the nucleus, whereas the genetically active euchromatin is positioned close to the nuclear membrane. This unique chromatin architecture suggests that the transcription and splicing machinery is also subject to specific adaptations in these cells. Recently, we described the protein Simiate, which is enriched in nuclear speckles and seems to be involved in transcription and splicing processes. Here, we examine the distribution of Simiate and nuclear speckles in neurons of mouse retinae. In retinal neurons of the inner nuclear and ganglion cell layer, Simiate is concentrated in a clustered pattern in the nuclear interior, whereas in rod and cone photoreceptor cells, Simiate is present at the nuclear periphery. Further staining with markers for the transcription and splicing machinery has confirmed the localization of nuclear speckle components at the periphery. Comparing the distribution of nuclear speckles in retinae of the nocturnal mouse with the diurnal degu, we found no differences in the arrangement of the transcription and splicing machinery in their photoreceptor cells, thus suggesting that the organization of these machineries is not related to the animal's lifestyle but rather represents a general characteristic of photoreceptor organization and function.

  13. Evolution of the genetic machinery of the visual cycle: a novelty of the vertebrate eye?

    Science.gov (United States)

    Albalat, Ricard

    2012-05-01

    The discovery in invertebrates of ciliary photoreceptor cells and ciliary (c)-opsins established that at least two of the three elements that characterize the vertebrate photoreceptor system were already present before vertebrate evolution. However, the origin of the third element, a series of biochemical reactions known as the "retinoid cycle," remained uncertain. To understand the evolution of the retinoid cycle, I have searched for the genetic machinery of the cycle in invertebrate genomes, with special emphasis on the cephalochordate amphioxus. Amphioxus is closely related to vertebrates, has a fairly prototypical genome, and possesses ciliary photoreceptor cells and c-opsins. Phylogenetic and structural analyses of the amphioxus sequences related with the vertebrate machinery do not support a function of amphioxus proteins in chromophore regeneration but suggest that the genetic machinery of the retinoid cycle arose in vertebrates due to duplications of ancestral nonvisual genes. These results favor the hypothesis that the retinoid cycle machinery was a functional innovation of the primitive vertebrate eye.

  14. Regulation of cytokinesis by membrane trafficking involving small GTPases and the ESCRT machinery.

    Science.gov (United States)

    Nakayama, Kazuhisa

    2016-01-01

    During cell division, cells undergo membrane remodeling to achieve changes in their size and shape. In addition, cell division entails local delivery and retrieval of membranes and specific proteins as well as remodeling of cytoskeletons, in particular, upon cytokinetic abscission. Accumulating lines of evidence highlight that endocytic membrane removal from and subsequent membrane delivery to the plasma membrane are crucial for the changes in cell size and shape, and that trafficking of vesicles carrying specific proteins to the abscission site participate in local remodeling of membranes and cytoskeletons. Furthermore, the endosomal sorting complex required for transport (ESCRT) machinery has been shown to play crucial roles in cytokinetic abscission. Here, the author briefly overviews membrane-trafficking events early in cell division, and subsequently focus on regulation and functional significance of membrane trafficking involving Rab11 and Arf6 small GTPases in late cytokinesis phases and assembly of the ESCRT machinery in cytokinetic abscission.

  15. Behavior of FRP Link Slabs in Jointless Bridge Decks

    Directory of Open Access Journals (Sweden)

    Aziz Saber

    2012-01-01

    Full Text Available The paper investigated the use of fiberglass-reinforced plastic (FRP grid for reinforcement in link slabs for jointless bridge decks. The design concept of link slab was examined based on the ductility of the fiberglass-reinforced plastic grid to accommodate bridge deck deformations. The implementation of hybrid simulation assisted in combining the experimental results and the theoretical work. The numerical analyses and the experimental work investigated the behavior of the link slab and confirmed its feasibility. The results indicated that the technique would allow simultaneous achievement of structural need, lower flexural stiffness of the link slab approaching the behavior of a hinge, and sustainability need of the link slab. The outcome of the study supports the contention that jointless concrete bridge decks may be designed and constructed with fiberglass-reinforced plastic grid link slabs. This concept would also provide a solution to a number of deterioration problems associated with bridge deck joints and can be used during new construction of bridge decks. The federal highway administration provided funds to Louisiana Department of Transportation through the innovative bridge research and development program to implement the use of FRP grid as link slab.

  16. Power dissipation and temperature distribution in piezoelectric ceramic slabs.

    Science.gov (United States)

    Thomas, D; Ebenezer, D D; Srinivasan, Sivakumar M

    2010-10-01

    A method is presented to determine power dissipation in one-dimensional piezoelectric slabs with internal losses and the resulting temperature distribution. The length of the slab is much greater than the lateral dimensions. Losses are represented using complex piezoelectric coefficients. It is shown that the spatially non-uniform power dissipation density in the slab can be determined by considering either hysteresis loops or the Poynting vector. The total power dissipated in the slab is obtained by integrating the power dissipation density over the slab and is shown to be equal to the power input to the slab for special cases of mechanically and electrically excited slabs. The one-dimensional heat equation that includes the effect of conduction and convection, and the boundary conditions, are then used to determine the temperature distribution. When the analytical expression for the power dissipation density is simple, direct integration is used. It is shown that a modified Fourier series approach yields the same results. For other cases, the temperature distribution is determined using only the latter approach. Numerical results are presented to illustrate the effects of internal losses, heat conduction and convection coefficients, and boundary conditions on the temperature distribution.

  17. Impact Resistance Behaviour of Banana Fiber Reinforced Slabs

    Science.gov (United States)

    Che Muda, Zakaria; Syamsir, Agusril; Nasharuddin Mustapha, Kamal; Rifdy Samsudin, Muhamad; Thiruchelvam, Sivadass; Usman, Fathoni; Beddu, Salmia; Liyana Mohd Kamal, Nur; Ashraful Alam, Md; Birima, Ahmed H.; Zaroog, O. S.

    2016-03-01

    This paper investigate the performance of banana fibre reinforced slabs 300mm × 300mm size with varied thickness subjected to low impact projectile test. A self-fabricated drop-weight impact test rig with a steel ball weight of 1.25 kg drop at 1 m height has been used in this research work. The main variables for the study is to find the relationship of the impact resistance against the BF contents and slab thickness. A linear relationship has been established between first and ultimate crack resistance against BF contents and slab thickness by the experiment. The linear relationship has also been established between the service (first) crack and ultimate crack resistance against the BF contents for a constant spacing for various banana fibre reinforced slab thickness. The increment in BF content has more effect on the first crack resistance than the ultimate crack resistance. The linear relationship has also been established between the service (first) crack and ultimate crack resistance against the various slab thickness. Overall 1.5% BF content with slab thickness of 40 mm exhibit better first and ultimate crack resistance up to 16 times and up to 17 times respectively against control slab (without BF)

  18. Exact exchange plane-wave-pseudopotential calculations for slabs.

    Science.gov (United States)

    Engel, Eberhard

    2014-05-14

    The exact exchange of density functional theory is applied to both free-standing graphene and a Si(111) slab, using the plane-wave pseudopotential (PWPP) approach and a periodic repetition of the supercell containing the slab. It is shown that (i) PWPP calculations with exact exchange for slabs in supercell geometry are basically feasible, (ii) the width of the vacuum required for a decoupling of the slabs is only moderately larger than in the case of the local-density approximation, and (iii) the resulting exchange potential vx shows an extended region, both far outside the surface of the slab and far from the middle of the vacuum region between the slabs, in which vx behaves as -e(2)/z, provided the width of the vacuum is chosen sufficiently large. This last result is corroborated by an analytical analysis of periodically repeated jellium slabs. The intermediate -e(2)/z behavior of vx can be used for an absolute normalization of vx and the total Kohn-Sham potential, which, in turn, allows the determination of the work function.

  19. A modularized pulse forming line using glass-ceramic slabs.

    Science.gov (United States)

    Wang, Songsong; Shu, Ting; Yang, Hanwu

    2012-08-01

    In our lab, a kind of glass-ceramic slab has been chosen to study the issues of applying solid-state dielectrics to pulse forming lines (PFLs). Limited by the manufacture of the glass-ceramic bulk with large sizes, a single ceramic slab is hard to store sufficient power for the PFL. Therefore, a modularized PFL design concept is proposed in this paper. We regard a single ceramic slab as a module to form each single Blumlein PFL. We connect ceramic slabs in series to enlarge pulse width, and stack the ceramic Blumlein PFLs in parallel to increase the output voltage amplitude. Testing results of a single Blumlein PFL indicate that one ceramic slab contributes about 11 ns to the total pulse width which has a linear relation to the number of the ceramic slabs. We have developed a prototype facility of the 2-stage stacked Blumlein PFL with a length of 2 ceramic slabs. The PFL is dc charged up to 5 kV, and the output voltage pulse of 10 kV, 22 ns is measured across an 8 Ω load. Simulation and experiment results in good agreement demonstrate that the modularized design is reasonable.

  20. Comparison between Ribbed Slab Structure using Lightweight Foam Concrete and Solid Slab Structure using Normal Concrete

    Directory of Open Access Journals (Sweden)

    Mohd Zailan Sulieman

    2010-03-01

    Full Text Available

    The aim of this study is to demonstrate that one-way ribbed slab with lightweight foam concrete can be used to reduce the dead load on slab concrete structure. This would allow the structural designer to reduce the size of column, footing and other load

  1. Machinery failure analysis and troubleshooting practical machinery management for process plants

    CERN Document Server

    Bloch, Heinz P

    2012-01-01

    Solve the machinery failure problems costing you time and money with this classic, comprehensive guide to analysis and troubleshooting  Provides detailed, complete and accurate information on anticipating risk of component failure and avoiding equipment downtime Includes numerous photographs of failed parts to ensure you are familiar with the visual evidence you need to recognize Covers proven approaches to failure definition and offers failure identification and analysis methods that can be applied to virtually all problem situations Demonstr

  2. The Place of RNA in the Origin and Early Evolution of the Genetic Machinery

    OpenAIRE

    Günter Wächtershäuser

    2014-01-01

    The extant genetic machinery revolves around three interrelated polymers: RNA, DNA and proteins. Two evolutionary views approach this vital connection from opposite perspectives. The RNA World theory posits that life began in a cold prebiotic broth of monomers with the de novo emergence of replicating RNA as functionally self-contained polymer and that subsequent evolution is characterized by RNA → DNA memory takeover and ribozyme → enzyme catalyst takeover. The FeS World theory posits that l...

  3. A near death experience: Shigella manipulates host death machinery to silence innate immunity.

    Science.gov (United States)

    Bronner, Denise N; O'Riordan, Mary Xd

    2014-10-01

    Release of mitochondrial contents often triggers inflammation and cell death, and modulating this process can be advantageous to invading pathogens. In this issue of The EMBO Journal, Andree and colleagues reveal new findings that an intracellular bacterial pathogen exploits apoptotic machinery to suppress host immune signaling, yet avoids cell death. This study emphasizes the need to expand our understanding of the roles played by pro‐apoptotic proteins in non‐death scenarios.

  4. Pink1 regulates mitochondrial dynamics through interaction with the fission/fusion machinery

    OpenAIRE

    Yang, Yufeng; Ouyang, Yingshi; Yang, Lichuan; Beal, M. Flint; McQuibban, Angus; Vogel, Hannes; Lu, Bingwei

    2008-01-01

    Mitochondria form dynamic tubular networks that undergo frequent morphological changes through fission and fusion, the imbalance of which can affect cell survival in general and impact synaptic transmission and plasticity in neurons in particular. Some core components of the mitochondrial fission/fusion machinery, including the dynamin-like GTPases Drp1, Mitofusin, Opa1, and the Drp1-interacting protein Fis1, have been identified. How the fission and fusion processes are regulated under norma...

  5. Industrial Machinery Maintenance and Repair. Florida Vocational Program Guide.

    Science.gov (United States)

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    This vocational program guide is intended to assist in the organization, operation, and evaluation of a program in industrial machinery maintenance and repair in school districts, area vocational centers, and community colleges. The following topics are covered: job duties of millwrights, maintenance mechanics, and machinery erectors; program…

  6. Recession Hits China’s Textile Machinery Markets

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China’s textile machinery industry saw a continued decline intotaI profit and a hefty slump in imports and exports in the first twomonths this year.Analysts anticipated a continued weakening ofmomentum for China’s textile machinery markets owing to weakerconsumer spending and easing export growth.

  7. ITALIAN TEXTILE MACHINERY WORKSHOP IN SUZHOU(CHINA)

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Association of Italian Textile Machinery Manufacturers (ACIMIT)and the Italian Trade Commission(ICE)held a technical workshop on Italian textile machinery for the production of technical textiles and nonwovens in China.The workshop occurred in Suzhou(Juangsu Province),on May 24th-25th,2007.

  8. 46 CFR 282.23 - Hull and machinery insurance.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Hull and machinery insurance. 282.23 Section 282.23... COMMERCE OF THE UNITED STATES Calculation of Subsidy Rates § 282.23 Hull and machinery insurance. (a) Subsidy items. The fair and reasonable net premium costs (including stamp taxes) of hull and...

  9. 46 CFR 111.103-9 - Machinery stop stations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery stop stations. 111.103-9 Section 111.103-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-9 Machinery stop stations. (a) Each forced...

  10. Occupational incidents with self-propelled machinery in Austrian agriculture.

    Science.gov (United States)

    Mayrhofer, Hannes; Quendler, Elisabeth; Boxberger, Josef

    2013-01-01

    Tractors, self-propelled harvesting machinery, and material handling machinery are the most commonly used self-propelled machineries in Austrian agriculture, and they have similarities in main accident scenarios. Statistical data of all occupational incidents with these machines reported between 2008 and 2010 were analyzed to obtain information about the circumstances of the incidents, and about the victims and their work environments. Criteria of recognized occupational incidents provided by the Austrian Social Insurance Institution for Farmers were analyzed according to machinery category by means of cross-tabulation and chi-square tests. The results were discussed and evaluated in the context of the literature. The results of the analysis of the databases show that 786 occupational incidents with tractors, self-propelled harvesting machinery, and material handling machinery occurred in Austrian agriculture between 2008 and 2010. There were 231 occupational incidents in 2008; the number rose to 268 in 2009 and to 286 in 2010. A total of 41 incidents were fatal. For the machinery categories analyzed, the majority of injured victims were male, older than 40 years, Austrian citizens, and managers of a mixed-agricultural farm. A large number of the incidents occurred in all machinery categories by loss of control during operating a vehicle.

  11. Origins and early evolution of the translation machinery

    Science.gov (United States)

    Fox, George E.

    2010-09-01

    The modern ribosome is a complex biological machine that is responsible for chiral synthesis of cellular proteins according to the genetic code as specified by a mRNA. Major portions of the ribosomal machinery were likely in place before the last universal common ancestor (LUCA) of life. The early evolution of the ribosome has implications for the origin of the genetic code, the emergence of chirality in peptide synthesis, and the emergence of LUCA. Although codon assignments may remain a mystery, the history of the ribosome provides a context for dating the first usage of mRNA. In the case of chirality, the modern ribosome suggests that a small initial chiral preference for L-amino acids in the environment may have been greatly enhanced by a two step process in which the charging of a primitive tRNA and the subsequent synthesis of a peptide bond both had the same chiral preference. The resulting ability to make largely chiral peptides may have provided an advantage over other prebiotic mechanisms for making peptides. Finally, the late addition of factors such as EF-G may have greatly accelerated the emerging ribosome's ability to synthesize proteins, thereby allowing entities with this novel capability to emerge as the LUCA.

  12. Broadband high reflectivity in subwavelength-grating slab waveguides

    CERN Document Server

    Cui, Xuan; Zhou, Zhongxiang

    2015-01-01

    We computationally study a subwavelength dielectric grating structure, show that slab waveguide modes can be used to obtain broadband high reflectivity, and analyze how slab waveguide modes influence reflection. A structure showing interference between Fabry-Perot modes, slab waveguide modes, and waveguide array modes is designed with ultra-broadband high reflectivity. Owing to the coupling of guided modes, the region with reflectivity R > 0.99 has an ultra-high bandwidth ( {\\Delta}f/f > 30%). The incident-angle region with R > 0.99 extends over a range greater than 40{\\deg}. Moreover, an asymmetric waveguide structure is studied using a semiconductor substrate.

  13. Fringe integral equation method for a truncated grounded dielectric slab

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Maci, S.; Toccafondi, A.

    2001-01-01

    The problem of scattering by a semi-infinite grounded dielectric slab illuminated by an arbitrary incident TMz polarized electric field is studied by solving a new set of “fringe” integral equations (F-IEs), whose functional unknowns are physically associated to the wave diffraction processes...... occurring at the truncation. The F-IEs are obtained by subtracting from the surface/surface integral equations pertinent to the truncated slab, an auxiliary set of equations obtained for the canonical problem of an infinite grounded slab illuminated by the same source. The F-IEs are solved by the method...

  14. Performance and damages of R.C. slabs in fire

    DEFF Research Database (Denmark)

    Giuliani, Luisa; Gentili, Filippo

    2015-01-01

    slabs with complex geometry exposed to fire and assessing the entity of the damage on the basis of the decrement of the load bearing capacity at the end of the fire. By considering this quantity for different time of exposure to a standard fire, a curve is obtained that provides important information...... on the vulnerability of the slab to the fire action and can be used for optimizing the design on the basis of the required class of resistance or for choosing between different slab alternatives....

  15. Interaction of an ion bunch with a plasma slab

    Energy Technology Data Exchange (ETDEWEB)

    Krasovitskiy, V. B., E-mail: krasovit@mail.ru [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Turikov, V. A. [Peoples’ Friendship University of Russia (Russian Federation)

    2016-11-15

    Charge neutralization of a short ion bunch passing through a plasma slab is studied by means of numerical simulation. It is shown that a fraction of plasma electrons are trapped by the bunch under the action of the collective charge separation field. The accelerated electrons generated in this process excite beam−plasma instability, thereby violating the trapping conditions. The process of electron trapping is also strongly affected by the high-frequency electric field caused by plasma oscillations at the slab boundaries. It is examined how the degree of charge neutralization depends on the parameters of the bunch and plasma slab.

  16. Light-assisted templated self assembly using photonic crystal slabs.

    Science.gov (United States)

    Mejia, Camilo A; Dutt, Avik; Povinelli, Michelle L

    2011-06-06

    We explore a technique which we term light-assisted templated self-assembly. We calculate the optical forces on colloidal particles over a photonic crystal slab. We show that exciting a guided resonance mode of the slab yields a resonantly-enhanced, attractive optical force. We calculate the lateral optical forces above the slab and predict that stably trapped periodic patterns of particles are dependent on wavelength and polarization. Tuning the wavelength or polarization of the light source may thus allow the formation and reconfiguration of patterns. We expect that this technique may be used to design all-optically reconfigurable photonic devices.

  17. 46 CFR 119.465 - Ventilation of spaces containing diesel machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation of spaces containing diesel machinery. 119... MACHINERY INSTALLATION Specific Machinery Requirements § 119.465 Ventilation of spaces containing diesel machinery. (a) A space containing diesel machinery must be fitted with adequate means, such as...

  18. Hierarchal order in the formation of chloroplast division machinery in the red alga Cyanidioschyzon merolae.

    Science.gov (United States)

    Sumiya, Nobuko; Miyagishima, Shin-Ya

    2017-01-01

    Chloroplasts have evolved from a cyanobacterial endosymbiont and multiply by dividing. Chloroplast division is performed by constriction of the ring-like protein complex (the PD machinery), which forms at the division site. The PD machinery is composed of cyanobacteria-descended components such as FtsZ and eukaryote-derived proteins such as the dynamin-related protein, DRP5B. In the red alga Cyanidioschyzon merolae, FtsZ ring formation on the stromal side precedes PDR1 and DRP5B ring formation on the cytosolic side. In this study, we impaired FtsZ ring formation in C. merolae by overexpressing FtsZ just before FtsZ ring formation. As a result, PDR1 and DRP5B failed to localize at the chloroplast division site, suggesting that FtsZ ring formation is required for the PDR1 and DRP5B rings. We further found, by expressing a dominant negative form of DRP5B, that DRP5B ring formation begins on the nuclear side of the chloroplast division site. These findings provide insight into how the PD machinery forms in red algae.

  19. The unconventional Xer recombination machinery of Streptococci/Lactococci.

    Directory of Open Access Journals (Sweden)

    Pascal Le Bourgeois

    2007-07-01

    Full Text Available Homologous recombination between circular sister chromosomes during DNA replication in bacteria can generate chromosome dimers that must be resolved into monomers prior to cell division. In Escherichia coli, dimer resolution is achieved by site-specific recombination, Xer recombination, involving two paralogous tyrosine recombinases, XerC and XerD, and a 28-bp recombination site (dif located at the junction of the two replication arms. Xer recombination is tightly controlled by the septal protein FtsK. XerCD recombinases and FtsK are found on most sequenced eubacterial genomes, suggesting that the Xer recombination system as described in E. coli is highly conserved among prokaryotes. We show here that Streptococci and Lactococci carry an alternative Xer recombination machinery, organized in a single recombination module. This corresponds to an atypical 31-bp recombination site (dif(SL associated with a dedicated tyrosine recombinase (XerS. In contrast to the E. coli Xer system, only a single recombinase is required to recombine dif(SL, suggesting a different mechanism in the recombination process. Despite this important difference, XerS can only perform efficient recombination when dif(SL sites are located on chromosome dimers. Moreover, the XerS/dif(SL recombination requires the streptococcal protein FtsK(SL, probably without the need for direct protein-protein interaction, which we demonstrated to be located at the division septum of Lactococcus lactis. Acquisition of the XerS recombination module can be considered as a landmark of the separation of Streptococci/Lactococci from other firmicutes and support the view that Xer recombination is a conserved cellular function in bacteria, but that can be achieved by functional analogs.

  20. Numerical Calculation of Concrete Slab Response to Blast Loading

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiaoqing; HAO Hong; KUZNETSOV Valerian A; WASCHL John

    2006-01-01

    In the present paper,a dynamic plastic damage model for concrete has been employed to estimate responses of a reinforced concrete slab subjected to blast loading.The interaction between the blast wave and the concrete slab is considered in 3D simulation.In the first stage,the initial detonation and blast wave propagation is modelled in 2D simulation before the blast wave reaches the concrete slab,then the results obtained from 2D calculation are remapped to a 3D model.The calculated blast load is compared with that obtained from TM5-1300.Numerical results of the concrete slab response are compared with the explosive test carried out in the Weapons System Division,Defence Science and Technology Organisation,Department of Defence,Australia.

  1. Active split-ring metamaterial slabs for magnetic resonance imaging

    CERN Document Server

    Lopez, Marcos A; Freire, Manuel J; Behr, Volker C; Jakob, Peter M; Marques, Ricardo

    2011-01-01

    In this work, it is analyzed the ability of split-ring metamaterial slabs with zero/high permeability to reject/confine the radiofrequency magnetic field in magnetic resonance imaging systems. Using an homogenization procedure, split-ring slabs have been designed and fabricated to work in a 1.5T system. Active elements consisting of pairs of crossed diodes are inserted in the split-rings. With these elements, the permeability of the slabs can be automatically switched between a unity value when interacting with the strong excitation field of the transmitting body coil, and zero or high values when interacting with the weak field produced by protons in tissue. Experiments are shown for different configurations where these slabs can help to locally increase the signal-to-noise-ratio.

  2. Formation mechanism of internal cracks in continuously cast slab

    Institute of Scientific and Technical Information of China (English)

    Guosen Zhu; Xinhua Wang; Huixiang Yu; Jiongming Zhang; Wanjun Wang

    2004-01-01

    In order to make clear the formation mechanism of centerline cracks in continuously cast slabs, the form, distribution and other characteristics of the cracks were analyzed. The final solidification point, surface temperature of the slabs and strain in solidifying shell were investigated. The results were that: (1) Five relatively low temperature zones exist on slab surface below the three water spraying nozzles and near the two edges, respectively, which corresponds to the places of centerline cracks and triangle-zone cracks. (2) Centerline cracks and triangle-zone cracks occur because of weak secondary cooling, uneven cooling along slab width,and large variation of roll gap. (3) After minimizing the variation of roll gap and applying the new secondary cooling pattern, the occurring frequency of centerline and triangle-zone cracks minimizes to zero.

  3. Waveform effects of a metastable olivine tongue in subducting slabs

    Science.gov (United States)

    Vidale, John E.; Williams, Quentin; Houston, Heidi

    1991-01-01

    Velocity models of subducting slabs with a kinetically-depressed olivine to beta- and gamma-spinel transition are constructed, and the effect that such structures would have on teleseismic P waveforms are examined using a full-wave finite-difference method. These 2D calculations yielded waveforms at a range of distances in the downdip direction. The slab models included a wedge-shaped, low-velocity metastable olivine tongue (MOTO) to a depth of 670 km, as well as a plausible thermal anomaly; one model further included a 10-km-thick fast layer on the surface of the slab. The principal effect of MOTO is to produce grazing reflections at wide angles off the phase boundary, generating a secondary arrival 0 to 4 seconds after the initial arrival depending on the take-off angle. The amplitude and timing of this feature vary with the lateral location of the seismic source within the slab cross-section.

  4. Casimir effect for two lossy dispersive dielectric slabs

    Science.gov (United States)

    Matloob, R.; Keshavarz, A.; Sedighi, D.

    1999-11-01

    The electromagnetic field is quantized using the Green's-function method for the geometry of a Fabry-Perot cavity, made up of two identical lossy dispersive slabs of finite thickness. The dielectric functions of the slabs are assumed to be an arbitrary complex function of frequency obeying causality requirements. The attractive Casimir force between the two slabs is calculated by the help of the latter field operators, via evaluating the difference between the vacuum pressures on both sides of each slab. Special attention is paid to the limiting case of the Casimir effect for two conducting plates. The Lorentz model of the dielectric function is used to demonstrate the variation of the force in terms of plasma frequency. The Casimir force expression is also related to the imaginary part of the response function. The latter expression is used to introduce the repulsive Casimir force between two conducting plates located inside a Fabry-Perot cavity.

  5. Innovation on RC Waffle and Ribbed Slab Analysis Models

    Directory of Open Access Journals (Sweden)

    P. Hájek

    2000-01-01

    Full Text Available Waffle and ribbed reinforced concrete slabs are widely used in building constructions in view of the flexibility design and structural efficiency. The wide range of reinforced concrete and composite waffle and ribbed slabs has been theoretically analysed and tested from the point of view of structural behaviour within the research performed in the last years. The results of the experimental investigation, supported by theoretical conclusions, have confirmed significantly better structural properties of the composite waffle slabs (composed from RC and ceramic fillers than the assumptions usually considered in common analysis models. New analysis equivalent models for structural analysis RC and composite waffle and ribbed structures have been developed and compared with the test results. In the paper are presented some generalized conclusions as a basis for the formulation of principles of an optimized design of RC waffle and ribbed slab structures.

  6. Radiative Transfer Model for Translucent Slab Ice on Mars

    Science.gov (United States)

    Andrieu, F.; Schmidt, F.; Douté, S.; Schmitt, B.; Brissaud, O.

    2016-09-01

    We developed a radiative transfer model that simulates in VIS/NIR the bidirectional reflectance of a contaminated slab layer of ice overlaying a granular medium, under geometrical optics conditions to study martian ices.

  7. Evaluation of precast concrete slabs using a heavy vehicle simulator

    CSIR Research Space (South Africa)

    Kohler, E

    2008-10-01

    Full Text Available -controlled conditions and that fully cured precast slabs can potentially be open to traffic almost immediately upon installation, making them attractive for use on heavily travelled highways. This paper describes an accelerated pavement testing experiment conducted...

  8. Fire resistance of extruded hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    2017-01-01

    Purpose – Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60 and 120 min found...... in most national building regulations. The paper aims to present a detailed analysis of the mechanisms responsible for the loss of loadbearing capacity of hollow-core slabs when exposed to fire. Design/methodology/approach – Furthermore, it compares theoretica calculation and assessment according...... to the structural codes with data derived from a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs. Findings – Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found. Originality...

  9. Hot dense magnetized ultrarelativistic spinor matter in a slab

    CERN Document Server

    Sitenko, Yu A

    2016-01-01

    Properties of hot dense ultrarelativistic spinor matter in a slab of finite width, placed in a transverse uniform magnetic field, are studied. The admissible set of boundary conditions is determined by the requirement that spinor matter be confined inside the slab. In thermal equilibrium, the chiral separation effect in the slab is shown to depend both on temperature and chemical potential; this is distinct from the unrealistic case of the magnetic field filling the unbounded (infinite) medium, when the effect is temperature-independent. In the realistic case of the slab, a stepwise behaviour of the axial current density at zero temperature is smoothed out as temperature increases, turning into a linear behaviour at infinitely large temperature. A choice of boundary conditions can facilitate either augmentation or attenuation of the chiral separation effect; in particular, the effect can persist even at zero chemical potential, if temperature is nonzero. Thus the boundary condition can serve as a source that ...

  10. Waveform effects of a metastable olivine tongue in subducting slabs

    Science.gov (United States)

    Vidale, John E.; Williams, Quentin; Houston, Heidi

    1991-01-01

    Velocity models of subducting slabs with a kinetically-depressed olivine to beta- and gamma-spinel transition are constructed, and the effect that such structures would have on teleseismic P waveforms are examined using a full-wave finite-difference method. These 2D calculations yielded waveforms at a range of distances in the downdip direction. The slab models included a wedge-shaped, low-velocity metastable olivine tongue (MOTO) to a depth of 670 km, as well as a plausible thermal anomaly; one model further included a 10-km-thick fast layer on the surface of the slab. The principal effect of MOTO is to produce grazing reflections at wide angles off the phase boundary, generating a secondary arrival 0 to 4 seconds after the initial arrival depending on the take-off angle. The amplitude and timing of this feature vary with the lateral location of the seismic source within the slab cross-section.

  11. Fire resistance of extruded hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Giuliani, Luisa; Sørensen, Lars Schiøtt

    2016-01-01

    Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60- and 120 minutes found in most...... national building regulations. The paper presents a detailed analysis of the mechanisms responsible for the loss of load-bearing capacity of hollow-core slabs when exposed to fire. Furthermore, it compares theoretical calculation and assessment according to the structural codes with data derived from...... a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs. Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found. For the first time the mechanisms responsible for loss of load...

  12. Benchmark study for total enery electrons in thick slabs

    Science.gov (United States)

    Jun, I.

    2002-01-01

    The total energy deposition profiles when highenergy electrons impinge on a thick slab of elemental aluminum, copper, and tungsten have been computed using representative Monte Carlo codes (NOVICE, TIGER, MCNP), and compared in this paper.

  13. Flexural Behavior of Two-Way Sandwiched Slabs

    OpenAIRE

    Pachpande, Jivan Vilas

    2015-01-01

    This dissertation presents the details of the findings of a study focused on evaluating the structural behavior of three-dimensional (3D) cementitious sandwich panels with Expanded Polystyrene (EPS) foam core for two-way slab applications. In this study, both theoretical and finite element numerical analysis procedures were adopted to predict the performance of such slabs under out-of-plane loading conditions. The results from theoretical and finite element analysis were verified by compariso...

  14. Analysis of flat slab building with and without shear wall

    OpenAIRE

    Dhanaji R. Chavan; Mohite D. D.; Dr. C. P. Pise; Pawar Y. P; Kadam S.S.; Deshmukh C. M.

    2016-01-01

    The analytical research carried out to study the behaviour flat slab building with and without shear wall reported in the present work. For analysis 15 storied flat slab building is analyzed for seismic behaviour. Response spectrum method is used for analysis considering different shear wall positions using ETABS software. Five different positions of shear wall were studied for analysis. From this analysis shear wall at core having square shape is most suitable case for construction of shear ...

  15. Analysis of flat slab building with and without shear wall

    Directory of Open Access Journals (Sweden)

    Dhanaji R. Chavan

    2016-10-01

    Full Text Available The analytical research carried out to study the behaviour flat slab building with and without shear wall reported in the present work. For analysis 15 storied flat slab building is analyzed for seismic behaviour. Response spectrum method is used for analysis considering different shear wall positions using ETABS software. Five different positions of shear wall were studied for analysis. From this analysis shear wall at core having square shape is most suitable case for construction of shear wall.

  16. Slab Tracking and Controlling on Hot Plate Rolling Line

    Institute of Scientific and Technical Information of China (English)

    姚小兰; 邓波; 梁启宏; 李保奎

    2004-01-01

    By studying the slab moving in detail in the plate rolling process, the problem of slab tracking and controlling was solved by using the distributed control system. The problems of rhythm control for the big-complex system, the exchange of manual and automatic operations, the data exchange between the levelⅠ, TCS (technology control system) and levelⅡ, PCS (process control system), are solved. By this way, the automatic level of the plate production line is improved.

  17. Problem of punching shear in slabs on culumns

    OpenAIRE

    Bartol, Jože

    2007-01-01

    Existing technical solutions enabling sufficient punching resistance failure of flot slabs were analyzed. The reasons that ultimately lead to punching shear and the consequences of shear punching were examined as well. The main causes of punching shear are the condensed shear stresses in the part of the slab that is in contact with the columns. Symbols used at punching shear and an overlook of elements with appropriate reinforcement calculation were presented. The control exten...

  18. Occupational Accidents with Agricultural Machinery in Austria.

    Science.gov (United States)

    Kogler, Robert; Quendler, Elisabeth; Boxberger, Josef

    2016-01-01

    The number of recognized accidents with fatalities during agricultural and forestry work, despite better technology and coordinated prevention and trainings, is still very high in Austria. The accident scenarios in which people are injured are very different on farms. The common causes of accidents in agriculture and forestry are the loss of control of machine, means of transport or handling equipment, hand-held tool, and object or animal, followed by slipping, stumbling and falling, breakage, bursting, splitting, slipping, fall, and collapse of material agent. In the literature, a number of studies of general (machine- and animal-related accidents) and specific (machine-related accidents) agricultural and forestry accident situations can be found that refer to different databases. From the database Data of the Austrian Workers Compensation Board (AUVA) about occupational accidents with different agricultural machinery over the period 2008-2010 in Austria, main characteristics of the accident, the victim, and the employer as well as variables on causes and circumstances by frequency and contexts of parameters were statistically analyzed by employing the chi-square test and odds ratio. The aim of the study was to determine the information content and quality of the European Statistics on Accidents at Work (ESAW) variables to evaluate safety gaps and risks as well as the accidental man-machine interaction.

  19. Identification and analysis of the RNA degrading complexes and machinery of Giardia lamblia using an in silico approach

    Science.gov (United States)

    2011-01-01

    Background RNA degradation is critical to the survival of all cells. With increasing evidence for pervasive transcription in cells, RNA degradation has gained recognition as a means of regulating gene expression. Yet, RNA degradation machinery has been studied extensively in only a few eukaryotic organisms, including Saccharomyces cerevisiae and humans. Giardia lamblia is a parasitic protist with unusual genomic traits: it is binucleated and tetraploid, has a very compact genome, displays a theme of genomic minimalism with cellular machinery commonly comprised of a reduced number of protein components, and has a remarkably large population of long, stable, noncoding, antisense RNAs. Results Here we use in silico approaches to investigate the major RNA degradation machinery in Giardia lamblia and compare it to a broad array of other parasitic protists. We have found key constituents of the deadenylation and decapping machinery and of the 5'-3' RNA degradation pathway. We have similarly found that all of the major 3'-5' RNA degradation pathways are present in Giardia, including both exosome-dependent and exosome-independent machinery. However, we observe significant loss of RNA degradation machinery genes that will result in important differences in the protein composition, and potentially functionality, of the various RNA degradation pathways. This is most apparent in the exosome, the central mediator of 3'-5' degradation, which apparently contains an altered core configuration in both Giardia and Plasmodium, with only four, instead of the canonical six, distinct subunits. Additionally the exosome in Giardia is missing both the Rrp6, Nab3, and Nrd1 proteins, known to be key regulators of noncoding transcript stability in other cells. Conclusions These findings suggest that although the full complement of the major RNA degradation mechanisms were present - and likely functional - early in eukaryotic evolution, the composition and function of the complexes is more

  20. Repulsive Casimir forces with finite-thickness slabs

    Science.gov (United States)

    Zhao, R.; Koschny, Th.; Economou, E. N.; Soukoulis, C. M.

    2011-02-01

    We use the extended Lifshitz theory to study the behaviors of the Casimir forces between finite-thickness effective medium slabs. We first study the interaction between a semi-infinite Drude metal and a finite-thickness magnetic slab with or without substrate. For no substrate, the large distance d dependence of the force is repulsive and goes as 1/d5; for the Drude metal substrate, a stable equilibrium point appears at an intermediate distance that can be tuned by the thickness of the slab. We then study the interaction between two identical chiral metamaterial slabs, with and without substrate. For no substrate, the finite thickness of the slabs D does not significantly influence the repulsive character of the force at short distances, while the attractive character at large distances becomes weaker and behaves as 1/d6; for the Drude metal substrate, the finite thickness of the slabs D does not influence the repulsive force too much at short distances until D=0.05λ0.

  1. Seismic Evidence for Possible Slab Melting from Strong Scattering Waves

    Directory of Open Access Journals (Sweden)

    Cheng-Horng Lin

    2011-01-01

    Full Text Available Slab melting in young and hot subduction zones has been studied using geochemical observations and thermal modelling, but there are few data from seismic studies to confirm slab melting. Also the detailed geometry in the deep part of the melting slab is often ambiguous in that the intraslab earthquakes within the Wadati-Benioff zone are only limited to shallower depths. To improve our understanding of both the seismic features and geometry found in a young and hot subducted slab, I analyzed anomalous moonquake-like seismograms that were generated by an intermediate-depth earthquake recorded in central Japan. For this study, possible reflected (or scattered sources were examined using detailed analyses of particle motions and a grid search for travel-time differences between the direct and later P-waves. The results show that using strong seismic scattering, slab melting is likely occurring in the deeper, flexing part of the subducted Philippine Sea plate. Because the subducted Philippine Sea plate in central Japan is young and therefore hot, partial melting might have taken place to produce abundant melting spots in the subducted slab. Melting spots, identified as ¡§bright spots,¡¨ could efficiently reflect or scatter seismic energy and generate many later phases with large amplitudes.

  2. CYCLIC TEMPERATURE LOADING RESIDUAL FLEXURAL STRENGHT OF REFRACTORY SLABS

    Directory of Open Access Journals (Sweden)

    Ondřej Holčapek

    2017-05-01

    Full Text Available This paper describes the effect of cyclic elevated temperature loading on refractory slabs made from high performance, fibre reinforced cement composite. Slabs were produced from aluminous cement-based composites, reinforced by different dosages of basalt fibres. The composite investigated in this study had self-compacting characteristics. The slabs used were exposed to different thermal loading – 600 °C, 1000 °C, six times applied 600 °C and 1000 °C. Then, flexural strength was investigated in all groups of slabs, including group reference slabs with no thermal loading. The results show that the appropriate combination of aluminous cement, natural basalt aggregate, fine filler and basalt fibres in dosage 1.00% of volume is able to successfully resist to cyclic temperature loading. Tensile strength in bending of these slabs (after cyclic temperature loading at 600 °C achieved 6.0 MPa. It was demonstrated that it is possible to use this composite for high extensive conditions in real industrial conditions.

  3. Strengthening of RC bridge slabs using CFRP sheets

    Directory of Open Access Journals (Sweden)

    Fahmy A. Fathelbab

    2014-12-01

    Full Text Available Many old structures became structurally insufficient to carry the new loading conditions requirements. Moreover, they suffer from structural degradation, reinforcement steel bars corrosion, bad weather conditions…etc. Many official authorities in several countries had recognized many old bridges and buildings as structurally deficient by today’s standards. Due to these reasons, structural strengthening became an essential requirement and different strengthening techniques appeared in market. Fiber Reinforced Polymer (FRP strengthening techniques established a good position among all other techniques, giving excellent structural results, low time required and moderate cost compared with the other techniques. The main purpose of this research is to study analytically the strengthening of a reinforced concrete bridge slabs due to excessive loads, using externally bonded FRP sheets technique. A commercial finite element program ANSYS was used to perform a structural linear and non-linear analysis for strengthened slab models using several schemes of FRP sheets. A parametric study was performed to evaluate analytically the effect of changing both FRP stiffness and FRP schemes in strengthening RC slabs. Comparing the results with control slab (reinforced concrete slab without strengthening it is obvious that attaching FRP sheets to the RC slab increases its capacity and enhances the ductility/toughness.

  4. Organization, Integration and Assembly of Genetic and Epigenetic Regulatory Machinery in Nuclear Microenvironments: Implications for Biological Control in Cancer

    OpenAIRE

    Stein, Gary S.; Zaidi, Sayyed K.; Stein, Janet L.; Lian, Jane B; van Wijnen, Andre; Montecino, Martin; Young, Daniel W.; Javed, Amjad; Pratap, Jitesh; Choi, Je-Yong; Ali, Syed A; Pande, Sandhya; Hassan, Mohammad Q.

    2009-01-01

    There is growing awareness that the fidelity of gene expression necessitates coordination of transcription factor metabolism and organization of genes and regulatory proteins within the three dimensional context of nuclear architecture. The regulatory machinery that governs genetic and epigenetic control of gene expression is compartmentalized in nuclear microenvironments. Temporal and spatial parameters of regulatory complex organization and assembly are functionally linked to biological con...

  5. Longin and GAF domains: structural evolution and adaptation to the subcellular trafficking machinery.

    Science.gov (United States)

    De Franceschi, Nicola; Wild, Klemens; Schlacht, Alexander; Dacks, Joel B; Sinning, Irmgard; Filippini, Francesco

    2014-01-01

    Endomembrane trafficking is one of the most prominent cytological features of eukaryotes. Given their widespread distribution and specialization, coiled-coil domains, coatomer domains, small GTPases and Longin domains are considered primordial 'building blocks' of the membrane trafficking machineries. Longin domains are conserved across eukaryotes and were likely to be present in the Last Eukaryotic Common Ancestor. The Longin fold is based on the α-β-α sandwich architecture and a unique topology, possibly accounting for the special adaptation to the eukaryotic trafficking machinery. The ancient Per ARNT Sim (PAS) and cGMP-specific phosphodiesterases, Adenylyl cyclases and FhlA (GAF) family domains show a similar architecture, and the identification of prokaryotic counterparts of GAF domains involved in trafficking provides an additional connection for the endomembrane system back into the pre-eukaryotic world. Proteome-wide, comparative bioinformatic analyses of the domains reveal three binding regions (A, B and C) mediating either specific or conserved protein-protein interactions. While the A region mediates intra- and inter-molecular interactions, the B region is involved in binding small GTPases, thus providing an evolutionary connection among major building blocks in the endomembrane system. Finally, we propose that the peculiar interaction surface of the C region of the Longin domain allowed it to extensively integrate into the endomembrane trafficking machinery in the earliest stages of building the eukaryotic cell. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. China's Textile Machinery Industry:Where to Go?

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    China's textile machinery especially cotton-spinning machinery, after several decades of development, has been relatively mature and closer to the foreign advanced level day by day; however, there are still many problems. Since China's entry into WTO, domestic textile enterprises have seized this excellent opportunity to obtain fast development and progress. Currently, accelerating the pace of technological innovation for the development of series of products, vigorously implementing the export strategy to seek new ways for technical upgrade, and exploring the new R&D mode for China's textile machinery are hanging over the enterprises' heads.

  7. Safe design and construction of machinery regulation, practice and performance

    CERN Document Server

    Bluff, Elizabeth

    2015-01-01

    The origin of this book is the compelling evidence that a high proportion of machinery-related deaths and injuries are attributable to genuine and serious risks originating within machine design and construction. This trend continues despite significant legal obligations, notably the European regulatory regime giving effect to the Machinery Directive (among others), and a substantial body of specialist knowledge originating in the disciplines of human factors and safety engineering. Grounded in empirical research with machinery manufacturers, this book aims to elucidate the factors and process

  8. Development and improvement: Status of Textile Machinery Manufacturing in China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The past over 20 years of reform & open-door practices has witnessed an amazingly rapid development in China’s textile machinery manufacturing.1. The change in the production scale: the number oftextile machinery manufacturers grew from over 150 plants listed exceptionally in the category of textile industrial system in the old traditional planned economy to the over 500 plants that come from all sectors of industries engaged in textile machinery manufacturing in the new socialist market-driven economy. The production output value grew from 870 million RMB(Chinese Yuan) in 1987 to 14.7 billion RMB, 18

  9. The ESCRT machinery: new roles at new holes.

    Science.gov (United States)

    Olmos, Y; Carlton, J G

    2016-02-01

    The ESCRT machinery drives a diverse collection of membrane remodeling events, including multivesicular body biogenesis, release of enveloped retroviruses and both reformation of the nuclear envelope and cytokinetic abscission during mitotic exit. These events share the requirement for a topologically equivalent membrane remodeling for their completion and the cells deployment of the ESCRT machinery in these different contexts highlights its functionality as a transposable membrane-fission machinery. Here, we will examine recent data describing ESCRT-III dependent membrane remodeling and explore new roles for the ESCRT-III complex at the nuclear envelope.

  10. The molecular machinery regulating apoptosis signal transduction and its implication in human physiology and pathophysiologies.

    Science.gov (United States)

    Hellwig, C T; Passante, E; Rehm, M

    2011-02-01

    The regulation of apoptotic cell death, a terminal and fatal cell fate decision, has been intensely investigated and, due to its paramount implications for human health and disease, has sparked one of the most prolific and competitive research fields in biological and biomedical sciences of the past decades. Many key components of the molecular machinery processing and transducing apoptotic cell death signals have been described in great detail by now, dramatically advancing our understanding of how the network of apoptosis signaling proteins integrates and regulates cell death signals, and ultimately executes apoptosis. Building on the latest significant advances in deciphering apoptosis signal transduction as well as on the central original groundbreaking discoveries in cell death research, we here present an in-depth description of the current knowledge on the core molecular machinery of apoptotic signaling and how it is implicated in human physiology and pathophysiologies.

  11. Standing sausage modes in curved coronal slabs

    Science.gov (United States)

    Pascoe, D. J.; Nakariakov, V. M.

    2016-09-01

    Context. Magnetohydrodynamic waveguides such as dense coronal loops can support standing modes. The ratios of the periods of oscillations for different longitudinal harmonics depend on the dispersive nature of the waveguide and so may be used as a seismological tool to determine coronal parameters. Aims: We extend models of standing sausage modes in low β coronal loops to include the effects of loop curvature. The behaviour of standing sausage modes in this geometry is used to explain the properties of observed oscillations that cannot be accounted for using straight loop models. Methods: We perform 2D numerical simulations of an oscillating coronal loop, modelled as a dense slab embedded in a potential magnetic field. The loop is field-aligned and so experiences expansion with height in addition to being curved. Standing sausage modes are excited by compressive perturbations of the loop and their properties are studied. Results: The spatial profiles of standing sausage modes are found to be modified by the expanding loop geometry typical for flaring loops and modelled by a potential magnetic field in our simulations. Longitudinal harmonics of order n > 1 have anti-nodes that are shifted towards the loop apex and the amplitude of anti-nodes near the loop apex is smaller than those near the loop footpoints. Conclusions: We find that the observation of standing sausage modes by the Nobeyama Radioheliograph in a flaring coronal loop on 12 January 2000 is consistent with interpretation in terms of the global mode (n = 1) and third harmonic (n = 3). This interpretation accounts for the period ratio and spatial structure of the observed oscillations.

  12. White-Paper Report: Textile Machinery Industry (2005-2009) Economic Performance in Chinese Textile Machinery Industry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Internal Impacts on Textile Machinery Sector 1.Industrial Scale Like many other industrial sectors,the textile machinery industry was also affected by global financial crisis that led to credit crunch in the important markets where consumers'spending plummeted.The textile machinery manufacturers ran into a lot of problems in the balance sheets when international markets were structured in a way that is different from domestic market in terms of consumers'demand.It is very hard for these manufacturers to gain some market share simply by shifting their export-oriented products to local clients in hope to overcome difficulties.

  13. ShanghaiTex 2011,Textile Machinery Giants Gather in China

    Institute of Scientific and Technical Information of China (English)

    Wang Ting

    2011-01-01

    "Over 1000 exhibitions from 18 countries and regions,taking an exhibition area of 92000 square meters wide,ShanghaiTex 2011 unveiled the textile machinery industrial exhibition shows in the city of Shanghai this June.

  14. The kinematics of machinery outlines of a theory of machines

    CERN Document Server

    Reuleaux, Franz

    2012-01-01

    A classic on the kinematics of machinery, this volume was written by the Father of Kinematics. Reuleaux writes with authority and precision, developing the subject from its fundamentals. 450 figures. 1876 edition.

  15. Open innovation and supply chain management in food machinery ...

    African Journals Online (AJOL)

    user

    companies are thus building strong supply chain partnerships with business .... Focusing on studies referring to food and food machinery fields, Sarkar and Costa (2008) reviews three examples of open ...... Harvard Business Review, Vol. 80,.

  16. Mantle flow and dynamic topography associated with slab window opening

    Science.gov (United States)

    Guillaume, Benjamin; Moroni, Monica; Funiciello, Francesca; Martinod, Joseph; Faccenna, Claudio

    2010-05-01

    A slab window is defined as an 'hole' in the subducting lithosphere. In the classical view, slab windows develop where a spreading ridge intersects a subduction zone. The main consequences of this phenomenon are the modifications of the physical, chemical and thermal conditions in the backarc mantle that in turn affect the tectonic and magmatic evolution of the overriding plate. In this work, we perform dynamically self-consistent mantle-scale laboratory models, to evaluate how the opening of a window in the subducting panel influences the geometry and the kinematics of the slab, the mantle circulation pattern and, finally, the overriding plate dynamic topography. The adopted setup consists in a two-layer linearly viscous system simulating the roll-back of a fixed subducting plate (simulated using silicone putty) into the upper mantle (simulated using glucose syrup). Our experimental setting is also characterized by a constant-width rectangular window located at the center of a laterally confined slab, modeling the case of the interaction of a trench-parallel spreading ridge with a wide subduction zone. We find that the geometry and the kinematics of the slab are only minorly affected by the opening of a slab window. On the contrary, slab induced mantle circulation, quantified using Feature Tracking image analysis technique, is strongly modified and produces a peculiar non-isostatic topographic signal on the overriding plate. Assuming that our modeling results can be representative of the natural behavior of subduction zones, we compare them to the Patagonian subduction zone finding that anomalous backarc volcanism that developed since middle Miocene could result from the lateral flowage of subslab mantle, and that part of the Patagonian uplift could be dynamically supported.

  17. Strength Behaviour Of Biomass Fiber-Reinforced Concrete Slab

    Directory of Open Access Journals (Sweden)

    Chai Teck Jung

    2012-05-01

    Full Text Available This paper investigates the compressive strength and flexural strength of biomass fibre-reinforced concrete slab. The main objective of this study is to examine the effect of biomass aggregate and fibre glass on the concrete slab strength. The biomass aggregate is used to replace the natural aggregates. A total of 36 slab samples (250 mm x 600 mm x 50mm thick and 36 numbers of 150 mm cube samples containing 0%, 30%, 60% and 100% biomass aggregate were prepared.  The E-class fibre and Supracoat SP800 were added to increase the strength and to achieve the required workability. All the samples were cured in water with room temperature of around 27oC and tested at the age of 7, 14 and 28 days respectively. The result showed that cube specimens containing 30% biomass aggregate concrete achieved minimum strength of 15 MPa at 28 days. The flexural strength for slab specimens containing 30% biomass aggregate, Supracoat SP 800 and fibre glass gained higher strength compared with control specimens. The 100% biomass aggregate slab achieved 88% of the control specimen strength. The workability was between 150 mm to 170mm slump. The density of the specimens was reduced 20% for cube and 28% for slab compared with control specimens. It can be concluded that the biomass aggregate has good potential as partial aggregate replacement in slab construction when combined with the use of glass fibre and superplasticizer. However, more research needs to be carried out to self-compacting biomass aggregate concrete for sustainable construction

  18. Modeling the surface photovoltage of silicon slabs with varying thickness.

    Science.gov (United States)

    Vazhappilly, Tijo; Kilin, Dmitri S; Micha, David A

    2015-04-10

    The variation with thickness of the energy band gap and photovoltage at the surface of a thin semiconductor film are of great interest in connection with their surface electronic structure and optical properties. In this work, the change of a surface photovoltage (SPV) with the number of layers of a crystalline silicon slab is extracted from models based on their atomic structure. Electronic properties of photoexcited slabs are investigated using generalized gradient and hybrid density functionals, and plane wave basis sets. Si(1 1 1) surfaces have been terminated by hydrogen atoms to compensate for dangling bonds and have been described by large supercells with periodic boundary conditions. Calculations of the SPV of the Si slabs have been done in terms of the reduced density matrix of the photoactive electrons including dissipative effects due to their interaction with medium phonons and excitons. Surface photovoltages have been calculated for model Si slabs with 4-12, and 16 layers, to determine convergence trends versus slab thickness. Band gaps and the inverse of the SPVs have been found to scale nearly linearly with the inverse thickness of the slab, while the electronic density of states increases quadratically with thickness. Our calculations show the same trends as experimental values indicating band gap reduction and absorption enhancement for Si films of increasing thickness. Simple arguments on confined electronic structures have been used to explain the main effects of changes with slab thickness. A procedure involving shifted electron excitation energies is described to improve results from generalized gradient functionals so they can be in better agreement with the more accurate but also more computer intensive values from screened exchange hybrid functionals.

  19. Tomographic imaging of the effects of Peruvian flat slab subduction on the Nazca slab and surrounding mantle under central and southern Peru

    Science.gov (United States)

    Scire, A. C.; Zandt, G.; Beck, S. L.; Bishop, B.; Biryol, C. B.; Wagner, L. S.; Long, M. D.; Minaya, E.; Tavera, H.

    2014-12-01

    The modern central Peruvian Andes are dominated by a laterally extensive region of flat slab subduction. The Peruvian flat slab extends for ~1500 km along the strike of the Andes, correlating with the subduction of the Nazca Ridge in the south and the theorized Inca Plateau in the north. We have used data from the CAUGHT and PULSE experiments for finite frequency teleseismic P- and S-wave tomography to image the Nazca slab in the upper mantle below 95 km depth under central Peru between 10°S and 18°S as well as the surrounding mantle. Since the slab inboard of the subducting Nazca Ridge is mostly aseismic, our results provide important constraints on the geometry of the subducting Nazca slab in this region. Our images of the Nazca slab suggest that steepening of the slab inboard of the subducting Nazca Ridge locally occurs ~100 km further inland than was indicated in previous studies. The region where we have imaged the steepening of the Nazca slab inboard of the Nazca Ridge correlates with the location of the Fitzcarrald Arch, a long wavelength upper plate topographic feature which has been suggested to be a consequence of ridge subduction. When the slab steepens inboard of the flat slab region, it does so at a very steep (~70°) angle. The transition from the Peruvian flat slab to the more normally dipping slab south of 16°S below Bolivia is characterized by an abrupt bending of the slab anomaly in the mantle in response to the shift from flat to normal subduction. The slab anomaly appears to be intact south of the Nazca Ridge with no evidence for tearing of the slab in response to the abrupt change in slab dip. A potential tear in the slab is inferred from an observed offset in the slab anomaly north of the Nazca Ridge extending subparallel to the ridge axis between 130 and 300 km depth. A high amplitude (-5-6%) slow S-wave velocity anomaly is observed below the projection of the Nazca Ridge. This anomaly appears to be laterally confined to the mantle

  20. Recent Advances in Precision Machinery and Manufacturing Technology

    DEFF Research Database (Denmark)

    Liu, Chien-Hung; Hsieh, Wen-Hsiang; Chang, Zong-Yu

    2014-01-01

    Precision machinery and manufacturing technology are be- coming more important in current and future technologies. New knowledge in this field will aid in the advancement of various technologies that are needed to gain industrial competitiveness. To this end, the special issue aims to disseminate...... manufacturing systems, sensors and materials, CAD/CAM/CAE for precision machinery, computation/numerical method, intelligent system and ap- proach, vibration engineering, mechanism design, and fluid- dynamics/thermodynamics....

  1. Designing a Machinery Control System (MCS) Security Testbed

    Science.gov (United States)

    2014-09-01

    smart carrier machinery control system SCADA supervisory control and data acquisition SPST single pole single throw TF functional test TE exception...in Supervisory Control and Data Acquisition ( SCADA ) systems, industrial control systems (ICS’s) and machinery control systems (MCS’s). Today’s modern...for newly discovered security flaws. The concern over vulnerabilities in SCADA systems is due to the equipment they control and their impact, as an

  2. A Study of Sugarcane Leaf-Removal Machinery during Harvest

    OpenAIRE

    2010-01-01

    Problem statement: Sugarcane leaf-removing tools could help speed up sugarcane harvest and reduce contamination. Moreover, leaf-removal machinery can solve the problems of sugarcane burning and workers can increase sugarcane harvest production too. The purpose of this research was to study the use of leaf-removal machinery in the post-harvest production of sugarcane to reduce harvest production time and contaminant. Approach: This study focused on the LK92-11 variety of sugarcane having a har...

  3. Selenocysteine biosynthesis and insertion machinery in Naegleria gruberi.

    Science.gov (United States)

    da Silva, M T A; Caldas, V E A; Costa, F C; Silvestre, D A M M; Thiemann, O H

    2013-04-01

    Selenium (Se) is an essential trace element primarily found in selenoproteins as the 21st amino acid (selenocysteine, Sec, or U). Selenoproteins play an important role in growth and proliferation and are typically involved in cellular redox balance. Selenocysteine is encoded by an in-frame UGA codon specified by a stem-loop structure, the Sec insertion sequence element (SECIS), which, in eukaryotes, is located in the 3'-untranslated region (UTR). The availability of the Naegleria gruberi (ATCC 30224) genome sequence and the use of this organism as a model system for the pathogenic amoeba N. fowleri allowed us to investigate the Sec incorporation pathway in this primitive eukaryote. Using bioinformatics tools, we identified gene sequences encoding PSTK (O-phosphoseryl-tRNA(Sec) kinase), SepSecS (O-phosphoseryl-tRNA:selenocysteinyl-tRNA synthase), SelD/SPS2 (selenophosphate synthetase), EFSec (selenocysteine-specific elongation factor) and SBP (SECIS binding protein). These findings were confirmed by RT-PCR and by sequencing. A potential tRNA(Ser)Sec (SelC) gene and a putative selenoprotein with sequence similarity to a mitochondrial thioredoxin reductase (TR3) were also identified. Our results show that the selenocysteine incorporation machinery is indeed present in N. gruberi. Interestingly, the SelD/SPS2 gene is 2214 bp in length and contains two distinct domains. The N-terminal region shows sequence similarity to predicted methyltransferase proteins, and the C-terminal region is homologous to prokaryotic SelD/SPS2. Our results suggest the possibility of novel selenoproteins.

  4. MRP transporters as membrane machinery in the bradykinin-inducible export of ATP.

    Science.gov (United States)

    Zhao, Yumei; Migita, Keisuke; Sun, Jing; Katsuragi, Takeshi

    2010-04-01

    Adenosine triphosphate (ATP) plays the role of an autocrine/paracrine signal molecule in a variety of cells. So far, however, the membrane machinery in the export of intracellular ATP remains poorly understood. Activation of B2-receptor with bradykinin-induced massive release of ATP from cultured taenia coli smooth muscle cells. The evoked release of ATP was unaffected by gap junction hemichannel blockers, such as 18alpha-glycyrrhetinic acid and Gap 26. Furthermore, the cystic fibrosis transmembrane regulator (CFTR) coupled Cl(-) channel blockers, CFTR(inh)172, 5-nitro-2-(3-phenylpropylamino)-benzoic acid, Gd3(+) and glibenclamide, failed to suppress the export of ATP by bradykinin. On the other, the evoked release of ATP was greatly reduced by multidrug resistance protein (MRP) transporter inhibitors, MK-571, indomethacin, and benzbromarone. From western blotting analysis, blots of MRP 1 protein only, but not MRP 2 and MRP 3 protein, appeared at 190 kD. However, the MRP 1 protein expression was not enhanced after loading with 1 muM bradykinin for 5 min. Likewise, niflumic acid and fulfenamic acid, Ca2(+)-activated Cl(-) channel blockers, largely abated the evoked release of ATP. The possibility that the MRP transporter system couples with Ca2(+)-activated Cl(-) channel activities is discussed here. These findings suggest that MRP transporters, probably MRP 1, unlike CFTR-Cl(-) channels and gap junction hemichannels, may contribute as membrane machinery to the export of ATP induced by G-protein-coupled receptor stimulation.

  5. Calibrating a large slab vessel: A battle of the bulge

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, I.R. [Westinghouse Idaho Nuclear Co., Inc., Idaho Falls, ID (United States). Safeguards and Security Section

    1993-12-31

    The accurate measurement of volume in slab vessels can be difficult because slab vessels expand--in spite of internal or external supports--as they are filled. One form of bulging is elastic deflection, a gradual expansion of the vessel wall resulting from an increased weight of contained solution. As part of an upgrade to the Idaho Chemical Processing Plant, slab tanks were proposed as accountability measurement vessels. A 1960 liter slab tank prototype was set up for preliminary calibrations. Two series of calibrations were conducted: the first using water, and the second using aluminum nitrate. It was conjectured that the increased weight of aluminum nitrate would cause the vessel walls to deflect more than they did for an equal level of water, resulting in a greater volume. As expected, a significant expansion was observed with the aluminum nitrate, but some of the deflection proved to be permanent rather than elastic. The consequence is that considerably more effort will be required to calibrate slab vessels for uranium accountability. Not only must a calibration curve (or family of curves) be developed giving volume as a function of both liquid level and density, but, if possible, a determination must be made as to when the deflection is no longer temporary.

  6. The subduction dichotomy of strong plates and weak slabs

    Science.gov (United States)

    Petersen, Robert I.; Stegman, Dave R.; Tackley, Paul J.

    2017-03-01

    A key element of plate tectonics on Earth is that the lithosphere is subducting into the mantle. Subduction results from forces that bend and pull the lithosphere into the interior of the Earth. Once subducted, lithospheric slabs are further modified by dynamic forces in the mantle, and their sinking is inhibited by the increase in viscosity of the lower mantle. These forces are resisted by the material strength of the lithosphere. Using geodynamic models, we investigate several subduction models, wherein we control material strength by setting a maximum viscosity for the surface plates and the subducted slabs independently. We find that models characterized by a dichotomy of lithosphere strengths produce a spectrum of results that are comparable to interpretations of observations of subduction on Earth. These models have strong lithospheric plates at the surface, which promotes Earth-like single-sided subduction. At the same time, these models have weakened lithospheric subducted slabs which can more easily bend to either lie flat or fold into a slab pile atop the lower mantle, reproducing the spectrum of slab morphologies that have been interpreted from images of seismic tomography.

  7. Investigations on Efficiently Interfaced Steel Concrete Composite Deck Slabs

    Directory of Open Access Journals (Sweden)

    K. N. Lakshmikandhan

    2013-01-01

    Full Text Available The strength of the composite deck slab depends mainly on the longitudinal shear transfer mechanism at the interface between steel and concrete. The bond strength developed by the cement paste is weak and causes premature failure of composite deck slab. This deficiency is effectively overcame by a shear transferring mechanism in the form of mechanical interlock through indentations, embossments, or fastening studs. Development of embossment patterns requires an advanced technology which makes the deck profile expensive. Fastening studs by welding weakens the joint strength and also escalates the cost. The present investigation is attempted to arrive at a better, simple interface mechanism. Three types of mechanical connector schemes are identified and investigated experimentally. All of the three shear connector schemes exhibited full shear interaction with negligible slip. The strength and stiffness of the composite slabs with shear connectors are superior about one and half time compared to these of the conventional reinforced concrete slabs and about twice compared to these of composite slabs without mechanical shear connectors. The scheme2 and scheme3 shear connector mechanisms integrate deck webs and improve strength and stiffness of the deck, which can effectively reduce the cost of formworks and supports efficiently.

  8. Fossil slabs attached to unsubducted fragments of the Farallon plate.

    Science.gov (United States)

    Wang, Yun; Forsyth, Donald W; Rau, Christina J; Carriero, Nina; Schmandt, Brandon; Gaherty, James B; Savage, Brian

    2013-04-02

    As the Pacific-Farallon spreading center approached North America, the Farallon plate fragmented into a number of small plates. Some of the microplate fragments ceased subducting before the spreading center reached the trench. Most tectonic models have assumed that the subducting oceanic slab detached from these microplates close to the trench, but recent seismic tomography studies have revealed a high-velocity anomaly beneath Baja California that appears to be a fossil slab still attached to the Guadalupe and Magdalena microplates. Here, using surface wave tomography, we establish the lateral extent of this fossil slab and show that it is correlated with the distribution of high-Mg andesites thought to derive from partial melting of the subducted oceanic crust. We also reinterpret the high seismic velocity anomaly beneath the southern central valley of California as another fossil slab extending to a depth of 200 km or more that is attached to the former Monterey microplate. The existence of these fossil slabs may force a reexamination of models of the tectonic evolution of western North America over the last 30 My.

  9. The Place of RNA in the Origin and Early Evolution of the Genetic Machinery

    Directory of Open Access Journals (Sweden)

    Günter Wächtershäuser

    2014-12-01

    Full Text Available The extant genetic machinery revolves around three interrelated polymers: RNA, DNA and proteins. Two evolutionary views approach this vital connection from opposite perspectives. The RNA World theory posits that life began in a cold prebiotic broth of monomers with the de novo emergence of replicating RNA as functionally self-contained polymer and that subsequent evolution is characterized by RNA → DNA memory takeover and ribozyme → enzyme catalyst takeover. The FeS World theory posits that life began as an autotrophic metabolism in hot volcanic-hydrothermal fluids and evolved with organic products turning into ligands for transition metal catalysts thereby eliciting feedback and feed-forward effects. In this latter context it is posited that the three polymers of the genetic machinery essentially coevolved from monomers through oligomers to polymers, operating functionally first as ligands for ligand-accelerated transition metal catalysis with later addition of base stacking and base pairing, whereby the functional dichotomy between hereditary DNA with stability on geologic time scales and transient, catalytic RNA with stability on metabolic time scales existed since the dawn of the genetic machinery. Both approaches are assessed comparatively for chemical soundness.

  10. The place of RNA in the origin and early evolution of the genetic machinery.

    Science.gov (United States)

    Wächtershäuser, Günter

    2014-12-19

    The extant genetic machinery revolves around three interrelated polymers: RNA, DNA and proteins. Two evolutionary views approach this vital connection from opposite perspectives. The RNA World theory posits that life began in a cold prebiotic broth of monomers with the de novo emergence of replicating RNA as functionally self-contained polymer and that subsequent evolution is characterized by RNA → DNA memory takeover and ribozyme → enzyme catalyst takeover. The FeS World theory posits that life began as an autotrophic metabolism in hot volcanic-hydrothermal fluids and evolved with organic products turning into ligands for transition metal catalysts thereby eliciting feedback and feed-forward effects. In this latter context it is posited that the three polymers of the genetic machinery essentially coevolved from monomers through oligomers to polymers, operating functionally first as ligands for ligand-accelerated transition metal catalysis with later addition of base stacking and base pairing, whereby the functional dichotomy between hereditary DNA with stability on geologic time scales and transient, catalytic RNA with stability on metabolic time scales existed since the dawn of the genetic machinery. Both approaches are assessed comparatively for chemical soundness.

  11. Slab detachment of subducted Indo-Australian plate beneath Sunda arc, Indonesia

    Indian Academy of Sciences (India)

    Bhaskar Kundu; V K Gahalaut

    2011-04-01

    Necking, tearing, slab detachment and subsequently slab loss complicate the subduction zone processes and slab architecture. Based on evidences which include patterns of seismicity, seismic tomography and geochemistry of arc volcanoes, we have identified a horizontal slab tear in the subducted Indo-Australian slab beneath the Sunda arc. It strongly reflects on trench migration, and causes along-strike variations in vertical motion and geochemically distinct subduction-related arc magmatism. We also propose a model for the geodynamic evolution of slab detachment.

  12. IMPROVEMENT OF SLAB REHEATING PROCESS AT USIMINAS THROUGH MATHEMATICAL SIMULATION

    Directory of Open Access Journals (Sweden)

    Antônio Adel dos Santos

    2012-09-01

    Full Text Available Basic characteristics and application examples of the mathematical simulator for reheating process in walking-beam type furnaces, that has been developed and applied to Usiminas plate mill line at Ipatinga, are shown in this paper. This is a bi-dimensional mathematical model solved by the finite volume method, validated by temperature measurements inside the slab during heating and coded as a visual tool. Among these applications, the following can be highlighted: (i determination of suitable furnace zone temperatures and residence times for processing steels by accelerated cooling technology; (ii determination of slab average temperature at discharging as well as at each zone exit, supplying data to be fed to the automation system at the comissioning stage; (iii analyses of slab thermal distribution through the reheating process, enabling operational optimization

  13. Systematic effects induced by a flat isotropic dielectric slab

    CERN Document Server

    Macculi, C; Cortiglioni, S; Peverini, O A; Tascone, R; Zannoni, M; Carretti, Ettore; Cortiglioni, Stefano; Macculi, Claudio; Peverini, Oscar Antonio; Tascone, Riccardo; Zannoni, Mario

    2006-01-01

    The instrumental polarization induced by a flat isotropic dielectric slab in microwave frequencies is faced. We find that, in spite of its isotropic nature, such a dielectric can produce spurious polarization either by transmitting incoming anisotropic diffuse radiation or emitting when it is thermally inhomogeneous. We present evaluations of instrumental polarization generated by materials usually adopted in Radioastronomy, by using the Mueller matrix formalism. As an application, results for different slabs in front of a 32 GHz receiver are discussed. Such results are based on measurements of their complex dielectric constant. We evaluate that a 0.33 cm thick Teflon slab introduces negligible spurious polarization ($< 2.6 \\times 10^{-5}$ in transmission and $< 6 \\times 10^{-7}$ in emission), even minimizing the leakage ($< 10^{-8}$ from $Q$ to $U$ Stokes parameters, and viceversa) and the depolarization ($\\sim 1.3 \\times 10^{-3}$).

  14. Casimir Force on Real Materials - the Slab and Cavity Geometry

    CERN Document Server

    Ellingsen, S A; Brevik, Iver; Ellingsen, Simen A.

    2006-01-01

    We analyse the potential of the geometry of a slab in a planar cavity for the purpose of Casimir force experiments. The force and its dependence on temperature, material properties and finite slab thickness are investigated both analytically and numerically for slab and walls made of aluminium and teflon FEP respectively. We conclude that such a setup is ideal for measurements of the temperature dependence of the Casimir force. By numerical calculation it is shown that temperature effects are dramatically larger for dielectrics, suggesting that a dielectric such as teflon FEP whose properties vary little within a moderate temperature range, should be considered for experimental purposes. We finally discuss the subtle but fundamental matter of the various Green's two-point function approaches present in the literature and show how they are different formulations describing the same phenomenon.

  15. Efficient Vortex Generation in Subwavelength Epsilon-Near-Zero Slabs

    Science.gov (United States)

    Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo

    2017-03-01

    We show that a homogeneous and isotropic slab, illuminated by a circularly polarized beam with no topological charge, produces vortices of order 2 in the opposite circularly polarized components of the reflected and transmitted fields, as a consequence of the transverse magnetic and transverse electric asymmetric response of the rotationally invariant system. In addition, in the epsilon-near-zero regime, we find that vortex generation is remarkably efficient in subwavelength thick slabs up to the paraxial regime. This physically stems from the fact that a vacuum paraxial field can excite a nonparaxial field inside an epsilon-near-zero slab since it hosts slowly varying fields over physically large portions of the bulk. Our theoretical predictions indicate that epsilon-near-zero media hold great potential as nanophotonic elements for manipulating the angular momentum of the radiation, since they are available without resorting to complicated micro- or nanofabrication processes and can operate even at very small (ultraviolet) wavelengths.

  16. Photonic-crystal slab for terahertz-wave technology platform

    Science.gov (United States)

    Fujita, Masayuki

    2016-03-01

    Photonic crystals manipulate photons in a manner analogous to solid-state crystals, and are composed of a dielectric material with a periodic refractive index distribution. In particular, two-dimensional photonic-crystal slabs with high index contrasts (semiconductor/air) are promising for practical applications, owing to the strong optical confinement in simple, thin planar structures. This paper presents the recent progress on a silicon photonic-crystal slab as a technology platform in the terahertz-wave region, which is located between the radio and light wave regions (0.1-10 THz). Extremely low-loss (edge effect are demonstrated. Terahertz photonic-crystal slabs hold the potential for developing ultralow-loss, compact terahertz components and integrated devices used in applications including wireless communication, spectroscopic sensing, and imaging.

  17. Can slabs melt beneath forearcs in hot subduction zones?

    Science.gov (United States)

    Ribeiro, J.; Maury, R.; Gregoire, M.

    2015-12-01

    At subduction zones, thermal modeling predict that the shallow part of the downgoing oceanic crust (test the hypothesis that adakites are pristine slab melts. We find that adakites from Baja California and Philippines formed by two distinct petrogenetic scenarios. In Baja California, hydrous mantle melts mixed/mingled with high-pressure (HP) adakite-type, slab melts within a lower crustal (~30 km depth) magma storage region before stalling into the upper arc crust (~7-15 km depth). In contrast, in the Philippines, primitive mantle melts stalled and crystallized within lower and upper crustal magma storage regions to produce silica-rich melts with an adakitic signature. Thereby, slab melting is not required to produce an adakitic geochemical fingerprint in hot subduction zones. However, our results also suggest that the downgoing crust potentially melted beneath Baja California.

  18. Requalification analysis of a circular composite slab for seismic load

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, M.G.; Kot, C.A.

    1992-11-01

    The circular roof slab of an existing facility was analyzed to requalify the structure for supporting a significant seismic load that it was not originally designed for. The slab has a clear span of 66 ft and consists of a 48 in thick reinforced concrete member and a steel liner plate. Besides a number of smaller penetrations, the slab contains two significant cutouts: a 9 ft square opening and a 3 ft dia hole. The issues that complicated the analysis of this non-typical structure, i.e., composite action and nonlinear stiffness of reinforced concrete (R. C.) sections, are discussed. It was possible to circumvent the difficulties by making conservative and simplifying assumptions. If codes incorporate guidelines on practical methods for dynamic analysis of R. C. structures, some of the unneeded conservatism could be eliminated in future designs.

  19. Dynamic triggering of deep earthquakes within a fossil slab

    Science.gov (United States)

    Cai, Chen; Wiens, Douglas A.

    2016-09-01

    The 9 November 2009 Mw 7.3 Fiji deep earthquake is the largest event in a region west of the Tonga slab defined by scattered seismicity and velocity anomalies. The main shock rupture was compact, but the aftershocks were distributed along a linear feature at distances of up to 126 km. The aftershocks and some background seismicity define a sharp northern boundary to the zone of outboard earthquakes, extending westward toward the Vitiaz deep earthquake cluster. The northern earthquake lineament is geometrically similar to tectonic reconstructions of the relict Vitiaz subduction zone at 8-10 Ma, suggesting the earthquakes are occurring in the final portion of the slab subducted at the now inactive Vitiaz trench. A Coulomb stress change calculation suggests many of the aftershocks were dynamically triggered. We propose that fossil slabs contain material that is too warm for earthquake nucleation but may be near the critical stress susceptible to dynamic triggering.

  20. Efficient Vortex Generation in Subwavelength Epsilon-Near-Zero Slabs.

    Science.gov (United States)

    Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo

    2017-03-10

    We show that a homogeneous and isotropic slab, illuminated by a circularly polarized beam with no topological charge, produces vortices of order 2 in the opposite circularly polarized components of the reflected and transmitted fields, as a consequence of the transverse magnetic and transverse electric asymmetric response of the rotationally invariant system. In addition, in the epsilon-near-zero regime, we find that vortex generation is remarkably efficient in subwavelength thick slabs up to the paraxial regime. This physically stems from the fact that a vacuum paraxial field can excite a nonparaxial field inside an epsilon-near-zero slab since it hosts slowly varying fields over physically large portions of the bulk. Our theoretical predictions indicate that epsilon-near-zero media hold great potential as nanophotonic elements for manipulating the angular momentum of the radiation, since they are available without resorting to complicated micro- or nanofabrication processes and can operate even at very small (ultraviolet) wavelengths.

  1. 30 CFR 75.1725 - Machinery and equipment; operation and maintenance.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machinery and equipment; operation and....1725 Machinery and equipment; operation and maintenance. (a) Mobile and stationary machinery and equipment shall be maintained in safe operating condition and machinery or equipment in unsafe...

  2. 46 CFR 91.15-1 - Standards in inspection of hulls, boilers, and machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Standards in inspection of hulls, boilers, and machinery... hulls, boilers, and machinery. In the inspection of hulls, boilers, and machinery of vessels, the..., respecting material and inspection of hulls, boilers, and machinery, and the certificate of...

  3. 46 CFR 62.50-20 - Additional requirements for minimally attended machinery plants.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Additional requirements for minimally attended machinery... requirements for minimally attended machinery plants. Note: Minimally attended machinery plants include vessel machinery plants and spaces that are automated, but not to a degree where the plant could be left...

  4. 46 CFR 169.631 - Separation of machinery and fuel tank spaces from accommodation spaces.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Separation of machinery and fuel tank spaces from...) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Ventilation § 169.631 Separation of machinery and fuel tank spaces from accommodation spaces. (a) Machinery and fuel tank spaces must...

  5. 46 CFR 189.15-1 - Standards in inspection of hulls, boilers, and machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Standards in inspection of hulls, boilers, and machinery... inspection of hulls, boilers, and machinery. In the inspection of hulls, boilers, and machinery of vessels... chapter, respecting material and construction of hulls, boilers, and machinery, and certificate...

  6. 46 CFR 169.629 - Compartments containing gasoline machinery or fuel tanks.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Compartments containing gasoline machinery or fuel tanks... SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Ventilation § 169.629 Compartments containing gasoline machinery or fuel tanks. Spaces containing gasoline machinery or fuel tanks must have...

  7. 46 CFR 71.15-1 - Standards in inspection of hulls, boilers, and machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Standards in inspection of hulls, boilers, and machinery..., boilers, and machinery. In the inspection of hulls, boilers, and machinery of vessels, the standards... and inspection of hulls, boilers, and machinery, and the certificate of classification...

  8. Numerical models of slab migration in continental collision zones

    Directory of Open Access Journals (Sweden)

    V. Magni

    2012-09-01

    Full Text Available Continental collision is an intrinsic feature of plate tectonics. The closure of an oceanic basin leads to the onset of subduction of buoyant continental material, which slows down and eventually stops the subduction process. In natural cases, evidence of advancing margins has been recognized in continental collision zones such as India-Eurasia and Arabia-Eurasia. We perform a parametric study of the geometrical and rheological influence on subduction dynamics during the subduction of continental lithosphere. In our 2-D numerical models of a free subduction system with temperature and stress-dependent rheology, the trench and the overriding plate move self-consistently as a function of the dynamics of the system (i.e. no external forces are imposed. This setup enables to study how continental subduction influences the trench migration. We found that in all models the slab starts to advance once the continent enters the subduction zone and continues to migrate until few million years after the ultimate slab detachment. Our results support the idea that the advancing mode is favoured and, in part, provided by the intrinsic force balance of continental collision. We suggest that the advance is first induced by the locking of the subduction zone and the subsequent steepening of the slab, and next by the sinking of the deepest oceanic part of the slab, during stretching and break-off of the slab. These processes are responsible for the migration of the subduction zone by triggering small-scale convection cells in the mantle that, in turn, drag the plates. The amount of advance ranges from 40 to 220 km and depends on the dip angle of the slab before the onset of collision.

  9. Bayesian Inference for Structured Spike and Slab Priors

    DEFF Research Database (Denmark)

    Andersen, Michael Riis; Winther, Ole; Hansen, Lars Kai

    2014-01-01

    Sparse signal recovery addresses the problem of solving underdetermined linear inverse problems subject to a sparsity constraint. We propose a novel prior formulation, the structured spike and slab prior, which allows to incorporate a priori knowledge of the sparsity pattern by imposing a spatial...... Gaussian process on the spike and slab probabilities. Thus, prior information on the structure of the sparsity pattern can be encoded using generic covariance functions. Furthermore, we provide a Bayesian inference scheme for the proposed model based on the expectation propagation framework. Using...

  10. Tunneling properties of electromagnetic wave in slab superconducting material

    Institute of Scientific and Technical Information of China (English)

    Khem B. Thapa; Sanjay Srivastava; Alka Vishwakarma; S. P. Ojha

    2011-01-01

    When the electromagnetic wave propagates through a slab superconducting material in microwave ranges, tunneling properties of the electromagnetic wave at critical temperature are investigated theoretically. The transmittance and the reflectance of the slab superconducting material vary with the thickness of material as well as the refractive index of substrates.The high transmittance is found for thin superconductor at low wavelength region.However, optical properties are strongly dependent upon temperature and incidence wavelength. The electromagnetic wave is totally transmitted without loss for incidence wavelength (λ = 5000 nm) due to the zero refractive index and infinite penetration depth of the superconductor at the critical temperature.

  11. Radon Sub-slab Suctioning System Integrated in Insulating Layer

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    of prefabricated lightweight elements were introduced and demonstrated. The principle was demonstrated on a concrete ground slab floor with a concrete slab on top of a thermal insulation layer above a capillary-breaking layer mounted on stable ground. The thermal insulation and the capillary-breaking layer...... consisted of a rigid insulation material. The new solution integrates the capillary-breaking layer and a pressure reduction zone,denoted the radon–suctioning layer, in one element. The new solution introduces the radonsuctioning layer as a horizontal grid of air ducts with low pressure to catch air...

  12. Repulsive Casimir forces with finite-thickness slabs

    OpenAIRE

    Zhao, R.; Koschny, Th.; Economou, E. N.; C M Soukoulis

    2010-01-01

    We use the extended Lifshitz theory to study the behaviors of the Casimir forces between finite-thickness effective medium slabs. We first study the interaction between a semi-infinite Drude metal and a finite-thickness magnetic slab with or without substrate. For no substrate, the large distance $d$ dependence of the force is repulsive and goes as $1/d^5$; for the Drude metal substrate, a stable equilibrium point appears at an intermediate distance which can be tuned by the thickness of the ...

  13. Three dimensional super-resolution in metamaterial slab lenses

    CERN Document Server

    Mesa, F; Freire, M; Baena, J D

    2005-01-01

    This letter presents a theoretical and experimental study on the viability of obtaining three dimensional super-resolution (i.e. resolution overcoming the diffraction limit for all directions in space) by means of metamaterial slab lenses. Although the source field cannot be actually reproduced at the back side of the lens with super-resolution in all space directions, the matching capabilities of metamaterial slabs does make it possible the detection of images with three-dimensional super-resolution. This imaging takes place because of the coupling between the evanescent space harmonic components of the field generated at both the source and the detector.

  14. Spalling of concrete: A synthesis of experimental tests on slabs

    Directory of Open Access Journals (Sweden)

    Taillefer Nicolas

    2013-09-01

    Full Text Available The article reviews the results of many commercial or research tests carried out in CSTB on middle size concrete slabs. They concern 22 concrete slabs, made of normal and high strength concrete, for a rather wide range of thickness and compressive strength classes. Test procedures and a synthesis of main results are presented in order to provide deeper understanding of near-reality conditions of concrete structures. The tests concerned both new and existing tunnels. Results are detailed in relation with main parameters that are identified as impacting spalling in previous studies, such as concrete composition, concrete properties and specimen size.

  15. Spalling tests on embedded cores and slabs: A comparative study

    Directory of Open Access Journals (Sweden)

    Pimienta P.

    2013-09-01

    Full Text Available A comparative analysis of the spalling of (a cores made of 3 concrete mixes embedded into 3 slabs made of the 3 same concrete mixes; and (b 3 reference slabs made again of the same 3 concrete mixes has been made. Samples have been exposed to the French Increased HydroCarbon temperature curve. Results confirm that concrete spalling phenomena is not only related to the material properties. Concrete spalling is also very much influenced by the geometry of the samples.

  16. Bayesian Inference for Structured Spike and Slab Priors

    DEFF Research Database (Denmark)

    Andersen, Michael Riis; Winther, Ole; Hansen, Lars Kai

    2014-01-01

    Sparse signal recovery addresses the problem of solving underdetermined linear inverse problems subject to a sparsity constraint. We propose a novel prior formulation, the structured spike and slab prior, which allows to incorporate a priori knowledge of the sparsity pattern by imposing a spatial...... Gaussian process on the spike and slab probabilities. Thus, prior information on the structure of the sparsity pattern can be encoded using generic covariance functions. Furthermore, we provide a Bayesian inference scheme for the proposed model based on the expectation propagation framework. Using...

  17. Links between fluid circulation, temperature, and metamorphism in subducting slabs

    Science.gov (United States)

    Spinelli, G.A.; Wang, K.

    2009-01-01

    The location and timing of metamorphic reactions in subducting lithosph??re are influenced by thermal effects of fluid circulation in the ocean crust aquifer. Fluid circulation in subducting crust extracts heat from the Nankai subduction zone, causing the crust to pass through cooler metamorphic faci??s than if no fluid circulation occurs. This fluid circulation shifts the basalt-to-eclogite transition and the associated slab dehydration 14 km deeper (35 km farther landward) than would be predicted with no fluid flow. For most subduction zones, hydrothermal cooling of the subducting slab will delay eclogitization relative to estimates made without considering fluid circulation. Copyright 2009 by the American Geophysical Union.

  18. Resonance-enhanced optical forces between coupled photonic crystal slabs.

    Science.gov (United States)

    Liu, Victor; Povinelli, Michelle; Fan, Shanhui

    2009-11-23

    The behaviors of lateral and normal optical forces between coupled photonic crystal slabs are analyzed. We show that the optical force is periodic with displacement, resulting in stable and unstable equilibrium positions. Moreover, the forces are strongly enhanced by guided resonances of the coupled slabs. Such enhancement is particularly prominent near dark states of the system, and the enhancement effect is strongly dependent on the types of guided resonances involved. These structures lead to enhancement of light-induced pressure over larger areas, in a configuration that is directly accessible to externally incident, free-space optical beams.

  19. The adaptive response of lichens to mercury exposure involves changes in the photosynthetic machinery.

    Science.gov (United States)

    Nicolardi, Valentina; Cai, Giampiero; Parrotta, Luigi; Puglia, Michele; Bianchi, Laura; Bini, Luca; Gaggi, Carlo

    2012-01-01

    Lichens are an excellent model to study the bioaccumulation of heavy metals but limited information is available on the molecular mechanisms occurring during bioaccumulation. We investigated the changes of the lichen proteome during exposure to constant concentrations of mercury. We found that most of changes involves proteins of the photosynthetic pathway, such as the chloroplastic photosystem I reaction center subunit II, the oxygen-evolving protein and the chloroplastic ATP synthase β-subunit. This suggests that photosynthesis is a target of the toxic effects of mercury. These findings are also supported by changes in the content of photosynthetic pigments (chlorophyll a and b, and β-carotene). Alterations to the photosynthetic machinery also reflect on the structure of thylakoid membranes of algal cells. Response of lichens to mercury also involves stress-related proteins (such as Hsp70) but not cytoskeletal proteins. Results suggest that lichens adapt to mercury exposure by changing the metabolic production of energy.

  20. Punching Shear Behavior of Continuous Bubbled Reinforced Reactive Powder Concrete Slab

    Directory of Open Access Journals (Sweden)

    Mohammad Redha K. Mahmood

    2017-03-01

    Full Text Available This paper presents an experimental investigation on punching shear behavior of continuous bubbled reinforced Reactive Powder Concrete (RPC slabs. Bubbled slab is one of the various types of voided slabs. It consists of bubbles placed inside a concrete slab which will reduce the self-weight of the structure by about 35% (Tina Lai 2009. On the other hand, using RPC make it possible for structural member to have smaller dimensions due to the great strength of this type of concrete. In this study, these two method to increase the building spaces dimensions by reducing self-weigh of the structure by using bubbled slabs and to decrease the structural members' dimensions by using RPC have been investigated together. To study the punching shear behavior of continuous bubbled flat slabs such as the ultimate load carrying capacity, central deflection and slabs crack pattern at the ultimate load, nine different types of slabs were tested. The parameters of the study were type of concrete (RPC and Normal Concrete (NC, bubbles diameter to slab thickness ratio (D/t of (0.6 and 0.7, bubbles location (at all slab area, started from distance D and 1.5D from the center slab and solid slab. The test results show that the crack pattern and ultimate load capacity as well as maximum deflection depends on all of the mentioned parameters, were by increasing (D/t ratio the ultimate load capacity increases about (6.49 and 9.58% for slabs with bubbles started at distance 2D and 3D, respectively. But in the slabs with bubbles at all slab area the ultimate load and the maximum deflection decreases about (6.63 and 9.47% and (7.96 and 6.84% for RPC and NC slabs, respectively. Also, the solid slab increases the ultimate load about (5.28% compare to bubbled slab at all area. It was found that by removing bubbles from center of the slab at distance 2D and 3D the ultimate load will increase about (14.72 and 8.76%, respectively for slabs with (D/t = 0.6 compare to slabs with

  1. Species-specific impact of the autophagy machinery on Chikungunya virus infection.

    Science.gov (United States)

    Judith, Delphine; Mostowy, Serge; Bourai, Mehdi; Gangneux, Nicolas; Lelek, Mickaël; Lucas-Hourani, Marianne; Cayet, Nadège; Jacob, Yves; Prévost, Marie-Christine; Pierre, Philippe; Tangy, Frédéric; Zimmer, Christophe; Vidalain, Pierre-Olivier; Couderc, Thérèse; Lecuit, Marc

    2013-06-01

    Chikungunya virus (CHIKV) is a recently re-emerged arbovirus that triggers autophagy. Here, we show that CHIKV interacts with components of the autophagy machinery during its replication cycle, inducing a cytoprotective effect. The autophagy receptor p62 protects cells from death by binding ubiquitinated capsid and targeting it to autophagolysosomes. By contrast, the human autophagy receptor NDP52--but not its mouse orthologue--interacts with the non-structural protein nsP2, thereby promoting viral replication. These results highlight the distinct roles of p62 and NDP52 in viral infection, and identify NDP52 as a cellular factor that accounts for CHIKV species specificity.

  2. Evolutionary conservancy of the endocytic and trafficking machinery in the unicellular eukaryote Paramecium.

    Science.gov (United States)

    Surmacz, Liliana; Wiejak, Jolanta; Wyroba, Elzbieta

    2003-01-01

    Molecular search for the homologues of the mammalian proteins in the unicellular eukaryote Paramecium involved in endocytosis and membrane trafficking is discussed. We cloned and sequenced the gene fragments encoding the following components participating in endosome formation, sorting and maturation of the proprotein precursors, respectively, dynamin 2, Rab7 and furin. There is a proof that all these genes are expressed in this unicellular organism. The function of the identified immunoanalogues of the above described components of Paramecium endocytic machinery as well as a high degree of sequence homology to the respective human counterparts points to the evolutionary conservancy of these pathways.

  3. HIPK2: a versatile switchboard regulating the transcription machinery and cell death.

    Science.gov (United States)

    Calzado, Marco A; Renner, Florian; Roscic, Ana; Schmitz, M Lienhard

    2007-01-15

    Homeodomain interacting protein kinase 2 (HIPK2) is an evolutionary conserved serine/threonine kinase that regulates gene expression by phosphorylation of transcription factors and accessory components of the transcription machinery. HIPK2 is activated in response to DNA-damaging agents or morphogenic signals and accordingly HIPK2-guided gene expression programs trigger differentiation and development or alternatively apoptosis. The kinase contributes to the regulation of remarkably diverse pathways such as p53 activation or Wnt signaling. Here we discuss recent findings from biochemical and functional experiments that allow a deeper understanding of the pleiotropic effects mediated by HIPK2.

  4. Post-tensioned concrete floor slab design of a shopping centre

    Institute of Scientific and Technical Information of China (English)

    刘洋; 于霞

    2011-01-01

    Post-tensioned Concrete slab can provide large clear span, and also has better performance in crack control and deflection. The topic below introduced the design process of the post-tensioned floor slab of a shopping centre.

  5. Resolution Ability and Surface Bright Spots of a Lossy Left-handed Material Slab

    Institute of Scientific and Technical Information of China (English)

    LI Chao; LI Fang

    2006-01-01

    @@ The imaging quality of a lossy left-handed material (LHM) slab is studied. The exact solution is obtained for the interaction of a monochromatic source with a lossy LHM slab by Fourier integrals in wave number domain.

  6. Importance of bulk states for the electronic structure of semiconductor surfaces: implications for finite slabs.

    Science.gov (United States)

    Sagisaka, Keisuke; Nara, Jun; Bowler, David

    2017-04-12

    We investigate the influence of slab thickness on the electronic structure of the Si(1 0 0)- p([Formula: see text]) surface in density functional theory (DFT) calculations, considering both density of states and band structure. Our calculations, with slab thicknesses of up to 78 atomic layers, reveal that the slab thickness profoundly affects the surface band structure, particularly the dangling bond states of the silicon dimers near the Fermi level. We find that, to precisely reproduce the surface bands, the slab thickness needs to be large enough to completely converge the bulk bands in the slab. In the case of the Si(1 0 0) surface, the dispersion features of the surface bands, such as the band shape and width, converge when the slab thickness is larger than 30 layers. Complete convergence of both the surface and bulk bands in the slab is only achieved when the slab thickness is greater than 60 layers.

  7. The cell stress machinery and retinal degeneration.

    Science.gov (United States)

    Athanasiou, Dimitra; Aguilà, Monica; Bevilacqua, Dalila; Novoselov, Sergey S; Parfitt, David A; Cheetham, Michael E

    2013-06-27

    Retinal degenerations are a group of clinically and genetically heterogeneous disorders characterised by progressive loss of vision due to neurodegeneration. The retina is a highly specialised tissue with a unique architecture and maintaining homeostasis in all the different retinal cell types is crucial for healthy vision. The retina can be exposed to a variety of environmental insults and stress, including light-induced damage, oxidative stress and inherited mutations that can lead to protein misfolding. Within retinal cells there are different mechanisms to cope with disturbances in proteostasis, such as the heat shock response, the unfolded protein response and autophagy. In this review, we discuss the multiple responses of the retina to different types of stress involved in retinal degenerations, such as retinitis pigmentosa, age-related macular degeneration and glaucoma. Understanding the mechanisms that maintain and re-establish proteostasis in the retina is important for developing new therapeutic approaches to fight blindness.

  8. Photosynthetic machineries in nano-systems.

    Science.gov (United States)

    Nagy, László; Magyar, Melinda; Szabó, Tibor; Hajdu, Kata; Giotta, Livia; Dorogi, Márta; Milano, Francesco

    2014-01-01

    Photosynthetic reaction centres are membrane-spanning proteins, found in several classes of autotroph organisms, where a photoinduced charge separation and stabilization takes place with a quantum efficiency close to unity. The protein remains stable and fully functional also when extracted and purified in detergents thereby biotechnological applications are possible, for example, assembling it in nano-structures or in optoelectronic systems. Several types of bionanocomposite materials have been assembled by using reaction centres and different carrier matrices for different purposes in the field of light energy conversion (e.g., photovoltaics) or biosensing (e.g., for specific detection of pesticides). In this review we will summarize the current status of knowledge, the kinds of applications available and the difficulties to be overcome in the different applications. We will also show possible research directions for the close future in this specific field.

  9. FOREWORD: 26th IAHR Symposium on Hydraulic Machinery and Systems

    Science.gov (United States)

    Wu, Yulin; Wang, Zhengwei; Liu, Shuhong; Yuan, Shouqi; Luo, Xingqi; Wang, Fujun

    2012-11-01

    The 26th IAHR Symposium on Hydraulic Machinery and Systems, will be held in Beijing, China, 19-23 August 2012. It is jointly organized by Tsinghua University, State Key Laboratory of Hydro Science and Hydraulic Engineering, China, Jiangsu University, Xi'an University of Technology, China Agricultural University, National Engineering Research Center of Hydropower Equipment and Dongfang Electric Machinery Co., Ltd. It is the second time that China hosts such a symposium. By the end of 2011, the China electrical power system had a total of 1 050 GW installed power, out of which 220 GW was in hydropower plants. The energy produced in hydropower facilities was 662.6 TWh from a total of 4,720 TWh electrical energy production in 2011. Moreover, in 2020, new hydropower capacities are going to be developed, with a total of 180 GW installed power and an estimated 708 TWh/year energy production. And in 2011, the installed power of pumped storage stations was about 25GW. In 2020, the data will be 70GW. At the same time, the number of pumps used in China is increasing rapidly. China produces about 29,000,000 pumps with more than 220 series per year. By the end of 2011, the Chinese pumping system has a total of 950 GW installed power. The energy consumed in pumping facilities was 530 TWh in 2011. The pump energy consumption accounted for about 12% of the national electrical energy production. Therefore, there is a large market in the field of hydraulic machinery including water turbines, pump turbines and a variety of pumps in China. There are also many research projects in this field. For example, we have conducted National Key Research Projects on 1000 MW hydraulic turbine, and on the pump turbines with high head, as well as on the large capacity pumps for water supply. Tsinghua University of Beijing is proud to host the 26th IAHR Symposium on Hydraulic Machinery and Systems. Tsinghua University was established in 1911, after the founding of the People's Republic of China. It

  10. Multiscale singular value manifold for rotating machinery fault diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yi; Lu, BaoChun; Zhang, Deng Feng [School of Mechanical Engineering, Nanjing University of Science and Technology,Nanjing (United States)

    2017-01-15

    Time-frequency distribution of vibration signal can be considered as an image that contains more information than signal in time domain. Manifold learning is a novel theory for image recognition that can be also applied to rotating machinery fault pattern recognition based on time-frequency distributions. However, the vibration signal of rotating machinery in fault condition contains cyclical transient impulses with different phrases which are detrimental to image recognition for time-frequency distribution. To eliminate the effects of phase differences and extract the inherent features of time-frequency distributions, a multiscale singular value manifold method is proposed. The obtained low-dimensional multiscale singular value manifold features can reveal the differences of different fault patterns and they are applicable to classification and diagnosis. Experimental verification proves that the performance of the proposed method is superior in rotating machinery fault diagnosis.

  11. Intelligent Control Scheme of Engineering Machinery of Cluster Hybrid System

    Institute of Scientific and Technical Information of China (English)

    GAO Qiang; WANG Hongli

    2005-01-01

    In a hybrid system, the subsystems with discrete dynamics play a central role in a hybrid system. In the course of engineering machinery of cluster construction, the discrete control law is hard to obtain because the construction environment is complex and there exist many affecting factors. In this paper, hierarchically intelligent control, expert control and fuzzy control are introduced into the discrete subsystems of engineering machinery of cluster hybrid system, so as to rebuild the hybrid system and make the discrete control law easily and effectively obtained. The structures, reasoning mechanism and arithmetic of intelligent control are replanted to discrete dynamic, conti-nuous process and the interface of the hybrid system. The structures of three types of intelligent hybrid system are presented and the human experiences summarized from engineering machinery of cluster are taken into account.

  12. A New Fault Diagnosis Method of Rotating Machinery

    Directory of Open Access Journals (Sweden)

    Chih-Hao Chen

    2008-01-01

    Full Text Available This paper presents a new fault diagnosis procedure for rotating machinery using the wavelet packets-fractal technology and a radial basis function neural network. The faults of rotating machinery considered in this study include imbalance, misalignment, looseness and imbalance combined with misalignment conditions. When such faults occur, they usually induce non-stationary vibrations to the machine. After measuring the vibration signals, the wavelet packets transform is applied to these signals. The fractal dimension of each frequency bands is extracted and the box counting dimension is used to depict the failure characteristics of the vibration signals. The failure modes are then classified by a radial basis function neural network. An experimental study was performed to evaluate the proposed method and the results show that the method can effectively detect and recognize different kinds of faults of rotating machinery.

  13. Integrated measure and control system for textile machinery

    Science.gov (United States)

    Liu, Yuantao; Zhao, Jinzhi; Zhao, Zexiang

    2010-12-01

    In this paper, textile mechanical drive control is researched. Textile machinery integrated measure and control system is established. The system is composed of micro-computer, PLC, transducer, implement device, all kinds of detective components and industrial Ethernet etc. Technology of industrial field bus control and Internet technique are applied. The system is on a background of textile production technique, such as spring, woven, chemical fiber, non-woven, dyeing and finishing. A network based open integrated control system is developed. Various characteristics of production technique flow and textile machinery movement discipline are presented. Configuration software is introduced according to user's control tasks. Final remote automatic controls are finished. This may make development cost reduced, and development periods shortened. Some problems in textile machinery development process are solved, which may make transparency factory and remote development realized.

  14. The Flow of the Gibbon LAVA Element Is Facilitated by the LINE-1 Retrotransposition Machinery.

    Science.gov (United States)

    Meyer, Thomas J; Held, Ulrike; Nevonen, Kimberly A; Klawitter, Sabine; Pirzer, Thomas; Carbone, Lucia; Schumann, Gerald G

    2016-10-30

    LINE-Alu-VNTR-Alu-like (LAVA) elements comprise a family of non-autonomous, composite, non-LTR retrotransposons specific to gibbons and may have played a role in the evolution of this lineage. A full-length LAVA element consists of portions of repeats found in most primate genomes: CT-rich, Alu-like, and VNTR regions from the SVA retrotransposon, and portions of the AluSz and L1ME5 elements. To evaluate whether the gibbon genome currently harbors functional LAVA elements capable of mobilization by the endogenous LINE-1 (L1) protein machinery and which LAVA components are important for retrotransposition, we established a trans-mobilization assay in HeLa cells. Specifically, we tested if a full-length member of the older LAVA subfamily C that was isolated from the gibbon genome and named LAVAC, or its components, can be mobilized in the presence of the human L1 protein machinery. We show that L1 proteins mobilize the LAVAC element at frequencies exceeding processed pseudogene formation and human SVAE retrotransposition by > 100-fold and ≥3-fold, respectively. We find that only the SVA-derived portions confer activity, and truncation of the 3' L1ME5 portion increases retrotransposition rates by at least 100%. Tagged de novo insertions integrated into intronic regions in cell culture, recapitulating findings in the gibbon genome. Finally, we present alternative models for the rise of the LAVA retrotransposon in the gibbon lineage.

  15. Shear and anchorage behaviour of fire exposed hollow core slabs

    NARCIS (Netherlands)

    Fellinger, J.

    2005-01-01

    The fire resistance of hollow core slabs is currently assessed considering flexural failure only. However, fire tests show that shear or anchorage failure can also govern the load bearing behaviour. This paper is based on the dissertation by the author1 and discusses existing and new fire tests. It

  16. Excitonic Doppler-Rabi Oscillations in a Moving Organic Slab

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    It is theoretically shown that excitonic Doppler-Rabi oscillations can occur in an organic slab moving along the axis of a high-Q cavity. Due to the √N enhancement of the vacuum Rabi frequency, this effect can be more easily observed than that in a moving two-level atom.

  17. CFRP strengthened openings in two-way concrete slabs

    DEFF Research Database (Denmark)

    Enochsson, O.; Lundqvist, J.; Täljsten, Björn

    2006-01-01

    Rehabilitation and strengthening of concrete structures with externally bonded fibre reinforced polymers (FRPs) has been a viable technique for at least a decade. An interesting and useful application is strengthening of slabs or walls where openings are introduced. In these situations, FRP sheet...

  18. Some consequences of the subduction of young slabs

    NARCIS (Netherlands)

    England, P.; Wortel, R.

    The negative buoyancy force exerted by a subducting oceanic slab depends on its descent velocity, and strongly on its age. For lithosphere close to thermal equilibrium, this force dominates by a large margin the resisting forces arising from friction on the plate boundary and compositional buoyancy.

  19. Electromagnetic fluctuation-induced interactions in randomly charged slabs

    Science.gov (United States)

    Rezvani, Vahid; Sarabadani, Jalal; Naji, Ali; Podgornik, Rudolf

    2012-09-01

    Randomly charged net-neutral dielectric slabs are shown to interact across a featureless dielectric continuum with long-range electrostatic forces that scale with the statistical variance of their quenched random charge distribution and inversely with the distance between their bounding surfaces. By accounting for the whole spectrum of electromagnetic field fluctuations, we show that this long-range disorder-generated interaction extends well into the retarded regime where higher order (non-zero) Matsubara frequencies contribute significantly. This occurs even for highly clean samples with only a trace amount of charge disorder and shows that disorder effects can be important down to the nanoscale. As a result, the previously predicted non-monotonic behavior for the total force between dissimilar slabs as a function of their separation distance is substantially modified by higher order contributions, and in almost all cases of interest, we find that the equilibrium inter-surface separation is shifted to substantially larger values compared to predictions based solely on the zero-frequency component. This suggests that the ensuing non-monotonic interaction is more easily amenable to experimental detection. The presence of charge disorder in the intervening dielectric medium between the two slabs is shown to lead to an additional force that can be repulsive or attractive depending on the system parameters and can, for instance, wash out the non-monotonic behavior of the total force when the intervening slab contains a sufficiently large amount of disorder charges.

  20. Eigenvalues of collective emission in multi-slice slab configurations

    Energy Technology Data Exchange (ETDEWEB)

    Friedberg, Richard [Department of Physics, Columbia University, New York, NY 10027 (United States); Manassah, Jamal T. [HMS Consultants, Inc., PO Box 592, New York, NY 10028 (United States)], E-mail: jmanassah@gmail.com

    2008-06-02

    We compute the eigenmodes of collective emission from multi-slice slab configurations, using the transfer matrix formalism. We elucidate within this formalism the phenomena of 'Invisible Gaps' in multiple-slice configuration and of 'Precocious Superradiance' in periodic structures previously observed in numerical solutions of Maxwell-Bloch equations.

  1. Topological optical Bloch oscillations in a deformed slab waveguide.

    Science.gov (United States)

    Longhi, Stefano

    2007-09-15

    Spatial Bloch oscillations of light waves of purely topological origin are theoretically shown to exist in weakly deformed slab waveguides. As the optical rays trapped in the deformed waveguide can roll freely, wave diffraction is strongly affected by the topology of the deformed surface, which can be tailored to simulate the effect of a tilted periodic refractive index.

  2. Fire-exposed continuous span composite steel-concrete slabs

    NARCIS (Netherlands)

    Both, C.

    1996-01-01

    From experimental evidence, it was concluded that existing rules for the calculation of the behaviour of fire-exposed composite beams and slabs often lead to conservative solutions. Furthermore, the range of common applications had grown beyond the limits of existing calculation mies. It was feit

  3. Fire-exposed continuous span composite steel-concrete slabs

    NARCIS (Netherlands)

    Both, K.

    1996-01-01

    From experimental evidence, it was concluded that existing rules for the calculation of the behaviour of fire-exposed composite beams and slabs often lead to conservative solutions. Furthermore, the range of common applications had grown beyond the limits of existing calculation rules. It was felt

  4. Fire-exposed continuous span composite steel-concrete slabs

    NARCIS (Netherlands)

    Both, K.

    1996-01-01

    From experimental evidence, it was concluded that existing rules for the calculation of the behaviour of fire-exposed composite beams and slabs often lead to conservative solutions. Furthermore, the range of common applications had grown beyond the limits of existing calculation rules. It was felt t

  5. Study of global stability of tall buildings with prestressed slabs

    Directory of Open Access Journals (Sweden)

    L. A. Feitosa

    Full Text Available The use of prestressed concrete flat slabs in buildings has been increasing in recent years in the Brazilian market. Since the implementation of tall and slender buildings a trend in civil engineering and architecture fields, arises from the use of prestressed slabs a difficulty in ensuring the overall stability of a building without beams. In order to evaluate the efficiency of the main bracing systems used in this type of building, namely pillars in formed "U" in elevator shafts and stairs, and pillars in which the lengths are significantly larger than their widths, was elaborated a computational models of fictional buildings, which were processed and analyzed using the software CAD/TQS. From the variation of parameters such as: geometry of the pillars, thick slabs, characteristic strength of the concrete, reduceofthe coefficient of inertia for consideration of non-linearities of the physical elements, stiffness of the connections between slabs and pillars, among others, to analyze the influence of these variables on the overall stability of the building from the facing of instability parameter Gama Z, under Brazilian standard NBR 6118, in addition to performing the processing of building using the P-Delta iterative calculation method for the same purpose.

  6. Designing Meta Material Slabs Exhibiting Negative Refraction Using Topology Optimization

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Sigmund, O.

    2016-01-01

    This paper proposes a topology optimization based approach for designing meta materials exhibiting a desired negative refraction with high transmission at a given angle of incidence and frequency. The approach considers a finite slab of meta material consisting of axis-symmetric designable unit...

  7. Lower Bound Limit Analysis Of Slabs With Nonlinear Yield Criteria

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Damkilde, Lars

    2002-01-01

    A finite element formulation of the limit analysis of perfectly plastic slabs is given. An element with linear moment fields for which equilibrium is satisfied exactly is used in connection with an optimization algorithm taking into account the full nonlinearity of the yield criteria. Both load...

  8. Electromagnetic fluctuation-induced interactions in randomly charged slabs.

    Science.gov (United States)

    Rezvani, Vahid; Sarabadani, Jalal; Naji, Ali; Podgornik, Rudolf

    2012-09-21

    Randomly charged net-neutral dielectric slabs are shown to interact across a featureless dielectric continuum with long-range electrostatic forces that scale with the statistical variance of their quenched random charge distribution and inversely with the distance between their bounding surfaces. By accounting for the whole spectrum of electromagnetic field fluctuations, we show that this long-range disorder-generated interaction extends well into the retarded regime where higher order (non-zero) Matsubara frequencies contribute significantly. This occurs even for highly clean samples with only a trace amount of charge disorder and shows that disorder effects can be important down to the nanoscale. As a result, the previously predicted non-monotonic behavior for the total force between dissimilar slabs as a function of their separation distance is substantially modified by higher order contributions, and in almost all cases of interest, we find that the equilibrium inter-surface separation is shifted to substantially larger values compared to predictions based solely on the zero-frequency component. This suggests that the ensuing non-monotonic interaction is more easily amenable to experimental detection. The presence of charge disorder in the intervening dielectric medium between the two slabs is shown to lead to an additional force that can be repulsive or attractive depending on the system parameters and can, for instance, wash out the non-monotonic behavior of the total force when the intervening slab contains a sufficiently large amount of disorder charges.

  9. An Analytical Study on Deflection and Stress Resultants of Composite Floor Slabs

    OpenAIRE

    山川, 哲雄; 郝, 洪濤; 田中, 躍一; Yamakawa, Tetsuo; Hao, Hongtao; Tanaka, Youichi

    1993-01-01

    The composite floor slab, which is composed of cast-in-place concrete and casting floor formworks, is assumed to be a double layered floor slab. This floor slab is proposed as ARC (Automation-oriented Reinforced Concrete Constructions) floor systems.Using the equivalent flexural rigidity for the double layered floor slabs consisting of two different elastic moduli, analytical solutions expressed in Fourier series by thin plate theory and by elementary beam theory can be easily applied to the ...

  10. Slab melting and magma formation beneath the southern Cascade arc

    Science.gov (United States)

    Walowski, K. J.; Wallace, P. J.; Clynne, M. A.; Rasmussen, D. J.; Weis, D.

    2016-07-01

    The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Lassen segment of the Cascade arc, where previous work has demonstrated across-arc geochemical variations related to subduction enrichment, and H-isotope data suggest that H2O in basaltic magmas is derived from the final breakdown of chlorite in the mantle portion of the slab. We use naturally glassy, olivine-hosted melt inclusions (MI) from the tephra deposits of eight primitive (MgO > 7 wt%) basaltic cinder cones to quantify the pre-eruptive volatile contents of mantle-derived melts in this region. The melt inclusions have B concentrations and isotope ratios that are similar to mid-ocean ridge basalt (MORB), suggesting extensive dehydration of the downgoing plate prior to reaching sub-arc depths and little input of slab-derived B into the mantle wedge. However, correlations of volatile and trace element ratios (H2O/Ce, Cl/Nb, Sr/Nd) in the melt inclusions demonstrate that geochemical variability is the result of variable addition of a hydrous subduction component to the mantle wedge. Furthermore, correlations between subduction component tracers and radiogenic isotope ratios show that the subduction component has less radiogenic Sr and Pb than the Lassen sub-arc mantle, which can be explained by melting of subducted Gorda MORB beneath the arc. Agreement between pMELTS melting models and melt inclusion volatile, major, and trace element data suggests that hydrous slab melt addition to the mantle wedge can produce the range in primitive compositions erupted in the Lassen region. Our results provide further evidence that chlorite-derived fluids from the mantle portion of the

  11. Origins of the machinery of recombination and sex.

    Science.gov (United States)

    Cavalier-Smith, T

    2002-02-01

    Mutation plays the primary role in evolution that Weismann mistakenly attributed to sex. Homologous recombination, as in sex, is important for population genetics--shuffling of minor variants, but relatively insignificant for large-scale evolution. Major evolutionary innovations depend much more on illegitimate recombination, which makes novel genes by gene duplication and by gene chimaerisation--essentially mutational forces. The machinery of recombination and sex evolved in two distinct bouts of quantum evolution separated by nearly 3 Gy of stasis; I discuss their nature and causes. The dominant selective force in the evolution of recombination and sex has been selection for replicational fidelity and viability; without the recombination machinery, accurate reproduction, stasis, resistance to radical deleterious evolutionary change and preservation of evolutionary innovations would be impossible. Recombination proteins betray in their phylogeny and domain structure a key role for gene duplication and chimaerisation in their own origin. They arose about 3.8 Gy ago to enable faithful replication and segregation of the first circular DNA genomes in precellular ancestors of Gram-negative eubacteria. Then they were recruited and modified by selfish genetic parasites (viruses; transposons) to help them spread from host to host. Bacteria differ fundamentally from eukaryotes in that gene transfer between cells, whether incidental to their absorptive feeding on DNA and virus infection or directly by plasmids, involves only genomic fragments. This was radically changed by the neomuran revolution about 850 million years ago when a posibacterium evolved into the thermophilic cenancestor of eukaryotes and archaebacteria (jointly called neomurans), radically modifying or substituting its DNA-handling enzymes (those responsible for transcription as well as for replication, repair and recombination) as a coadaptive consequence of the origin of core histones to stabilise its

  12. Influence of concrete slabs on lateral torsional buckling of steel beams

    NARCIS (Netherlands)

    Maljaars, J.; Snijder, H.H.; Hoenderkamp, J.C.D.

    2007-01-01

    The use of pre-cast concrete floor slabs in steel framed structures is quite common. In the de-sign of the steel beams, the lateral restraining effect of the pre-cast concrete slab is normally safely neglected. However, the concrete slab will provide some horizontal restraint, even without special p

  13. High-power diode-pumped Tm:YLF slab laser

    CSIR Research Space (South Africa)

    Schellhorn, M

    2009-06-01

    Full Text Available The aim is to develop a high-power Tm:YLF slab laser which can be utilized to pump a Ho slab laser. A 68 W Tm:YLF slab laser was recently presented in [1] pumped from one end by a single 6-bar stack delivering ~300 W of pump power. In this work, we...

  14. Slab melting and magma generation beneath the southern Cascade Arc

    Science.gov (United States)

    Walowski, K. J.; Wallace, P. J.; Clynne, M. A.

    2014-12-01

    Magma formation in subduction zones is interpreted to be caused by flux melting of the mantle wedge by fluids derived from dehydration of the downgoing oceanic lithosphere. In the Cascade Arc and other hot-slab subduction zones, however, most dehydration reactions occur beneath the forearc, necessitating a closer investigation of magma generation processes in this setting. Recent work combining 2-D steady state thermal models and the hydrogen isotope composition of olivine-hosted melt inclusions from the Lassen segment of the Cascades (Walowski et al., 2014; in review) has shown that partial melting of the subducted basaltic crust may be a key part of the subduction component in hot arcs. In this model, fluids from the slab interior (hydrated upper mantle) rise through the slab and cause flux-melting of the already dehydrated MORB volcanics in the upper oceanic crust. In the Shasta and Lassen segments of the southern Cascades, support for this interpretation comes from primitive magmas that have MORB-like Sr isotope compositions that correlate with subduction component tracers (H2O/Ce, Sr/P) (Grove et al. 2002, Borg et al. 2002). In addition, mass balance calculations of the composition of subduction components show ratios of trace elements to H2O that are at the high end of the global arc array (Ruscitto et al. 2012), consistent with the role of a slab-derived melt. Melting of the subducted basaltic crust should contribute a hydrous dacitic or rhyolitic melt (e.g. Jego and Dasgupta, 2013) to the mantle wedge rather than an H2O-rich aqueous fluid. We are using pHMELTS and pMELTS to model the reaction of hydrous slab melts with mantle peridotite as the melts rise through the inverted thermal gradient in the mantle wedge. The results of the modeling will be useful for understanding magma generation processes in arcs that are associated with subduction of relatively young oceanic lithosphere.

  15. Conserved machinery of the bacterial flagellar motor.

    Science.gov (United States)

    Stahlberg, A; Schuster, S C; Bauer, M; Baeuerlein, E; Zhao, R; Reese, T S; Khan, S

    1995-04-01

    Novel periplasmic and cytoplasmic structural modules of the bases of bacterial flagella have been observed in situ and isolated using new biochemical protocols. Flagellar rotation may depend upon interactions of these modules with the intramembrane particle rings, a ubiquitous feature of flagellar bases necessary for torque generation. The outer membrane-associated basal disk of the Wolinella succinogenes polar flagellum has architecture well suited for interaction with the ring particles. However, antibody against the main W. succinogenes basal disk protein did not cross-react with flagella-enriched fractions from Salmonella typhimurium and Bacillus firmus; nor have such structures been observed in these species thus far. Antibodies against two S. typhimurium proteins, FliG and FliM, known to be involved in motor function and part of the cytoplasmic module in this species cross-reacted with flagella-enriched fractions from both W. succinogenes and B. firmus. In addition, flagellar cytoplasmic structure could be isolated from B. firmus. The basal disk may anchor the flagellar motor to the cell wall in some polar bacteria, but this does not seem to be a unique strategy. In contrast, the data indicate that the cytoplasmic module is conserved.

  16. Direct activation of the apoptosis machinery as a mechanism to target cancer cells.

    Science.gov (United States)

    Nguyen, Jack T; Wells, James A

    2003-06-24

    Apoptosis plays a pivotal role in the cytotoxic activity of most chemotherapeutic drugs, and defects in this pathway provide a basis for drug resistance in many cancers. Thus the ability to restore apoptosis by using small molecules could have important therapeutic implications. Using a cell-free assay to simultaneously target multiple components of the apoptosis pathway, we identified a class of compounds that activate caspases in a cytochrome c-dependent manner and induce apoptosis in whole cells. By reconstituting the apoptosis pathway with purified proteins, we determined that these compounds promote the protein-protein association of Apaf-1 into the functional apoptosome. These compounds exert cytostatic and cytotoxic effects on a variety of cancer cell lines while having little or no activity against the normal cell lines tested. These findings suggest that direct activation of the basic apoptosis machinery may be a viable mechanism to selectively target cancer.

  17. White-Paper Report:Textile Machinery Industry (2005-2009) Economic Performance in Chinese Textile Machinery Industry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This report is accomplished by China Textile Machinery and Accessories Association to be part of the Annual Report of China Textile Industry that comes out in the middle of the year.Given that all the official statistics are channeled to each industrial sector four times a year(March,May,Aug.Nov.) ,it comes as no surprise at all when an annual report is prepared at the beginning of the new year by taking eleven months into account because of the data availability from the government.This report of Chinese textile machinery industry is also based on the data attainable from Jan.to Nov.in 2009.

  18. The intraflagellar transport machinery in ciliary signaling

    DEFF Research Database (Denmark)

    Mourão, André; Christensen, Søren Tvorup; Lorentzen, Esben

    2016-01-01

    Cilia and flagella on eukaryotic cells are slender microtubule-based projections surrounded by a membrane with a unique lipid and protein composition. It is now appreciated that cilia in addition to their established roles in motility also constitute hubs for cellular signaling by sensing external...... environmental cues necessary for organ development and maintenance of human health. Pathways reported to rely on the cilium organelle include Hedgehog, TGF-β, Wnt, PDGFRα, integrin and DNA damage repair signaling. An emerging theme in ciliary signaling is the requirement for active transport of signaling...... components into and out of the cilium proper. Here, we review the current state-of-the-art regarding the importance of intraflagellar transport and BBSome multi-subunit complexes in ciliary signaling....

  19. Rapid Growth of China Petroleum Machinery Manufacturing (continued)

    Institute of Scientific and Technical Information of China (English)

    Huang Zhiqian; Sun Zuchen; Wang Keyu

    1996-01-01

    @@ Technology for petroleum machinery design and manufacturing upgraded remarkably The basic research on rock bit. drilling pump. pump valve, piston, flooding pumps, derrick, shale shaker.hydraulic blowout preventer, torque converter, pumping unit. sucker rod. submersible pump. fracturing pump centrifugal pump. pneumatic parts, geophone and acquisition station has reached the advanced international level.

  20. 46 CFR 58.01-50 - Machinery space, noise.

    Science.gov (United States)

    2010-10-01

    ... around machinery—90 dB(A) (c) If adding a source of noise would cause a machinery space to exceed the... isolated so that the space does not exceed that noise level. If the space is manned, a refuge from noise...

  1. The capacity of sugar beet farms’ machinery and equipment

    Directory of Open Access Journals (Sweden)

    Małgorzata BZOWSKA – BAKALARZ

    2012-12-01

    Full Text Available The survey investigates into equipment of sugar beet farms of the Lublin region, Poland, with machinery – with reference to plantation size and yields. To assess the production potential of the farms, the authors determined the age structure of the machinery owned by the farmers and established the scale of investment in new equipment. The machinery most important for sugar beet production are pre-sowing and post-harvest tillage units, sprayers, seed drills, combine harvesters and self-unloading trailers. In most cases, the surveyed farmers own most of these machines, but they are often obsolete: 37% of them is in operation for more than 15 years. As for the machines dedicated solely to sugar beet growing (harvesters and seeders, their age structure is most unfavourable – 70% of them have been used for over 15 years. A trend towards increasing plantation sizes provides incentives for introducing innovation to cultivation methods. However, the scale of investment in new machinery is small, especially in the case of small and medium-sized farms that dominate in the region. The authors surveyed also the scale of using professional services in the field of tillage processes to determine changes in farming practices.

  2. TRACTOR REPAIR. AGRICULTURAL MACHINERY--SERVICE OCCUPATIONS, MODULE NUMBER 16.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    THE PURPOSE OF THIS GUIDE IS TO HELP TEACHERS PREPARE POSTSECONDARY STUDENTS FOR THE AGRICULTURAL MACHINERY SERVICE OCCUPATIONS AS PARTS MEN, MECHANICS, MECHANIC'S HELPERS, AND SERVICE SUPERVISORS. IT WAS DESIGNED BY A NATIONAL TASK FORCE ON THE BASIS OF RESEARCH FROM STATE STUDIES. THE MAJOR OBJECTIVE IS TO DEVELOP (1) AN UNDERSTANDING OF THE…

  3. Analysis of noise control measures on outdoor machinery using EQUIP+

    NARCIS (Netherlands)

    Dittrich, M.G.

    2006-01-01

    Noise control of different types of outdoor machinery covered by EU Directive 2000/14/EC such as construction machines, generators and other equipment powered by internal combustion engines requires knowledge of the noise path model and the potential noise control measures. As there is often a

  4. Implications of material selection on the design of packaging machinery.

    Science.gov (United States)

    Merritt, J P

    2009-01-01

    Material selection has significant implications on the design and cost of horizontal-form-fill-seal packaging machinery. To avoid excessive costs, machine redesigns and project delays, material selection must be reconciled early in the project and revisited throughout the construction of the machine.

  5. PTP1B targets the endosomal sorting machinery

    DEFF Research Database (Denmark)

    Stuible, Matthew; Abella, Jasmine V; Feldhammer, Matthew;

    2010-01-01

    STAM2 specifically suppressed Akt activation, and a phosphorylation-deficient STAM2 mutant displayed prolonged localization on endosomes following EGF stimulation. These results reveal a novel link between the dephosphorylation and endocytic machinery and suggest that PTP1B can affect RTK signaling...

  6. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation (other than machinery spaces). 169.315 Section 169.315 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Construction and Arrangement Hull Structure § 169.315 Ventilation (other than...

  7. 500 Million Yuan Textile Machinery Project Located in Laiyang

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Textile machinery project with 500 million Yuan investment was formally signed in Yantai Laiyang Development Zone on November 15, which is the l Oth project in the development zone with more than 100 million Yuan investment, and the 5th project in the development zone with more than 500 million Yuan investment.

  8. TESTS ON STRUCTURALLY DEFICIENT RC SLABS STRENGTHENED WITH FIBRE REINFORCED POLYMER (FRP) COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    S.T. Smith; S.J. Kim

    2004-01-01

    This paper reports the results of a series of tests on fibre reinforced polymer (FRP) strengthened reinforced concrete (RC) slabs, which were recently undertaken at the University of Technology,Sydney. The slabs were reinforced with high-strength low-ductile steel reinforcement and strengthened with either carbon FRP (CFRP) or glass FRP (GFRP) composites. The unstrengthened control slabs failed by fracture of the steel tension reinforcement while the FRP strengthened slabs failed by debonding of the FRP followed by rupture of the tension steel. The FRP-strengthened slabs were stronger than their unstrengthened counterparts and displayed considerable ductility.

  9. An investigation on the behaviour and stiffness of reinforced concrete slabs subjected to torsion

    Science.gov (United States)

    Nguyen, M. C. T.; Pham, P. T.

    2017-01-01

    This paper presents an investigation on RC slab under torsion, by both experiment and finite element analysis. The torsion tests were done on three similar square RC slabs with dimensions of 1900×1900×150 mm. The behaviour of slabs at pre-cracking and post-cracking of concrete phases were investigated, via Load-displacement, twisting moment-curvature relationships, and torsional stiffness of slabs. The experimental results are compared with the FEA and the results in literatures. The torsional stiffness of slab at the phase of concrete cracked and steel yield is about 1/25 of the stiffness at the pre-cracking phase.

  10. Enhanced bandgap in annular photonic-crystal silicon-on-insulator asymmetric slabs.

    Science.gov (United States)

    Hou, Jin; Citrin, D S; Wu, Huaming; Gao, Dingshan; Zhou, Zhiping

    2011-06-15

    Photonic band structures of annular photonic-crystal (APC) silicon-on-insulator (SOI) asymmetric slabs with finite thickness were investigated by the three-dimensional plane-wave expansion method. The results show that for a broad range of air-volume filling factors, APC slabs can exhibit a significantly larger bandgap than conventional circular-hole photonic-crystal (PC) slabs. Bandgap enhancements over conventional air hole PC SOI slabs as large as twofold are predicted for low air-volume filling factors below 15%. This desirable behavior suggests a potential for APC SOI slabs to serve as the basis of various optical cavities, waveguides, and mirrors.

  11. Components of the CtBP1/BARS-dependent fission machinery.

    Science.gov (United States)

    Valente, Carmen; Luini, Alberto; Corda, Daniela

    2013-10-01

    The brefeldin A ADP-ribosylated substrate, a member of the C-terminal-binding protein family that is referred to as CtBP1/BARS, is a dual-function protein that acts as a transcriptional co-repressor in the nucleus and as an inducer of membrane fission in the cytoplasm. In this review, we first discuss the mechanisms that enable CtBP1/BARS to shift between the nuclear transcriptional co-repressor and the cytosolic fission-inducing activities. Then, we focus on the role of CtBP1/BARS in membrane fission. CtBP1/BARS controls several fission events including macropinocytosis, fluid-phase endocytosis, COPI-coated vesicle formation, basolaterally directed post-Golgi carrier formation, and Golgi partitioning in mitosis. We report on recent advances in our understanding of the CtBP1/BARS membrane fission machineries that operate at the trans-side and at the cis-side of the Golgi complex. Specifically, we discuss how these machineries are assembled and regulated, and how they operate in the formation of the basolaterally directed post-Golgi carriers.

  12. A Comparative Study of RNA Polymerase II Transcription Machinery in Yeasts

    Science.gov (United States)

    Sharma, Nimisha; Mehta, Surbhi

    The control of gene expression, predominantly at the level of transcription, plays a fundamental role in biological processes determining the phenotypic changes in cells and organisms. The eukaryotes have evolved a complex and sophisticated transcription machinery to transcribe DNA into RNA. RNA polymerase II enzyme lies at the centre of the transcription apparatus that comprises nearly 60 polypeptides and is responsible for the expression and regulation of proteinencoding genes. Much of our present understanding and knowledge of the RNA polymerase II transcription apparatus in eukaryotes has been derived from studies in Saccharomyces cerevisiae. More recently, Schizosaccharomyces pombe has emerged as a better model system to study transcription because the transcription mechanism in this yeast is closer to that in higher eukaryotes. Also, studies on components of the basal transcription machinery have revealed a number of properties that are common with other eukaryotes, but have also highlighted some features unique to S. pombe. In fact, the fungal transcription associated protein families show greater species specificity and only 15% of these proteins contain homologues shared between both S. cerevisiae and S. pombe. In this chapter, we compare the RNA polymerase II transcription apparatus in different yeasts.

  13. Outer membrane machinery and alginate synthesis regulators control membrane vesicle production in Pseudomonas aeruginosa.

    Science.gov (United States)

    Tashiro, Yosuke; Sakai, Ryosuke; Toyofuku, Masanori; Sawada, Isao; Nakajima-Kambe, Toshiaki; Uchiyama, Hiroo; Nomura, Nobuhiko

    2009-12-01

    The opportunistic human bacterial pathogen Pseudomonas aeruginosa produces membrane vesicles (MVs) in its surrounding environment. Several features of the P. aeruginosa MV production mechanism are still unknown. We previously observed that depletion of Opr86, which has a role in outer membrane protein (OMP) assembly, resulted in hypervesiculation. In this study, we showed that the outer membrane machinery and alginate synthesis regulatory machinery are closely related to MV production in P. aeruginosa. Depletion of Opr86 resulted in increased expression of the periplasmic serine protease MucD, suggesting that the accumulation of misfolded OMPs in the periplasm is related to MV production. Indeed, the mucD mutant showed a mucoid phenotype and the mucD mutation caused increased MV production. Strains with the gene encoding alginate synthetic regulator AlgU, MucA, or MucB deleted also caused altered MV production. Overexpression of either MucD or AlgW serine proteases resulted in decreased MV production, suggesting that proteases localized in the periplasm repress MV production in P. aeruginosa. Deletion of mucD resulted in increased MV proteins, even in strains with mutations in the Pseudomonas quinolone signal (PQS), which serves as a positive regulator of MV production. This study suggests that misfolded OMPs may be important for MV production, in addition to PQS, and that these regulators act in independent pathways.

  14. The STIM1/Orai signaling machinery

    Science.gov (United States)

    Fahrner, Marc; Derler, Isabella; Jardin, Isaac; Romanin, Christoph

    2013-01-01

    Ca2+ influx via store-operated Ca2+ release activated Ca2+ (CRAC) channels represents a main signaling pathway for T-cell activation as well as mast-cell degranulation. The ER-located Ca2+-sensor, STIM1 and the Ca2+-selective ion pore, Orai1 in the membrane are sufficient to fully reconstitute CRAC currents. Their identification, but even more the recent structural resolution of both proteins by X-ray crystallography has substantially advanced the understanding of the activation mechanism of CRAC channels. In this review, we provide a detailed description of the STIM1/Orai1 signaling pathway thereby focusing on the critical domains mediating both, intra- as well as intermolecular interactions and on the ion permeation pathway. Based on the results of functional studies as well as the recently published crystal structures, we portray a mechanistic view of the steps in the CRAC channel signaling cascade ranging from STIM1 oligomerization over STIM1-Orai1 coupling to the ultimate Orai1 channel activation and permeation. PMID:24107921

  15. Heterologous synthesis of cytochrome c' by Escherichia coli is not dependent on the System I cytochrome c biogenesis machinery.

    Science.gov (United States)

    Inoue, Hiroki; Wakai, Satoshi; Nishihara, Hirofumi; Sambongi, Yoshihiro

    2011-07-01

    Hydrogenophilus thermoluteolus cytochrome c' (PHCP) has typical spectral properties previously observed for other cytochromes c', which comprise Ambler's class II cytochromes c. The PHCP protein sequence (135 amino acids) deduced from the cloned gene is the most homologous (55% identity) to that of cytochrome c' from Allochromatium vinosum (AVCP). These findings indicate that PHCP forms a four-helix bundle structure, similar to AVCP. Strikingly, PHCP with a covalently bound heme was heterologously synthesized in the periplasm of Escherichia coli strains deficient in the DsbD protein, a component of the System I cytochrome c biogenesis machinery. The heterologous synthesis of PHCP by aerobically growing E. coli also occurred without a plasmid carrying the genes for Ccm proteins, other components of the System I machinery. Unlike Ambler's class I general cytochromes c, the synthesis of PHCP is not dependent on the System I machinery and exhibits similarity to that of E. coli periplasmic cytochrome b(562), a 106-residue four-helix bundle.

  16. APP and APLP2 interact with the synaptic release machinery and facilitate transmitter release at hippocampal synapses

    Science.gov (United States)

    Fanutza, Tomas; Del Prete, Dolores; Ford, Michael J; Castillo, Pablo E; D’Adamio, Luciano

    2015-01-01

    The amyloid precursor protein (APP), whose mutations cause familial Alzheimer’s disease, interacts with the synaptic release machinery, suggesting a role in neurotransmission. Here we mapped this interaction to the NH2-terminal region of the APP intracellular domain. A peptide encompassing this binding domain -named JCasp- is naturally produced by a γ-secretase/caspase double-cut of APP. JCasp interferes with the APP-presynaptic proteins interaction and, if linked to a cell-penetrating peptide, reduces glutamate release in acute hippocampal slices from wild-type but not APP deficient mice, indicating that JCasp inhibits APP function.The APP-like protein-2 (APLP2) also binds the synaptic release machinery. Deletion of APP and APLP2 produces synaptic deficits similar to those caused by JCasp. Our data support the notion that APP and APLP2 facilitate transmitter release, likely through the interaction with the neurotransmitter release machinery. Given the link of APP to Alzheimer’s disease, alterations of this synaptic role of APP could contribute to dementia. DOI: http://dx.doi.org/10.7554/eLife.09743.001 PMID:26551565

  17. APP and APLP2 interact with the synaptic release machinery and facilitate transmitter release at hippocampal synapses.

    Science.gov (United States)

    Fanutza, Tomas; Del Prete, Dolores; Ford, Michael J; Castillo, Pablo E; D'Adamio, Luciano

    2015-11-09

    The amyloid precursor protein (APP), whose mutations cause familial Alzheimer's disease, interacts with the synaptic release machinery, suggesting a role in neurotransmission. Here we mapped this interaction to the NH2-terminal region of the APP intracellular domain. A peptide encompassing this binding domain -named JCasp- is naturally produced by a γ-secretase/caspase double-cut of APP. JCasp interferes with the APP-presynaptic proteins interaction and, if linked to a cell-penetrating peptide, reduces glutamate release in acute hippocampal slices from wild-type but not APP deficient mice, indicating that JCasp inhibits APP function.The APP-like protein-2 (APLP2) also binds the synaptic release machinery. Deletion of APP and APLP2 produces synaptic deficits similar to those caused by JCasp. Our data support the notion that APP and APLP2 facilitate transmitter release, likely through the interaction with the neurotransmitter release machinery. Given the link of APP to Alzheimer's disease, alterations of this synaptic role of APP could contribute to dementia.

  18. Analysis of the Behaviour of Composite Steel and Steel Fiber Reinforced Concrete Slabs

    Directory of Open Access Journals (Sweden)

    Mindaugas Petkevičius

    2011-04-01

    Full Text Available There was a pending influence of steel fiber on the strength and stiffness of composite steel–concrete slabs under statical short–time load. Steel profiled sheeting and steel fiber reinforced concrete were used for specimens. Four composite slabs were made. Experimental investigations into the behaviour and influence of steel fiber reinforced concrete in composite slabs were conducted. Transverse, longitudinal, shear deformation and deflection of the slab were measured. The results indicated that the use of steel fiber in composite slabs was effective: strength was 20–24 % higher and the meanings of deflections under the action of the bending moment were 0,6MR (where MR is the bending moment at failure of the slabs and were 16–18 % lower for slabs with usual concrete. Article in Lithuanian

  19. Investigation of Effect of Slab Opening Location to the Shear Stress

    Directory of Open Access Journals (Sweden)

    Burak Yön

    2010-01-01

    Full Text Available In this study, it is investigated the effect of slab opening location in reinforced concrete building to the structural behavior. For investigation of slab irregularity, three multi storey irregular structures that have different slab opening locations in structure plans and one regular structure are designed. Linear dynamic analyses are performed for the structure models using Time History Analysis method. 13 March 1992 Erzincan Earthquake acceleration records are used for these analyses. It is assumed that slabs of selected structures are modeled as elastic diaphragm. SAP2000 Structural Analysis Program is used in the analyses. Values of slab that near space shear stress obtained from dynamic analyses of selected structures are comparatively evaluated. According to analyses results, it is determined that location of slab opening of structures reasonably both affects the behavior of structures and occurs great slab shear stress.

  20. ADJUSTMENT, MAINTENANCE, AND REPAIR OF TILLAGE, PLANTING, SPRAYING, AND FERTILIZING MACHINERY. AGRICULTURAL MACHINERY--SERVICE OCCUPATIONS, MODULE NUMBER 10.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    THE PURPOSE OF THIS GUIDE IS TO HELP TEACHERS PREPARE POSTSECONDARY-LEVEL STUDENTS FOR THE AGRICULTURAL MACHINERY SERVICE OCCUPATIONS AS PARTS MEN, MECHANICS, MECHANIC'S HELPERS, AND SERVICE SUPERVISORS. IT WAS DESIGNED BY A NATIONAL TASK FORCE ON THE BASIS OF RESEARCH FROM STATE STUDIES. THE MAJOR OBJECTIVE IS TO DEVELOP (1) STUDENT UNDERSTANDING…

  1. Flexural Behavior of Continuous Bubbled Reinforced Reactive Powder Concrete Flat Slab

    Directory of Open Access Journals (Sweden)

    Mohammad Redha K. Mahmood

    2017-05-01

    Full Text Available This paper presents an experimental investigation on flexural behavior of continuous bubbled reinforced Reactive Powder Concrete (RPC flat slabs. Bubbled slab is one of the various types of voided slabs. It consist of bubbles placed inside a concrete slab which will reduce the self-weight of the structure by about 35% (Tina Lai 2009. On the other hand, using RPC make it possible for structural member to have smaller dimensions due to the great strength of this type of concrete. In this study these two method are used to increase the building spaces dimensions by reducing self-weigh of the structure by using bubbled slabs and to decrease the structural members' dimensions by using RPC have been investigated together. To study the flexural behavior of continuous bubbled flat slabs such as the ultimate load carrying capacity, central deflection and slabs crack pattern at the ultimate load, seven types of slabs were tested. The parameters of the study were type of concrete (RPC and Normal Concrete (NC, bubbles diameter to slab thickness ratio (D/t of (0.6 and 0.7, type of loading (distributed and line load and solid slab. The test results show that the crack pattern and ultimate load capacity as well as maximum deflection depends on all of the mentioned parameters, were by increasing (D/t ratio the ultimate load capacity increases about (7.36%, 5.46% and 16.52% for RPC slabs under distributed load, line load and NC slabs, respectively. The solid slab increases the ultimate load about (4.05% compare to bubbled slab. Also, the line load decreases the ultimate load compare to distributed load by (3.45-5.16% for different (D/t ratio, and using the NC also decreases the ultimate load compare to RPC by (48-52.13% for different (D/t ratio

  2. Slab2 - Providing updated subduction zone geometries and modeling tools to the community

    Science.gov (United States)

    Hayes, G. P.; Hearne, M. G.; Portner, D. E.; Borjas, C.; Moore, G.; Flamme, H.

    2015-12-01

    The U.S. Geological Survey database of global subduction zone geometries (Slab1.0) combines a variety of geophysical data sets (earthquake hypocenters, moment tensors, active source seismic survey images of the shallow subduction zone, bathymetry, trench locations, and sediment thickness information) to image the shape of subducting slabs in three dimensions, at approximately 85% of the world's convergent margins. The database is used extensively for a variety of purposes, from earthquake source imaging, to magnetotelluric modeling. Gaps in Slab1.0 exist where input data are sparse and/or where slabs are geometrically complex (and difficult to image with an automated approach). Slab1.0 also does not include information on the uncertainty in the modeled geometrical parameters, or the input data used to image them, and provides no means to reproduce the models it described. Currently underway, Slab2 will update and replace Slab1.0 by: (1) extending modeled slab geometries to all global subduction zones; (2) incorporating regional data sets that may describe slab geometry in finer detail than do previously used teleseismic data; (3) providing information on the uncertainties in each modeled slab surface; (4) modifying our modeling approach to a fully-three dimensional data interpolation, rather than following the 2-D to 3-D steps of Slab1.0; (5) migrating the slab modeling code base to a more universally distributable language, Python; and (6) providing the code base and input data we use to create our models, such that the community can both reproduce the slab geometries, and add their own data sets to ours to further improve upon those models in the future. In this presentation we describe our vision for Slab2, and the first results of this modeling process.

  3. Dynamics of Mantle Circulation Associated with Slab Window Formation: Insights from 3D Laboratory Models

    Science.gov (United States)

    Guillaume, B.; Funiciello, F.; Moroni, M.; Faccenna, C.; Martinod, J.

    2009-12-01

    Slab window can form either by the intersection of a spreading ridge with a subduction zone or because of internal deformation of the slab that leads to its disruption. The main consequences of this phenomenon are the modifications of the physical, chemical and thermal conditions in the backarc mantle that in turn affect the tectonic and magmatic evolution of the overriding plate. We performed laboratory models of a two-layer linear viscous slab (silicone putty)-upper mantle (glucose syrup) system to quantitatively investigate the pattern of mantle circulation within the slab window (using Feature Tracking image analysis technique) and its influence on the kinematics of the system. Two different geometries have been tested considering a window located (a) at slab edges or (b) within the slab. Kinematic consequences of slab window have been explored to understand the dynamics of the mantle-slab interaction. Configuration (a) implies a reduction of the slab width (W) during subduction and is characterized by toroidal fluxes around the slab edges. The abrupt opening of lateral slab windows produces an acceleration of the trench retreat and subduction velocity, such as 40% for a three-fold width reduction. We interpret this behavior as mostly due to the decrease in the toroidal flow inside subduction windows, scaling with W2. Configuration (b) has been designed to explore the pattern of mantle flow within the window in the case of a laterally constrained subduction system. Slab window, which had a width (Ww) fixed to 15 % of the slab width, opened in the trench-perpendicular direction. It produced the formation of two toroidal mantle cells, centered on the slab midpoint and laterally growing as the slab window enlarged. Particles extruded through the slab window did not mix with particles located in the mantle wedge, the boundary between both reaching distances from the trench up to 3×Ww in the trench-perpendicular direction, and up to 1.5×Ww from the window edge in

  4. Optimal Material Layout - Applied on Reinforced Concrete Slabs

    DEFF Research Database (Denmark)

    Dollerup, Niels; Jepsen, Michael S.; Damkilde, Lars

    2015-01-01

    to determine the optimal material layout of a slab in the ultimate load state, based on simple inputs such as outer geometry, boundary conditions, multiple load cases and design domains. The material layout of the optimal design can either be fully orthotropic or isotropic, or a combination with a predefined......This paper introduces a general, finite-element-based optimisation tool for improving the material layout of concrete structures. The application presented is general and exemplified by material optimisation of reinforced concrete slabs. By utilising the optimisation tool, it is possible...... coupling between design domains and reinforcement directions. The implementation is a lower bound formulation, resulting in a convex optimisation problem that consists of a number of linear constraints from the equilibrium equations and a number of convex non-linear constraints from the yield criteria...

  5. Designing Meta Material Slabs Exhibiting Negative Refraction Using Topology Optimization

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Sigmund, O.

    2016-01-01

    This paper proposes a topology optimization based approach for designing meta materials exhibiting a desired negative refraction with high transmission at a given angle of incidence and frequency. The approach considers a finite slab of meta material consisting of axis-symmetric designable unit...... cells subjected to an exterior field. The unit cell is designed to achieve the desired properties based on tailoring the response of the meta material slab underthe exterior field. The approach is directly applicable to physical problems modeled by the Helmholtz equation, such as acoustic, elastic...... and electromagnetic wave problems. Acoustic meta materials with unit cell size on the order of half the wave length are considered as examples. Optimized designs are presented and their performance under varying frequency and angle of incidence is investigated....

  6. Characteristics of shell thickness in a slab continuous casting mold

    Institute of Scientific and Technical Information of China (English)

    Di-feng Wu; Shu-sen Cheng; Zi-jian Cheng

    2009-01-01

    The key to reduce shell breakout in the continuous casting process is to control shell thickness in the mold.A numerical simulation on the turbulent flow and heat transfer coupled with solidification in the slab mold using the volume of fluid (VOF) model and the enthalpy-porosity scheme was conducted and the emphasis was put upon the flow effect on the shell thickness profiles in longitudinal and transverse directions.The results show that the jet acts a stronger impingement on the shell of narrow face,which causes a zero-increase of shell thickness in a certain range near the impingement point.The thinnest shell on the slab cross-section locates primarily in the center of the narrow face,and secondly near the comer of the wide face.Nozzle optimization can obviously increase the shell thickness and make it more uniform.

  7. Oscillating Casimir force between two slabs in a Fermi sea

    DEFF Research Database (Denmark)

    Li-Wei, Chen; Guo-Zhen, Su; Jin-Can, Chen

    2012-01-01

    The Casimir effect for two parallel slabs immersed in an ideal Fermi sea is investigated at both zero and nonzero temperatures. It is found that the Casimir effect in a Fermi gas is distinctly different from that in an electromagnetic field or a massive Bose gas. In contrast to the familiar result...... that the Casimir force decreases monotonically with the increase of the separation L between two slabs in an electromagnetic field and a massive Bose gas, the Casimir force in a Fermi gas oscillates as a function of L. The Casimir force can be either attractive or repulsive, depending sensitively on the magnitude...... of L. In addition, it is found that the amplitude of the Casimir force in a Fermi gas decreases with the increase of the temperature, which also is contrary to the case in a Bose gas, since the bosonic Casimir force increases linearly with the increase of the temperature in the region T

  8. Non-Fourier heat conduction in an exponentially graded slab

    Science.gov (United States)

    Raveshi, M. R.

    2016-03-01

    The present article investigates one-dimensional non-Fourier heat conduction in a functionally graded material by using the differential transformation method. The studied geometry is a finite functionally graded slab, which is initially at a uniform temperature and suddenly experiences a temperature rise at one side, while the other side is kept insulated. A general non-Fourier heat transfer equation related to the functionally graded slab is derived. The problem is solved in the Laplace domain analytically, and the final results in the time domain are obtained by using numerical inversion of the Laplace transform. The obtained results are compared with the exact solution to verify the accuracy of the proposed method, which shows excellent agreement.

  9. Bolometric detection of ferromagnetic resonance in YIG slab

    Science.gov (United States)

    Tu, Sa; Białek, Marcin; Zhang, Youguang; Zhao, Weisheng; Yu, Haiming; Ansermet, Jean-Philippe

    2017-10-01

    The resistance of the Pt bar deposited on the YIG slab was monitored while the magnetic field was ramped through the ferromagnetic resonance with the YIG slab facing a coplanar waveguide resonator excited at 4.3 GHz excitation. The resistance change provides detection of the ferromagnetic resonance with a high signal-to-noise ratio. It is ascribed to a change in the temperature of the Pt bars. The thermal origin of the signal is confirmed by the observation that the signal vanishes when field modulation is applied at frequencies above 6 Hz. The spin pumping effect was vanishingly small, and the anisotropic magnetoresistance of the Pt bar, though quite easily observed, would imply a rectification voltage that is much smaller than the bolometric effect.

  10. Laplace-Fourier analysis and instabilities of a gainy slab

    CERN Document Server

    Hågenvik, Hans Olaf

    2015-01-01

    The idealization of monochromatic plane waves leads to considerable simplifications in the analysis of electromagnetic systems. However, for active systems this idealization may be dangerous due to the presence of growing waves. Here we consider a gainy slab, and use a realistic incident beam, which is both causal and has finite width. This clarifies some apparent paradoxes arising from earlier analyses of this setup. In general it turns out to be necessary to involve complex frequencies $\\omega$ and/or complex transversal wavenumbers $k_x$. Simultaneously real $\\omega$ and $k_x$ cannot describe amplified waves in a slab which is infinite in the transversal direction. We also show that the only possibility to have an absolute instability for a finite width beam, is if a normally incident plane wave would experience an instability.

  11. Negotiating Multicollinearity with Spike-and-Slab Priors.

    Science.gov (United States)

    Ročková, Veronika; George, Edward I

    2014-08-01

    In multiple regression under the normal linear model, the presence of multicollinearity is well known to lead to unreliable and unstable maximum likelihood estimates. This can be particularly troublesome for the problem of variable selection where it becomes more difficult to distinguish between subset models. Here we show how adding a spike-and-slab prior mitigates this difficulty by filtering the likelihood surface into a posterior distribution that allocates the relevant likelihood information to each of the subset model modes. For identification of promising high posterior models in this setting, we consider three EM algorithms, the fast closed form EMVS version of Rockova and George (2014) and two new versions designed for variants of the spike-and-slab formulation. For a multimodal posterior under multicollinearity, we compare the regions of convergence of these three algorithms. Deterministic annealing versions of the EMVS algorithm are seen to substantially mitigate this multimodality. A single simple running example is used for illustration throughout.

  12. Factors affecting the deterioration of concrete pavement slabs

    Directory of Open Access Journals (Sweden)

    N.M. Morozov

    2015-11-01

    Full Text Available The behavior of constructions under actual operating conditions is affected by exposure to the environment. It is important that concrete roads and airport pavings are resistant not only to mechanical damage, but also to the effects of alternate freezing and thawing. The causes of early failure in concrete have been shown using prefabricated road slabs as an example. The causes of loss of performance properties of the roadway have been established, which are primarily dependent on the quality of raw materials in the concrete. It was found that, aside from durability, uniformity and porosity are important factors in determining the frost resistance of concrete roadways. It was shown that high aluminate content in the cement leads to concrete destruction in the first year of structure use. The results may also indirectly indicate a violation of forming technology during slab production.

  13. Electromagnetic wave propagation through a slab of a dispersive medium

    CERN Document Server

    Ismail, Mohamed

    2016-01-01

    A method is proposed for the analysis of the propagation of electromagnetic waves through a homogeneous slab of a medium with Drude-Lorentz dispersion behavior, and excited by a causal sinusoidal source. An expression of the time dependent field, free from branch-cuts in the plane of complex frequencies, is established. This method provides the complete temporal response in both the steady-state and transient regimes in terms of discrete poles contributions. The Sommerfeld and Brillouin precursors are retrieved and the corresponding set of poles are identified. In addition, the contribution in the transient field of the resonance frequency in the Drude-Lorentz model is exhybited, and the effect of reflections resulting from the refractive index mismatch at the interfaces of the slab are analyzed.

  14. Dichromatic nonlinear eigenmodes in slab waveguide with chi(2) nonlinearity.

    Science.gov (United States)

    Darmanyan, S A; Nevière, M

    2001-03-01

    The existence of purely nonlinear eigenmodes in a waveguiding structure composed of a slab with quadratic nonlinearity surrounded by (non)linear claddings is reported. Modes having bright and dark solitonlike shapes and consisting of two mutually locked harmonics are identified. Asymmetrical modes are shown to exist in symmetrical environments. Constraints for the existence of the modes are derived in terms of parameters of guiding structure materials.

  15. Transverse Mode Formation in Longitudinally Pumped Miniature Slab Lasers

    Institute of Scientific and Technical Information of China (English)

    XU Jian-Qiu; YE Xin; FANG Tao

    2006-01-01

    The formation of transverse modes in longitudinally pumped miniature slab lasers is investigated theoretically and experimentally. The longitudinally non-uniform gain-guiding is studied by expanding the electric field into the Hermite-Gaussian functions that satisfy boundary conditions of the resonator. Non-Gaussian transversal beam profiles in the near field are found and the beam diameter is reduced when the pump spot becomes smaller. The experimental observation agrees with the theoretical calculation.

  16. End-Pumped Tm:YAG Ceramic Slab Lasers

    Institute of Scientific and Technical Information of China (English)

    CHENG Xiao-Jin; XU Jian-Qiu; ZHANG Wen-Xin; JIANG Sen-Xue; PAN Yu-Bai

    2009-01-01

    Lasers from a Tm:YAG ceramic aare reported for the first time to our best knowledge. The Tm:YAG ceramic slab is end-pumped by a laser diode with central wavelength 792nm. At room temperature, the maximum continuous-wave output power is 4.5 W, and the sloping efficiency is obtained to be 20.5%. The laser spectrum of the Tm: YAG ceramic is centered at 2015 nm.

  17. Beam splitting by a plane-parallel absorptive slab.

    Science.gov (United States)

    Halevi, P

    1982-10-01

    A study of the transmission of inhomogeneous electromagnetic waves through an interface between a transparent and an absorbing medium leads to the prediction of a novel effect. A beam of unpolarized light passing through a dissipative plane-parallel slab splits into two parallel beams. The electric field in one beam is perpendicular to the plane of incidence, whereas in the other beam it is parallel to this plane.

  18. Oscillation modes and transmission into a Fibonacci slab

    Science.gov (United States)

    Castro-Arce, Lamberto; Molinar-Tabares, Martin; Campos-Garcia, Julio; Figueroa-Navarro, Carlos; Isasi-Siqueiros, Leonardo; Manzanares-Martinez, Betsabe

    In our contribution we developed a study on the behavior of the transmission modes and a Pt / Zn slab of a Fibonacci array of longitudinal and transverse acoustic waves. We have worked with arrangements from n = 1 to10 and has managed to find the energy bands and transmission, filling factor 0.4 observing the appearance of Pseudo-Gaps in the evolution of the study when the arrangement Fibonacci increases. We acknowledge the support of SNI CONACYT.

  19. Hydrogen sensor based on metallic photonic crystal slabs.

    Science.gov (United States)

    Nau, D; Seidel, A; Orzekowsky, R B; Lee, S-H; Deb, S; Giessen, H

    2010-09-15

    We present a hydrogen sensor based on metallic photonic crystal slabs. Tungsten trioxide (WO(3)) is used as a waveguide layer below an array of gold nanowires. Hydrogen exposure influences the optical properties of this photonic crystal arrangement by gasochromic mechanisms, where the photonic crystal geometry leads to sharp spectral resonances. Measurements reveal a change of the transmission depending on the hydrogen concentration. Theoretical limits for the detection range and sensitivity of this approach are discussed.

  20. An Incursion on Punching of Reinforced Concrete Flat Slabs

    OpenAIRE

    2009-01-01

    Starting from the early 60s continuous studies have been made regarding punching of concrete flat slabs. The evolution of technology and calculus systems influenced this engineering branch. Nowadays is possible to account in structural analysis all the non-linear behaviour of reinforced and prestressed concrete and to get the most close structural response in comparison with the real behaviour. As a controversy matter, several tests and theories have been developed. Nowadays researchers try t...

  1. DESIGN METHOD OF BENDING CAPACITY OF CONTINUOUS COMPOSITE SLAB

    Directory of Open Access Journals (Sweden)

    Liu Jin

    2016-04-01

    Full Text Available This paper presents a calculation method for predicting the ultimate loading capacity of continuous composite slabs. Only the small scale slide block test was needed to determine few mechanical parameters, and less cost had to be paid, in comparison to the conventional m-k method. Various load conditions and parameters were considered. Comparisons between test results and predicted results have shown that the proposed method has enough precision. Furthermore, the simplified method was also proposed for practical design.

  2. Temperature distribution of an infinite slab under point heat source

    Directory of Open Access Journals (Sweden)

    Wu Zhao-Chun

    2014-01-01

    Full Text Available The temperature field in an infinite slab under an instantaneous or continuous point heat source is studied numerically. The numerical results reveal the temperature distribution and its change regularity, which are significant for the temperature control encountered in many practical manufacturing processes, such as the laser treatment processes on the surface of films, welding and cutting, and even the design of measuring devices for thermal properties of material.

  3. Project B: Improved Liquid Steel Feed For Slab Casters

    Energy Technology Data Exchange (ETDEWEB)

    Brent S. Isaacson; Mike Slepian; Thomas Richter

    1998-10-01

    This report describes the completion of the development of an electromagnetic valve to control liquid steel flow for improved liquid steel feeding for slab casters. Achievements result from a joint research effort between Westinghouse Science and Technology Center, North American Refractories and U.S. Steel. This effort is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. Department of Energy (DOE) and fifteen North American steel makers.

  4. Technical Report: Optimizing the Slab Yard Planning and Crane Scheduling Problem using a Two-Stage Approach

    DEFF Research Database (Denmark)

    Hansen, Anders Dohn; Clausen, Jens

    2008-01-01

    In this paper, we present The Slab Yard Planning and Crane Scheduling Problem. The problem has its origin in steel production facilities with a large throughput. A slab yard is used as a buffer for slabs that are needed in the upcoming production. Slabs are transported by cranes and the problem c...

  5. The Research of Computer Aided Farm Machinery Designing Method Based on Ergonomics

    Science.gov (United States)

    Gao, Xiyin; Li, Xinling; Song, Qiang; Zheng, Ying

    Along with agricultural economy development, the farm machinery product type Increases gradually, the ergonomics question is also getting more and more prominent. The widespread application of computer aided machinery design makes it possible that farm machinery design is intuitive, flexible and convenient. At present, because the developed computer aided ergonomics software has not suitable human body database, which is needed in view of farm machinery design in China, the farm machinery design have deviation in ergonomics analysis. This article puts forward that using the open database interface procedure in CATIA to establish human body database which aims at the farm machinery design, and reading the human body data to ergonomics module of CATIA can product practical application virtual body, using human posture analysis and human activity analysis module to analysis the ergonomics in farm machinery, thus computer aided farm machinery designing method based on engineering can be realized.

  6. Brief introduction of under- stage machinery (continued)%舞台下部机械(续)

    Institute of Scientific and Technical Information of China (English)

    宋宏

    2003-01-01

    It briefly introduces the use of typical under- stage machinery such as stage lifts, stage wagons and turntables in theater. It summarizes the functions,characteristics and drive modes of each type of under -stage machinery at present time.

  7. 49 CFR 1242.42 - Administration, repair and maintenance, machinery repair, equipment damaged, dismantling retired...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Administration, repair and maintenance, machinery repair, equipment damaged, dismantling retired property, fringe benefits, other casualties and insurance... maintenance, machinery repair, equipment damaged, dismantling retired property, fringe benefits,...

  8. Protein

    Science.gov (United States)

    ... Food Service Resources Additional Resources About FAQ Contact Protein Protein is found throughout the body—in muscle, ... the heart and respiratory system, and death. All Protein Isn’t Alike Protein is built from building ...

  9. Electromagnetic and ultrasonic investigations on a roman marble slab

    Science.gov (United States)

    Capizzi, Patrizia; Cosentino, Pietro L.

    2010-05-01

    The archaeological Museum of Rome (Museo delle Terme di Diocleziano) asked our group about the physical consistency of a marble slab (II - III century AD) that has recently fallen down during the transportation for an exhibition. In fact, due to insurance conflict, it was necessary to control the new fractures due to the recent accident and distinguish them from the ancient ones. The sculptured slab (today's size is 1280 x 70 x 9 cm), cut at the ends for a re-use as an inscription in the rear face, was restored (assemblage of different broken parts and cleaning) in contemporary times. We used different methodologies to investigate the slab: namely a pacometer (Protovale Elcometer) to individuate internal coupling pins, GPR (2000 MHz) and Ultrasonic (55 kHz) tomographic high-density surveys to investigate the internal extension of all the visible fractures and to search for the unknown internal ones. For every methodology used the quality of the acquired data was relatively high. They have been processed and compared to give a set of information useful for the bureaucratic problems of the Museum. Later on, the data have been processed in depth, for studying how to improve the data processing and for extracting all the information contained in the whole set of experimental data. Finally, the results of such a study in depth are exposed in detail.

  10. Calibrating a large slab vessel: A battle of the bulge

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, I.R.

    1993-10-01

    Slab tanks (critically-safe-by-geometry vessels) were proposed for the storage of concentrated, highly-enriched uranium solution in the design of the Fuel Processing Restoration (FPR) Facility at the Idaho Chemical Processing Plant (ICPP). Currently, measurements of bulk mass in ICPP annular vessels have standard deviations on the order of 0.2%, or less. ICPP personnel felt that their inexperience with the aforementioned expansions would prevent them from attaining comparable precision with slab tanks. To help assess the measurement accuracy of slab vessels, a full-scale mockup of those proposed for the FPR Facility was installed for test calibrations. These calibrations were designed to detect vessel expansion under differing conditions. This paper will compare the base-line, water calibrations with those of the higher-density aluminum nitrate, and any observed deflection will be described using vessel calibration techniques. The calibration using water at an elevated temperature was not performed due to the difficulty of maintaining the elevated temperature. This calibration probably will not be conducted because the construction of the FPR Facility has been halted.

  11. Prediction of temperature distribution in the hot rolling of slabs

    Science.gov (United States)

    Serajzadeh, S.; Karimi Taheri, A.; Mucciardi, F.

    2002-03-01

    In the process of continuous hot slab rolling, it is vital to know the temperature distribution within the slab along the length of the rolling mill because temperature is the dominant parameter controlling the kinetics of metallurgical transformations and the flow stress of the rolled metal. In other words, the microstructural changes, the mechanical properties as well as the final dimensions of the product and roll-force depend on the temperature distribution within the metal being rolled. In this paper, a mathematical model based on the finite element method is utilized to predict the temperature distribution and microstructural changes during the continuous hot slab rolling process. The effects of various parameters such as the heat of deformation, the work-roll temperature, the rolling speed, and the heat transfer coefficient between the work-roll and the metal are all taken into account in the analyses. To verify the validity of the model and the generated computer code, a comparison is carried out between the theoretical and plant-recorded results.

  12. Reducing Railway Noise with Porous Sound-Absorbing Concrete Slabs

    Directory of Open Access Journals (Sweden)

    Caiyou Zhao

    2014-01-01

    Full Text Available The effect of porous sound-absorbing concrete slabs on railway noise reduction is examined in this paper. First, the acoustical absorption coefficients of porous concrete materials with various aggregate types, gradations, fibre contents, and compaction indexes are measured in the laboratory. The laboratory results show that porous concrete that uses a composite of expanded perlite and slag as aggregate can not only obtain good acoustical absorption properties but also satisfy mechanical requirements. Also, the gradation of the combined aggregate has a significant effect on the acoustic absorption performance of the porous concrete, with an optimal aggregate gradation of 1~3 mm. Furthermore, the fibre content and compaction index affect both the strength and the acoustic absorption property of the porous concrete, with the optimum value of 0.3% and 1.6, respectively. Then, the findings from the laboratory studies are used to make porous sound-absorbing concrete slabs, which are applied in a test section. The measurements indicate that porous sound-absorbing concrete slabs can significantly reduce railway noise at different train speeds and that the amount of the noise reduction changes roughly linearly with speed when the train is traveling at less than 200 km/h. The maximum noise reduction is 4.05 dB at a speed of 200 km/h.

  13. High Performance Slab-on-Grade Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Mosiman, Garrett E. [NorthernSTAR, St. Paul, MN (United States)

    2015-09-01

    ?A more accurate assessment of SOG foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated). The optimum insulation strategy was applied to single and multi-family residential buildings in climate zone 4 - 7. The highest site energy savings of 5% was realized for a single family home in Duluth, MN, and the lowest savings of 1.4 % for a 4-unit townhouse in Richmond, VA. SOG foundation insulation retrofit simple paybacks ranged from 18 to 47 years. There are other benefits of SOG foundation insulation resulting from the increase in the slab surface temperatures. These include increased occupant thermal comfort, and a decrease in slab surface condensation particularly around the slab perimeter.

  14. Wet or dry bandages for plaster back-slabs?

    Science.gov (United States)

    Baliga, Santosh; Finlayson, D

    2012-12-01

    Cotton crêpe and stretch bandages are commonly used in back-slabs and casts in orthopaedic practice. In theory they allow swelling to occur after injury while splinting the fracture. The application of a wet bandage prevents the Plaster-of-Paris (POP) setting too rapidly, giving time to apply a mould or attain correct limb position. However, we hypothesised that a wet bandage contracts upon drying and may cause constriction of the splint. This study aimed at determining whether there was any significant change in length of commonly used bandages when wet as well as any further change when left to dry again. Two types of bandage were evaluated. 250 mm strips of bandage were dipped into water, gently squeezed and laid flat on a bench. The bandage was then immediately measured in length. The strips were then left to dry and re-measured. This experimental study shows that both cotton crepe and cling significantly shrink by around 7% when wet. This phenomenon has the potential to significantly increase the pressure exerted on the limb by a back-slab. We speculate that the application of wet bandages is why some back-slabs may need released. It is therefore recommended that bandages should be applied only in the dry form. Copyright © 2011 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  15. On the consistency of seismically imaged lower mantle slabs.

    Science.gov (United States)

    Shephard, G E; Matthews, K J; Hosseini, K; Domeier, M

    2017-09-08

    The geoscience community is increasingly utilizing seismic tomography to interpret mantle heterogeneity and its links to past tectonic and geodynamic processes. To assess the robustness and distribution of positive seismic anomalies, inferred as subducted slabs, we create a set of vote maps for the lower mantle with 14 global P-wave or S-wave tomography models. Based on a depth-dependent threshold metric, an average of 20% of any given tomography model depth is identified as a potential slab. However, upon combining the 14 models, the most consistent positive wavespeed features are identified by an increasing vote count. An overall peak in the most robust anomalies is found between 1000-1400 km depth, followed by a decline to a minimum around 2000 km. While this trend could reflect reduced tomographic resolution in the middle mantle, we show that it may alternatively relate to real changes in the time-dependent subduction flux and/or a mid-lower mantle viscosity increase. An apparent secondary peak in agreement below 2500 km depth may reflect the degree-two lower mantle slow seismic structures. Vote maps illustrate the potential shortcomings of using a limited number or type of tomography models and slab threshold criteria.

  16. PRRT2 Is a Key Component of the Ca2+-Dependent Neurotransmitter Release Machinery

    Directory of Open Access Journals (Sweden)

    Pierluigi Valente

    2016-04-01

    Full Text Available Heterozygous mutations in proline-rich transmembrane protein 2 (PRRT2 underlie a group of paroxysmal disorders, including epilepsy, kinesigenic dyskinesia, and migraine. Most of the mutations lead to impaired PRRT2 expression, suggesting that loss of PRRT2 function may contribute to pathogenesis. We show that PRRT2 is enriched in presynaptic terminals and that its silencing decreases the number of synapses and increases the number of docked synaptic vesicles at rest. PRRT2-silenced neurons exhibit a severe impairment of synchronous release, attributable to a sharp decrease in release probability and Ca2+ sensitivity and associated with a marked increase of the asynchronous/synchronous release ratio. PRRT2 interacts with the synaptic proteins SNAP-25 and synaptotagmin 1/2. The results indicate that PRRT2 is intimately connected with the Ca2+-sensing machinery and that it plays an important role in the final steps of neurotransmitter release.

  17. PRRT2 Is a Key Component of the Ca(2+)-Dependent Neurotransmitter Release Machinery.

    Science.gov (United States)

    Valente, Pierluigi; Castroflorio, Enrico; Rossi, Pia; Fadda, Manuela; Sterlini, Bruno; Cervigni, Romina Ines; Prestigio, Cosimo; Giovedì, Silvia; Onofri, Franco; Mura, Elisa; Guarnieri, Fabrizia C; Marte, Antonella; Orlando, Marta; Zara, Federico; Fassio, Anna; Valtorta, Flavia; Baldelli, Pietro; Corradi, Anna; Benfenati, Fabio

    2016-04-05

    Heterozygous mutations in proline-rich transmembrane protein 2 (PRRT2) underlie a group of paroxysmal disorders, including epilepsy, kinesigenic dyskinesia, and migraine. Most of the mutations lead to impaired PRRT2 expression, suggesting that loss of PRRT2 function may contribute to pathogenesis. We show that PRRT2 is enriched in presynaptic terminals and that its silencing decreases the number of synapses and increases the number of docked synaptic vesicles at rest. PRRT2-silenced neurons exhibit a severe impairment of synchronous release, attributable to a sharp decrease in release probability and Ca(2+) sensitivity and associated with a marked increase of the asynchronous/synchronous release ratio. PRRT2 interacts with the synaptic proteins SNAP-25 and synaptotagmin 1/2. The results indicate that PRRT2 is intimately connected with the Ca(2+)-sensing machinery and that it plays an important role in the final steps of neurotransmitter release.

  18. PRRT2 Is a Key Component of the Ca2+-Dependent Neurotransmitter Release Machinery

    Science.gov (United States)

    Valente, Pierluigi; Castroflorio, Enrico; Rossi, Pia; Fadda, Manuela; Sterlini, Bruno; Cervigni, Romina Ines; Prestigio, Cosimo; Giovedì, Silvia; Onofri, Franco; Mura, Elisa; Guarnieri, Fabrizia C.; Marte, Antonella; Orlando, Marta; Zara, Federico; Fassio, Anna; Valtorta, Flavia; Baldelli, Pietro; Corradi, Anna; Benfenati, Fabio

    2016-01-01

    Summary Heterozygous mutations in proline-rich transmembrane protein 2 (PRRT2) underlie a group of paroxysmal disorders, including epilepsy, kinesigenic dyskinesia, and migraine. Most of the mutations lead to impaired PRRT2 expression, suggesting that loss of PRRT2 function may contribute to pathogenesis. We show that PRRT2 is enriched in presynaptic terminals and that its silencing decreases the number of synapses and increases the number of docked synaptic vesicles at rest. PRRT2-silenced neurons exhibit a severe impairment of synchronous release, attributable to a sharp decrease in release probability and Ca2+ sensitivity and associated with a marked increase of the asynchronous/synchronous release ratio. PRRT2 interacts with the synaptic proteins SNAP-25 and synaptotagmin 1/2. The results indicate that PRRT2 is intimately connected with the Ca2+-sensing machinery and that it plays an important role in the final steps of neurotransmitter release. PMID:27052163

  19. 46 CFR 30.10-6a - Category A machinery space-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Category A machinery space-TB/ALL. 30.10-6a Section 30... Definitions § 30.10-6a Category A machinery space—TB/ALL. The term Category A machinery space means any space and trunks and ducts to such a space that contains: (a) Internal combustion machinery used for...

  20. Elucidation of the early infection machinery of hepatitis B virus by using bio-nanocapsule

    Science.gov (United States)

    Liu, Qiushi; Somiya, Masaharu; Kuroda, Shun’ichi

    2016-01-01

    Currently, hepatitis B virus (HBV), upon attaching to human hepatocytes, is considered to interact first with heparan sulfate proteoglycan (HSPG) via an antigenic loop of HBV envelope S protein. Then, it is promptly transferred to the sodium taurocholate cotransporting polypeptide (NTCP) via the myristoylated N-terminal sequence of pre-S1 region (from Gly-2 to Gly-48, HBV genotype D), and it finally enters the cell by endocytosis. However, it is not clear how HSPG passes HBV to NTCP and how NTCP contributes to the cellular entry of HBV. Owing to the poor availability and the difficulty of manipulations, including fluorophore encapsulation, it has been nearly impossible to perform biochemical and cytochemical analyses using a substantial amount of HBV. A bio-nanocapsule (BNC), which is a hollow nanoparticle consisting of HBV envelope L protein, was efficiently synthesized in Saccharomyces cerevisiae. Since BNC could encapsulate payloads (drugs, genes, proteins) and specifically enter human hepatic cells utilizing HBV-derived infection machinery, it could be used as a model of HBV infection to elucidate the early infection machinery. Recently, it was demonstrated that the N-terminal sequence of pre-S1 region (from Asn-9 to Gly-24) possesses low pH-dependent fusogenic activity, which might play a crucial role in the endosomal escape of BNC payloads and in the uncoating process of HBV. In this minireview, we describe a model in which each domain of the HBV L protein contributes to attachment onto human hepatic cells through HSPG, initiation of endocytosis, interaction with NTCP in endosomes, and consequent provocation of membrane fusion followed by endosomal escape.